CA2217520A1 - Tissue paper containing a fine particulate filler - Google Patents

Tissue paper containing a fine particulate filler Download PDF

Info

Publication number
CA2217520A1
CA2217520A1 CA002217520A CA2217520A CA2217520A1 CA 2217520 A1 CA2217520 A1 CA 2217520A1 CA 002217520 A CA002217520 A CA 002217520A CA 2217520 A CA2217520 A CA 2217520A CA 2217520 A1 CA2217520 A1 CA 2217520A1
Authority
CA
Canada
Prior art keywords
tissue paper
fibers
paper
tissue
web
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002217520A
Other languages
French (fr)
Inventor
Kenneth Douglas Vinson
Charles William Neal
John Paul Erspamer
Jeffress Paul Halter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Georgia Tech Research Corp
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2217520A1 publication Critical patent/CA2217520A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00Special paper not otherwise provided for, e.g. made by multi-step processes
    • D21H27/30Multi-ply
    • D21H27/40Multi-ply at least one of the sheets being non-planar, e.g. crêped
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63Inorganic compounds
    • D21H17/67Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/68Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24355Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
    • Y10T428/24446Wrinkled, creased, crinkled or creped
    • Y10T428/24455Paper
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24355Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
    • Y10T428/24446Wrinkled, creased, crinkled or creped
    • Y10T428/24455Paper
    • Y10T428/24463Plural paper components

Abstract

Strong, soft, and low dusting tissue paper webs useful in the manufacture of soft, absorbent sanitary products such as bath tissue, facial tissue, and absorbent towels are disclosed. The tissue papers comprise fibers such as wood pulp and a non-cellulosic, water insoluble particulate filler such as kaolin clay.

Description

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 TISSUE PAPER C~NTAINING A FINE PARTICULATE FILLER

TECHNICAL FIELD

This invention relates, in general, to creped tissue paper products 10 and processes. More specifically, it relates to creped tissue paper products made from cellulose pulps and non-cellulosic water insoluble particulate fillers.

BACKGROUND OF THE INVENTION
Sanitary paper tissue products are widely used. Such items are commercially offered in for",als tailored for a variety of uses such as facial tissues, toilet tiss~ ~es and absorbent towels. The formats, i.e. basis weight, thickness, s~,eng~l" sheet size, dispensing medium, etc. of these products 20 often differ widely, but they are linked by the common process by which they originate, the so-called creped papermaking process.

Creping is a means of mechanically compacting paper in the machine direction. The result is an increase in basis weight (mass per unit 25 area) as well as dldlllalic changes in many physical properties, particularly when measured in the machine direction. Creping is generally ac~""~lished with a flexible blade, a so-called doctor blade, against a Yankee dryer in an on machine operation.

A Yankee dryer is a large diameter, generally 8-20 foot drum which is designed to be pressurized with steam to provide a hot surface for completing the drying of papermaking webs at the end of the papermaking process. The paper web which is first formed on a foraminous forming carrier, such as a Fourdrinier wire, where it is freed of the copious water needed to disperse the fibrous slurry is generally transferred to a felt or fabric in a so-called press section where de-watering is continued either by SUBSTI~UTE St~ E ~6) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 mechanically compacting the paper or by some other de-watering method such as through-drying with hot air, before finally being transferred in the semi-dry condition to the surface of the Yankee for the drying to be completed.
s The various creped tissue paper products are further linked by common consumer demand for a generally conflicting set of physical properties: A pleasing tactile impression, i.e. softness while, at the same time having a high strength and a resistance to linting and dusting.
Softness is the tactile sensation perceived by the consumer as he/she holds a particular product, rubs it across his/her skin, or crumples it within his/her hand. This tactile sensation is provided by a combination of several physical properties. One of the most important physical properties 15 related to softness is generally considered by those skilled in the art to bethe stiffness of the paper web from which the product is made. Stiffness, in turn, is usually considered to be directly dependent on the strength of the web.
Strength is the ability of the product, and its constituent webs, to 20 maintain physical integrity and to resist tearing, bursting, and shredding under use conditions.
Linting and dusting refers to the tendency of a web to release unbound or loosely bound fibers or particulate fillers during handling or use.
Creped tissue papers are generally comprised essentially of 25 papermaking fibers. Small amounts of chemical functional agents such as wet strength or dry strength binders, retention aids, surfactants, size, chemical softeners, crepe facilitating compositions are frequently included but these are typically only used in minor amounts. The papermaking fibers most frequently used in creped tissue papers are virgin chemical wood 30 pulps.
As the world's supply of natural resources comes under increasing economic and environmental scrutiny, pressure is mounting to reduce consumption of forest products such as virgin chemical wood pulps in products such as sanitary tissues. One way to extend a given supply of SU~STITUTE SH~ '~E 26) CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/04134 wood pulp without sacrificing product mass is to replace virgin chemical pulp fibers with high yield fibers such as mechanical or chemi-mechanical pulps or to use fibers which have been recycled. Unfortunately, comparatively severe deterioration in performance usually accompanies such changes. Such fibers are prone to have a high coarseness and this contributes to the loss of the velvety feel which is imparted by prime fibers selected bec~ ~se of their flaccidness. In the case of the mechanical or chemi-mechanical liberated fiber, high coarseness is due to the retention of the non-cellulosic components of the original wood substance, such 10 components including lignin and so-called hemicelluloses. This makes each fiber weigh more without increasing its length. Recycled paper can also tend to have a high mechanical pulp content, but, even when all due care is exercised in selecting the wastepaper grade to minimize this, a high coarseness still often occurs. This is thought to be due to the impure 15 mixture of fiber morphologies which naturally occurs when paper from many sources is blended to make a recycled pulp. For example, a certain wastepaper might be selected because it is primarily North American hardwood in nature; however, one wili often find extensive conlar"ination from coarser softwood fibers, even of the most deleterious species such as 20 variations of Southern U.S. pine. U.S. Patent 4,300,981, Carstens, issued November 17, 1981, and incorporated herein by reference, explains the textural and surface qualities which are imparted by prime fibers. U.S.
Patent 5,228,954, Vinson, issued July 20, 1993, and U.S. Patent 5,405,499, Vinson, to issue April 11, 1995, both incorporated herein by reference, 25 disclose methods for upgrading such fiber sources so that they have less deleterious effects, but still the level of replacement is limited and the new fiber sources themselves are in limited supply and this often limits their use.
Applicants have discovered that another method of limiting the use of wood pulp in sanitary tissue paper is to replace part of it with a lower cost, 30 readily available filling material such as kaolin clay or calcium carbonate.
While those skilled in the art will recognize that this practice has been common in some parts of the paper industry for many years, they will also appreciate that extending this approach to sanitary tissue products has involved particular difficulties which have prevented it from being practiced 35 up to now.
One major restriction is the retention of the filling agent during the SUBSTITUTE SHE~T (R~JLE 26) CA 02217~20 1997-10-03 W O96/316S3 PCTrUS96/04134 papermaking process. Among paper products, sanitary tissues are at an extreme of low basis weight. The basis weight of a tissue web as it is wound on a reel from a Yankee machine is typically only about 15 g/m2 and because of the crepe, or foreshortening, introduced at the creping blade, 5 the dry fiber basis weight in the forming, press, and drying sections of the machine is actually lower than the finished dry basis weight by from about 10% to about 20%. To compound the difficulties in retention caused by the low basis weight, tissue webs occupy an extreme of low density, often having an apparent density as wound on the reel of only about 0.1 g/cm3 or 10 less; While it is recognized that some of this loft is introduced at the creping blade, those skilled in the art will recognize that tissue webs are generally formed from relatively free stock which means that the fibers of which they are comprised are not rendered flaccid from beating. Tissue machines are required to operate at very high speeds to be practical; thus 15 free stock is needed to prevent excessive forming pressures and drying load. The relatively stiff fibers comprising the free stock retain their abilityto prop open the embryonic web as it is forming. Those skilled in the art will at once recognize that such light weight, low density structures do not afford any significant opportunity to filter fine particulates as the web is 20 forming. Filler particles not substantively affixed to fiber surfaces will betorn away by the torrent of the high speed approach flow systems, hurled into the liquid phase, and driven through the embryonic web into the water drained from the forming web. Only with repeated recycling of the water used to form the web does the concentration of particulate build to a point 25 where the filler begins to exit with the paper. Such concentrations of solids in water effluent are impractical.
A second major limitation is the general failure of particulate fillers to naturally bond to papermaking fibers in the fashion that papermaking fibers tend to bond to each other as the formed web is dried. This reduces the 30 strength of the product. Filler inclusion causes a reduction in strength, which if left uncorrected, severely limits products which are already quite weak. Steps required to restore strength such as increased fiber beating or the use of chemical strengthening agents is often restricted as well.
The deleterious effects of filler on sheet integrity also often cause 35 hygiene problems by plugging press felts or by transferring poorly from the press section to the Yankee dryer.

SU3STITUTESH~I (RULE2 CA 02217~20 1997-10-03 W O96/31653 PCTrUS9610~134 s Finally, tissue products containing fillers are prone to lint or dust.
This is not only because the fillers themselves can be poorly trapped within the web, but also because they have the aforementioned bond inhibiting effect which causes a localized weakening of fiber anchoring into the 5 structure. This tendency can cause operational difficulties in the creped papermaking processes and in subsequent converting operations, ber~use of exressive dust created when the paper is handled. Another consideration is that the users of the sanitary tissue products made from the filled tissue demand that they be relatively free of lint and dust.
Consequently, the use of fillers in papers made on Yankee machines has been severely limited. United States Patent 2,216,143, issued toThiele on October 1, 1940, and incorporated herein by reference discusses the limitations of fillers on Yankee machines and discloses a method of incorporation which overcomes those limitations. Unfortunately, the method 15 requires a cumbersome unit operation to coat a layer of adhesively bound particles onto the felt side of the sheet while it is in contact with the Yankeedryer. This operation is not practical for modern high speed Yankee machines and, those skilled in the art will recognize that the Thiele method would produce a coated rather than filled tissue product. A "filled tissue 20 papeP is distinguished from "coated tissue paper" essentially by the methods practiced to produce them, i.e. a "filled tissue paper" is one which has the particulate matter added to the fibers prior to their assembly into a web while a "coated tissue paper" is one which has the particulate matter added after the web has been essentially assembled. As a result of this 25 difference, a filled tissue paper product can be described as a relatively lightweight, low density creped tissue paper made on a Yankee machine which contains a filler dispersed throughout the thickness of at least one layer of a multi-layer tissue paper, or throughout the entire thickness of a single-layered tissue paper. The term "dispersed throughout" means that 30 essentially all portions of a particular layer of a filled tissue product contain filler particles, but, it specifically does not imply that such dispersion necessarily be uniform in that layer. In fact, certain advantages can be anticipated by achieving a difference in filler concentration as a function of thickness in a filled layer of tissue.
Therefore, it is the object of the present invention to provide for a tissue paper comprising a fine particulate filler which overcomes the SU~STITUTE SHEET (RULE 2~3) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 aforementioned limitations of the prior art. The tissue paper of the present invention is soft, contains a retentive filler, has a high level of tensile strength, and is'low in dust.
This and other objects are obtained using the present invention as will be taught in the following disclosure.

SUMMARY OF THE INVENTION

The invention is a strong, soft filled tissue paper, low in lint and dust l0 and comprising papermaking fibers and a non-cellulosic particulate filler, said filler comprising at least about 5% and up to about 50%, but, more preferably from about 8% to about 20% by weight of said tissue.
Unexpected combinations of softness, strength, and resistance to dusting have been obtained by filling creped tissue paper with these levels of 15 particulate fillers.
In its preferred embodiment, the filled tissue paper of the present invention has a basis weight between about 10 g/m2 and about 50 g/m2 and, more preferably, between about 10 g/m2 and about 30 g/m2. It has a density between about 0.03 g/m3 and about 0.6 g/m3 and, more preferably, 20 between about 0.05 g/m3 and 0.2 g/m3.
The preferred embodiment further comprises papermaking fibers of both hardwood and softwood types wherein at least about 50% of the papermaking fibers are hardwood and at least about 10% are softwood.
The hardwood and softwood fibers are most preferably isolated by relegating each to separate layers wherein the tissue comprises an inner layer and at least one outer layer.
The preferred tissue paper of the present invention is pattern densified such that zones of relatively high density are dispersed within a high bulk field, including pattern densified tissue wherein zones of relatively 30 high density are continuous and the high bulk field is discrete. Most preferably, the tissue paper is through air dried.
The invention provides for a creped tissue paper comprising papermaking fibers and a particulate filler. In its preferred embodiment, the Sl JE3~;T~TUTE SffEEr (P~LE 26) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 particulate filler is selected from the group consisting of clay, calcium carbonate, titanium dioxide, talc, aluminum silicate, calcium silicate, alumina trihydràte, activated carbon, pearl starch, calcium sulfate, glass microspheres, diatomaceous earth, and mixtures thereof. When selecting a 5 filler from the above group several factors need to be evaluated. These include cost, availability, ease of retaining into the tissue paper, color, scattering potential, refractive index, and chemical compatibility with the selected papermaking environment.
It has now been found that a particularly suitable filler is kaolin clay.
10 Most preferably the so called "hydrous aluminum silicate" form of kaolin clayis preferred as contrasted to the kaolins which are further processed by calcining.
The morphology of kaolin is naturally platy or blocky, but it is preferable to use clays which have not been subjected to mechanical 15 delamination treatments as this tends to reduce the mean particle size. It iscommon to refer to the mean particle size in terms of equivalent spherical diameter. An average equivalent spherical diameter greater than about 0.2 micron, more preferably greater than about 0.5 micron is preferred in the practice of the present invention. Most preferably, an equivalent spherical 20 diameter greater than about 1.0 micron is preferred.
All percentages, ratios and proportions herein are by weight unless otherwise specified.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation illustrating a creped papermaking process of the present invention for producing a strong, soft, and low lint creped tissue paper comprising papermaking fibers and particulate fillers.
Figure 2 is a schematic representation illustrating the steps for preparing the aqueous papermaking furnish for the creped papermaking process, according to one embodiment of the present invention based on cationic flocculant.

SlJ~i 11 l ~ITE SHE~T ~R~LE 2B~

CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/01134 Figure 3 is a schematic representation illustrating the steps for preparing the aqueous papermaking furnish for the creped papermaking process, according to another embodiment of the present invention based 5 on anionic flocculant.

DETAILED DESCRIPTION OF THE INVENTION

While this specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as the invention, it is believed that the invention can be better understood from a reading of the following detailed description and of the appended examples.

As used herein, the term "comprising" means that the various components, ingredients, or steps, can be conjointly employed in practicing the present invention. Accordingly, the term "comprising" encompasses the more restrictive terms "consisting essentially oft' and "consisting of."

As used herein, the term "water soluble" refers to materials that are soluble in water to at least 3%, by weight, at 25 ~C.

As used herein, the terms "tissue paper web, paper web, web, paper sheet and paper product" all refer to sheets of paper made by a process comprising the steps of forming an aqueous papermaking furnish, depositing this furnish on a foraminous surface, such as a Fourdrinier wire, and removing the water from the furnish as by gravity or vacuum-assisted drainage, with or without pressing, and by evaporation, comprising the final steps of adhering the sheet in a semi-dry condition to the surface of a Yankee dryer, completing the water removal by evaporation to an essentially dry state, removal of the web from the Yankee dryer by means of a flexible creping blade, and winding the resultant sheet onto a reel.

As used herein, the term "filled tissue paper" means a paper product that can be described as a relatively lightweight, low density creped tissue paper made on a Yankee machine which contains a filler dispersed throughout the thickness of at ieast one layer of a multi-layer tissue paper, SUBS~ITUTE SHEET (RULE 26) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 or throughout the entire thickness of a single-layered tissue paper. The term "dispersed throughout" means that essentially all portions of a particular layer of a filled tissue product contain filler particles, but, it specifically does not imply that such dispersion necessarily be uniform in 5 that layer. In fact, certain advantages can be anticipated by achieving a difference in filler concentration as a function of thickness in a filled layer of tissue.
The terms "multi-layered tissue paper web, multi-layered paper web, multi-layered web, multi-layered paper sheet and multi-layered paper 10 product" are all used interchangeably in the art to refer to sheets of paper prepared from two or more layers of aqueous paper making furnish which are preferably comprised of different fiber types, the fibers typically being relatively long softwood and relatively short hardwood fibers as used in tissue paper making. The layers are preferably formed from the deposition 15 of separate streams of dilute fiber slurries upon one or more endless foraminous surfaces. If the individual layers are initially formed on separate foraminous surfaces, the layers can be subsequently combined when wet to form a multi-layered tissue paper web.

As used herein, the term Usingle-ply tissue product" means that it is comprised of one ply of creped tissue; the ply can be substantially homogeneous in nature or it can be a multi-layered tissue paper web. As used herein, the term Umulti-ply tissue product" means that it is comprised of more than one ply of creped tissue. The plies of a multi-ply tissue product can be substantially homogeneous in nature or they can be multi-layered tissue paper webs.

The first step in the process of this invention is the forming of at least one "aqueous papermaking furnish", a term which, as used herein, refers to a suspension of papermaking fibers, usually comprised of wood pulp, and particulate fillers, along with the additives which are essential to provide theretention of the particulate filler and any other functional properties by optionally including modifying chemicals as described hereinafter. Some typical components of the papermaking furnish are described in the 3 5 following section.

SU~ ' . iTV~t ~UEET (P.ULE 2~) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96104134 Ingredients of the Papermaking Furnish The PaPermakin~ Fibers S It is anticipated that wood pulp in all its varieties will normally comprise the papermaking fibers used in this invention. However, other cellulose fibrous pulps, such as cotton linters, bagasse, rayon, etc., can be used and none are disclaimed. Wood pulps useful herein include chemical pulps such as, sulflte and sulfate (sometimes called Kraft) pulps as well as mechanical pulps including for example, ground wood, ThermoMechanical Pulp (TMP) and Chemi-ThermoMechanical Pulp (CTMP). Pulps derived from both deciduous and coniferous trees can be used.

Both hardwood pulps and softwood pulps as well as combinations of the two may be employed as papermaking fibers for the tissue paper of the present invention. The term "hardwood pulps" as used herein refers to fibrous pulp derived from the woody substance of deciduous trees (angiosperms), whereas "softwood pulps" are fibrous pulps derived from the woody substance of coniferous trees (gymnosperms). Blends of hardwood Kraft pulps, especially eucalyptus, and northern softwood Kraft (NSK) pulps are particularly suitable for making the tissue webs of the present invention.
A preferred embodiment of the present invention comprises layered tissue webs wherein, most preferably, hardwood pulps such as eucalyptus are used for outer layer(s) and wherein northern softwood Kraft pulps are used for the inner layer(s). Also applicable to the present invention are fibers derived from recycled paper, which may contain any or all of the above categories of fibers.

The Particulate Filler The invention provides for a creped tissue paper comprising papermaking fibers and a particulate filler. In its preferred embodiment, the particulate filler is seiected from the group consisting of clay, calcium carbonate, titanium dioxide, talc, aluminum silicate, calcium silicate, alumina trihydrate, activated carbon, pearl starch, calcium sulfate, glass microspheres, diatomaceous earth, and mixtures thereof. When selecting a filler from the above group several factors need to be evaluated. These SUE~ T '~U~E ~;HEET (F~LE 2~3) CA 022l7~20 l997-lO-03 W O 96/316~3 PCTrUS96/04134 include cost, availability, ease of retaining into the tissue paper, color, scattering potential, refractive index, and chemical compatibility with the selected papermaking environment.
It has now been found that a particularly suitable particulate filler is S kaolin clay. Kaolin clay is the common name for a class of naturally occurring aluminum silicate mineral beneficiated as a particulate.
With respect to terminology, it is noted that it is common in the industry, as well as in the prior art patent literature, when rerer, i"g to kaolin products or processing, to use the term Uhydrous" to refer to kaolin which has not been subject to calcination. Calcination subjects the clay to temperatures above 450~C, which temperatures serve to alter the basic crystal structure of kaolin. The so-called "hydrous" kaolins may have been produced from crude kaolins, which have been subjected to beneficiation, as, for example, to froth flotation, to magnetic separation, to mechanical delamination, grinding, or similar comminution, but not to the mentioned heating as would impair the crystal structure.
To be accurate in a technical sense, the description of these materials as Uhydrous'' is inappropriate. More specifically, there is no molecular water actually present in the kaolinite structure. Thus although the composition can be, and often is, arbitrarily written in the form 2H2O-A12O3-2SiO2, it has long been known that kaolinite is an aluminum hydroxide silicate of approximate composition A12(OH)4Si2Os, which equates to the hydrated formula just cited. Once kaolin is subjected to calcination, which for the purposes of this specification refers to subjecting a kaolin to temperatures exceeding 450~C, for a period sufficient to eliminate the hydroxyl groups, the original crystalline structure of the kaolinite is destroyed. Therefore, although technically such calcined clays are no longer Ukaolin", it is common in the industry to refer to these as calcined kaolin, and, for the purposes of this specification, the calcined - 30 materials are included when the class of materials "kaolin" is cited.
Accordingly, the term Uhydrous aluminum silicate" refers to natural kaolin, ~ which has not been subjected to calcination.
Hydrous aluminum silicate is the kaolin form most preferred in the practice of the present invention. It is therefore characterized by the before SUE~TITUT' SHE'T ~F~LE 26) CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 mentioned approximate 13% by weight loss as water vapor at temperatures exceeding 450~C.
The morphology of kaolin is naturaliy platy or blocky, be~~ ~se it naturally occurs in the form of thin platelets which adhere toge~her to form 5 "stacks" or "books". The stacks separaLe to some degree into the individual -platelets during processing, but it is preferable to use clays which have not been subjected to extensive mechanical delamination treatments as this tends to reduce the mean particle size. It is common to refer to the mean particle size in terms of equivalent spherical diameter. An average 10 equivalent spherical diameter greater than about 0.2 micron, more preferabiy greater than about 0.5 micron is preferl ed in the practice of the present invention. Most preferably, an equivalent spherical diameter greater than about 1.0 micron is preferred.
Most mined clay is subjected to wet processing. Aqueous 15 suspending of the crude clay allows the coarse impurities to be removed by centrifugation and provides a media for chemical bleaching. A
polyacrylate polymer or phosphate salt is sometimes added to such slurries to reduce viscosity and slow settling. Resultant clays are normally shipped without drying at about 70% solids suspensions, or they can be spray dried.
Treatments to the clay, such as air floating, froth flotation, washing, bleaching, spray drying, the addition of agents as slurry stabilizers and viscosity modifiers, are generally acceptable and should be selected based upon the specific commercial considerations at hand in a particular circumstance.
Each clay platelet is itself a multi-layered structure of aluminum polysilicates. A continuous array of oxygen atoms forms one face of each basic layer. The polysilicate sheet structure edges are united by these oxygen atoms. A continuous array of hydroxyl groups of joined octahedral alumina structures forms the other face forming a two-dimensional polyaluminum oxide structure. The oxygen atoms sharing the tetrahedral and octahedral structures bind the aluminum atoms to the silicon atoms.

SUE~ ~ ITU l ~ ''~ EEr (R~ILE 26) CA 02217~20 1997-10-03 W O96/316~3 PCTnUS96/04134 . 13 Imperfections in the assembly are primarily responsible for the natural clay particles possessing an anionic charge in suspension. This happens because other di-, tri-, and tetra-valent cations substitute for aluminum. The consequence is that some of the oxygen atoms on the 5 surface become anionic and become weakly ~isssci~hle hydroxyl groups.
Natural clay also has a cationic characler capable of exchang;n~J
their anions for others that are preferred. This happens because aluminum atoms lacking a full complement of bonds occur at some frequency around the peripheral edge of the platelet. They must satisfy their remaining 10 valencies by attracting anions from the aq~ ~eous suspension that they occupy. If these cationic sites are not satisfied with anions from solutions, the clay can satisfy its own charge balance by orienting itself edge to face assembling a "card house" structure which forms thick dispersions.
Polyacrylate dispersants ion excl ,a"ge with the cationic sites providing a 15 repulsive character to the clay preventing these assemblies and simplifying the prod~ ~ction, shipping, and use of the clay.
A kaolin grade WW Fil SD~) is a spray dried kaolin marketed by Dry Branch Kaolin Company of Dry Branch, Georgia suitable to make creped tissue paper webs of the present invention.

- Starch In some aspects of the invention, it is useful to include starch as one of the ingredients of the papermaking furnish. A starch that has limited solubility in water in the presence of particul~te fillers and fibers is particularly useful in certain aspects of the invention to be detailed later. A
common means of achieving this is to use a so called "cationic starch".
As used herein the term "cationic starch" is defined as starch, as naturally derived, which has been further chemically modified to impart a - 30 cationic constituent moiety. Preferably the starch is derived from corn or potatoes, but can be derived from other sources such as rice, wheat, or - tapioca. Starch from waxy maize also known industrially as amioca starch is particularly preferred. Amioca starch differs from common dent corn starch in that it is entirely amylopectin, whereas common corn starch contains both amylopectin and amylose. Various unique characteristics of CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 amioca starch are further described in "Amioca - The Starch from Waxy Corn", H. H. Schopmeyer, Food Industries, December 1945, pp. 106-108.
The starch can be in granular form, pre-gelatinized granular form, or dispersed form. The dispersed form is ,~refer, ed. If in granular pre-5 gelatinized form, it need only be dispersed in cold water prior to its use, withthe only pre-caution being to use equipr,~enl which overcomes any tendency to gel-block in forming the dispersion. Suitable dispersers known as eductors are common in the industry. If the starch is in granular form and has not been pre-gelatinized, it is necess~ry to cook the starch to induce 10 swelling of the granules. Preferably, such starch granules are swollen, as by cooking, to a point just prior to dispersion of the starch granule. Such highly swollen starch granules shall be referred to as being "fully cooked".
The conditions for dispersion in general can vary depending upon the size of the starch granules, the degree of crystallinity of the granules, and the 15 amount of amylose present. Fully cooked amioca starch, for example, can be pre~uared by heating an ~ eous slurry of about 4% consisle,~cy of starch granules at about 190 ~F (about 88 ~C) for between about 30 and about 40 minutes.

Cationic starches can be divided into the following ge"erdl classifications: (1 ) tertiary aminoalkyl ethers, (2) onium starch ethers including qua~e",c"~ amines, phosphonium, and sulfonium derivatives, (3) primary and sec~nda"~ aminoalkyl starches, and (4) miscellaneous (e.g., imino starches). New cationic products continue to be developed, but the 25 tertiary aminoalkyl ethers and quaternary a"""Gnium alkyl ethers are the main commercial types. r, ererably, the cationic starch has a degree of substitution ranging from about 0.01 to about 0.1 cationic substituent per anhydroglucose units of starch; the substituents preferably chosen from the above mentioned types. Suitable starches are produced by National Starch 30 and Chemical Company, (Bridgewater, New Jersey) under the tradename, RediBOND~. Grades with cationic moieties only such as RediBOND
5320~ and RediBOND 5327~) are suitable, and grades with additional anionic functionality such as RediBOND 2005@~) are also suitable.

While not wishing to be bound by theory, it is believed that the cationic starch which is initially dissolved in water, becomes insoluble in the presence of filler because of its attraction for the anionic sites on the filler CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 surface. This ~uses the filler to be covered with the bushy starch molecules which provide an alll d~;live surface for more filler particles, ultimately resulting in agglomeration of the filler. The essential element of this step is believed to be the size and shape of the starch molecule rather S than the charge cl ,aracteristics of the starch. For example, inferior resultswould be expected by substituting a charge biasing species such as synthetic linear polyelectrolyte for the cationic starch.

In one embodiment of the present invention, cationic starch is 10 preferably added to the particulate filler. In this case, the amount of cationic starch added is from about 0.1% to about 2%, but most preferably from about 0.25% to about 0.75%, by weight based on the weight of the particulate filler. In this aspect of the invention, it is preferable to use a cationic flocculant as a retention aid.
In another e"~bodi",ent of the present invention, it is prefer,ed to add cationic starch to an entire ~ueo~ ~s papermaking furnish, prQferably at a point before the final dilution at the fan pump. This aspect of the invention makes use of an anionic flocc~ t as a re~enlio,) aid. In this aspect of the 20 invention, it is preferable to add cationic starch at a rate from about five to about twenty times the rate of the anionic floccu~ t.

The cationic and anionic flocc~ nts mentioned in the above are described in detail in the following sections.
Retention Aids A number of materials are marketed as so-called "rete"lion aidsn, a term as used herein, refer, ing to additives used to increase the retention of 30 the fine furnish solids in the web during the papermaking process. Without adequate retention of the fine solids, they are either lost to the process effluent or accumulate to exc~ssively high conce"L, alions in the recirculating white water loop and cause production difficulties including - deposit build-up and impaired drainage. Chapter 17 entitled "Retention 35 Chemistry" of "Pulp and Paper, Chemistry and Chemical Technology", 3rd ed. Vol. 3, by J. E. Unbehend and K. W. Britt, A Wiley Interscience Publication, incorporated herein by reference, provides the essential CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/04134 understanding of the types and mechanisms by which polymeric reter,lion aids function. A flocculant agglomerates suspended particles generally by a bridging mechanism. While certain multivalent cations are considered common flocculants, they are generally being replaced in practice by 5 superior acting polymers which carry many charge sites along the polymer chain.

Cationic Flocculant Tissue products accordi"g to the present invention can be effectively produced using as a retention aid a Ucationic flocu ~'~ntn, a term which, as used herein, refers to a class of polyelectrolyte. These polymers generally originate from copolymerization of one or more ethylenically unsaturated monomers, generally acrylic monomers, that consist of or include cationic 15 monomer.

Suitable cationic ~"o.,ori,ers are dialkyl amino alkyl-(meth) acrylates or -(meth) acrylamides, either as acid salts or quatemary a",..,o,)ium salts.
Suitable alkyl groups include dialkylaminoethyl (meth) acrylates, 20 dialkylaminoethyl (meth) acrylamides and dialkylaminomethyl (meth) acrylamides and dialkylamino -1,3-propyl (meth) acrylamides. These cationic monomers are ~rererdL,ly copoly--~eri~ed with a nonionic monomer, preferably acrylamide. Other suitable polymers are polyethylene imines, polyamide epichlorohydrin polymers, and homopolymers or copolymers, 25 generally with acrylamide, of mGnG",ers such as diallyl dimethyl ai"",onium chloride.

Any conventional cationic synthetic polymeric flocculant suitable for use on paper as a retention aid can be usefully employed to make products 30 accorcling to the present invention.

The polymer is preferably s~ ~hst~ntially linear in comparison to the globular structure of cationized starches.

A wide range of charge densities is useful, although a medium density is preferred. Polymers useful to make products of the present invention contain cationic functional groups at a frequency ranging from as CA 022l7~20 l997-lO-03 W O96/31653 PCTnUS96/04134 low as about 0.2 to as high as 2.5, but more preferably in a range of about 1 to about 1.5 milliequivalents per gram of polymer.

Polymers useful to make tissue products accordir,g to the present S invention should have a molecular weight of at least about 500,000, and preferably a molecular weight above about 1,000,000, and, may advantageously have a molecul~~ weight above 5,000,000.

Examples of acceplable materials are RETEN 1232~) and Microf~r"
10 2321~), both emulsion polymerized cationic polyacrylamides and RETEN
157~), which is delivered as a solid granule; all are products of Hercules, Inc. of Wilmington, Delaware. Another ~c~ceptahle cationic flocculant is Accurac 91, a product of Cytec, Inc. of Sta",ro,d, CT.

Those skilled in the art will recognize that the desired usage rates of these polymers will vary widely. Amounts as low as about 0.005% polymer ~ by weight based on the dry weight of the polymer and the dry finished weight of tissue paper will deliver useful results, but normally the usage rate would be expected to be higher; even higher for the purposes of the present 20 invention than commonly practiced as application of these materials.
Amounts as high as about 0.5% might be employed, but normally about 0.1% is optimum.

Anionic Flocculant In another aspect of the present invention, an "anionic flocculant" is an useful ingredient. An "anionic flocculant" as used herein refers to a high molecuLar weight polymer having pendant anionic groups.
Anionic polymers often have a carboxylic acid (-COOH) moiety.
These can be immediately pendant to the polymer backbone or pendant ~ through typically, an alkalene group, particularly an alkalene group of a few carbons. In ~ eo~ ~s medium, except at low pH, such carboxylic acid groups ionize to provide to the polymer a negative charge.
Anionic polymers suitable for anionic flocculants do not wholly or essentially consist of monomeric units prone to yield a carboxylic acid group CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/04134 upon polymerization, instead they are comprised of a combinaLio" of monomers yielding both nonionic and anionic functionality. Monomers yielding nonionic functionality, especially if possessing a polar character, often exhibit the same flocu ll~tirl9 tendencies as ionic functionality. The s i. ,cor~,oralion of such monomers is often practiced for this reason. An oftenused nonionic unit is (meth) acrylamide.

Anionic polyacrylamides having relatively high molecular weights are satisractoi y flo~ ing agents. Such anionic polyacrylamides contain a 10 combination of (meth) acrylamide and (meth) acrylic acid, the latter of whichcan be derived from the incorporation of (meth)acrylic acid I l lGi ,o, . ,er during the pol~me, i~alion step or by the hydrolysis of some (meth) acrylamide units after the polyrnerization, or combined methods.

The polymer is pre~rdbly suLalanlially linear in cc",pa,ison to the globular structure of anionic starch.

A wide range of charge densities is useful, although a medium density is ~,rerer,ed. Polymers useful to make products of the present invention contain cationic functional groups at a frequency, dl Iyil 19 from as low as about 0.2 to as high as about 7 or higher, but more prt:ferdbly in a range of about 2 to about 4 milliequivalents per gram of polymer.

Polymers useful to make tissue products according to the present invention should have a molecular weight of at least about 500,000, and prererably a molec~ weight above about 1,000,000, and, may advantageously have a molecular weight above 5,000,000.

An example of an acceptable material is RETEN 235~, which is delivered-as a solid granule; a product of Hercules, Inc. of Wilmington, Delaware. Another acceptable anionic flocculant is Accurac 62~), a product of Cytec, Inc. of Stamford, CT.

Those skilled in the art will recognize that the desired usage rates of these polymers will vary widely. Arnounts as low as about 0.005% polymer by weight based on the finished dry weight of tissue paper will deliver useful results, but normally the usage rate would be expected to be higher; even CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 higher for the purposes of the present invention than commonly practiced as application of these materials. Amounts as high as about 0.5% might be employed but normally about 0.1% is optimum.

Other Additives Other rllalerials can be added to the ~ueo~ ~s paper",ahing furnish or the embryonic web to impart other charac~eristics to the product or improve the papermaking process so long as they are co""~dlible with the chemistry of the selected particulate filler and do not significantly and adversely affect10 the softness sllt:llylll or low dusting character of the ~resenl invention.
The following materials are expressly included, but their inclusion is not offered to be all-inclusive. Other materials can be included as well so long as they do not interfere or counteract the advantages of the present invention.
It is co" ,r,lGn to add a cationic charge biasing species to the papermaking process to control the zeta potential of the ~queol --s papermaking furnish as it is delivered to the papermaking process. These materials are used becz use most of the solids in nature have negative 20 surface charges including the surfaces of cellulosic fibers and fines and most inorga"ic fillers. Many ex~,el l~ in the field believe that a cationic charge biasing species is desirable as it partially neutralizes these solids making them more easily floccl ~-ted by cationic floccl ~-nts such as the before mentioned cationic starch and cationic polyelectrolyte. One 25 traditionally used cationic charge biasing species is alum. More recently in the art charge biasing is done by use of relatively low molecular weight cationic sy. Ilh~lic polymers prererably having a molecular weight of no more than about 500 000 and more ~,referdbly no more than about 200 000 or even about 100 000. The charge densities of such low molecular weight 30 cationic synthetic polymers are relatively high. These charge densities range from about 4 to about 8 equivalents of cationic nitrogen per kilogram of polymer. One suitable material is Cypro 514~) a product of Cytec Inc. of Sta")rord CT. The use of such materials is expressly allowed within the practice of the present invention. Caution should be used in their 35 application however. It is well known that while a small amount of such agents can actually aid retention by neutralizing anionic centers CA 02217~20 1997-10-03 W O96/316~3 PCTrUS96/04134 in~ccessihle to the larger flocc~ nt molecules and thereby lowering the particle repulsion; however, since such materials can compete with cationic flocculants for anionic anchoring sites, they can actually have an effect opposite to the intended one by negatively illlpacLillg retention when 5 anionic sites are limited.

The use of high surface area, high anionic charge microparticles for the purposes of improving formation, drainage, strength, and retention is well taught in the art. See, for example, U. S. Patent, 5,221,435, issued to Smith on June 22,1993, incorporated herein by rererence. Collllllo, materials for this purpose are silica colloid, or bentonite clay. The incorporation of such materials is expressly included within the scope of the present invention.

If permanent wet strength is desired, the group of chemicals: including polyamide-epichlorohydrin, polyacrylamides, styrene-butadiene latices;
insolubilized polyvinyl alcohol; urea-formaldehyde; polyethyleneimine;
chitosan polymers and mixtures thereof can be added to the pa,ue, making furnish or to the embryonic web. Polyamide-epichlorohydrin resins are cationic wet strength resins which have been found to be of particular utility.
Suitable types of such resins are described in U.S. Patent No. 3,700,623, issued on October 24, 1972, and 3,772,076, issued on November 13,1973, both issued to Keim and both being hereby inco".oraled by rererel.ce. One commercial source of a useful polyamide-epichlorohydrin resins is Hercules, Inc. of Wilmington, Delaware, which markets such resin under the mark Kymene 557H~9.

Many creped paper products must have limited strength when wet because of the need to dispose of them through toilets into septic or sewer 30 systems. If wet strength is imparted to these products, it is prefel,ed to befugitive wet strength characterized by a decay of part or all of its potency upon standing in presence of water. If fugitive wet strength is desired, the binder materials can be chosen from the group consisting of dialdehyde starch or other resins with aldehyde functionality such as Co-Bond 1000~) -35 offered by National Starch and Chemical Company, Parez 750@~) offered by Cytec of Stamford, CT and the resin described in U.S. Patent No. 4,981,557 issued on .)anuary 1, 1991, to Bjorkquist and incorporated herein by CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 reference.

If enhanced absorbency is needed, surfactants may be used to treat the creped tissue paper webs of the present invention. The level of 5 surfactant, if used, is preferably from about 0.01% to about 2.0% by weight, based on the dry fiber weight of the tissue paper. The su, ra~ , lls ~,, ererdbly have alkyl chains with eight or more carbon atoms. Exel"plary anionic su,ra~al.~s are linear alkyl sulfonates, and alk~lLel,~e,.e sulru,,ales.Exemplary nonionic slll ra~;~anls are alkylglycosides including alkylglycoside 10 esters such as Crodesta SL40~) which is available from Croda, Inc. (New York, NY); alkylglycoside ethers as des~ ibed in U.S. Patent 4.011,389, issued to W. K. Langdon, et al. on March 8, 1977; and alkylpolyethoxylated esters such as Pegosperse 200 ML available from Glyco Chemicals, Inc.
(Greenwich, CT) and IGEPAL RC-520~) available from Rhone Poulenc 15 Corporation (Cranbury, NJ).

Chemical sorlel ,i. ,g agents are expressly included as optional ingredients. Acce,utable chemical sonel ,i"g agents cGn",, ise the well known dialkyldimethylammonium salts such as ditallowdimethylammonium chloride, ditallowdimethyla,r,n,ol,ium methyl sulfate, di(hydrogenated) tallow dimethyl am~onium chloride; with di(hydrogenated) tallow dimethyl a",r,~unium methyl sulfate being ~,efel ,ed. This particular material is available col,.",ercially from Witco Chemical CGr"pdl-y Inc. of Dublin, Ohio under the tradename Varisoft 137~). Biodey, adaL le mono and di-ester variations of the quaternary ammonium compound can also be used and are within the scope of the present invention.

The present invention can also be used in conjunction with adhesives and coatings designed to be sprayed onto the surface of the web 30 or onto the Yankee dryer, such products designed for controlling adhesion to the Yankee dryer. For example, U. S. Patent 3,926,716, Bates, ~ incorporated here by reference, discloses a process using an aqueousdispersion of polyvinyl alcohol of certain degree of hydrolysis and viscosity for improving the adhesion of paper webs to Yankee dryers. Such polyvinyl 35 alcohols, sold under the tradename Airvol~) by Air Products and Chemicals, Inc. of Allentown, PA can be used in conjunction with the present invention.
Other Yankee coatings similarly recommended for use directly on the CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/0~134 Yankee or on the surface of the sheet are cationic polyamide or polyamine resins such as those made under the tradename Rezosol~) and Unisoft@~ by Houghton International of Valley Forge, PA and the Crepetrol~ tradename by Hercules, Inc. of Wilmington, Delaware. These can also be used with the 5 present invention. Preferably the web is secured to the Yankee dryer by means of an adhesive selected from the group consisting of partiall hydrolyzed polyvinyl alcohol resin, polyamide resin, polyamine resin, mineral oil, and mixtures thereof. More preferably, the adhesive is selected from the group consisting of polyamide epichlorohydrin resin, mineral oil, 10 and mixtures thereof.
The above listings of optional chemical additives is intended to be merely exemplary in nature, and are not meant to limit the scope of the invention.

Preparation of the A~ s r~ aking Furnish Those skilled in the art will recc yni~e that not only the qualitative chemical composition of the papermaking furnish is important to the creped papermaking process, but also the relative amounts of each component, 20 and the sequence and timing of addition, among other factors. It has now been found that the following techniq-Jes are suitable in preparing the aqueous pape""alcing furnish, but its delineation should not be regarded as limiting the scope of the present invention, which is defined by the claims set forth at the end of this specification.
Papermaking fibers are first pre~.ared by liberating the individual fibers into a aqueous slurry by any of the common pulping methods adequately described in the prior art. Refining, if necess~. y, is then carried out on the selected parts of the papermaking furnish. It has been found that 30 there is an advantage in retention, if the aqueous slurry which will later beused to adsorb the particulate filler is refined at least to the equivalent of aCanadian Standard Freeness of about 600 ml, but, more pr~rerably 550 ml or below. Dilution generally favors the absorption of polymers and retention aids; consequently, the slurry or slurries of papermaking fibers at 35 this point in the preparation is preferably no more than from about 3-5%
solids by weight.

CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 The selected partic~ te filler is first prepared by also dispersing it into an aqueous slurry. Dilution generally favors the absorption of polymers and retention aids onto solids surfaces; consequently, the slurry or slurries of particulate fillers at this point in the preparation is ~ rererably no more 5 than from about 1-5% solids by weight.

One aspéct of the invention is based on a cationic floccul~lt retention chemistry. It involves first the addilion of a starch with a limited water solubility in the presence of the particulate filler. Prererably, the 10 starch is cationic and it is added as an ~q~ ~eous dispersion in an amount ranging from about 0.3 % by weight to 1.0% by weight, based on the dry weight of the starch and the dry weight of the particulate filler, strictly to the dilute aqueous slurry of particulate filler.

While not wishing to be bound by theory, it is believed that the starch acts as an agglomerating agent onto the filler and results in agglomeration of the particles. Agglomerali"g the filler in this manner makes it more effectively adsorbed onto the surfaces of the papermaking fibers.
Adsorption of the filler onto the fiber surfaces can be accomplished by combining the slurry of agglomerates with at least one slurry of papermaking fibers and adding a cationic flocculant to the resultant mixture.
Again, while not wishing to be bound by theory, the action of the flocculant is thought to be effective at this point by bridging between anionic sites on the pa~,er",aking fibers and anionic sites on the filler agglomerates.
2~
The cationic flocculant can be added at any suitable point in the ap~,roach flow of the stock preparation system of the papermaking process.
It is particularly preferred to add the cationic flocculant after the fan pump in which the final dilution with the recycled machine water returned from the 30 process is made. It is well known in the papermaking field that shear stages break down bridges formed by flocculating agents, and hence it is general practice to add the flocc~ fing agent after as many shear stages encountered by the aqueous papermaking slurry as feasible.

A second aspect of the invention is based on an anionic flocculant.
In this aspect, the anionic flocculant is preferably added at least to an aqueous slurry of the particulate filler while it is essentially isolated from the CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 remainder of the aqueous papermaking furnish. The combination of anionic flocculant and particulate filler is then combined with at least a portion of the paper",aking fibers and cationic starch is added to the mixture; this combination and starch addition is preferably accomplished 5 prior to the final dilution of the process wherein the recycled machine water is combined with the aqueous papermaking furnish and conveyed to a headbox by a fan pump.

Ad\ a~ geously, there is provided an additional dose of floccul- lt lO after the starch is added. While it is essential in this aspect of the invention that the initial dose of floccul~rlt be of the anionic type, the portion of floccl ~nt added after the fan pump can be of either the anionic type or cationic type. Most prererably, this second dose of flocculant occurs after the final dilution with the recycled machine water, i.e. after the fan pump. It 15 is well known in the papermaking field that shear stages break down the flocs formed by flocculating agents, and hence it is general practice to add the flscc~ ing agent after as many shear stages enco~ Lere,~ by the aqueous papermaking slurry as feasible.

Those skilled in the art will recognize that the before mentioned recommended addition of flocculant directly to the particulate filler is an exception to minimum shear stage approach; thus this aspect of the present invention yields an unexpected advantage when at least a portion of the anionic flocculant is added to the particulate filler while it is essentially free of the other components of the :-ql ~eo~ ~s papermaking furnish and the floccul~rlt treated particulate filler is added to the papermaking fibers prior to the final dilution stage. A suitable ratio for point of addition of the anionic flocc~ t is about 4:1, i.e. for each 1 part of the total flocculant dosage that is added after the fan pump, about 4 parts are advantageously added directly to the particulate filler. This ratio can vary considerably, and it is anticipated that ratios from about 0.5:1 to 10:1 might be appropriate depending on varying circumstances.

In preparing products representing either aspect of the invention, if multiple s~urries of papermaking fibers are prepared, one or more of the slurries can be used to adsorb particulate fibers in accordance with the present invention. Even if one or more aqueous slurries of papermaking CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 fibers in the papermaking process is maintained relatively free of particulate fillers prior to reaching its fan pump, it is preferred to add a cationic or anionic flocculant after the fan pump of such slurries. This is because the recycled water used in that fan pump contains filler agglomerates which S failed to retain in previous p~sses over the foraminous screen. When multiple dilute fiber slurries are used in the creped papermaking process, the flow of cationic or anionic floccul~rlt is ,~.referably added to all dilute fiber slurries and it should be added in a manner which a~pro,(i",alely propo, lions it to the flow of solids in the ~ eo~ ~s papermaking furnish of 10 each dilute fiber slurry.

In a prefe" ad arrangement, a slurry of relatively short papermaking fibers, comprising hardwood pulp, is prepared and used to adsorb fine particl ~l~te fibers, while a slurry of relatively long papermaking fibers, 15 comprising softwood pulp, is prepared and left essentially free of fine partiu ~l~tes The fate of the resultant short fibered slurry is to be d;rected to the outer chambers of a three layered headL,ox to form surface layers of a three layered tissue in which a long fibered inner layer is forrned out of a inner chamber in the he~hox in which the slurry of relatively long papermaking fibers is directed. The resultant filled tissue web is particularly suitable for converting into a single-ply tissue product.

In an alternate ~rere"ed arrangement, a slurry of relatively short papermaking fibers, comprising hardwood pulp, is prepared and used to adsorb fine particulate fibers, while a slurry of relatively long paper",alcing fibers, comprising softwood pulp, is prepared and left essentially free of fine particul-~es. The fate of the resultant short fibered slurry is to be directed to one chamber of a two chambered headbox to form one layer of a two layered tissue in which a long fibered alternate layer is formed out of the 30 second chamber in the headbox in which the slurry of relatively long papermaking fibers is directed. The resultant filled tissue web is particularly suitable for converting into a multi-ply tissue product comprising two plies in which each ply is oriented so that the layer comprised of relatively short papermaking fibers is on the surface of the two-ply tissue product.
Those skilled in the art will also recognize that the apparent number of chambers of a headbox can be reduced by directing the same type of CA 02217~20 1997-10-03 W O96/31653 PCTrUS96104131 aqueous papermaking fumish to ~ ce, ll chambers. For example the aforementioned three cha",bered headbox couid be used as a two chambered headbox simply by dire~i"g essentially the same aqueo~ ~s papermaking furnish to either of two adjacent chambers.

Further insight into preparation methods for the aq~ ~eous papermaking furnish can be gained by re~erence to Figure 2 which is a schematic representation illuslr~li"g a preparalion of the aqueous papermaking furnish for the creped papermaking operation yielding a 10 product accordi,-g to the aspect of the invention based on cationic flocu ~~nt and Figure 3 which is a schematic represe"l2lion illusll aling a preparation of the aqueous papermaking furnish for the creped papermaking operation yielding a product according to another aspect of the invention based on anionic flocc~ nt. The following ~isc~ ~ssion refers 15 to Figure 2:

A storage vessel 1 is provided for staging an ~ eo~ ~s slurry of relatively long papermaking fibers. The slurry is conveyed by means of a pump 2 and optionally through a refiner 3 to fully develop the strength 20 potential of the long papermaking fibers. Additive pipe 4 conveys a resin to provide for wet or dry strength as desired in the finished product. The slurry is then further conditioned in mixer 5 to aid in absorption of the resin.The suitably conditioned slurry is then diluted with white water 7 in a fan pump 6 forming a dilute long papermaking fiber slurry 15. Pipe 20 adds a 25 cationic flocculant to the slurry 15 producing a flocc~ ted long fibered slurry 22.

Still referring to Figure 2 a storage vessel 8 is a repository for a fine particulate filler slurry. Additive pipe 9 conveys an aqueous dispersion of a 30 cationic starch additive. Pump 10 acts to convey the fine particulate slurry as well as provide for dispersion of the starch. The slurry is conditioned in a mixer 12 to aid in absorption of the additives. Resultant slurry 13 is conveyed to a point where it is mixed with an aqueous dispersion of refined short fiber papermaking fibers.
Still referring to Figure 2 short papermaking fiber slurry originates from a repository 11 from which it is conveyed through pipe 49 by pump 14 CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/04134 through a refiner 15 where it becomes a refined slurry of short paper",aking fibers 16. After mixing with the conditioned slurry of fine particulate filler 13 it becomes the short fiber based aqueous papermaking slurry 17. White water 7 is mixed with slurry 17 in a fan pump 18 at which point the slurry 5 becomes a dilute ~q~eo~ls papermaking slurry 19. Pipe 21 directs a cationic floccul~rlt into slurry 19 after which the slurry becomes a flsccul~ted A~l ~eous pape,ll.akil,g slurry 23.

P, efer~bly the flocc~ te~ short-fiber based aq~ ~eo~ ~s paper" ,ahi"g 10 slurry 23 is directed to the creped pape""alcing process illusl,aled in Figure 1 and is divided into two ~ roxi,,,alely equal streams which are then directed into he~hsx chambers 82 and 83 ultimately evolving into off-Yankee-side-layer 75 and Yankee-side-layer 71 respectively of the strong soft low dusting filled creped tissue paper. Similarly the aqueous 15 flocc~ ted long paper".aking fiber slurry 22 referring to Figure 2 is preferably directed into headbox cha".ber 82b ulli",alely evolving into center layer 73 of the strong soft low dusting filled creped tissue paper.

The following ~isc~ ~ssion refers to Figure 3:
A storage vessel 24 is provided for staging an aq~ ~eo~ ~s slurry of relatively long papermaking fibers. The slurry is conveyed by means of a pump 25 and optionally through a refiner 26 to fully develop the strength potential of the long ,c,ape".,aking fibers. Additive pipe 27 conveys a resin 25 to provide for wet or dry sl, e, lyU " as desired in the finished product. The slurry is then further conditioned in mixer 28 to aid in absorption of the resin. The suitably conditioned slurry is then diluted with white water 29 in a fan pump 30 forming a dilute long papermaking fiber slurry 31.
Optionally pipe 32 conveys an flocculant to mix with slurry 31 forming an 30 aqueous floccul~ted long fiber papermaking slurry 33.

~ Still refer, ing to Figure 3 a storage vessel 34 is a repository for a fine particulate filler slurry. Additive pipe 35 conveys an aqueous dispersion of a anionic floccul~rlt. Pump 36 acts to convey the fine particulate slurry as 35 well as provide for dispersion of the flocculant. The slurry is conditioned in a mixer 37 to aid in absorption of the additive. Resultant slurry 38 is conveyed to a point where it is mixed with an aqueous dispersion of short CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 papermaking fibers.

Still rerer, ing to Figure 3, a short papermaking fiber slurry originates from a reposilo,y 39, from which it is conveyed through pipe 48 by pump 40 s to a point where it mixes with the conditioned fine particulate filler slurry 38 to become the short fiber based ~q~ ~eous papermaking slurry 41. Pipe 46 conveys an aqueous dispersion of cationic starch which mixes with slurry 41, aided by in line mixer 50, to form flocc~ ted slurry 47. White water 29 is directed into the flocc~ ted slurry which mixes in fan pump 42 to become 10 the dilute floccl ~ ed short fiber based ag~ leo~ ls papermaking slurry 43.
Optionally, pipe 44 conveys additional floccu~nt to increase the level of flocull~fion of dilute slurry 43 forming slurry 45.

Preferably, the short papermaking fiber slurry 45 from Figure 3 is 15 directed to the prerer~ed papermaking process illusll dled in Figure 1 and isdivided into two approki,nalely equal streams which are then directed into headbox chambers 82 and 83 ulli"lalely evolving into off-Yankcc ~ide-layer 75 and Yankee-side-layer 71, respectively of the strong, soft, low dusting, filled creped tissue paper. Similarly, the long papermaking fiber slurry 33, 20 r~rer, ing to Figure 3, is ~r~reraL,ly directed into he~hox chamber 82b ultimately evolving into center layer 73 of the strong, soft, low dusting, filled creped tissue paper.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 The Creped Papermaking Process Figure 1 is a schematic representation illustrating a creped papermaking process for producing a strong, soft, and low dust filled creped tissue paper. These prerer,ed embodiments are described in the following ~lisc~ ~ssion, wherein rerere"ce is made to Figure 1.

Figure 1 is a side elevational view of a ~rerer, ed papermaking machine 80 for manufacturing paper according to the present invention.
Re~(ting to Figure 1, papermaking machine 80 comprises a layered headbox 81 having a top d~a"~ber 82 a center chamber 82b, and a bottom chamber 83, a slice roof 84, and a Fourdrinier wire 85 which is looped over and about breast roll 86, deflector 90, vacuum suction boxes 91, couch roll 92, and a plurality of tuming rolls 94. In operation, one papermaking furnish is pumped through top chamber 82 a second paper",aking furnish is pumped through center chamber 82b, while a third furnish is pumped through bottom chamber 83 and thence out of the slice roof 84 in over and under relation onto Fourdrinier wire 85 to form thereon an embryonic web 88 co",~risi,.g Iayers 88a, and 88b, and 88c. Dewatering occurs through the Fourdrinier wire 85 and is assis~ed by deflector 90 and vacuum boxes 91. As the Fourdrinier wire makes its return run in the direction shown by the arrow, showers 95 clean it prior to its commencing another pass over breast roll 86. At web transfer zone 93, the embryonic web 88 is transferred to a foraminous carrier fabric 96 by the action of vacuum transfer box 97.
Carrier fabric 96 carries the web from the transfer zone 93 past vacuum dewatering box 98, through blow-through predryers 100 and past two turning rolls 101 after which the web is transferred to a Yankee dryer 108 by the action of pressure roll 102. The carrier fabric 96 is then cleaned and dewatered as it completes its loop by passing over and around additional turning rolls 101, showers 103, and vacuum dewatering box 105. The predried paper web is adhesively secured to the cylindrical surface of ~ 30 Yankee dryer 108 aided by adhesive applied by spray applicator 109.
Drying is completed on the steam heated Yankee dryer 108 and by hot air - which is heated and circulated through drying hood 110 by means not shown. The web is then dry creped from the Yankee dryer 108 by doctor blade 111 after which it is designated paper sheet 70 comprising a Yankee-side layer 71 a center layer 73, and an off-Yankee-side layer 75. Paper CA 02217~20 1997-10-03 W O96131653 PCTrUS96/04134 sheet 70 then passes between calendar rolls 112 and 113, about a circumferential portion of reel 115, and thence is wound into a roll 116 on a core 117 disposed on shaft 118.

Still referring to Figure 1, the genesis of Yankee-side layer 71 of paper sheet 70 is the furnish pumped through bottom chamber 83 of headbox 81, and which fumish is applied directly to the Fourdrinier wire 85 whereupon it becomes layer 88c of embryonic web 88. The genesis of the center layer 73 of paper sheet 70 is the furnish delivered through chamber 82.5 of heA~hox 81, and which furnish forms layer 88b on top of layer 88c.
The genesis of the off-Yankee-side layer 75 of paper sheet 70 is the furnish delivered through top chamber 82 of he~lhox 81, and which furnish forms layer 88a on top of layer 88b of embryonic web 88. Although Figure 1 shows papermachine 80 having he~lhox 81 adapted to make a three-layer web, headbox 81 may alternatively be adapted to make unlayered, two layer or other multi-layer webs.

Further, with respect to making paper sheet 70 embodying the present invention on papermaking machine 80, Figure 1, the Fourdrinier wire 85 must be of a fine mesh having relatively small spans with respect to the average lengths of the fibers constituting the short fiber furnish so that good fo...,alion will occur; and the fordmi. ,ous carrier fabric 96 should have a fine mesh having relatively small opening spans with respect to the average lengths of the fibers consliLuting the long fiber furnish to sl ~hst~ntially obviate bulking the fabric side of the embryonic web into the inter-filamentary sp~ces of the fabric 96. Also, with respect to the process conditions for making exemplary paper sheet 70, the paper web is preferably dried to about 80% fiber consistency, and more preferably to about 95% fiber consistency prior to creping.
The present invention is applicable to creped tissue paper in general, including but not limited to conventionally felt-pressed creped tissue paper;
high bulk pattern densified creped tissue paper; and high bulk, uncompacted creped tissue paper.
3s The filled creped tissue paper webs of the present invention have a basis weight of between 10 g/m2 and about 100 g/m2. In its preferred CA 02217~20 1997-10-03 W O96131653 PCTnUS96/04134 embodiment, the filled tissue paper of the present invention has a basis weight between about 10 g/m2 and about 50 g/m2 and, most prererably, between about 10 g/m2 and about 30 g/m2. Creped tissue paper webs suitable for the present invention possess a density of about 0.60 glcm3 or 5 less. In its prerer.ed e",bodi,nent, the filled tissue paper of the present invention has a density between about 0.03 g/m3 and about 0.6 g/m3 and, most prererably, between about 0.05 g/m3 and 0.2 g/m3.

The present invention is further applicable to multi-layered tissue 10 paper webs. Tissue structures formed from layered paper webs are described in U.S. Patent 3,994,771, 1~1Organ, Jr. et al. issued November 30, 1976, U.S. Patent No. 4,300,981, Carstens, issued November 17, 1981, U.S. Patent No. 4,166,001, Dunning et al., issued August 28, 1979, and European Patent Publication No. 0 613 979 A1, Edwards et al., published September 7, 1994, all of which are incorporated herein by refere.,ce. The layers are preferably corl ~ ised of dirrert n l fiber types, the fibers typically being relatively long softwood and relatively short hardwood fibers as used in multi-layered tissue paper making. Multi-layered tissue paper webs suitable for the present invention comprise at least two superposed layers, 20 an inner layer and at least one outer layer contiguous with the inner layer.
F'l ererably, the multi-layered tissue papers comprise three superposed layers, an inner or center layer, and two outer layers, with the inner layer lo~ted between the two outer layers. The two outer layers preferably comprise a primary filamentary constituent of relatively short paper making 25 fibers having an average fiber length between about 0.5 and about 1.5 mm, ~,referably less than about 1.0 mm. These short paper making fibers typically comprise hardwood fibers, prere~ably hardwood Kraft fibers, and most ,~ rererably derived from eucalyptus. The inner layer preferably comprises a primary filamentary cGnsLiLuent of relatively long paper making 30 fibers having an average fiber length of least about 2.0 mm. These long paper making fibers are typically softwood fibers, preferably, northern softwood Kraft fibers. Preferably, the majority of the particulate filler of thepresent invention is contained in at least one of the outer layers of the multi-layered tissue paper web of the present invention. More ,ureferably, the 35 majority of the particulate filler of the present invention is contained in both of the outer layers.
The creped tissue paper products made from single-layered or multi-CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 layered creped tissue paper webs can be single-ply tissue products or multi-ply tissue products.

The equipment and methods are well known to those skilled in the S art. In a typical process, a low consistency pulp furnish is provided in a pressurized headbox. The headbox has an opening for delivering a thin deposit of pulp fumish onto the Fourdrinier wire to form a wet web. The web is then typically dewatered to a fiber consialency of between about 7%
and about 25% (total web weight basis) by vacuum dewatering.
To prepare filled tissue paper products according to those disclosed in the present invention, an aqueous papermaking furnish is deposited on a foraminous surface to form an embryonic web. The scope of the invention also includes tissue paper products resultant from the ror",alion of multiple 15 paper layers in which two or more layers of furnish are prererably fo,lned from the deposition of se~,arale streams of dilute fiber slurries for example ina multi-channeled headbox. The layers are pr~:rerdbly comprised of dirrerei ll fiber types, the fibers typically being relatively long softwood andrelatively short hardwood fibers as used in multi-layered tissue paper 20 making. If the individual layers are initially formed on separate wires, the layers are subsequently combined when wet to form a multi-layered tissue paper web. The ~aper-"aking fibers are preferably comprised of dirrerenl fiber types, the fibers typically being relatively long softwood and relatively short hardwood fibers. More ~,referably, the hardwood fibers comprise at 25 least about 50% and said softwood fibers comprise at least about 10% of said papermaking fibers.

In the papermaking process used to make filled tissue products according to the present invention, the step comprising the ll dl ,arer of the 30 web to a felt or fabric, e.g., conventionally felt pressing tissue paper, well known in the art, is expressly included within the scope of this invention. In this process step, the web is dewatered by transferring to a dewatering felt and pressing the web so that water is removed from the web into the felt by pressing operations wherein the web is subjected to pressure developed by 35 opposing mechanical members, for example, cylindrical rolls. Because of the substantial pressures needed to de-water the web in this fashion, the resultant webs made by conventional felt pressing are relatively high in CA 022l7~20 l997-lO-03 W O96131653 PCTrUS96104134 density and are characterized by having a uniform density throughout the web structure.

In the papermaking process used to make filled tissue products according to the present invention the step comprising the transfer of the semi-dry web to a Yankee dryer the web is pressed during transfer to the cylindrical steam drum apparatus known in the art as a Yankee dryer. The transfer is effected by mecl Idl ,ical means such as an opposing cylindrical drum pressing against the web. Vacuum may also be applied to the web as it is pressed against the Yankee surface. Multiple Yankee dryer drums can be employed.

More preferable variations of the papermaking process for making filled tissue papers include the so~alled pdller-, densified methods in which the resultant structure is, 1 ,ara~eri~ed by having a relatively high bulk fieldof relatively low fiber density and an array of densified zones of relatively high fiber density dispersed within the high bulk field. The high bulk field is aller.,ali~fely characterized as a field of pillow regions. The densified zones are alternatively referred to as knuckle regions. The densified zones may be discretely spaced within the high bulk field or may be ir"er~""ected either fully or partially within the high bulk field. r, e~erably the zones of relatively high density are continuous and the high bulk field is discrete.
Prere"ed processes for making pattern densified tissue webs are disclosed in U.S. Patent N o. 3,301,746, issued to Sanford and Sisson on January 31, 1967, U.s. Patent N o. 3,974,025, issued to Peter G. Ayers on August 10 1976, and U.S. Patent N o. 4,191,609, issued to Paul D. Trokhan on March 4,1980, and U.S. Patent 4,637,859, issued to Paul D. Trokhan on January 20,1987, U.S. Patent 4,942,077 issued to Wendt et ai. on July 17,1990, European Patent Publication N o. 0 617164 A1 Hyland et al. published Sep~e",L:,er 28,1994, European Patent Publication N o. 0616 074 A1 Hermans et al. published September 21,1994; all of which are incorporated herein by reference.
To form pattern densified webs the web transfer step immediately after forming the web is to a forming fabric rather than a felt. The web is juxtaposed against an array of supports comprising the forming fabric. The web is pressed against the array of supports thereby resulting in densified CA 02217~20 1997-10-03 W O96/316S3 PCTrUS96/04134 zones in the web at the locations geoyl dpl ,ically corresponding to the points of contact between the array of supports and the wet web. The remainder of the web not col"pressed during this operation is referred to as the high bulk field. This high bulk field can be further dedensified by 5 application of fluid pressure, such as with a vacuum type device or a blow-through dryer. The web is dewatered, and optionally predried, in such a manner so as to substantially avoid cor"pression of the high bulk field. This is pl efer~bly accomplished by fluid pressure, such as with a vacuum type device or blow-through dryer, or aller, .ately by mechanically pressing the 10 web against an array of supports wherein the high bulk field is not ~",pressed. The operations of dewaleri,)y, optional predrying and formation of the densified zones may be integrated or partially intey~ aled to reduce the total number of processing steps performed. The moisture co"~e, ll of the semi-dry web at the point of ll al)srer to the Yankee surface is 15 less than about 40% and the hot air is forced through said semi~ry web while the semi-dry web is on said forming fabric to form a low density structure.

The pattern densified web is transferred to the Yankee dryer and 20 dried to completion, pr~ferably still avoiding mechanical pressing. In the present invention, p(eferably from about 8% to about 55% of the creped tissue paper surface comprises densified knuckles having a relative density of at least 125% of the density of the high bulk field.

The array of supports is preferably an i" ,prinlil)g carrier fabric having a pallel I ,ed displacement of knuckles which operate as the array of supports which facilitate the formation of the densified zones upon application of pressure. The pattern of knuckles constitutes the array of supports previously referred to. Ill,,uri,)li,)9 carrier fabrics are disclosed in U.S. Patent No. 3,301,746, Sanford and Sisson, issued January 31, 1967, U.S. Patent No. 3,821,068, Salvucci, Jr. et al., issued May 21, 1974, U.S.
Patent No. 3,974,025, Ayers, issued August 10, 1976, U.S. Patent No.
3,573,164, Friedberg et al., issued March 30, 1971, U.S. Patent No.
3,473,576, Amneus, issued October 21, 1969, U.S. Patent No. 4,239,065, Trokhan, issued December 16, 1980, and U.S. Patent No. 4,528,239, Trokhan, issued July 9, 1985, all of which are incorporated herein by reference.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 Most preferably, the embryonic web is caused to co"ror", to the surface of an open mesh drying/i"ll,, inling fabric by the appiication of a fluid force to the web and thereafter thermally predried on said fabric as part of a low density paper making process.

Another variation of the processing steps included within the present invention includés the formation of, so-called uncompacted, non pattern-densified multi-layered tissue paper structures such as are described in U.S. Patent No. 3,812,000 issued to Joseph L. Salvucci, Jr. and Peter N.
Yiannos on May 21, 1974 and U.S. Patent No. 4,208,459, issued to Henry E. Becker, Albert L. McConnell, and Richard Schutte on June 17, 1980, both of which are incorporated herein by refere"ce. In general uncompacted, non pdller" densified multi-layered tissue paper structures are pr~pared by depositing a paper making furnish on a foraminous forming wire such as a Fourdrinier wire to form a wet web, draining the web and removing additional water without mechanical co""~ression until the web has a fiber consistency of at least 80%, and creping the web. Water is removed from the web by vacuum dewatering and thermal drying. The resulting structure is a soft but weak high bulk sheet of relatively uncompacted fibers. Bonding material is ~,referably applied to portions of the web prior to creping.

The advantages related to the practice of the present invention include the ability to reduce the amount of papermaking fibers required to produce a given amount of tissue paper product. Further, the optical pro~e, lies, particularly the opacity, of the tissue product are improved.
These adva"lages are realized in a tissue paper web which has a high level of sl, enyll . and is low dusting.

The term Uopacity" as used herein refers to the resistance of a tissue paper web from transmitting light of a wavelength corresponding to the visible portion of the electromagnetic spectrum. The Uspecific opacity"
is the measure of the degree of opacity imparted for each 1 g/m2 unit of basis weight of a tissue paper web. The method of measuring opacity and calculating specific opacity are detailed in a later section of this specification. Tissue paper webs according to the present invention preferably have more than about 5%, more preferably more than about CA 02217~20 1997-10-03 W 096/31653 PCT~US96/04134 5.5%, and most prererably more than about 6% specific opacity.

The term Ustrength" as used herein refers to the specific total tensile sl,enylll~ the deter",i"dlion metllod for this measure is included in a later S section of this specification. The tissue paper webs according to the present invention are strong. This generally means that their specific total tensile strength=is at least about 0.25 meters, more preferably more than about 0.40 meters.

The terms Ulint" and Udust" are used interchangeably herein and refer to the tendency of a tissue paper web to release fibers or partiu ~-te fillers as measured in a controlled abrasion test, the methodology for which is detailed in a later section of this specification. Lint and dust are related to strength since the tendency to release fibers or particles is directly 15 related to the degree to which such fibers or particles are anchored into thestructure. As the overall level of anchoring is increased, the strength will be increased. However, it is possihle to have a level of strength which is regarded as acce~table but have an unacceptable level of linting or dusting.
This is because linting or dusting can be localized. For example, the 20 surface of a tissue paper web can be prone to linting or dusting, while the degree of bonding beneath the surface can be sufficient to raise the overall level of strength to quite acce~,table levels. In another case, the strength can be derived from a skeleton of relatively long papermaking fibers, while fiber fines or the particulate filler can be insufficiently bound within the 25 structure. The filled tissue paper webs according to the present invention are relatively low in lint. Levels of lint below about 12 are preferable, below about 10 are more ~,rerer;3ble, and below 8 are most preferable.

The multi-layered tissue paper web of this invention can be used in 30 any application where soft, absorbent multi-layered tissue paper webs are required Particularly advantageous uses of the multi-layered tissue paper web of this invention are in toilet tissue and facial tissue products. Both single-ply and multi-ply tissue paper products can be produced from the webs of the present invention.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/0~134 Analytical and Testing Procedures A. n- ,5jl~

s The density of multi-layered tissue paper as that term is used herein is the average density calcul~ed as the basis weight of that paper divided by the caiiper with the appro~riate unit conversions incorporated therein.
Caliper of the multi-layered tissue paper as used herein is the thickness of the paper when subjected to a co""~ressive load of 95 g/jn2 (15.5 g/cm2).
B. Molecular Weight Determination The essential distinguishing characteristic of polymeric materials is their molecular size. The prope, lies which have enabled polymers to be used in a diversity of applicalic" .s derive almost entirely from their macro-molecular nature. In order to cl ,aracteri~e fully these ",alerials it is essenlial to have some means of d~r"~i"g and determining their molec~ weights and molec~ ~-- weight distributions. It is more co" ecl to use the term relativemolecular mass rather the molecular weight but the latter is used more generally in polymer technology. It is not always practical to deter",i. .e molecular weight distributions. However this is becoming more common practice using ~Irollldlographic techniques. Rather recourse is made to e~ressi"y mcle~ ll~r size in terms of molecular weight averages.

Molecular Weight Aver._~es If we consider a simple molecular weight distribution which represents the weight fraction (wj) of molecules having relative molecular mass (Mj) it is possible to define several useful average values. Averaging 30 carried out on the basis of the number of molecules (Nj) of a particular size(Mj) gives the Number Average Molecular Weight Mn = ~.NiMi ~ Ni An important conse~ lence of this definition is that the Number Average Molecular Weight in grams contains Avogadro s Number of CA 02217~20 1997-10-03 W O96/316S3 PCTrUS96/04134 .

molecules. This definition of molecular weight is consistent with that of monodisperse molecul~r species, i.e. molecules having the same molecular weight. Of more significance is the recognition that if the number of molecules in a given mass of a polydisperse polymer can be determined in S some way then M n. can be calculated readily. This is the basis of colligative property measurements.
Averaging on the basis of the weight fractions (Wj) of molecules of a given mass (Mj) leads to the definition of Weight Average Molecular Weights Mw = ~Wi Ni = ~ Ni Mj2 Wj ~NjMj ~w is a more useful means for expressing polymer molecular weights than ~~n since it ref,ects more accurately such properties as melt viscosity and mechanical properties of polymers and is ll ,ereror used in the present invention.
C. Filler Particle Size Dele..ni.,ation Particle size is an important c,etermi"ant of pe~ ror",ance of filler, especially as it relates to the ability to retain it in a paper sheet. Clay particles, in particular, are platy or blocky, not spherical, but a measure referred to as "equivalent spl ,erical diameter" can be used as a relative measure of odd shaped particles and this is one of the main methods that the industry uses to measure the particle size of clays and other particulate fillers. Equivalent spherical diameter determinations of fillers can be made using TAPPI Useful Method 655, which is based on the Sedigraph~
analysis, i.e., by the instrument of such type available from the Micromeritics Instrument Corporation of Norcross, Georgia. The instrument uses soft x-rays to deter",ine gravity sedimentation rate of a dispersed 30 slurry of particulate filler and employs Stokes Law to calculate the equivalent spherical diameter.

CA 02217~20 1997-10-03 W O 96/31653 PCTnUS96/04134 D. Filler Qua"lilali~e Analysis in Paper Those skiiled in the art will recognize that there are many methods ~ for quar,lilalive analysis of non-cellulosic filler .. ale. ials in paper. To aid in the practice of this invention, two methods will be detailed applicable to the 5 most prerer. ed inorganic type fillers. The first method, ashing, is applicable to inorganic fillers in general. The secGnd method, deter--,ination of kaolin by XRF, is tailored specifically to the filler found particularly suitable in the practice of the present invention, i.e. kaolin.
Ashing Ashing is performed by use of a muffle fumace. In this method, a four place balance is first cleaned, calibrated and tarred. Next, a clean and empty platinum dish is weighed on the pan of the four place balance.
Record the weight of the empty platinum dish in units of grams to the ten-thousandths place. Without re-tarring the balance, approximately 10 grams 15 of the filled tissue paper sample is carefully folded into the platinum dish.T~e weight of the piatinum boat and paper is recGr~ed in units o~ grams to the ten-thousandths place.

The paper in the platinum dish is then pre-ashed at low te",peraL.Ires 20 with a Bunsen bumer flame. Care must be taken to do this slowly to avoid the for,.,alion of air-bome ash. If air-borne ash is observed, a new sample must be pre~,a, ed. After the flame from this pre-ashing step has subsided, plaoe the sample in the muffle furnace. The muffle fumace should be at a te,n~erdLure of 57~ C. Allow the sample to completely ash in the muffle 25 fumace for a~",fo~i...ately 4 hours. After this time, remove the sample with thongs and place on a clean, flame retarda, .l surface. Allow the sample to cool for 30 minutes. After cooling, weigh the platinum dish/ash cc ",binaliGn in units of grams to the ten-thousandths place. Record this weight.

The ash CGI ,lenl in the filled tissue paper is calculated by subl, a~;li- ,9 the weight of the clean, empty platinum dish from the weight of the platinum dish/ash col"biilaLion. Record this ash content weight in units of grams to the ten-thousandths place.

The ash content weight may be converted to a filler weight by CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 knowledge of the filler loss on ashing (due for example to water vapor loss in kaolin). To deter",i"e this, first weigh a clean and empty platinum dish on the pan of a four place balance. Record the weight of the empty platinum dish in units of grams to the ten-thousandths place. Without re-S tarring the balance, a~ r.~i",alely 3 grams of the filler is carefully pouredinto the platinum dish. The weight of the platinum dish/filler combination is recorded in units of grams to the ten-thousandths place.

This sample is then carefully placed in the muffle furnace at 575 C.
10 Allow the sample to completely ash in the muffle furnace for approximately 4 hours. After this time, remove the sample with thongs and place on a clean, flame retardan~ surface. Allow the sample to cool for 30 minutes.
After cooling, weigh the platinum dish/ash combination in units of grams to the ten-thousandths place. Record this weight.
Calculate the percent loss on ashing in the original filler sample using the following e~ ~ation:

% Loss on ashing= r(Wt. of Oriqinal Filler Sdlll. ' - ~ ~-t dish~ (Wt. of Filler Ash8pt dish)l x 100 [(Wt. of Original Filler S.. " ~ '- ~ pt dish) - (Wt of pt dish)]

The % loss on ashing in kaolin is 10 to 15%. The original ash weight in units of grams can then be converted to a filler weight in units of grams with 25 thefollowing e~ tion:

Weight of Filler (g) = Weiqht of Ash (q) [1 - (% Loss on Ashing/100)]

The percent filler in the original filled tissue paper can then be calculated asfollows:

% Filler in Tissue Paper = Weiaht of Filler (a) x 100 [(VVeight of Platinum Dish&Paper) - (Weight of Platinum Dish)]

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96104134 Deterrnination of Kaolin Clay by XRF
The main advantage of the XRF téchnique over the muffle fumace - ashing technique is speed but it is not as universally applicable. The XRF
speclrc ",eter can qu~nlilale the level of kaolin clay in a paper sample within 5 5 minutes cG,~"~a~ed to the hours it takes in the muffle furnace ashing method.

The X-ray Fluorescence technique is based on the bo"lbard~"ent of the sample of interest with X-ray photons from a X-ray tube source. This 10 bombardme"l by high energy ~hotons c~ ~ses core level electrons to be photoemitted by the elements present in the sample. These empty core levels are then filled by outer shell electrons. This filling by the outer shellelectrons results in the fluorescence ~,-ocess such that additional X-ray photons are emitted by the elements present in the sample. Each element has distinct '~i"yel ~.ri, Il ' energies for these X-ray fluorescenl 11 ansiliGns.
The energy and thus the identity of the element of interest of these emitted X-ray fluoresce"ce photc,l)s is Jetel ",ined with a lithium doped silicon sel"iconductor detector. This delector makes it possible to determine the energy of the impinging pholons and thus the identify the eler"ents present in the sample. The ele",el)l-~ from sodium to uranium may be identified in most sample matrices.

In the case of the clay fillers the dete~Led elel"enls are both silicon and aluminum. The particular X-ray Fluorescence instrument used in this clay analysis is a Spectrace 5000 made by Baker-Hughes Inc. of Mountain View, California. The first step in the quanlilalive analysis of clay is to calibrate the instrument with a set of known clay filled tissue standards using clay inclusions ranging from 8% to 20% for example.

The exact clay level in these standard paper samples is determined with the muffle furnace ashing technique described above. A blank paper sample is also included as one of the standards. At least 5 standards bracketing the desired target clay level should be used to calibrate the instrument.
Before the actual calibration process the X-ray tube is powered to CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 settings of 13 kilovolts and 0.20 miiliamps. The instrument is also set up to integrate the detecled signals for the aluminum and silicon contained in the clay. The paper sample is prepared by first cutting a 2" by 4" strip. This strip is then folded to make a 2" X 2" with the off-Yankee side facing out.
5 This sample is placed on top of the sample cup and held in place with a retaining ring. During sample preparalion care must be taken to keep the sample flat on top of the sample cup. The instrument is then calibrated using this set of known slandar~ls.

After calibrating the instrument with the set of known slandarcls, the linear calibration curve is stored in the computer system's memory. This linear calibration curve is used to calculate clay levels in the unknowns. To insure the X-ray Fluorescei ,ce system is stable and working properly a check sample of known clay co"tenl is run with every set of unknowns. If 15 the analysis of the check sample results in an inaccurate result (10 to 15%
off from its known clay contenl) the instrument is subjected to trouble-shooting and/or re-calibrated.

For every paper-making condition the clay conlent in at least 3 20 unknown samples is dete""ined. The average and standard deviation is taken for these 3 sa"lFles. If the clay application procedure is suspected or intentionally set up to vary the clay c~ntel ,t in either the cross direction (CD) or machine dil~:~tiGn (MD) of the paper more samples should be measured in these CD and MD directions.

E. Measure.~e.,L of Tissue Paper Lint The amount of lint generated from a tissue product is dele""ined with a Sutherland Rub Tester. This tester uses a motor to rub a weighted 30 felt 5 times over the stationary toilet tissue. The Hunter Color L value is measured before and after the rub test. The difference between these two Hunter Coior L values is calculated as lint.

SAMPLE PREPAi~ATlON:
Prior to the iint rub testing the paper samples to be tested should CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/01134 be conditioned accGrcling to Tappi Method #T4020M-88. Here, samples are preconditioned for 24 hours at a relative humidity level of 10 to 35% and within a te"~perdLure range of 22 to 40 ~C. After this preconditioning step, samples should be conditioned for 24 hours at a relative humidity of 48 to 52% and within a temperature range of 22 to 24 ~C. This rub testing should aiso take place within the confines of the consla(,t temperalure and humidity room.

The Sutherland Rub Tester may be obtained from Testing Machines, Inc. (Amityville, NY, 11701). The tissue is first prepared by removing and discarding any product which might have been abraded in handling, e.g. on the outside of the roll. For multi-ply finished product, three sectio"s with each containing two sheets of multi-ply product are removed and set on the bench-top. For single-ply product, six sections with each CGI ,laining two lS sheets of single-ply product are removed and set on the bench-top. Each sample is then folded in half such that the crease is running along the cross direction (CD) of the tissue sa""~le. For the multi-ply product, make sure one of the sides facing out is the same side facing out after the sample is folded. In other words, do not tear the plies apart from one another and rub test the sides facing one another on the inside of the product. For the single-ply product, make up 3 samples with the off-Yankee side out and 3 with the Yankee side out. Keep track of which samples are Yankee side out and which are off-Yankee side out.

2s Obtain a 30" X 40" piece of Crescent #300 cardboard from Cordage Inc. (800 E. Ross Road, Cincinnati, Ohio, 45217). Using a paper cutter, cut out six pieces of car.lLoard of dimensions of 2.5" X 6". Puncture two holes into each of the six cards by forcing the cardboard onto the hold down pins of the Sutherland Rub tester.
If working with single-ply finished product, center and carefully place each of the 2.5" X 6" cardboard pieces on top of the six previously folded samples. Make sure the 6" dimension of the cardboard is running parallel to the machine direction (MD) of each of the tissue samples. If working with 3s multi-ply finished product, only three pieces of the 2.5" X 6" cardboard will be required. Center and carefully place each of the cardboard pieces on top of the three previously folded samples. Once again, make sure the 6"

CA 02217~20 1997-10-03 W O96/31653 PCT~US96/0413 dimension of the cardboard is running parallel to the machine direction (MD) of each of the tissue samples.

Fold one edge of the exposed portion of tissue sample onto the back 5 of the cardboard. Secure this edge to the cardboard with adhesive tape obtained from 3M Inc. (3/4" wide Scotch Brand, St. Paul, MN). Carefully grasp the other over-hanging tissue edge and snugly fold it over onto the back of the cardboard. While maintaining a snug fit of the paper onto the board, tape this second edge to the back of the cardboard. Repeat this l0 procedure for each sample.

Turn over each sample and tape the cross direction edge of the tissue paper to the car JL,oar~. One half of the adhesive tape should conlact the tissue paper while the other half is adhering to the cardboard.
15 Repeat this procedure for each of the samples. If the tissue sample breaks, tears, or becomes frayed at any time during the course of this sample prepardlion procedure, discard and make up a new sample with a new tissue sample strip.

If working with multi-ply converted product, there will now be 3 samples on the car.ll,oar~. For single-ply finished product, there will now be 3 off-Yankee side out samples on cardboard and 3 Yankee side out samples on cardboard.

FELT PREPARATION:
Obtain a 30" X 40" piece of Crescent #300 cardboard from Cordage Inc. (800 E. Ross Road, Cincinnati, Ohio, 45217). Using a paper cutter, cut out six pieces of cardboard of dimensions of 2.25" X 7.25". Draw two lines parallel to the short dimension and down 1.125" from the top and bottom most edges on the white side of the cardboard. Carefully score the length of the line with a razor blade using a straight edge as a guide. Score it to a depth about half way through the thickness of the sheet. This scoring allows the cardboard/felt combination to fit tightly around the weight of the Sutherland Rub tester. Draw an arrow running parallel to the long dimension of the cardboard on this scored side of the cardboard.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 Cut the six pieces of black felt (F-55 or equivalent from New England Gasket, 550 Broad Street, Bristol, CT 06010) to the dimensions of 2.25" X
8.5" X 0.0625." Place the felt on top of the u"scored, green side of the cardboard such that the long edges of both the felt and cardL.oard are parallel and in aliynlnent. Make sure the flufly side of the felt is facing up.
Also allow about 0.5" to overhang the top and bottom most edges of the ca, ~Jboa, d. Snuggly fold over both overhanging felt edges onto the backside of the ca, dl,oard with Scotch brand tape. r, epare a total of six of these felVcardL,~ard combinations.
For best reproducibility, all samples should be run with the same lot of felt. Obviously, there are occasions where a single lot of felt L,ecG",es completely depleted. In those cases where a new lot of felt must be obtained, a correction factor should be deter" ,ined for the new lot of felt. Todeter",ine the co"ection factor, obtain a representative single tissue sample of interest, and enough felt to make up 24 cardboard/felt samples for the new and old lots.

As described below and before any rubbing has taken place, obtain Hunter L readings for each of the 24 cardboard/felt samples of the new and old lots of felt. C~u ~ e the averages for both the 24 car.lLoard/felt samples of the old lot and the 24 cardboardlfelt samples of the new lot.

Next, rub test the 24 cai dl,oard/felt boards of the new lot and the 24 cardboard/felt boards of the old lot as described below. Make sure the same tissue lot number is used for each of the 24 samples for the old and new lots. In addition, sampling of the paper in the ~,repara~iol, of the cardboard/tissue samples must be done so the new lot of felt and the old lot of felt are exposed to as representative as possible of a tissue sample. For 30 the case of 1-ply tissue product, discard any product which might have been damaged or abraded. Next, obtain 48 strips of tissue each two usable units - (also termed sheets) long. Place the first two usable unit strip on the far left of the lab bench and the last of the 48 samples on the far right of the bench.
Mark the sample to the far left with the number "1" in a 1 cm by 1 cm area of 3s the corner of the sample. Continue to mark the samples consecutively up to 48 such that the last sample to the far right is numbered 48.

CA 02217~20 1997-10-03 W O96/316S3 PCTrUS96/04134 Use the 24 odd numbered samples for the new felt and the 24 even numbered samples for the old felt. Order the odd number samples from lowest to highest. Order the even numbered samples from lowest to highest. Now mark the lowest number for each set with a letter '~. ' Mark the next highest number with the letter "O." Continue marking the samples in this alternating r r o pattern. Use the '~" samples for yankee side out lint analyses and the 'O ' samples for off-Yankee side lint analyses. For 1-ply product there are now a total of 24 samples for the new lot of felt and the old lot of felt. Of this 24 twelve are for yankee side out lint analysis and10 12 are for off-yankee side lint analysis.

Rub and measure the Hunter Color L values for all 24 samples of the old felt as described below. Record the 12 yankee side Hunter Color L
values for the old felt. Average the 12 values. Record the 12 off-yankee side Hunter Color L values for the old felt. Average the 12 values. Subtract the average initial un-rubbed Hunter Color L felt reading from the average Hunter Color L reading for the yankee side rubbed sambles. This is the delta average difference for the yankee side samples. Subtract the average initial un-rubbed Hunter Color L felt reading from the average Hunter Color 20 L reading for the off-yankee side rubbed sambles. This is the delta average difference for the ofl-yankee side samples. Calculate the sum of the delta average dirrare"ce for the yankee-side and the delta average dirra-e"ce for the off-yankee side and divide this sum by 2. This is the unco,-a~;ted lint value for the old felt. If there is a current felt correction factor for the oldfelt add it to the uncc,. ~ acted lint value for the old felt. This value is thecorrected Lint Value for the old felt.

Rub and measure the Hunter Color L values for all 24 samples of the new felt as described below. Record the 12 yankee side Hunter Color L
values for the new felt. Average the 12 values. Record the 12 off-yankee side Hunter Color L values for the new felt. Average the 12 values.
Subtract the average initial un-rubbed Hunter Color L felt reading from the average Hunter Color L reading for the yankee side rubbed sambles. This is the delta average difference for the yankee side samples. Subtract the average initial un-rubbed Hunter Color L felt reading from the average Hunter Color L reading for the off-yankee side rubbed sambles. This is the delta average difference for the off-yankee side samples. Calculate the CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 sum of the delta average dirrerence for the yankee-side and the delta average dirrerence for the off-yankee side and divide this sum by 2. This is the uncorrected lint value for the new felt.

Take the difference between the corrected Lint Value from the old felt and the uncorrected lint value for the new felt. This dirrarence is the felt correction factor for the new lot of felt.

Adding this felt correction factor to the ~.ncor,ecled lint value for the new felt should be identical to the corrected Lint Value for the old felt.

The same type procedure is applied to two-ply tissue product with 24 samples run for the old felt and 24 run for the new felt. But, only the consumer used outcide layers of the plies are rub tested. As noted above, make sure the samples are prepared such that a representali~/e sample is obtained for the old and new felts.

CARE OF 4 POUND WEIGHT:
The four pound weight has four square inches of effective conlact area providing a contact pressure of one pound per square inch. Since the contact pressure can be changed by alteration of the rubber pads mounted on the face of the weight, it is i",po, La"~ to use only the rubber pads supplied by the manufacturer (Brown Inc., Mechanical Services Dep,~,l,nent, Kala",d~oo, Ml). These pads must be replaced if they become hard, abraded or chipped off.

When not in use, the weight must be positioned such that the pads are not su~po, ling the full weight of the weight. It is best to store the weight on its side.

RUB TESTER INSTRUMENT CALIBRATION:

The Sutherland Rub Tester must first be calibrated prior to use.
First, turn on the Sutherland Rub Tester by moving the tester switch to the "cont" position. When the tester arm is in its position closest to the user, CA 02217~20 1997-10-03 W O 96/31653 PCTrUS96/04131 turn the tester's switch to the "auto" position. Set the tester to run 5 strokesby moving the pointer arm on the large dial to the "five" position setting.
One stroke is a single and complete forward and reverse motion of the weight. The end of the rubbing block should be in the position closest to 5 the operator at the beginning and at the end of each test.

Prepare a tissue paper on cardboard sample as described above. In addition, I,repare a felt on cardboard sample as clesc, ibed above. Both of these samples will be used for calibration of the instrument and will not be 10 used in the ~cq~ ~isition of data for the actual samples.

Place this calibration tissue sample on the base plate of the tester by slipping the holes in the board over the hold-down pins. The hold-down pins prevent the sample from moving during the test. Clip the calibralio"
15 felV~rdboard sample onto the four pound weight with the cardL,oard side contacting the pads of the weight. Make sure the cardboard/f~lt combination is resting flat ayail Isl the weight. Hook this weight onto the tester arm and gently place the tissue sample under"eath the weight/felt combination. The end of the weight closest to the operator must be over 20 the cardboard of the tissue sample and not the tissue sample itself. The feltmust rest flat on the tissue sample and must be in 100% co"lacl with the tissue surface. Activate the tester by depressil-g the "push" button.

Keep a count of the number of strokes and observe and make a 25 mental note of the starting and stopping position of the felt covered weight in relationship to the sample. If the total number of strokes is five and if theend of the felt covered weight closest to the operator is over the cardboard of the tissue sample at the beginning and end of this test, the tester is calibrated and ready to use If the total number of strokes is not five or if 30 the end of the felt covered weight closest to the operator is over the actualpaper tissue sample either at the beginning or end of the test, repeat this calibration procedure until 5 strokes are counted the end of the felt covered weight closest to the operator is situated over the cardboard at the both the start and end of the test.
During the actual testing of samples, monitor and observe the stroke count and the starting and stopping point of the felt covered weight.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 Recalibrate when necess~ry.

~ HUNTER COLOR METER CALIBRATION:

Adjust the Hunter Color Dirrere, Ice Meter for the black and white standard plates accordi. ,9 to the p(oceclures outlined in the operation manual of the instrument. Also run the stability check for slandardi alion as well as the daily color stability check if this has not been done during the past eight hours. In addition, the zero refle~;td, Ice must be checked and readjusted if necess~

Place the white standard plate on the sample stage under the instrument port. Release the sample stage and allow the sample plate to be raised beneath the sample port.

Using the "L-~', "a-X", and "b-Z" sla, Idardi~il lg knobs, adjust the instrument to read the Stal IJard White Plate Values of "L", "a", and "b"
when the "L", "a", and "b" push buttons are depressed in tum.

MEASUREMENT OF SAMPLES:

The first step in the measurement of lint is to measure the Hunter color values of the black felVcardl,oard samples prior to being rubbed on the toilet tissue. The first step in this measurement is to lower the slandard white plate from under the instrument port of the Hunter color instrument.
Center a felt covered cardboard, with the arrow pointing to the back of the color meter, on top of the ~la. Iddl d plate. Release the sample stage, allowing the felt covered cal dLoard to be raised under the sample port.

Since the felt width is only slightly larger than the viewing area diameter, make sure the felt completely covers the viewing area. After conrll Illing complete coverage, depress the L push button and wait for the reading to stabilize. Read and record this L value to the nearest 0.1 unit.

If a D25D2A head is in use, lower the felt covered cardboard and plate, rotate the felt covered cardboard 90 degrees so the arrow points to the right side of the meter. Next, release the sample stage and check once CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 more to make sure the viewing area is completely covered with felt.
Depress the L push button. Read and record this value to the nearest 0.1 unit. For the D25D2M unit the recorded value is the Hunter Color L value.
For the D25D2A head where a rotated sample reading is also recorded the 5 Hunter Color L value is the average of the two recorded values.

Measure the Hunter Color L values for all of the felt covered cardboards using this technique. If the Hunter Color L values are all within 0.3 units of one another, take the average to obtain the initial L reading. If 10 the Hunter Color L values are not within the 0.3 units, discard those felt/cardboard combinations outside the limit. Prepare new samples and repeat the Hunter Color L measurement until all samples are within 0.3 units of one another.

For the measurement of the actual tissue paper/ca-dl,oard co",binalions place the tissue sample/cardboard combination on the base plate of the tester by slipping the holes in the board over the hold-down pins. The hold-down pins prevent the sample from moving during the test.
Clip the calibration felVcardl,oard sample onto the four pound weight with 20 the cardL,oard side conlacling the pads of the weight. Make sure the cardboard/felt co,.,b;naliG,) is resting flat against the weight. Hook this weight onto the tester arm and gently place the tissue sample Ul ,der"eall.
the weight/felt combination. The end of the weight closest to the o,~,erdtor must be over the cardboard of the tissue sample and not the tissue sample 25 itself. The felt must rest flat on the tissue sample and must be in 100%
CGI ,lacl with the tissue surface.

Next activate the tester by depressing the "push" button. At the end of the five strokes the tester will automatically stop. Note the stopping 30 position of the felt covered weight in relation to the sample. If the end of the felt covered weight toward the operator is over cardboard the tester is operating properly. If the end of the felt covered weight toward the operator is over sample disregard this measurement and recalibrate as directed above in the Sutherland Rub Tester Calibration section.
Remove the weight with the felt covered cardboard. Inspect the tissue sample. If tom discard the felt and tissue and start over. If the CA 02217~20 1997-10-03 W O96/31653 PCTÇUS96/04134 tissue sample is intact, remove the felt covered cardboard from the weight.
Determine the Hunter Color L value on the felt covered canJL,oard as described above for the blank felts. Record the Hunter Color L readings for the felt after rubbing. Rub, measure, and record the Hunter Color L values 5 for all remaining samples.

After all tiss~ ~es have been measured, remove and discard all felt.
Felts strips are not used again. Cardl oa,-ls are used until they are bent, torn, limp, or no longer have a smooth surface.
CALCULATIONS:

Determine the delta L values by suL,t, acti"g the average initial L
reading found for the unused felts from each of the measured values for the 15 off-Yankee and Yankee sides of the sample. Recall, multi-ply-ply product will only rub one side of the paper. Thus, three delta L values will be obtained for the multi-ply product. Average the three delta L values and subtract the felt factor from this final average. This final result is termed the lint for the fabric side of the 2-ply product.
For the single-ply product where both Yankee side and off-Yankee side measurements are obtained, subtract the average initial L reading found for the unused felts from each of the three Yankee side L readings and each of the three off-Yankee side L readings. Calculate the average 25 delta for the three Yankee side values. Calculate the average delta for the three fabric side values. Subtract the felt factor from each of these averages. The final results are termed a lint for the fabric side and a lint forthe Yankee side of the single-ply product. By taking the average of these two values, an ulli",aie lint is obtained for the entire single-ply product.
F. Meas~.fe...e..t of Panel Softness of Tissue Papers Ideally, prior to softness testing, the paper samples to be tested - should be conditioned according to Tappi Method #T4020M-88. Here, samples are preconditioned for 24 hours at a relative humidity level of 10 to 35% and within a temperature range of 22 to 40 ~C. After this preconditioning step, samples should be conditioned for 24 hours at a CA 02217~20 1997-10-03 W O96/31653 PCTrUS9610~134 . 52 relative humidity of 48 to 52% and within a temperature range of 22 to 24 ~C.

Ideally, the softness panel testing should take place within the 5 confines of a conslant temperature and humidity room. If this is not feasible, all samples, including the controls, should experience identical environmental exposure conditions.

Sorl"ess testing is performed as a paired co,nparison in a form similar lO to that described in "Manual on Sensory Testing Methods", ASTM Special Technical Publication 434, published by the American Society For Testing and Materials 1968 and is ii ,co, ~o(aLed herein by reference. Sc,rlness is evaluated by subjective testing using what is referred to as a Paired Difference Test. The ~ lhod employs a standard external to the test 15 material itself. For tactile perceived softness two samples are presented such that the subject cannot see the samples, and the subject is required to choose one of them on the basis of tactile softness. The result of the test is reported in what is referred to as Panel Score Unit (PSU). With respect to softness testing to obtain the softness data reported herein in PSU, a 20 number of softness panel tests are performed. In each test ten practiced softness judges are asked to rate the relative softness of three sets of paired samples. The pairs of samples are judged one pair at a time by each judge: one sample of each pair being designated X and the other Y.
Briefly, each X sample is graded against its paired Y sample as follows:
2s 1. a grade of plus one is given if X is judged to may be a little softerthan Y, and a grade of minus one is given if Y is judged to may be a little softer than X;
2. a grade of plus two is given if X is judged to surely be a little softer than Y, and a grade of minus two is given if Y is judged to surely be a little softer than X;
3. a grade of plus three is given to X if it is judged to be a lot softer than Y, and a grade of minus three is given if Y is judged to be a lot softer than X; and, lastly:
4. a grade of plus four is given to X if it is judged to be a whole lot softer CA 022l7~20 l997-lO-03 W O96/31653 PCTnUS96/04134 than Y and a grade of minus 4 is given if Y is judged to be a whole lot softer than X.

The grades are aver~ged and the resultant value is in units of PSU.
5 The resulting data are considered the results of one panel test. If more than one sampie pair is evaluated then all sample pairs are rank ordered accordi"g to their grades by paired st~tistir~l analysis. Then the rank is shifted up or down in value as required to give a zero PSU value to which ever sample is chosen to be the zero-base slal ,dard. The other samples 10 then have plus or minus values as deter",ined by their relative grades with respect to the zero base standard. The number of panel tests pe, rOl l l ,ed and averaged is such that about 0.2 PSU represents a significant dirrerel ,ce in s~jectively perceived softness.

15 G. Meas~ .,t of Opacity of Tissue Papers The percent opacity is measured using a Colorquest DP-9000 Spectrocolorimeter. Locate the onloff switch on the back of the ~rocessor and turn it on. Allow the instrument to warm up for two hours. If the system has gone into sla, I-Jby mode press any key on the key pad and allow the 20 instrument 30 minutes of additional warm-up time.

Standardize the instrument using the black glass and white tile.
Make sure the standardi~a~ion is done in the read mode and according to the instructions given in the standardi~ation section of the DP9000 2s instrument manual. To sla"dardi~e the DP-9000 press the CAL key on the processor and follow the prompts as shown on the screen. You are then p,-o,~"~t~d to read the black glass and the white tile.

The DP-9000 must also be zeroed according the instructions given in 30 the DP-9000 instrument manual. Press the setup key to get into the setup mode. Define the following parameters:
UF filter: OUT
Display: ABSOLUTE
35 Read Interval: SINGLE
Sample ID: ON or OFF
Average: OFF
-CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 Statistics: SKIP
Color Scale: XYZ
Color Index: SKIP
Color Difference Scale: SKIP
Color Difference Index: SKIP
CMC Ratio: SKIP
CMC Commercial Factor: SKIP
Observer: 10 de~rees Illulllil~alll. D
M1 2nd illu",i"a"L SKIP
Sta,)dard. WORKING
Target Values: SKIP
Tolerances: SKIP

Confirm the color scale is set to XYZ, the observer set to 10 degrees, and the illuminant set to D. Place the one ply sample on the white uncalibrated tile. The white calibrated tile can also be used. Raise the sample and tile into place under the sample port and dete",~i,)e the Y value.

Lower the sample and tile. Without rotating the sample itself, remove the white tile and replace with the black glass. Again, raise the sample and black glass and determine the Y value. Make sure the 1-ply tissue sample is not rolaled between the white tile and black glass readings.
The percent opacity is calculated by taking the ratio of the Y reading on the black glass to the Y reading on the white tile. This value is then multiplied by 100 to obtain the percent opacity value.

For the purposes of this specification, the measure of opacity is converted into a "specific opacity", which, in effect, cor,e~ the opacity for variations in basis weight. The formula to convert opacity % into specific opacity % is as follows:

pecific Opacity = (1 - (Opacity/ 1oo)(1lBasis Weight)) X 100 where the specific opacity unit is per cent for each g/m2, opacity is in units of per cent, and basis weight is in units of g/m2.
Specific opacity should be reported to 0.01%

CA 02217~20 1997-10-03 W O961316S3 PCTrUS96/04134 G. Meas~f~.",~"t of St~ ll. of Tissue Papers DRY TENSILE STRENGTH:
The tensile strength is deter",ined on one inch wide strips of sample 5 using a Thwing-Albert Intelect ll Standard Tensile Tester (Thwing-Albert Instrument Co., 10960 Dutton Rd., Philadelphia, PA, 19154). This method is inle, Icled for use on finished paper products, reel samples, and unconverted stocks.
10 SAMPLE CONDITIONING AND PREPARATION:
Prior to tensile testing, the paper samples to be tested should be conditioned according to Tappi Method #T4020M-88. All plastic and paper board packaging ",alerials must be carefully removed from the paper 15 samples prior to testing. The paper samples should be condiliu, ,ed for at least 2 hours at a relative humidity of 48 to 52% and within a temperature range of 22 to 24 ~C. Sample p, eparalion and all aspects of the tensile testing should also take place within the confines of the conslant temperature and humidity room.
For finished product, cliscard any damaged product. Next, remove 5 strips of four usable units (also termed sheets) and stack one on top to the other to form a long stack with the pe, roralions between the sheets coincident. Identify sheets 1 and 3 for machine direction tensile 25 measurements and sheets 2 and 4 for cross direction tensile meas~"~",~"ls. Next, cut through the perforation line using a paper cutter (JDC-1-10 or JDC-1-12 with safety shield from Thwing-Albert Instrument Co., 10960 Dutton Road, Philadelphia, PA, 19154) to make 4 separate stocks. Make sure stacks 1 and 3 are still identified for machine direction 30 testing and stacks 2 and 4 are identified for cross direction testing.

Cut two 1" wide strips in the machine direction from stacks 1 and 3.
Cut two 1" wide strips in the cross direction from stacks 2 and 4. There are now four 1~ wide strips for machine direction tensile testing and four 1" wide 35 strips for cross direction tensile testing. For these finished product samples, all eight 1" wide strips are five usable units (also termed sheets) thick.

CA 02217~20 1997-10-03 W O96/31653 PCT~US96/0413 For unconverted stock and/or reel samples, cut a 15" by 15" sample which is 8 plies thick from a region of interest of the sample using a paper cutter (JDC-1-10 or JDC-1-12 with safety shield from Thwing-Albert Instrument Co., 10960 Dutton Road, Philadelphia, PA, 19154) . Make sure one 15" cut runs parallel to the machine direction while the other runs parallet to the cross direction. Make sure the sample is conditioned for at least 2 hours at a relative humidity of 48 to 52% and within a temperature range of 22 to 24 ~C. Sample ~re~,ara~ion and all ~spects of the tensile testing should also take place within the confines of the cc nsla,)l 10 temperature and humidity room.
From this preconditioned 15" by 15" sample which is 8 plies thick, cut four strips 1" by 7" with the long 7" dimension running parallel to the machine direction. Note these samples as machine direction reel or 15 unconverted stock samples. Cut an additional four strips 1" by 7" with the long 7" di",ension running parellel to the cross direction. Note these samples as cross direction reel or unconverted stock samples. Make sure all previous cuts are made using a paper cutter (JDC-1-10 or JDC-1-12 with safety shield from Thwing-Albert Instrument Co., 10960 Dutton Road, 20 Philadelphia, PA, 19154). There are now a total of eight samples: four 1"
by 7" strips which are 8 plies thick with the 7" dimension running parallel to the machine direction and four 1" by 7" strips which are 8 plies thick with the 7" dimension running parallel to the cross direction.
25 OPERATION OF TENSILE TESTER:
For the actual measurement of the tensile strength, use a Thwing-Albert Intelect ll Standard Tensile Tester (Thwing-Albert Instrument Co., 1 Og60 Dutton Rd., Philadelphia, PA, 19154). Insert the flat face clamps into 30 the unit and calibrate the tester according to the instructions given in the operation manual of the Thwing-Albert Intelect ll. Set the instrument crosshead speed to 4.00 in/min and the 1 st and 2nd gauge lengths to 2.00 inches. The break sensitivity should be set to 20.0 grams and the sample width should be set to 1.00" and the sample thickness at 0.025".
A load cell is selected such that the predicted tensile result for the sample to be tested lies between 25% and 75% of the range in use. For example, a 5000 gram load cell may be used for samples with a predicted CA 02217~20 1997-10-03 W O 96131653 PCTrUS96/04134 tensile range of 1250 grams (25% of 5000 grams) and 3750 grams (75% of 5000 grams). The tensiie tester can also be set up in the 10% range with the 5000 gram load cell such that samples with predicted tensiles of 125 grams to 375 grams could be tested.
. 5 Take one of the tensile strips and place one end of it in one clamp of the tensile tester. Place the other end of the paper strip in the other clamp.
Make sure the long dimension of the strip is running parallel to the sides of the tensile tester. Also make sure the strips are not overhanging to the 10 either side of the two clamps. In addition, the pressure of each of the clamps must be in full co"ta.;l with the paper sample.

After inserting the paper test strip into the two clamps, the instrument tension can be monitored. If it shows a value of 5 grams or more, the sample is too taut. Conversely, if a period of 2-3 seconds passes after starting the test before any value is recor:led, the tensile strip is too slack.
Start the tensile tester as described in the tensile tester instrument manual. The test is complete after the crosshead automatically returns to its initial starting position. Read and record the tensile load in units of grams from the instrument scale or the digital panel meter to the nearest unit.

If the reset condition is not performed automatically by the instrument, pe,ror", the necess~ry adjustment to set the instrument clamps to their initial st~, ling positions. Insert the next paper strip into the two clar"~,s as described above and obtain a tensile reading in units of grams.
Obtain tensile readings from all the paper test strips. It should be noted that readings should be rejected if the strip slips or breaks in or at the edge of the clamps while performing the test.

~ CALCULATIONS:

For the four machine direction 1" wide finished product strips, sum the four individual recorded tensile readings. Divide this sum by the number of strips tested. This number should normally be four. Also divide the sum of recorded tensiles by the number of usable units per tensile strip.

CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 This is normally five for both 1-ply and 2-ply products.

Repeat this calu ~l~tion for the cross direction finished product strips.

For the unconverted stock or reel samples cut in the machine direction, sum the four individual recorded tensile readings. Divide this sum by the number of -~trips tested. This number should normally be four. Also divide the sum of recorded tensiles by the number of usable units per tensile strip. This is normally eight.
Repeat this ~Ic~ tion for the cross direction unconverted or reel sample paper strips.
All results are in units of grams/inch.
For purposes of this specification, the tensile strength should be converted into a "specific total tensile ~l,er,yll ," defined as the sum of the tensile strength measured in the machine and cross machine directions, divided by the basis weight, and corrected in units to a value in meters.

EXAMPLES

The following examples are offered to illustrate the practice of the present invention. These examples are intended to aid in the description of the present invention, but, in no way, should be inter~reted as limiting the 25 scope ll ,ereor. The presenl invention is bounded only by the appended claims.

E)CAMPLE 1 This comparative Example illustrates a re~ere"ce process not inco"~orali"g the features of the present invention. This process is illustrated in the following steps:
First, an aqueous slurry of NSK of about 3% consistency is made up using a conventional pulper and is passed through a stock pipe toward the headbox of the Fourdrinier.
In order to impart a temporary wet strength to the finished product, a CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 1% dispersion of National Starch Co-BOND 1000~) is prepared and is added to the NSK stock pipe at a rate sufficient to deliver 1% Co-BOND
1000~) based on the dry weight of the NSK fibers. The absorption of the temporary wet sll ~nyli, resin is enhdnced by passing the treated slurry 5 through an in-line mixer.
The NSK slurry is diluted with white water to about 0.2% consisle"~
at the fan pump.
An ~ueo~ ~s slurry of eucalyptus fibers of about 3% by weight is made up using a conventional repulper.
The eucalyptus is p~ssed through a stock pipe to another fan pump where it is diluted with white water to a consistency of about 0.2%.
The slurries of NSK and eucalyptus are directed into a multi-channeled headbox suitably equipped with layering leaves to maintain the streams as separate layers until dischal-ge onto a traveling Fourdrinier wire.
15 A three-chambered I ,e~ ~ox is used. The eucalyptus slurry containing 80%
of the dry weight of the ulli,-,ale paper is directed to chal~lL.era leading to each of the two outer layers, while the NSK slurry comprising 20% of the dry weight of the ulli."ale paper is directed to a c;l ,a",ber leading to a layer between the two eucalyptus layers. The NSK and eucalyptus slurries are 20 combined at the dis~ ,arge of the headbox into a composite slurry.
The composite slurry is discharged onto the traveling Fourdrinier wire and is dewatered ~ssisted by a deflector and vacuum boxes.
The embryonic wet web is l, di ,arerred from the Fourdrinier wire at a fiber consistency of about 15% at the point of l,ansrer to a patterned 25 forming fabric of a 5-shed satin weave configuration having 84 machine-direction and 76 cross-machine-direction monofilaments per inch respectively and about 36 % knuckle area.
Further de-watering is accomplished by vacuum assisted drainage until the web has a fiber consistency of about 28%.
While remaining in contact with the patterned forming fabric the patterned web is pre-dried by air blow-through to a fiber consistency of about 62% by weight.
The semi-dry web is then adhered to the surface of a Yankee dryer with a sprayed creping adhesive comprising a 0.125% aqueous solution of CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/0413 polyvinyl alcohol. The creping adhesive is delivered to the Yankee surface at a rate of 0.1 ~/O adhesive solids based on the dry weight of the web.
The fiber consistency is increased to about 96% before the web is dry creped from the Yankee with a doctor blade.
S The doctor blade has a bevel angle of about 25 degrees and is positioned with respect to the Yankee dryer to provide an impact angle of about 81 degrees.
The percent crepe is adjusted to about 18% by operating the Yankee dryer at about 800 fpm (feet per minute) (about 244 meters per minute), while the dry web is formed into roll at a speed of 656 fpm (201 meters per minutes).
The web is converted into a three-layer, single-ply creped p,~ller"ed densified tissue paper product of about 18 Ib per 3000 ~t2 basis weight.

This Example illustrates preparalion of a filled tissue paper exhibiting one embodiment of the present invention based upon the use of cationic flocculant.
An ~ eo~ ~s slurry of eucalyptus fibers of about 3% by weight is made up using a conventional repulper. The eucalyptus is passed through a refiner where its freeness is decreased from about 640 CSF to about 600 CSF. It then is carried through a stock pipe toward the papermachine.
The particulate filler is kaolin clay, grade WW Fil SD~), made by Dry Branch Kaolin of Dry Branch, GA. It is first made down to an aqueous slurry by mixing it with water to a consistency of about 1 % solids. It is then carriedthrough a stock pipe where it is mixed with a cationic starch, RediBOND
5327~9, which is delivered as a 1 % dispersion in water. RediBOND 5327~
is a pre-dispersed form of waxy maize corn starch a rate equivalent to about 0.5% based on the amount of solid weight of the starch per solid weight of the filler. The adsorption of the cationic starch is promoted by passing the mixture through an in line mixer. This forms an agglomerated suspension of filler particles.
The agglomerated suspension of filler particles is then mixed into the CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 stock pipe carrying the refined eucalyptus fibers and the final mixture is diluted with white water at the inlet of a fan pump to a consistency of about 0.2% based on the weight of the solid filler particles and eucalyptus fibers.
After the fan pump carrying the combination of agglomerated filler particles 5 and eucalyptus fibers Reten 1232 a cationic flocculant is added to the mixture at a rate cor, espo"ding to 0.067 % based on the solids weight of the filler and eucalyptus fiber.
An aqueous slurry of NSK of about 3% consistency is made up using a conventional pulper and is p~ssed through a stock pipe toward the 10 headbox of the Fourdrinier.
In order to impart a temporary wet strength to the finished product a 1% dispersion of National Starch Co-BOND 1000~ is prepared and is added to the NSK stock pipe at a rate sufficient to deliver 1% Co-BOND
1000~9 based on the dry weight of the NSK fibers. The absorption of the 15 te""~ora,y wet sl,engll, resin is enhanced by passing the treated slurry through an in-line mixer.
The NSK slurry is diluted with white water to about 0.2% consistency atthefanpump. Afterthefanpump RETEN1232~) acationicflocc~~ tis added at a rate correspG"ding to 0.067 % based on the dry weight of the 20 NSK fiber.
The slurries of NSK and eucalyptus are directed into a multi-channeled he~lhox suitably equipped with layering leaves to maintain the streams as separate layers until discharge onto a traveling Fourdrinier wire.
A three-chambered headbox is used. The combined eucalyptus and 25 particulate filler slurry contain sufficient solids flow to achieve 80% of the dry weight of the ulli",a~e paper. This combined slurry is directed to chambers leading to each of the two outer layers while the NSK slurry comprising sufficient solids flow to achieve 20% of the dry weight of the ultimate paper is directed to a chamber leading to a layer between the two 30 eucalyptus layers. The NSK and eucalyptus slurries are combined at the discharge of the headbox into a composite slurry.
The composite slurry is discharged onto the traveling Fourdrinier wire and is dewatered assisted by a deflector and vacuum boxes.

The embryonic wet web is transferred from the Fourdrinier wire at a CA 02217~20 1997-10-03 W O96/31653 PCTrUS9610~134 fiber consistency of about 15% at the point of transfer to a patterned forming fabric of a 5-shed satin weave configuration having 84 machine-direction and 76 cross-",achi"e-direction monofilaments per inch respectively and about 36% knuckle area.
S Further de-~alerin~a is accomplished by vacuum assisted drainage until the web has a fiber consistency of about 28%.
While remaining in co"lacl with the patterned forming fabric the paller"ed web is pre-dried by air blow-through to a fiber consistency of about 62% by weight.
The semi-dry web is then adhered to the surface of a Yankee dryer with a sprayed creping adhesive comprising a 0.125% aqueous solution of polyvinyl alcohol. The creping adhesive is delivered to the Yankee surface at a rate of 0.1 % adhesive solids based on the dry weight of the web.
The fiber consistency is increased to about 96% before the web is dry creped from the Yankee with a doctor blade.
The doctor blade has a bevel angle of about 20 degrees and is positioned with respect to the Yankee dryer to provide an impact angle of about 76 degrees.
The percent crepe is adjusted to about 18% by operating the Yankee dryer at about 800 fpm (feet per minute) (about 244 meters per minute) while the dry web is formed into roll at a speed of 656 fpm (200 meters per minutes).
The web is converted into a three-layer single-ply creped pattemed densified tissue paper product of about 18 Ib per 3000 ft2 basis weight.

This Example illustrates preparation of a filled tissue paper exhibiting a second embodiment of the present invention based upon the use of anionic floccul~nt.
An aqueous slurry of eucalyptus fibers of about 3% by weight is made up using a conventional repulper. It then is carried through a stock pipe toward the paper machine.

CA 02217~20 1997-10-03 W O96/316S3 PCTrUS96/04131 The particulate filler is kaolin clay, grade WW Fil SD~), made by Dry Branch Kaolin of Dry Branch, GA. It is first made down to an aqueous slurry by mixing it with water to a consistency of about 1% solids. It is then ca, . ied through a stock pipe where it is mixed with an anionic floccul~rlt, RETEN
235~, which is delivered as a 0.1% dispersion in water. RETEN 235~g) is conveyed at a rate equivalent to about 0.05% based on a the amount of solid weight of the floocul~rlt and finished dry weight of the resultant c(epecltissue product. The adsor~tion of the floccul~rlt is promoted by passing the mixture through an in line mixer. This forms a conditioned slurry of filler l0 particles.
The agglomerated slurry of filler particles is then mixed into the stock pipe carrying the refined eucalyptus fibers and the final mixture is treated with a cationic starch RediBOND 5320~)~ which is delivered as a 1%
dispersion in water and at a rate of 0.5% based on the dry weight of starch 15 and the finished dry weight of the resultant creped tissue product.
Absorption of the cationic starch is improved by passing the resultant mixture through an in line mixer. The resultant slurry is then diluted with white water at the inlet of a fan pump to a consistency of about 0.2% based on the weight of the solid filler particles and eucalyptus fibers. After the fanpump carrying the combination of agglomerated filler particles and eucalyptus fibers, Microrc"" 2321, a cationic flocc~ t is added to the mixture at a rate corresponding to 0.05% based on the solids weight of the filler and eucalyptus fiber.
An ~ eous slurry of NSK of about 3% consistency is made up using a conventional pulper and is passed through a stock pipe toward the he~dbox of the Fourdrinier.
In order to impart a temporary wet sl,t:nylh to the finished product, a 1% dispersion of National Starch Co-BOND 1000~ is prepared and is added to the NSK stock pipe at a rate sufficient to deliver 1% Co-BOND
1000~ based on the dry weight of the NSK fibers. The absorption of the temporary wet strength resin is enhanced by passing the treated slurry through an in-line mixer.
The NSK slurry is diluted with white water to about 0.2% consistency at the fan pump. After the fan pump, Microfor", 2321, a cationic flocculant is added at a rate corresponding to 0.05% based on the dry weight of the NSK fiber.

CA 02217~20 1997-10-03 W O96/31653 PCT~US96/04134 The siurries of NSK and eucalyptus are directed into a multi-channeled headbox suitably equipped with layering leaves to maintain the streams as separate layers until discharge onto a traveling Fourdrinier wire.
A three-chambered headLox is used. The combined eucalyptus and particulate filler containing sufficient solids flow to achieve 80% of the dry weight of the ultimate paper is directed to cha",bers leading to each of the two outer layers while the NSK slurry comprising sufficient solids flow to achieve 20% of the dry weight of the ulli",ale paper is directed to a chamber leading to a layer between the two eucalyptus layers. The NSK and 10 eucalyptus slurries are combined at the discharge of the headbox into a composite slurry.

The composite slurry is discharged onto the traveling Fourdrinier wire and is dewatered ~ssisted by a deflector and vacuum boxes.
The embryonic wet web is l, dl ,srer~ ed from the Fourdrinier wire, at a fiber consistency of about 15% at the point of l, ansrer to a patterned forming fabric of a 5-shed satin weave configuration having 84 machine-direction and 76 cross-machine-direction monofilaments per inch respectively and about 36% knuckle area.

Further de-watering is acco""~lished by vacuum assisted drainage until the web has a fiber collsisle,)-;y of about 28%.

While remaining in contact with the patterned forming fabric the pattemed web is pre-dried by air blow-through to a fiber consistency of about 62% by weight.

The semi-dry web is then adhered to the surface of a Yankee dryer 30 with a sprayed creping adhesive comprising a 0.125% aqueous solution of polyvinyl alcohol. The creping adhesive is delivered to the Yankee surface at a rate of 0.1% adhesive solids based on the dry weight of the web.

The fiber consistency is increased to about 96% before the web is dry 35 creped from the Yankee with a doctor blade.
The doctor blade has a bevel angie of about 20 degrees and is positioned with respect to the Yankee dryer to provide an impact angle of CA 02217~20 1997-10-03 W O96/31653 PCTrUS96/04134 about 76 degrees.

The percent crepe is adjusted to about 18% by operating the Yankee dryer at about 800 fpm (feet per minute) (about 244 meters per minute), while the dry web is formed into roll at a speed of 656 fpm (200 meters per minutes).

The web is converted into a three-layer, single-ply creped patterned densifed tissue paper product of about 18 Ib per 3000 ft2 basis weight.

Example 1 Example2 Example 3 Kaolin co,llenl % None 13.3 16.0 Kaolin Retention NA 74 88.6 (Overall) %
Tensile Stl~llylh 400 396 407 (g/in) Specific Opacity % 5.23 5.84 5.90 Ultimate Lint 7.0 6.9 7.0 Number Softness score 0.0 +0.02 +0.01

Claims (10)

WHAT IS CLAIMED IS:
1. A strong, soft and low dusting filled, tissue paper characterized in that it comprises papermaking fibers and a non-cellulosic particulate filler, said filler comprising from 5% to 50%, more preferably from 8% to 20% by weight of said tissue.
2. The filled tissue paper of Claim 1 wherein said particulate filler is selected from clay, calcium carbonate, titanium dioxide, talc, aluminum silicate, calcium silicate, alumina trihydrate, activated carbon, pearl starch, calcium sulfate, glass microspheres, diatomaceous earth, and mixtures thereof.
3. The filled tissue paper of Claim 1 or 2 wherein said tissue paper has a basis weight between 10 g/m2 and 50 g/m2, more preferably between 10 g/m2 and 30 g/m2, and a density between 0.03 g/m3 and 0.6 g/m3, more preferably between 0.05 g/m3 and 0.2 g/m3.
4. The filled tissue paper of any of Claims 1 - 3 wherein said papermaking fibers comprise a blend of hardwood fibers and softwood fibers, said hardwood fibers comprising at least 50% and said softwood fibers comprising at least 10% of said papermaking fibers.
5. The filled tissue paper of any of Claims 1 - 4 wherein said tissue paper comprises at least two superposed layers, an inner layer and at least one outer layer contiguous with said inner layer, more preferably said tissue paper comprises three superposed layers, an inner layer and two outer layers, said inner layer being located between two said outer layers.
6. The filled tissue paper of Claim 5 wherein said inner layer comprises softwood fibers having an average length greater than at least 2.0 mm, and said outer layers comprise hardwood fibers having an average length less than 1.0 mm.
7. The filled tissue paper of any of Claims 4 - 6 wherein the softwood fibers comprise northern softwood Kraft fibers and the hardwood fibers comprise eucalyptus Kraft fibers.
8. The filled tissue paper of any of Claims 1 - 7 wherein said particulate filler is kaolin clay.
9. The filled tissue paper of Claim 8 wherein said kaolin clay is comprised of hydrous aluminum silicate having an average equivalent spherical diameter greater than 0.5 microns, more preferably greater than 1.0 microns.
10. The filled tissue paper of any of Claims 1 - 9 wherein said creped tissue paper is pattern densified paper such that zones of relatively high density are dispersed within a high bulk field, preferably said zones of relatively high density are continuous and the high bulk field is discrete.
CA002217520A 1995-04-07 1996-03-27 Tissue paper containing a fine particulate filler Abandoned CA2217520A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/418,990 1995-04-07
US08/418,990 US5611890A (en) 1995-04-07 1995-04-07 Tissue paper containing a fine particulate filler

Publications (1)

Publication Number Publication Date
CA2217520A1 true CA2217520A1 (en) 1996-10-10

Family

ID=23660344

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002217520A Abandoned CA2217520A1 (en) 1995-04-07 1996-03-27 Tissue paper containing a fine particulate filler

Country Status (20)

Country Link
US (1) US5611890A (en)
EP (1) EP0819195B1 (en)
JP (1) JPH11503495A (en)
KR (1) KR100264040B1 (en)
CN (1) CN1083920C (en)
AT (1) ATE210225T1 (en)
AU (1) AU721197B2 (en)
BR (1) BR9610752A (en)
CA (1) CA2217520A1 (en)
CZ (1) CZ323697A3 (en)
DE (1) DE69617662T2 (en)
DK (1) DK0819195T3 (en)
ES (1) ES2169236T3 (en)
HK (1) HK1008555A1 (en)
HU (1) HUP9800978A2 (en)
MX (1) MX9707705A (en)
NZ (1) NZ305665A (en)
PT (1) PT819195E (en)
WO (1) WO1996031653A1 (en)
ZA (1) ZA962500B (en)

Families Citing this family (107)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5958185A (en) * 1995-11-07 1999-09-28 Vinson; Kenneth Douglas Soft filled tissue paper with biased surface properties
US5830317A (en) * 1995-04-07 1998-11-03 The Procter & Gamble Company Soft tissue paper with biased surface properties containing fine particulate fillers
SE505388C2 (en) * 1995-11-24 1997-08-18 Sca Hygiene Paper Ab Soft, bulky, absorbent paper containing chemitermomechanical pulp
US5938894A (en) * 1996-03-25 1999-08-17 Eka Chemicals Ab Absorbent cellulosic material and production thereof
US5672249A (en) * 1996-04-03 1997-09-30 The Procter & Gamble Company Process for including a fine particulate filler into tissue paper using starch
US5700352A (en) * 1996-04-03 1997-12-23 The Procter & Gamble Company Process for including a fine particulate filler into tissue paper using an anionic polyelectrolyte
US6136422A (en) 1996-04-05 2000-10-24 Eatern Pulp & Paper Corporation Spray bonded multi-ply tissue
US5759346A (en) * 1996-09-27 1998-06-02 The Procter & Gamble Company Process for making smooth uncreped tissue paper containing fine particulate fillers
US6074524A (en) * 1996-10-23 2000-06-13 Weyerhaeuser Company Readily defibered pulp products
US6162329A (en) 1997-10-01 2000-12-19 The Procter & Gamble Company Soft tissue paper having a softening composition containing an electrolyte deposited thereon
US6174412B1 (en) * 1998-03-02 2001-01-16 Purely Cotton, Inc. Cotton linter tissue products and method for preparing same
US6511579B1 (en) * 1998-06-12 2003-01-28 Fort James Corporation Method of making a paper web having a high internal void volume of secondary fibers and a product made by the process
EP1128753A1 (en) 1998-11-09 2001-09-05 The Procter & Gamble Company Food container having substrate impregnated with particulate material
WO2000027256A1 (en) 1998-11-09 2000-05-18 The Procter & Gamble Company Food container having external facing with limited binder materials
AU755081B2 (en) 1998-11-09 2002-12-05 Procter & Gamble Company, The Food container having cut resistance surface
US6562743B1 (en) * 1998-12-24 2003-05-13 Bki Holding Corporation Absorbent structures of chemically treated cellulose fibers
CO5150202A1 (en) 1998-12-31 2002-04-29 Kimberly Clark Co COMPOSITION OF FACIAL TISSU AND METHOD FOR USE FOR THE SECRETARY OF SKIN IRRITANTS OF THE NASAL SECRETION
JP3352421B2 (en) * 1999-02-04 2002-12-03 静雄 宇山 Toilet paper and manufacturing method thereof
US6265052B1 (en) * 1999-02-09 2001-07-24 The Procter & Gamble Company Tissue paper
US6514384B1 (en) * 1999-03-19 2003-02-04 Weyerhaeuser Company Method for increasing filler retention of cellulosic fiber sheets
TW438579B (en) 1999-04-02 2001-06-07 Kao Corp Base material for wiping sheet
US6241850B1 (en) 1999-06-16 2001-06-05 The Procter & Gamble Company Soft tissue product exhibiting improved lint resistance and process for making
US6383336B1 (en) * 1999-12-14 2002-05-07 Kimberly-Clark Worldwide, Inc. Strong, soft non-compressively dried tissue products containing particulate fillers
US6425981B1 (en) 1999-12-16 2002-07-30 Metso Paper Karlstad Aktiebolg (Ab) Apparatus and associated method for drying a wet web of paper
JP4715076B2 (en) * 2000-02-01 2011-07-06 王子製紙株式会社 Tissue paper
US6797117B1 (en) * 2000-11-30 2004-09-28 The Procter & Gamble Company Low viscosity bilayer disrupted softening composition for tissue paper
US6547928B2 (en) * 2000-12-15 2003-04-15 The Procter & Gamble Company Soft tissue paper having a softening composition containing an extensional viscosity modifier deposited thereon
US7622020B2 (en) * 2002-04-23 2009-11-24 Georgia-Pacific Consumer Products Lp Creped towel and tissue incorporating high yield fiber
US20040133439A1 (en) * 2002-08-21 2004-07-08 Dirk Noetzold Method and system for valuation of complex systems, in particular for corporate rating and valuation
US7311853B2 (en) * 2002-09-20 2007-12-25 The Procter & Gamble Company Paper softening compositions containing quaternary ammonium compound and high levels of free amine and soft tissue paper products comprising said compositions
WO2004035923A2 (en) * 2002-10-17 2004-04-29 The Procter & Gamble Company Tissue paper softening compositions and tissue papers comprising the same
FI122074B (en) * 2002-10-24 2011-08-15 M Real Oyj Process for making a fiber product
US7258764B2 (en) * 2002-12-23 2007-08-21 Sca Hygiene Products Gmbh Soft and strong webs from highly refined cellulosic fibres
MXPA05012844A (en) * 2003-06-23 2006-02-13 Procter & Gamble Absorbent tissue-towel products comprising related embossed and printed indicia.
US7175741B2 (en) * 2003-07-16 2007-02-13 Weyerhaeuser, Co. Reducing odor in absorbent products
EP1696972B1 (en) 2003-12-19 2016-10-26 Buckeye Technologies Inc. Fibers of variable wettability and materials containing the fibers
US7208429B2 (en) * 2004-12-02 2007-04-24 The Procter + Gamble Company Fibrous structures comprising a nonoparticle additive
US20060134384A1 (en) * 2004-12-02 2006-06-22 Vinson Kenneth D Fibrous structures comprising a solid additive
US7976679B2 (en) 2004-12-02 2011-07-12 The Procter & Gamble Company Fibrous structures comprising a low surface energy additive
US7459179B2 (en) * 2004-12-02 2008-12-02 The Procter & Gamble Company Process for making a fibrous structure comprising an additive
US20060142432A1 (en) * 2004-12-29 2006-06-29 Harrington John C Retention and drainage in the manufacture of paper
US7935222B2 (en) * 2005-03-04 2011-05-03 Kemira Chemicals, Inc. Papermaking method using one or more quaternized dialkanolamine fatty acid ester compounds to control opacity and paper product made thereby
WO2006113963A1 (en) * 2005-04-27 2006-11-02 Joy Kogias A paper product containing mineral material which stimulates micro-organism activity in naturally occurring environmental conditions
US20060289139A1 (en) * 2005-06-24 2006-12-28 Fushan Zhang Retention and drainage in the manufacture of paper
US8921244B2 (en) * 2005-08-22 2014-12-30 The Procter & Gamble Company Hydroxyl polymer fiber fibrous structures and processes for making same
US20080178489A1 (en) * 2007-01-15 2008-07-31 Roger Dionne Shaver saver
US9327888B2 (en) 2007-02-23 2016-05-03 The Procter & Gamble Company Array of sanitary tissue products
US20080227182A1 (en) * 2007-03-16 2008-09-18 Weyerhaeuser Company Systems and methods for enzymatic hydrolysis of lignocellulosic materials
US20080271864A1 (en) * 2007-05-03 2008-11-06 The Procter & Gamble Company Soft tissue paper having a chemical softening agent applied onto a surface thereof
US20080271867A1 (en) * 2007-05-03 2008-11-06 The Procter & Gamble Company Soft tissue paper having a chemical softening agent applied onto a surface thereof
PT2158359E (en) * 2007-06-08 2013-12-09 Fpinnovations Latex-treated filler slurries for use in papermaking
US8852474B2 (en) 2007-07-17 2014-10-07 The Procter & Gamble Company Process for making fibrous structures
US20090022960A1 (en) * 2007-07-17 2009-01-22 Michael Donald Suer Fibrous structures and methods for making same
US10024000B2 (en) * 2007-07-17 2018-07-17 The Procter & Gamble Company Fibrous structures and methods for making same
US7972986B2 (en) 2007-07-17 2011-07-05 The Procter & Gamble Company Fibrous structures and methods for making same
US20090022983A1 (en) * 2007-07-17 2009-01-22 David William Cabell Fibrous structures
DK2093261T3 (en) 2007-11-02 2013-12-02 Omya Int Ag Use of a Surface-Responded Calcium Carbonate in Tissue Paper, Process for Producing a Tissue Paper Product of Improved Softness, and Resulting Tissue Paper Products of Improved Softness
US8758567B2 (en) * 2009-06-03 2014-06-24 Hercules Incorporated Cationic wet strength resin modified pigments in barrier coating applications
CN101597876B (en) * 2009-07-10 2014-06-18 南京林业大学 New technique of starch addition used for improving paper strength
CN101591870A (en) * 2009-07-10 2009-12-02 南京林业大学 A kind of manufacture craft of high-strength pulp plate
ES2464128T3 (en) * 2009-11-02 2014-05-30 The Procter & Gamble Company Fibrous polypropylene elements and manufacturing processes
WO2011053956A1 (en) * 2009-11-02 2011-05-05 The Procter & Gamble Company Fibrous elements and fibrous structures employing same
AU2010313169A1 (en) * 2009-11-02 2012-05-24 The Procter & Gamble Company Fibrous structures that exhibit consumer relevant property values
EP2496768B1 (en) * 2009-11-02 2015-07-29 The Procter and Gamble Company Low lint fibrous sturctures and methods for making same
ES2588209T3 (en) 2009-11-02 2016-10-31 The Procter & Gamble Company Fibrous structures and methods to manufacture them
WO2011123584A1 (en) 2010-03-31 2011-10-06 The Procter & Gamble Company Fibrous structures and methods for making same
US8916012B2 (en) 2010-12-28 2014-12-23 Kimberly-Clark Worldwide, Inc. Method of making substrates comprising frothed benefit agents
US8426031B2 (en) * 2011-09-21 2013-04-23 Kimberly-Clark Worldwide, Inc. Soft tissue product comprising cotton
CN102605668B (en) * 2012-03-31 2014-12-24 陕西科技大学 Method for making high-bulk paper by adopting chemical wood pulp
CN102644214B (en) * 2012-04-12 2014-06-11 华南理工大学 Preparation method and application of polyacrylamide/keramite nanotube composite papermaking filler
PL2662419T3 (en) 2012-05-11 2015-11-30 Omya Int Ag Charge controlled PHCH
DK2662416T3 (en) 2012-05-11 2015-10-05 Omya Int Ag Treatment of calcium carbonate containing materials to the increased filler loading in the paper
CN102677548B (en) * 2012-05-28 2014-12-10 金红叶纸业集团有限公司 Life paper and manufacture method thereof
CN102720092B (en) * 2012-06-12 2014-04-16 陕西科技大学 Method for improving performance of finished paper
US8968517B2 (en) 2012-08-03 2015-03-03 First Quality Tissue, Llc Soft through air dried tissue
CN103669097B (en) * 2012-09-10 2017-06-16 国能纸业有限公司 A kind of multi-cylinder long mesh paper machine for producing filler paper high
CN102912669A (en) * 2012-11-06 2013-02-06 大唐国际发电股份有限公司 Light offset paper filled with synthetic calcium silicate and manufacturing method thereof
CN103073926A (en) * 2012-12-24 2013-05-01 华泰集团有限公司 Manufacturing method of cationic starch modified calcium carbonate filler
CN103410045B (en) * 2013-08-15 2016-04-20 金红叶纸业集团有限公司 Paper and preparation method thereof
US9017916B1 (en) * 2013-12-12 2015-04-28 Xerox Corporation Preparing resin emulsions
CN103669104B (en) * 2013-12-30 2016-01-20 大唐国际发电股份有限公司高铝煤炭资源开发利用研发中心 Eakleite is as the purposes of papermaking filler
US9254504B2 (en) * 2014-01-24 2016-02-09 Kemira Oyj Arrangement and method for simulating creping of tissue paper
US11391000B2 (en) 2014-05-16 2022-07-19 First Quality Tissue, Llc Flushable wipe and method of forming the same
CN104313936B (en) * 2014-08-26 2016-08-24 淄博欧木特种纸业有限公司 Composite decoration paper of wood-based plate and preparation method thereof
ES2723284T3 (en) 2014-11-07 2019-08-23 Omya Int Ag A procedure for the preparation of flocculated filler particles
EP3018176B1 (en) 2014-11-07 2018-04-25 Omya International AG A process for the preparation of flocculated filler particles
US9988763B2 (en) 2014-11-12 2018-06-05 First Quality Tissue, Llc Cannabis fiber, absorbent cellulosic structures containing cannabis fiber and methods of making the same
WO2016086019A1 (en) 2014-11-24 2016-06-02 First Quality Tissue, Llc Soft tissue produced using a structured fabric and energy efficient pressing
MX2017006840A (en) 2014-12-05 2018-11-09 Manufacturing process for papermaking belts using 3d printing technology.
US10544547B2 (en) 2015-10-13 2020-01-28 First Quality Tissue, Llc Disposable towel produced with large volume surface depressions
US10538882B2 (en) 2015-10-13 2020-01-21 Structured I, Llc Disposable towel produced with large volume surface depressions
CA3001608C (en) 2015-10-14 2023-12-19 First Quality Tissue, Llc Bundled product and system and method for forming the same
BR112018007748B1 (en) 2015-11-03 2022-07-26 Kimberly-Clark Worldwide, Inc. PAPER FABRIC PRODUCT, CLEANING PRODUCT, AND, PERSONAL CARE ABSORBING ARTICLE
AU2017218159A1 (en) 2016-02-11 2018-08-30 Structured I, Llc Belt or fabric including polymeric layer for papermaking machine
US20170314206A1 (en) 2016-04-27 2017-11-02 First Quality Tissue, Llc Soft, low lint, through air dried tissue and method of forming the same
CN105951494B (en) * 2016-07-04 2017-09-29 山东太阳纸业股份有限公司 A kind of preparation method of the toilet paper containing high yield pulp
WO2018039623A1 (en) 2016-08-26 2018-03-01 Structured I, Llc Method of producing absorbent structures with high wet strength, absorbency, and softness
WO2018049390A1 (en) 2016-09-12 2018-03-15 Structured I, Llc Former of water laid asset that utilizes a structured fabric as the outer wire
US11583489B2 (en) 2016-11-18 2023-02-21 First Quality Tissue, Llc Flushable wipe and method of forming the same
CN106930133A (en) * 2017-04-12 2017-07-07 上海馨星环保科技有限公司 A kind of method with bagasse papermaking and its cup being made
US10619309B2 (en) 2017-08-23 2020-04-14 Structured I, Llc Tissue product made using laser engraved structuring belt
WO2019108172A1 (en) 2017-11-29 2019-06-06 Kimberly-Clark Worldwide, Inc. Fibrous sheet with improved properties
DE102018114748A1 (en) 2018-06-20 2019-12-24 Voith Patent Gmbh Laminated paper machine clothing
US11738927B2 (en) 2018-06-21 2023-08-29 First Quality Tissue, Llc Bundled product and system and method for forming the same
US11697538B2 (en) 2018-06-21 2023-07-11 First Quality Tissue, Llc Bundled product and system and method for forming the same
AU2018433810A1 (en) 2018-07-25 2021-02-04 Kimberly-Clark Worldwide, Inc. Process for making three-dimensional foam-laid nonwovens
CN111204607A (en) * 2018-11-22 2020-05-29 上海寰驰印刷机械有限公司 Non-stop waste discharge mechanism

Family Cites Families (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2216143A (en) * 1936-05-11 1940-10-01 Cons Water Power & Paper Co Process of coating paper
BE661981A (en) * 1964-04-03
US3301746A (en) * 1964-04-13 1967-01-31 Procter & Gamble Process for forming absorbent paper by imprinting a fabric knuckle pattern thereon prior to drying and paper thereof
DE1469513A1 (en) * 1965-07-19 1968-12-19 Billingsfors Langed Ab Method for producing a substitute material for textile material
US3823062A (en) * 1972-02-28 1974-07-09 Int Paper Co Twin-wire papermaking employing stabilized stock flow and water filled seal(drainage)boxes
US3821068A (en) * 1972-10-17 1974-06-28 Scott Paper Co Soft,absorbent,fibrous,sheet material formed by avoiding mechanical compression of the fiber furnish until the sheet is at least 80% dry
US3974025A (en) * 1974-04-01 1976-08-10 The Procter & Gamble Company Absorbent paper having imprinted thereon a semi-twill, fabric knuckle pattern prior to final drying
US4166001A (en) * 1974-06-21 1979-08-28 Kimberly-Clark Corporation Multiple layer formation process for creped tissue
US3994771A (en) * 1975-05-30 1976-11-30 The Procter & Gamble Company Process for forming a layered paper web having improved bulk, tactile impression and absorbency and paper thereof
US4308092A (en) * 1975-12-15 1981-12-29 Rohm And Haas Company Creping paper using cationic water soluble addition
US4406737A (en) * 1976-05-07 1983-09-27 Rohm And Haas Company Creping paper using cationic water soluble addition polymer
SE7708115L (en) * 1976-07-14 1978-01-15 English Clays Lovering Pochin PROCEDURE FOR PREPARING PAPER OR CARDBOARD
IE47019B1 (en) * 1977-07-12 1983-11-30 Blue Circle Ind Ltd Producing dispersions of polymeric material and preflocculated fillers for use in papermaking
US4191609A (en) * 1979-03-09 1980-03-04 The Procter & Gamble Company Soft absorbent imprinted paper sheet and method of manufacture thereof
US4300981A (en) * 1979-11-13 1981-11-17 The Procter & Gamble Company Layered paper having a soft and smooth velutinous surface, and method of making such paper
FR2492425A1 (en) * 1980-10-21 1982-04-23 Gascogne Papeteries PROCESS FOR THE PREPARATION BY PAPER TECHNIQUES OF A SHEET MATERIAL WITH IMPROVED MACHINE RETENTION, SHEET MATERIAL OBTAINED AND ITS APPLICATION IN PARTICULAR IN THE FIELD OF PRINTING WRITING, PACKAGING AND COATINGS
US4529480A (en) * 1983-08-23 1985-07-16 The Procter & Gamble Company Tissue paper
US4637859A (en) * 1983-08-23 1987-01-20 The Procter & Gamble Company Tissue paper
SE453206B (en) * 1983-10-21 1988-01-18 Valmet Paper Machinery Inc HYGIENE PAPER COAT, PROCEDURE FOR PREPARING THEREOF AND USING EXPANDABLE MICROSPHERES OF THERMOPLASTIC IN PREPARING HYGIENE PAPER COAT
FR2578870B1 (en) * 1985-03-18 1988-07-29 Gascogne Papeteries PROCESS FOR PREPARING A FIBROUS SHEET BY PAPER TO IMPROVE RETENTION AND IN PARTICULAR OPACITY.
US4795530A (en) * 1985-11-05 1989-01-03 Kimberly-Clark Corporation Process for making soft, strong cellulosic sheet and products made thereby
GB8531558D0 (en) * 1985-12-21 1986-02-05 Wiggins Teape Group Ltd Loaded paper
GB8602121D0 (en) * 1986-01-29 1986-03-05 Allied Colloids Ltd Paper & paper board
JPH0670317B2 (en) * 1986-02-07 1994-09-07 三菱製紙株式会社 Manufacturing method of paper with internal filler
GB8621680D0 (en) * 1986-09-09 1986-10-15 Du Pont Filler compositions
US4772332A (en) * 1987-04-21 1988-09-20 Engelhard Corporation Use of mixture of high molecular weight sulfonates as auxiliary dispersant for structured kaolins
US4927498A (en) * 1988-01-13 1990-05-22 E. I. Du Pont De Nemours And Company Retention and drainage aid for papermaking
US5266622A (en) * 1988-05-05 1993-11-30 Bayer Aktiengesellschaft Aqueous dispersions containing a synergistic dispersant combination
EP0341598A3 (en) * 1988-05-13 1991-04-10 BASF Aktiengesellschaft High solids paper coating composition
SE461156B (en) * 1988-05-25 1990-01-15 Eka Nobel Ab SET FOR PREPARATION OF PAPER WHICH SHAPES AND DRAINAGE OWN ROOMS IN THE PRESENCE OF AN ALUMINUM SUBSTANCE, A COTTONIC RETENTION AND POLYMER SILICON ACID
US4940513A (en) * 1988-12-05 1990-07-10 The Procter & Gamble Company Process for preparing soft tissue paper treated with noncationic surfactant
US4959125A (en) * 1988-12-05 1990-09-25 The Procter & Gamble Company Soft tissue paper containing noncationic surfactant
US4954220A (en) * 1988-09-16 1990-09-04 E. I. Du Pont De Nemours And Company Polysilicate microgels as retention/drainage aids in papermaking
US5185206A (en) * 1988-09-16 1993-02-09 E. I. Du Pont De Nemours And Company Polysilicate microgels as retention/drainage aids in papermaking
US5164046A (en) * 1989-01-19 1992-11-17 The Procter & Gamble Company Method for making soft tissue paper using polysiloxane compound
US4978396A (en) * 1989-05-12 1990-12-18 Kerr-Mcgee Chemical Corporation Process for preparing high solids slurries
US5068276A (en) * 1989-12-29 1991-11-26 E.C.C. America Inc. Chemically aggregated mineral pigments
US5178729A (en) * 1991-01-15 1993-01-12 James River Corporation Of Virginia High purity stratified tissue and method of making same
US5164045A (en) * 1991-03-04 1992-11-17 James River Corporation Of Virginia Soft, high bulk foam-formed stratified tissue and method for making same
US5415740A (en) * 1991-04-25 1995-05-16 Betz Paperchem, Inc. Method for improving retention and drainage characteristics in alkaline papermaking
US5228954A (en) * 1991-05-28 1993-07-20 The Procter & Gamble Cellulose Company Cellulose pulps of selected morphology for improved paper strength potential
US5227023A (en) * 1991-08-26 1993-07-13 James River Corporation Of Virginia Multi-layer papers and tissues
WO1996006225A1 (en) * 1992-08-05 1996-02-29 Reynolds Metals Company Process for preparing ultra-white alumina trihydrate
US5405499A (en) * 1993-06-24 1995-04-11 The Procter & Gamble Company Cellulose pulps having improved softness potential
JPH0818646A (en) * 1994-07-02 1996-01-19 Mototake Kuwabara Opposed type division id transmitter-receiver system
JP3647909B2 (en) * 1994-08-24 2005-05-18 リンテック株式会社 Cosmetic degreasing paper
EP0699446A1 (en) * 1994-08-31 1996-03-06 The Procter & Gamble Company Odour control material
US5487813A (en) * 1994-12-02 1996-01-30 The Procter & Gamble Company Strong and soft creped tissue paper and process for making the same by use of biodegradable crepe facilitating compositions

Also Published As

Publication number Publication date
CN1083920C (en) 2002-05-01
PT819195E (en) 2002-05-31
DE69617662D1 (en) 2002-01-17
HUP9800978A2 (en) 1998-07-28
KR19980703689A (en) 1998-12-05
ZA962500B (en) 1996-10-02
KR100264040B1 (en) 2000-11-01
US5611890A (en) 1997-03-18
WO1996031653A1 (en) 1996-10-10
DE69617662T2 (en) 2002-09-12
BR9610752A (en) 1999-07-13
AU5373196A (en) 1996-10-23
CN1187226A (en) 1998-07-08
CZ323697A3 (en) 1998-06-17
ES2169236T3 (en) 2002-07-01
ATE210225T1 (en) 2001-12-15
HK1008555A1 (en) 1999-05-14
AU721197B2 (en) 2000-06-29
EP0819195A1 (en) 1998-01-21
MX9707705A (en) 1997-12-31
NZ305665A (en) 1999-06-29
DK0819195T3 (en) 2002-04-02
JPH11503495A (en) 1999-03-26
EP0819195B1 (en) 2001-12-05

Similar Documents

Publication Publication Date Title
AU721197B2 (en) Tissue paper containing a fine particulate filler
AU706062B2 (en) Soft filled tissue paper with biased surface properties
AU729430B2 (en) Soft tissue paper containing fine particulate fillers
EP0891444B1 (en) A process for including a fine particulate filler into tissue paper using an anionic polyelectrolyte
CA2266932C (en) A process for making smooth uncreped tissue paper containing fine particulate fillers
EP0891443B1 (en) A process for including a fine particulate filler into tissue paper using starch

Legal Events

Date Code Title Description
EEER Examination request
FZDE Discontinued