US20080120954A1

US20080120954A1 - Tackified And Non-Tackified Nonwovens Of Controlled Stiffness And Retained Foldability

Info

Publication number: US20080120954A1
Application number: US11/937,245
Authority: US
Inventors: Leonard E. Duello; Thomas D. Hawkins; Christopher B. Peart; Nathaniel J. Nance
Original assignee: Individual
Current assignee: Polyester Fibers LLC
Priority date: 2006-05-16
Filing date: 2007-11-08
Publication date: 2008-05-29
Also published as: WO2009060118A2; US20110016839A1; WO2009060118A3; US8668758B2

Abstract

The present disclosure relates generally to a nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. In some embodiments a tackifier is added to the nonwoven filtration media to provide a sticky or adhesive surface on the fibers. The nonwoven media has an advantageous combination of stiffness, foldability, efficiency and the ability to retain a fold. The nonwoven media can be thermally bonded during the production process. The advantageous combination of mechanical properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the mix of different fibers provides desirable filtration properties.

Description

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International Application No. PCT/FI2007/050281, filed May 16, 2007, which claims the benefit of U.S. Provisional Application No. 60/866,820, filed Nov. 21, 2006 and from U.S. Provisional Application No. 60/800,613, filed May 16, 2006, the contents of each of which are incorporated herein by reference in their entirety.

FIELD

The present disclosure relates generally to a nonwoven web comprising a mix of discontinuous, thermoplastic resin fibers having a combination of high stiffness, foldability and filtration properties. In some embodiments the fibers of the web are coated with a tackifier. The nonwoven web can advantageously be used as a filtration media. The present disclosure also provides a method of making the filtration media. In some embodiments the nonwoven filtration media can advantageously be used as part of an air filter.

BACKGROUND

Some desirable filtration properties of nonwoven fabrics used as filtration media are that they be permeable to the fluid being filtered yet have high filtration efficiency. High permeability to the fluid being filtered is desirable as less energy is required to move the fluid through the filter media. High filtration efficiency is, of course, desirable as it allows the filtration media to more effectively remove contaminants in the fluid being filtered. Filtration properties can be quantified using tests such as Frazier Permeability, dP, PFE efficiency and Index.
In many applications, filtration media are required which have structural integrity by themselves for conversion into various shapes. For example, the filtration media can be folded into a pleated shape that gives far more surface area than a non-pleated shape in the same space.
Large fibers in a filtration media provide stiffness for pleating but undesirably degrade filtration efficiency. Further, some stiff filtration media are difficult to fold and may not “hold” the pleat, allowing the pleat to close and degrading filtration properties. Small fibers in a filtration media improve efficiency and foldability but reduce stiffness. A filtration media having an advantageous combination of stiffness, foldability, filtration properties and the ability to retain a fold is desirable.

SUMMARY

The present disclosure relates generally to a nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. The nonwoven media has an advantageous combination of Gurley Stiffness and LED score foldability within a preselected range dependent on the Gurley Stiffness, filtration properties and the ability to retain a fold. The nonwoven filtration media can be thermally bonded during the production process. The advantageous combination of high stiffness and foldability properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the mix of different fibers provides desirable filtration properties.
One embodiment of the nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. The nonwoven filtration media can be thermally bonded during the production process. At least some of the fibers are coated with a tackiness agent. The tackified, nonwoven media has an advantageous combination of Gurley Stiffness, an LED score foldability within a preselected range dependent on the Gurley Stiffness, filtration properties and the ability to retain a fold. The advantageous combination of high stiffness and foldability properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the tackiness agent and mix of different fibers provides desirable filtration properties.
One embodiment of a nonwoven filtration media comprises a mix of 0 percent to about 90 percent of staple length fibers having a denier of 10 or greater and about 10 percent to about 100 percent of the fibers having a denier of 4 or less. About 30 percent to about 85 percent of the fibers will be conjugate fibers. Preferably, the nonwoven filtration media will comprise a mixture of 0 percent to about 85 percent conjugate fibers having a denier of 15 or more and 0 percent to about 80 percent of conjugate fibers having a denier of 4 or less. The staple length fibers are carded and cross lapped to form a single layer with the different fibers homogeneously distributed through the thickness of the layer. The nonwoven filtration media is thermally bonded by contact with heated rollers. This nonwoven filtration media will have a basis weight between about 90 gsm to about 370 gsm, a Frazier Permeability between about 150 CFM/square foot/square foot and about 850 CFM/square foot, a PFE greater than or equal to 30 percent, a dP between about 0.03 inches water gauge at 110 fpm and about 0.22 inches water gauge at 110 fpm, an Index between about 300 and about 1600, a MD Gurley stiffness of more than 1400 and an LED score foldability within a preselected range dependent on the Gurley Stiffness
One embodiment of a nonwoven filtration media comprises a mix of staple length fibers all having a denier of 5 or less. Advantageously, about 30 percent to about 85 percent of the fibers in the nonwoven filtration media will be conjugate fibers having a denier of 5 or less. The staple length fibers are carded and cross lapped to form a single layer with the different fibers homogeneously distributed through the thickness of the layer. The nonwoven filtration media is thermally bonded by contact with heated rollers. This nonwoven filtration media will have a basis weight between about 90 gsm to about 370 gsm, a Frazier Permeability between about 150 CFM/square foot and about 850 CFM/square foot, a PFE greater than or equal to 30 percent, a dP between about 0.03 inches water gauge at 110 fpm and about 0.22 inches water gauge at 110 fpm, an Index between about 300 and about 1600 a MD Gurley stiffness of more than 1400 and an LED score foldability within a preselected range dependent on the Gurley Stiffness
The disclosed nonwoven filtration media may be used in a number of different applications. The media is advantageously used in air filtration for home or commercial heating, ventilating and air conditioning (HVAC) services. It may also be used in filtration of breathing air in transportation applications like automobile cabin air filtration, airplane cabin air filtration, and train and boat air filtration. While the nonwoven filtration media is preferably directed to air filtration, in different embodiments other gasses and other fluids may be filtered as well. Such other gasses may include, for example, nitrogen. Other fluids may include liquids like oil or water.
In general, unless otherwise explicitly stated the disclosed materials and processes may be alternately formulated to comprise, consist of, or consist essentially of, any appropriate components, moieties or steps herein disclosed. The disclosed materials and processes may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants, moieties, species and steps used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objective of the present disclosure.
When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond the stated amount so long as the function and/or objective of the disclosure are realized. The skilled artisan understands that there is seldom time to fully explore the extent of any area and expects that the disclosed result might extend, at least somewhat, beyond one or more of the disclosed limits. Later, having the benefit of this disclosure and understanding the concept and embodiments disclosed herein, a person of ordinary skill can, without inventive effort, explore beyond the disclosed limits and, when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein.

DEFINITIONS

Biconstituent fiber—A fiber that has been formed from a mixture of two or more polymers extruded from the same spinneret. Biconstituent fibers do not have the various polymer components arranged in relatively constantly positioned distinct zones across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead usually forming fibrils which start and end at random. Biconstituent fibers are sometimes also referred to as multiconstituent fibers.
Binder—An adhesive material used to bind a web of fibers together or bond one web to another. The principal properties of a binder are adhesion and cohesion. The binder can be in solid form, for example a powder, film or fiber, in liquid form, for example a solution, dispersion or emulsion or in foam form.
Bonding—The process of securing fibers or filaments to each other in a nonwoven web. The fibers or filaments can be secured by thermal bonding such as in calendering or through air bonding; mechanical means such as in needlepunching; or jets of pressurized fluid such as water in hydroentangling.
Calendering—the process of moving a nonwoven material between opposing surfaces. The opposing surfaces include flat platens, rollers, rollers having projections and combinations thereof. Either or both of the opposing surfaces may be heated.
Card—A machine designed to separate fibers from impurities, to align the fibers and deliver the aligned fibers as a batt or web. The fibers in the web can be aligned randomly or parallel with each other predominantly in the machine direction. The card consists of a series of rolls and drums that are covered with a plurality of projecting wires or metal teeth.
Carded web—A nonwoven web of discontinuous fibers produced by carding.
Carding—A process for making nonwoven webs on a card.
Cellulose fiber—A fiber comprised substantially of cellulose. Cellulosic fibers come from manmade sources (for example, regenerated cellulose fibers or lyocell fibers) or natural sources such as cellulose fibers or cellulose pulp from woody and non-woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto grass, kenaf, sisal, abaca, milkweed, straw, jute, hemp, and bagasse.
Cellulose material—A material comprised substantially of cellulose. The material may be a fiber or a film. Cellulosic materials come from manmade sources (for example, regenerated cellulose films and fibers) or natural sources such as fibers or pulp from woody and non-woody plants.
Conjugate fiber—A fiber comprising a first fiber portion extending substantially continuously along the length of the fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of the fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point. Typically, the second melting point is lower than the first melting point. The fiber portions are arranged in substantially constantly positioned distinct zones across the cross-section of the fiber. A conjugate fiber includes fibers comprising two or more polymers or fiber portions. Conjugate fibers are formed by extruding polymer sources from separate extruders through a spinneret to form a single fiber. Typically, different polymeric materials are extruded from each extruder, although a conjugate fiber may encompass extrusion of the same polymeric material from separate extruders. The configuration of conjugate fibers can be symmetric (e.g., sheath:core or side:side) or they can be asymmetric (e.g., offset core within sheath; crescent moon configuration within a fiber having an overall round shape). The shape of the conjugate fiber can be any shape that is convenient to the producer for the intended end use, e.g., round, trilobal, triangular, dog-boned, flat or hollow.
Cross machine direction (CD)—The nonwoven web direction perpendicular to the machine direction.
Denier—A unit used to indicate the fineness of a filament given by the weight in grams for 9,000 meters of filament. A filament of 1 denier has a mass of 1 gram for 9,000 meters of length.
Entanglement—A method of bonding a web by interlocking or wrapping fibers in the web about each other. The method may use mechanical means such as in needlepunching or jets of pressurized fluid such as water in hydroentangling.
Fiber—A material form characterized by an extremely high ratio of length to diameter. As used herein, the terms fiber and filament are used interchangeably unless otherwise specifically indicated.
Filament—A substantially continuous fiber. As used herein, the terms fiber and filament are used interchangeably unless otherwise specifically indicated.
Foam application—A method of applying a material such as a binder or tackifier in a foam form to a fibrous web. The foam form contains less fluid than the same material in a liquid form and thus requires less energy and time to dry the foam and, if applicable, cure the material.
Lyocell—Manmade cellulose material obtained by the direct dissolution of cellulose in an organic solvent without the formation of an intermediate compound and subsequent extrusion of the solution of cellulose and organic solvent into a coagulating bath.
Machine direction (MD)—The long direction of a nonwoven web material that is parallel to and in the direction in which the nonwoven web material is finally accumulated.
Meltblown fiber—A fiber formed by extruding a molten thermoplastic material as filaments from a plurality of fine, usually circular, die capillaries into a high velocity gas (e.g., air) stream which attenuates the filaments of molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. The meltblown process includes the melt spray process.
MERV—Minimum Efficiency Reporting Value which is defined in ASHRAE Standard 52.2-1999, Section 11.2.L and Section 12. As an example a MERV 6 filter will have the ability, as per the standard and under its specified conditions, to remove 35% to 50% of a 3-10 micron KCI particle insult. A MERV 7 filter will have the ability to remove 50% to 70% of a 3-10 micron KCI particle insult and a MERV 8 filter will have the ability to remove over 70% of a 3-10 micron KCI particle insult. The higher the MERV number, the higher the filtration performance of a filter.
Monocomponent fiber—A fiber formed from one or more extruders using only one polymer. This is not meant to exclude fibers formed from one polymer to which small amounts of additives have been added for coloration, anti-static properties, lubrication, hydrophilicity, etc. These additives, e.g. titanium dioxide for color, are generally present in low amounts such as less than 5 weight percent.
Needlepunching or Needling—A method of bonding a web by interlocking or wrapping fibers in the web about each other. The method uses a plurality of barbed needles to carry fiber portions in a vertical direction through the web.
Non-thermoplastic polymer—Any polymer material that does not fall within the definition of thermoplastic polymer.
Nonwoven fabric, sheet or web—A material having a structure of individual fibers that are interlaid, but not in an identifiable manner as in a woven or knitted fabric. Nonwoven materials have been formed from many processes such as, for example, meltblowing, spin laying, carding, air laying and water laying processes. The basis weight of nonwoven materials is usually expressed in weight per unit area, for example in grams per square meter (gsm) or ounces per square foot (osf) or ounces per square yard (osy). As used herein a nonwoven sheet includes a wetlaid paper sheet.
Polymer—A long chain of repeating, organic structural units. Generally includes, for example, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc, and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” includes all possible geometrical configurations. These configurations include, for example, isotactic, syndiotactic and random symmetries.
Regenerated cellulose—Manmade cellulose obtained by chemical treatment of natural cellulose to form a soluble chemical derivative or intermediate compound and subsequent decomposition of the derivative to regenerate the cellulose. Regenerated cellulose includes spun rayon and cellophane film. Regenerated cellulose processes include the viscose process, the cuprammonium process and saponification of cellulose acetate.
Short fiber—A fiber that has been formed at, or cut to, lengths of generally one quarter to one half inch (0.6 to 1.3 cm).
Spunlaid filament—A filament formed by extruding molten thermoplastic materials from a plurality of fine, usually circular, capillaries of a spinneret. The diameter of the extruded filaments is then rapidly reduced as by, for example, eductive drawing and/or other well-known mechanisms. Spunlaid fibers are generally continuous with deniers within the range of about 0.1 to 5 or more.
Spunbond nonwoven web—Webs formed (usually) in a single process by extruding at least one molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries of a spinneret. The filaments are partly quenched and then drawn out to reduce fiber denier and increase molecular orientation within the fiber. The filaments are generally continuous and not tacky when they are deposited onto a collecting surface as a fibrous batt. The spunlaid fibrous batt is then bonded by, for example, thermal bonding, calendering, chemical binders, mechanical needling, hydraulic entanglement or combinations thereof, to produce a nonwoven fabric.
Staple fiber—A fiber that has been formed at, or cut to, staple lengths of generally one quarter to eight inches (0.6 to 20 cm).
Synthetic fiber—a fiber comprised of manmade material, for example glass, polymer, combination of polymers, metal, carbon, regenerated cellulose or lyocell.
Substantially continuous—in reference to the polymeric filaments of a nonwoven web, it is meant that a majority of the filaments or fibers formed by extrusion through orifices remain continuous as they are drawn and then impacted on a collection device. Some filaments may be broken during the attenuation or drawing process, with a substantial majority of the filaments remaining continuous.
Tackifier or Tackiness Agent—a material such as a resin used to impart adhesive properties to otherwise nonadhesive materials such as a nonwoven web. A tackifier can coat the fibers in a nonwoven web to provide the web with adhesive fiber surfaces. Binder resins are typically not tackifiers as curing the binder resin substantially eliminates the ability of the binder to impart adhesive properties to the web.
Tex—A unit used to indicate the fineness of a filament given by the weight in grams for 1,000 meters of filament. A filament of 1 tex has a mass of 1 gram for 1,000 meters of length.
Thermal bonding—A calender process comprising passing a web of fibers to be bonded between a heated calender roll and an anvil roll. The anvil is usually flat. Filaments or fibers in the bonding area are joined by heat and pressure imparted by the rolls. Thermal bonding can also be used to join layers together in a composite material as well as to impart integrity to each individual layer by bonding filaments and/or fibers within each layer.
Thermal point bonding—A thermal bonding process comprising passing a web of fibers to be bonded between a heated calender roll and an anvil roll. The calender roll is patterned in some way so that the fabric is not bonded across its entire surface and the anvil is usually flat. Filaments or fibers in the bonding area are joined by heat and pressure imparted by the rolls. Typically, the percent bonding area varies from around 10% to around 30% of the web surface area. Thermal point bonding can also be used to join layers together in a composite material as well as to impart integrity to each individual layer by bonding filaments and/or fibers within each layer.
Thermoplastic polymer—A polymer that softens and is fusible when exposed to heat, returning generally to its unsoftened state when cooled to room temperature. Thermoplastic materials include, for example, polyvinyl chlorides, some polyesters, polyamides, polyfluorocarbons, polyolefins, some polyurethanes, polystyrenes, polyvinyl alcohol, copolymers of ethylene and at least one vinyl monomer (e.g., poly (ethylene vinyl acetates), and acrylic resins.
Triboelectrically charged fibers—Two yarns of dissimilar polymers that can be rubbed together and exchange charges in such a consistent manner that one fiber forms a positive charge and the other a negative charge.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings wherein like elements are numbered alike in the several Figures:

FIG. 1 is an illustration of preparation of a specimen for the LED score foldability test.

FIG. 2 is an illustration of compression of a specimen for the LED score foldability test.

FIG. 3 is an illustration of measurement of the LED score test angle.

FIG. 4 is an illustration of a Gurley Stiffness specimen showing orientation of the specimen to the nonwoven filtration media.

FIG. 5 is an illustration of a LED Score specimen showing orientation of the specimen to the nonwoven filtration media.

FIG. 6 is a schematic illustration of one embodiment of a thermal bonding system using a single heated roller.

FIG. 7 is a schematic illustration of one embodiment of a thermal bonding system using multiple heated rollers.

FIG. 8 is a graph of MD Gurley Stiffness versus LED foldability for some of the Examples.

DETAILED DESCRIPTION

In one embodiment, a thermally bonded nonwoven filtration media comprising a mixture of discontinuous, fibers is disclosed. The different fibers are substantially homogeneously distributed throughout the thickness of the media. The nonwoven filtration media has an advantageous combination of Gurley Stiffness, foldability within a predetermined range dependent on the Gurley Stiffness and filtration efficiency.
The nonwoven filtration media can be comprised of many different staple length fibers, including synthetic fibers and cellulose fibers. Advantageously, the synthetic fibers include thermoplastic polymer fibers such as one or more of polyester, polyolefin and polyamide. Typically, at least some of the polymer fibers will be conjugate fibers. Advantageously, about 30 percent to about 85 percent of the polymer fibers will be conjugate fibers. As used in this disclosure fiber percentages are by weight of total fibers in the final nonwoven filtration media. Some suitable synthetic fibers are listed below.


Denier	Polymer	Supplier

4	denier	conjugate polyester core	Stein of West Point GA
		and polyester sheath
15	denier	Polyester	Stein
2.25	denier	Polyester	RSM of Charlotte, NC
3	denier	Polyester	Invista of Spartanburg, SC
3	denier	Polypropylene	American Synthetics of
			Pendergrass, GA

Triboelectrically charged fibers can comprise a combination of 2 to 4 decitex low finish or scoured polypropylene fibers and 2 to 4 denier scoured modacrylic fibers.

Advantageously the cellulosic fibers include one or more of cotton fibers, rayon fibers, lyocell fibers and kenaf bast fibers. Other cellulosic fibers may be useful in the disclosed nonwoven filtration media. It is believed that the cost of some cellulosic fiber materials, for example lyocell, may limit their use in some applications.
Some suitable cellulosic fibers are listed below.


Denier	Polymer	Supplier

Mixed	Polyester/cotton	Leigh Fibers of Charlotte, NC
3.33 denier	lyocell	Tencel of Axis, AL
Mixed	Cotton	Leigh Fibers

The nonwoven filtration media can also comprise a mixture or blend of recycled, staple length polyester fibers and cotton fibers.

The chosen fiber denier for each fiber type of the nonwoven filtration media will be in the range of about 0.1 to about 45. Commercially available nonwoven, higher efficiency (MERV 7 and above), self supporting media, for example pleated air filtration media, use fibers having deniers of 6 and less. Use of fibers having these lower deniers was thought necessary to achieve the desired efficiency (MERV 7 or above). Using fibers with deniers higher than 6 in a self supporting media was not thought desirable as the larger fibers were not thought to provide as efficient a barrier to contamination as smaller fibers and would not allow the media to achieve the desired higher efficiency. Surprisingly and contrary to conventional practice, some of the disclosed embodiments provide a nonwoven, self supporting media having higher efficiency that is formed using a combination of fiber types having small denier fibers in the range of about 6 or less and fiber types having large denier fibers in the range of about 8 to about 45. Advantageously, at least one fiber type is a conjugate fiber. Further, large denier fibers can provide a nonwoven, self supporting, high efficiency media with increased pleat holding ability when compared to a higher efficiency media comprising only small denier fibers. Some disclosed embodiments comprise a nonwoven, self supporting filtration media having an efficiency of MERV 7 or above and including both fiber types having a denier of 6 or less and fiber types having a denier of 8 and above, including a conjugate fiber type. Presently, nonwoven materials comprising 6 denier fibers, for example 6 denier polyester fibers, are excluded from some disclosed embodiments.
Some exemplary staple fibers for use in the disclosed nonwoven filtration media are 0.9 denier monocomponent polyester fibers; 2.25 denier monocomponent polyester fibers; 3 denier monocomponent polyester fibers; 3 denier monocomponent polypropylene fibers; 4 denier polyester core/polyester sheath conjugate fibers; 10 denier polyester core/polyester sheath conjugate fibers; 15 denier monocomponent polyester fibers; 15 denier polyester core/polyester sheath conjugate fibers; 45 denier monocomponent polyester fibers; 2 to 4 decitex low finish or scoured polypropylene fibers; 2 to 4 denier scoured modacrylic fibers; kenaf fibers; and rayon fibers. Naturally, fibers of other deniers, other polymers and other configurations may prove useful in the disclosed nonwoven filtration media.
The nonwoven filtration media will have a basis weight (weight per unit area) of about 0.3 ounces per square foot (osf) (about 90 gsm) and up. The high limit for basis weight will depend on the end use application. Advantageously, the nonwoven filtration media will have a basis weight of about 0.3 osf (about 90 gsm) to about 1.2 osf (about 370 gsm).
The nonwoven filtration media will have a thickness of about 0.04 inches (about 1 mm) to about 0.25 inches (about 6.4 mm) or more depending on the end use application. Advantageously, the nonwoven filtration media will have a thickness of about 0.08 inches (about 2.0 mm) to about 0.12 inches (about 3 mm).
There are numerous known technologies for forming a nonwoven filtration media from staple length fibers, including air laying, wet laying and carding. Presently, carding is considered an advantageous method for making the nonwoven filtration media. Preselected types of staple length fibers are mixed in preselected proportions and the mixture is fed to a card machine. The card machine forms the mixed fibers into a matt. Fibers in the carded matt will be homogeneously distributed, although the majority of fibers will typically be aligned in the machine direction. The matt may optionally be layered using, for example, a cross lapper machine. The cross lapper machine layers the lighter web leaving the card. The carded web enters the cross lapper machine in one direction and the layered matt leaves the cross lapper machine in a direction perpendicular to the entry direction. The layered matt will typically have an increased basis weight as compared to the carded matt. The layered maft may have a cross direction fiber orientation, although fibers in the layered maft are typically more randomly oriented than in the carded matt.
Many technologies can be employed to join or bond the fibers in the matt. Some useful bonding technologies include, for example, one or more of entangling, thermal calendering of the matt to fuse thermoplastic fibers therein, application of ultrasonic energy to the matt and/or application of resin materials to the matt. Presently, mechanical entanglement such as needlepunching is considered advantageous forjoining fibers of the matt.
Heat can be applied to the entangled matt to at least partially melt the thermoplastic fibers therein. Upon cooling, the melted thermoplastic fibers harden and fuse the fibers in the entangled matt. One advantageous method of thermal bonding is running the entangled matt over one or more heated rolls. The media can be threaded through the system utilizing additional rolls, which may not be shown, to heat one or both sides of the entangled matt. FIG. 6 schematically illustrates one embodiment of a thermal bonding system using a single heated roller. FIG. 7 schematically illustrates one embodiment of a thermal bonding system using multiple heated rollers. The third roll in FIG. 7 can optionally be moved into contact with the opposite side of the matt for compression and heating of the matt. The rolls are heated to a temperature sufficient to soften and fuse the thermoplastic fibers. Suitable temperatures are generally in the range of about 300° F. to about 420° F., depending on the matt contact time. The thermally bonded matt can optionally be further bonded by passing the matt through ovens after thermal bonding over heated rollers. It may be possible to thermal bond the matt by oven heating alone to form the disclosed nonwoven filtration media. Nonwoven filtration media bonded using both heated rollers and oven are exemplified in examples 166, 180 and 211.
Resin binders can be added to the nonwoven filtration media after carding or bonding. Some suitable resin binders are ethylene vinyl chloride, ethylene vinyl acetates, acrylics and acrylates. Resin binders are typically applied as a solution and are dried and/or cured by heating. The resin binder solution can be added using conventional processes, for example, by spraying, dipping or foaming the matt. Resin binders are typically non-adhesive after curing.
The nonwoven filtration media can be coupled to a second nonwoven web to form a composite filtration media. The second nonwoven web can be comprised of continuous filaments, for example a spunbonded web, or discontinuous fiber, for example a carded web or a wet laid web. Typically, the coupled media and web will be in continuous face to face contact. The coupled webs can be joined by adhesive bonding; thermal bonding; mechanical entanglement or ultrasonic bonding. Alternately, the nonwoven filtration media can be used as a base over which charged fibers, such as triboelectrically charged fibers, can be laid and mechanically entangled. Additionally, different layers comprising cotton and polyester-cotton mixtures layers can be layered between the nonwoven filtration media and the triboelectrically charged fibers. See Table 5, Examples 208 to 210.
After formation and bonding, the filtration media material may be charged or corona treated. Corona treatment further increases filtration efficiency by drawing particles to be filtered toward the nonwoven filtration media by virtue of its electrical charge. Corona treatment can be carried out by a number of different techniques. One technique is described in U.S. Pat. No. 5,401,446 to Tsai et al. assigned to the University of Tennessee Research Corporation and incorporated herein by reference in its entirety. Other methods of corona treatment are known in the art.
The disclosed nonwoven filtration media may be made into a filter by any suitable means known in the art, for example by rotary pleating. Rotary pleating, while faster than many other pleating methods, is indicated to be quite dependent upon the stiffness of the filter medium. Gurley Stiffness values of at least 600 mg are required to allow pleating on high speed rotary pleating equipment. Other methods of pleating are not as sensitive to filtration media stiffness but are slower. Rotary pleating is discussed in, for example, U.S. Pat. No. 5,709,735 to Midkiff and Neely.
In one advantageous embodiment one or more tackifiers are coated over fibers of the nonwoven media. A tackifier is a natural or synthetic material that adheres to, and provides a long lasting sticky or adhesive surface on, the fibers of the nonwoven filtration media. Some suitable tackifiers include elastomeric polymeric emulsions such as HYSTRETCH® elastomeric emulsions available from Lubrizol Advanced materials of Pittsburgh, Pa.; FLEXCRYL® adhesive emulsions available from Air Products Polymers L.P. of Allentown, Pa.; and SPAR CRYL materials available from Spartan Chemical Laboratories, Inc. of Spartanburg, S.C. The amount of tackifier added to the nonwoven filtration media can typically be in the range of about 0.5 percent by weight of the nonwoven filtration media to about 30 percent by weight of the nonwoven filtration media. Advantageously, the amount of tackifier added to the nonwoven filtration media can be in the range of about 1.5 percent by weight of the nonwoven filtration media to about 15 percent by weight of the nonwoven filtration media. The preferred amount of tackifier in some embodiments can be in the range of about 1.5% to about 6% while in other embodiments the amount of tackifier can be in the range of about 1.5% to about 3%.
Tackifiers are typically applied as an emulsion, solution or foam and excess fluid removed, for example by heating. The tackifier emulsion or solution can be added using conventional processes, for example, by foaming, spraying brushing or dipping the nonwoven filtration media.
In one presently preferred method, preselected types of staple length fibers are mixed in preselected proportions. The staple length fiber mixture is fed to a card machine. The card machine forms the mixed, staple length fibers into a matt. The matt is cross lapped to increase basis weight and rearrange fiber orientation. The carded and lapped matt is needle punched to mechanically entangle the fibers therein. The entangled matt is thermally bonded by running the matt over one or more heated rolls. The matt can also be optionally compressed by rolls during thermal bonding. Liquid resin binders are optionally applied to the thermal bonded matt. The binder comprising matt is heated to dry the matt and/or to cure the binder. A nonwoven web can optionally be superimposed on the carded matt prior to needle punching so that the carded matt and nonwoven web are mechanically entangled into a composite filtration media.
A tackifier, typically in solution, can be added to the nonwoven filtration media at any convenient point during manufacturing. Application of a tackifier solution to the fibers before carding or to the carded matt before thermal bonding can lead to problems with formation of the desired nonwoven filtration media. It is advantageous to apply the tackifier to the nonwoven filtration media after thermal bonding of the fibers.
As discussed above the nonwoven filtration media has an advantageous combination of Gurley Stiffness, foldability within a predetermined range dependent on the Gurley Stiffness and filtration properties. Filtration properties can be quantified using tests such as Frazier Permeability, dP, PFE efficiency and Index. Test methods are discussed below.
Frazier Air Permeability
Frazier air permeability test is a measure of the permeability of a filtration media to air. The Frazier test is performed in accordance with ASTM D461-72, D737-75, F778-82, TAPPI T251 and ISO 9237, and is reported as an average of 4 sample readings. The test reports the amount of air that flows in cubic feet per minute per square foot at a resistance of 0.5″ water gauge. CFM/square foot results can be converted to liters per square meter per minute (LSM) by multiplying CFM/square foot by 304.8. It is believed advantageous that the disclosed nonwoven filtration media have a Frazier Permeability in the range of about 150 CFM/square foot to about 850 CFM/square foot.
dP and PFE Efficiency
dP and PFE are test results from ASHRAE standard ASHRAE 52.2-1999. dP is pressure drop or resistance as measured in inches of water gauge at 110 feet per minute air velocity. PFE is the particle fraction efficiency percentage removal efficiency at 110 feet per minute air velocity. One reportable PFE range averages the efficiency between 3 to 10 micron particle sizes and another reportable range averages the efficiency between the 1 to 3 micron particle sizes. It is believed advantageous that the disclosed nonwoven filtration media have a dP in the range of about 0.03 to about 0.22. inches water gauge and a 3 to 10 micron range particle fraction efficiency of between 17.8% and 93.3% and/or a 1 to 3 micron range particle fraction efficiency of between 1.5% and 71.4%.
Index
Index is calculated using the PFE result for 3 to 10 micron efficiency divided by dP. Index is unitless. It is believed advantageous that the disclosed nonwoven filtration media have an Index in the range of about 300 to about 1600.
Gurley Stiffness
Gurley Stiffness measures nonwoven filtration media stiffness. The Gurley Stiffness test method, discussed in more detail below, generally follows TAPPI Method T 543 om-94. Gurley stiffness is measured in the machine direction (MD) and results are reported in milligrams.

- 1) Level the tester using the bubble level on front/top.
- 2) Obtain a square foot sample of media with the MD marked on it, ensuring the product has not been excessively handled or bent.
- 3) With reference to FIG. 4, cut three specimens across the width that are 1″×2″ with 2″ side being parallel to the CD. Mark samples “CD”. These samples reflect flexure in the MD plane and are used to obtain MD Gurley stiffness values.
- 4) Cut three specimens across the width that are 2″×1″ with 2″ side being parallel to the MD. Mark samples “CD”. These samples reflect flexure in the CD plane and are used to obtain CD Gurley stiffness values.
- 5) Set up tester as in table below.
- 6) Orient the specimen in Gurley holder with 2″ side in jaws and fuzzy (AIR ENTERING) side facing right, position sample to the right.
- 7) Always start first arm movement from right to left.
- 8) Once media releases from vane stop all movement. Wait one minute to allow arm movement to slow and stop it (+/−¼″) gently.
- 9) Start arm movement to left until media releases from vane.
- 10) Push the converter button and record the record values.
- 11) Average the three tests for both MD and CD separately and report average of three for each.

Parameter Setting

Length (inches) 1.5

Width (inches) 2.0

Weight position (inches) 2.0

Weight (grams) 200

The stiffer the nonwoven, the higher the Gurley stiffness reading. A Gurley Bending Resistance Tester model 4171D available from Gurley Precision Instruments of Troy, N.Y. has been found suitable for the above testing.
LED Foldability Score
The “LED score” test measures the ability of a nonwoven media to accept and retain a fold. The “LED score” test is similar to a Shirley Crease Retention Test, (American Association of Textile and Color Chemists (AATCC)-66-2003 et al). Briefly, the “LED score” test is performed using the following procedure:

- 1) Obtain specimen.
- 2) With reference to FIG. 5, cut specimen into a ½″ wide×4″ long test sample with long direction parallel to CD.
- 3) Place test sample on flat metal surface.
- 4) Place angle iron in contact with test sample with apex against sample.
- 5) Strike angle iron once with 1170 gram hammer.
- 6) Fold test sample at score and place in file folder type cardboard sleeve. See FIG. 1.
- 7) Place folded test sample and sleeve under 1800 gram weight for 30 seconds. See FIG. 2.
- 8) Remove weight from folded test sample and sleeve and remove test sample from sleeve keeping it closed.
- 9) Position test sample vertically immediately in front of measuring apparatus.
- 10) Release and slip vertical leg of test sample into measuring apparatus.
- 11) Within 3 to 5 seconds align bottom of protractor portion with free leg of test sample.
- 12) Read “LED Score” test result. See FIG. 3.
- 13) Repeat three times for each specimen.
- 14) Average results.
  The measured angle is related to the nonwoven filtration media's resistance to opening, e.g. the ability to retain a fold or pleat. The more foldable a nonwoven, the higher the LED score angle.

The right combination or range of Gurley stiffness and retained foldability properties allows a nonwoven filtration media material to accept and hold a better fold or pleat with a straighter line between the fold peak and valley than other nonwoven filtration medias having properties outside of this range. Such combinations of Gurley stiffness and retained foldability properties are desirable in the manufacture of filter products. Naturally, not every nonwoven will have the advantageous combinations of Gurley stiffness and retained foldability properties disclosed herein. Further, even nonwoven media having similar combinations of Gurley stiffness and retained foldability properties to those disclosed herein will not have the presently disclosed filtration properties.
Filters used in heating, ventilation and air conditioning (HVAC) systems can comprise a peripheral housing defining an open center with nonwoven filtration media sealed to the housing and spanning the open center. The housing allows the filter to be handled and sealed to the HVAC system. Air to be filtered is moved through the media. Thus, during use the nonwoven filtration media is subjected to a pressure drop caused by air movement through that media. The filter and nonwoven filtration media are also subjected to varying temperature and humidity conditions depending on geographic location and time of year.
Some nonwoven media cannot maintain their shape, for example pleats, when subjected to the pressure drop and varying temperature and humidity conditions of a HVAC system unless one or both faces of the nonwoven media is supported by an open mesh framework spanning the edges of the housing.
In some embodiments the disclosed nonwoven filtration media is self supporting, that is the media has a combination of MD Gurley stiffness and retained (LED) foldability to allow it to maintain its shape when used in a HVAC system without requiring face support by an open mesh framework spanning the edges of the housing.
In some advantageous embodiments of the disclosed nonwoven filtration media the MD Gurley stiffness is above about 2400 milligrams and the retained (LED) foldability is maintained between about 39.3 degrees and about 134 degrees. In some other advantageous embodiments of the disclosed nonwoven filtration media the MD Gurley stiffness is below 2400 milligrams and retained (LED) foldability is maintained between about 40 degrees and about 108 degrees.
Especially advantageous combinations of Gurley stiffness and retained (LED) foldability (wherein ranges are indicated by letters A to H) are shown in Table 1.

TABLE 1

Range	Gurley Stiffness - MD (mg)	LED Foldability (degrees)

A	Over 3000	60.2 to 101.7
B	2800 to 3000	55.0 to 104.2
C	2400 to 2800	53.3 to 101.5
D	1800 to 2400	39.7 to 108.2
E	1400 to 1800	41.2 to 98.3
F	1200 to 1400	77.0 to 86.0
G	800 to 1200	39.3 to 68.2
H	Under 800	42.7 to 68.8

As illustrated in Table 1 and FIG. 8, foldability is seen to increase with MD Gurley stiffness.

Having generally described the invention, the following examples and those on the attached Tables are included for purposes of illustration so that the invention may be more readily understood and are in no way intended to limit the scope of the invention unless otherwise specifically indicated. The Examples were comprised of staple fibers in the combinations shown on the Tables and were prepared using conventional carding and cross lapping equipment and conditions. Unless otherwise noted the examples were bonded using heated rollers, sometimes in combination with oven heating unless otherwise indicated. Some examples were bonded using ultrasonic energy. Table 5 lists bonding conditions for some examples.
Nonwoven Filtration Media Comprising a Mix of Staple Length Fibers Having a Denier of 4 or Less and 10 or More.
Example 2 in range A was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 85% staple length fibers having a denier of 4 or less and 15% staple length fibers having a denier of 10 or more. 70% of the fibers of Example 2 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 177 gsm, a Frazier permeability of about 321 CFM/square foot, a dP of about 0.18, a PFE efficiency of about 58, a MD Gurley stiffness of about 3266 milligrams and a LED score test result of about 62 degrees.
Example 17 in range C was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 75% staple length fibers having a denier of 4 or less and 25% staple length fibers having a denier of 10 or more. 50% of the fibers of Example 17 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 180 gsm, a Frazier permeability of about 615 CFM/square foot, a MD Gurley stiffness of about 2630 milligrams and a LED score test result of about 66 degrees.
Example 50 in range E was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 75% staple length fibers having a denier of 4 or less and 25% staple length fibers having a denier of 10 or more. 75% of the fibers of Example 50 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 131 gsm, a Frazier permeability of about 580 CFM/square foot, a dP of about 0.076, a PFE efficiency of about 44, a MD Gurley stiffness of about 1770 milligrams and a LED score test result of about 85 degrees.
Nonwoven Filtration Media Comprising Staple Length Fibers all Having a Denier of 5 or Less.
Example 8 in range B was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 80% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 10% 0.9 denier staple length polyester fibers; and 10% 2.25 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 150 gsm, a Frazier permeability of about 409 CFM/square foot, a dP of about 0.12, a PFE efficiency of about 50, a MD Gurley stiffness of about 2900 milligrams and a LED score test result of about 91 degrees.
Example 38 in range D was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 52% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 5% 0.9 denier staple length polyester fibers; and 43% 2.25 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 180 gsm, a Frazier permeability of about 340 CFM/square foot, a dP of about 0.16, a PFE efficiency of about 62, a MD Gurley stiffness of about 2000 milligrams and a LED score test result of about 40 degrees.
Nonwoven Filtration Media Comprising Staple Length Kenaf Fibers.
Example 18 in range C was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 25% 4 denier staple length polyester fibers; and 25% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 165 gsm, a Frazier permeability of about 460, a dP of about 0.1, a PFE efficiency of about 52, a MD Gurley stiffness of about 2585 milligrams and a LED score test result of about 64.5 degrees.
Example 21 in range C was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 4 denier staple length polyester fibers; and 15% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 168 gsm, a Frazier permeability of about 430, a dP of about 0.1, a PFE efficiency of about 48, a MD Gurley stiffness of about 2515 and a LED score test result of about 69.7 degrees.
Example 61 in range E was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 35% 4 denier staple length polyester fibers; and 25% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 525, a dP of about 0.08, a PFE efficiency of about 54, a MD Gurley stiffness of about 1650 milligrams and an LED score test result of about 64.5 degrees.
Example 82 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 30% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 35% 4 denier staple length polyester fibers; and 35% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 530, a dP of about 0.08, a PFE efficiency of about 48, a MD Gurley stiffness of about 1297 milligrams and an LED score test result of about 63.5 degrees.
Nonwoven Filtration Media Comprising a Blend of Recycled, Staple Length, Polyester Fibers and Cotton Fibers.
Example 29 in range D was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 0.9 denier staple length polyester fibers; and 15% of a blend of recycled, staple length, polyester fibers and cotton fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to 380° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 190 gsm, a Frazier permeability of about 290, a dP of about 0.2, a PFE efficiency of about 66, a MD Gurley stiffness of about 2209 milligrams and a LED score test result of about 63.3 degrees.
Example 30 in range D was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; and 30% of a blend of recycled, staple length, polyester fibers and cotton fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to 400° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 200 gsm, a Frazier permeability of about 330, a dP of about 0.16, a PFE efficiency of about 73, a MD Gurley stiffness of about 2195 milligrams and a LED score test result in the range of about 53.0 degrees.
Nonwoven Filtration Media Comprising Staple Length Polypropylene Fibers.
Example 75 in range E was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 65% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 3 denier staple length uncharged polypropylene fibers; and 20% 0.9 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 116 gsm, a Frazier permeability of about 418, a MD Gurley stiffness of between about 1411 milligrams and a LED score test result in the range of about 66.5 degrees.
Example 77 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 30% 3 denier staple length uncharged polypropylene fibers; and about 30% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 514, a dP of about 0.08, a PFE efficiency of about 41, a MD Gurley stiffness of about 1371 milligrams and a LED score test result of about 50.8 degrees.
Example 105 in range G was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 60% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 25% 3 denier staple length uncharged polypropylene fibers; and about 15% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 113 gsm, a Frazier permeability of about 613, a MD Gurley stiffness of about 955 milligrams and a LED score test result in the range of about 65.0 degrees.
Example 111 in range H was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 30% 3 denier staple length uncharged polypropylene fibers; and about 30% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 120 gsm, a Frazier permeability of about 630, a MD Gurley stiffness of about 637 milligrams and a LED score test result of about 56.7 degrees.
Nonwoven Filtration Media Comprising 10 Denier, Staple Length, Conjugate Polyester Fibers.
Example 85 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 35% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 35% 10 denier, staple length conjugate polyester fibers; and about 30% 0.9 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 116 gsm, a Frazier permeability of about 500, a dP of about 0.1, a PFE efficiency of about 48, a MD Gurley stiffness of about 1258 milligrams and a LED score test result in the range of about 59.5 degrees.
Example 104 in range G was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 55% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 10% 10 denier, staple length conjugate polyester fibers; and 35% 3 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 120 gsm, a Frazier permeability of about 560, a dP of about 0.08, a PFE efficiency of about 38, a MD Gurley stiffness of about 960 milligrams and a LED score test result of about 68.2 degrees.
Nonwoven Filtration Media Comprising More than One Layer.
Example 19 in range C was prepared by carding and heat bonding fibers to form a first nonwoven filtration media. This first nonwoven media includes about 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 30% 15 denier polyester fibers. The first filtration media was needled onto a second spunbond nonwoven filtration media comprising 0.5 osy polypropylene filaments to form the nonwoven composite material. One side of the composite material was run over a roller heated to about 320° F. to partially melt and fuse the fibers. This nonwoven composite material has a basis weight of about 168 gsm, a Frazier permeability of about 530, a MD Gurley stiffness of about 2583 milligrams and a LED score test result of about 74.0 degrees.
Example 26 in range D was prepared by carding and heat bonding fibers to form a first nonwoven filtration media. This first nonwoven media includes about 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 30% 15 denier staple length polyester fibers. The first filtration media was needled onto a second spunbond nonwoven filtration media comprising 0.5 osy polypropylene filaments to form the nonwoven composite material. One side of the material was run over a roller heated to about 335° F. to partially melt and fuse the fibers. This nonwoven composite material has a basis weight of about 153 gsm, a Frazier permeability of about 540, a dP of about 0.07, a PFE efficiency of about 44, a MD Gurley stiffness of about 2298 milligrams and a LED score test result of about 86.7 degrees.
Example 169 in range D is a 2 layer nonwoven filtration media. Each layer was an independently carded matt formed using a different card machine. One carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. The other carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 45 denier, staple length polyester fibers. Each carded matt was cross lapped using a separate cross lapper. The cross lapped matts were overlaid, mechanically entangled by needling and thermally bonded using a heated roller. Each carded matt contributed one half to the weight of this 2 layer nonwoven filtration media. This nonwoven composite material has a basis weight of about 150 gsm, a Frazier permeability of about 500, a dP of about 0.075, a PFE efficiency of about 45, a MD Gurley stiffness of about 2300 milligrams and a LED score test result of about 73 degrees.
Resin and Thermal Bonded Nonwoven Filtration Media.
Nonwoven filtration medias can be bonded using liquid resins or binders.
Example 180 in range D was prepared by carding fibers to form a matt. This matt comprises about 15% 2.25 denier staple length, monocomponent polyester fibers; about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 35% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers. A solution of resin binder was applied to the heat bonded matt. The impregnated matt was run through an oven having multiple heating zones with each zone heated to between 241 and 298° F. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 140 gsm, a Frazier permeability of about 580, a dP of about 0.04, a PFE efficiency of about 30, a and a MD Gurley stiffness of about 1965 milligrams and a LED score test result of about 94 degrees.
Example 194 in range F was prepared by carding fibers to form a matt. This matt comprises about 35% 3 denier staple length, monocomponent polyester fibers; about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 15% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. A solution of resin binder was applied to the heat bonded matt. One side of the matt was heated over a heated roller to partially melt and fuse the fibers and dry the resin binder. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 150 gsm, a Frazier permeability of about 614, a MD Gurley stiffness of about 1371 milligrams and a LED score test result of about 72 degrees.
Example 211 in range C was prepared by carding fibers to form a matt. This matt comprises about 10% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 65% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 25% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers. A solution of resin binder was applied to the heat bonded matt. The impregnated matt was run through an oven having multiple heating zones with each zone heated to between 186 and 220° F. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 165 gsm, a Frazier permeability of about 671, a dP of about 0.033, a PFE efficiency of about 18, a MD Gurley stiffness of about 2615 milligrams and a LED score test result of about 101.5 degrees.
Ultrasonic Bonded Nonwoven Filtration Media.
Nonwoven filtration medias can be bonded using ultrasonic energy. Ultrasonic bonding is generally performed using a specifically tuned horn vibrating at a high frequency in close proximity to an anvil roll. The anvil roll can either be flat or have a pattern engraved into the roll.
Example 116 in range H was prepared by carding and ultrasonic bonding fibers to form a nonwoven filtration media. This filtration media comprises about 25% 15 denier polyester fibers; about 25% 45 denier polyester fibers and about 50% 3 denier polypropylene fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media was ultrasonically bonded using a flat anvil roll, a horn and a frequency of 20 kHz, a step position of 7378 with a target force of 800 Newtons on a Hermann Ultrasonics laboratory scale unit (Schaumberg, Ill.). This filtration media has a basis weight of about 170 gsm, a Frazier permeability of about 413, a MD Gurley stiffness of about 140 milligrams and a LED score test result of about 73.3 degrees.
Tackified Nonwoven Filtration Media 1
Examples 218 and 219 and Example 220 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 63% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 17% 15 denier staple length, monocomponent polyester fibers and about 20% 3 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.
One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 218, 219 and 220.
This filtration media has a basis weight of about 157 gsm, a Frazier permeability of about 496, a dP of about 0.073, a PFE efficiency of about 51.8, an index of about 710, a and a MD Gurley stiffness of about 2493 milligrams and a LED score test result of about 66.1 degrees.
Examples 221, 222 and 223 used the media of examples 218 to 220. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against one side of the media to provide the add-ons shown in Table 6. Examples 221 and 222 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Example 223 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.
Examples 224, 225, 226, 227 and 228 used the media of examples 218 to 220. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 224 and 225 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Examples 226, 227 and 228 were dried in still air at ambient temperatures (about 65° F. to about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.
Example 229 used the media of examples 218 to 220. An aqueous emulsion of Flexacryl 1625 tack agent, available from Air Products Polymers of Allentown, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 229 was dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.
Examples 230 and 231 used the media of examples 218 to 220. An aqueous emulsion of Spar Cryl 102 tack agent, available from Spartan Chemical Laboratories, Inc of Spartanburg, S.C., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 230 and 231 were dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.
Tackified Nonwoven Filtration Media 2
Examples 232 and 233 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 15% 2.25 denier staple length, monocomponent polyester fibers and about 35% 45 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.
One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 232 and 233.
This filtration media has a basis weight of about 159 gsm, a Frazier permeability of about 621, a dP of about 0.051, a PFE efficiency of about 43.3, an index of about 847, a MD Gurley stiffness of about 1872 milligrams and a LED score test result of about 78.6 degrees.
Examples 234 and 235 used the media of examples 232 to 233. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against one side of the media to provide the add-ons shown in Table 6. Examples 234 and 235 were dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.
Examples 236, 237 and 238 used the media of Examples 232 and 233. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 236 and 237 were dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Example 238 was dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of these Examples are illustrated on Table 6.
Tackified Nonwoven Filtration Media 3
Example 239 comprises about 38% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 11.4% 2.25 denier staple length, monocomponent polyester fibers, about 26% 45 denier staple length, monocomponent polyester fibers, about 12% 3.3 denier staple length, triboelectrically chargeable polypropylene fibers and about 12% 3 denier staple length, triboelectrically chargeable modacrylic fibers. Example 239 was prepared by carding and cross lapping a combination of 50% 15 denier conjugate fibers, 15% 2.25 denier polyester fibers and 35% 45 denier polyester fibers to form a matt. The malt was entangled by needling and heated over a heated roller to partially melt and fuse the fibers. The tribocharged fibers (about 12% 3.3 denier staple length, triboelectrically chargeable polypropylene fibers and about 12% 3 denier staple length, triboelectrically chargeable modacrylic fibers) were homogeneously blended, applied over the matt and entangled into the matt using needling. The matt and entangled, tribocharged fibers were heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 239.
This filtration media has a basis weight of about 159 gsm, a Frazier permeability of about 505, a dP of about 0.077, a PFE efficiency of about 77.9, an index of about 1012, a MD Gurley stiffness of about 1731 milligrams and a LED score test result of about 65.3 degrees.
Example 240 used the media of example 239. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 240 was dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch.
Example 241 used the media of example 239. An aqueous emulsion of Flexacryl 1625 tack agent, available from Air Products Polymers of Allentown, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 241 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch.
Example 242 used the media of examples 239. An aqueous emulsion of Spar Cryl 102 tack agent, available from Spartan Chemical Laboratories, Inc of Spartanburg, S.C., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 242 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch.
Physical properties of these Examples are illustrated on Table 6.
Tackified, Two Layer, Nonwoven Filtration Media 4
Example 243 is a 2 layer nonwoven filtration media. Each layer was an independently carded matt formed using a different card machine. One carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. The other carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. Each carded matt was cross lapped using a separate cross lapper.
The cross lapped matts were overlaid, mechanically entangled by needling. One side of the entangled matts was run over a heated roller to partially melt and fuse the fibers in the media. Each carded matt contributed one half to the weight of this 2 layer nonwoven filtration media. No tackifier or tack agent was applied to the media of Examples 243.
This filtration media has a basis weight of about 150 gsm, a Frazier permeability of about 500, a dP of about 0.075, a PFE efficiency of about 45.4, an index of about 605, a MD Gurley stiffness of about 2300 milligrams and a LED score test result of about 71.6 degrees.
Example 244 used the media of example 243. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 244 was dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of this Example are illustrated on Table 6.
Tackified Nonwoven Filtration Media 5
Example 245 was prepared by carding and cross lapping fibers to form a matt. This matt comprises about 50% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 8% 0.9 denier staple length, monocomponent polyester fibers and about 43% 2.25 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.
One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Example 245.
This filtration media has a basis weight of about 174 gsm, a Frazier permeability of about 230, a dP of about 0.169, a PFE efficiency of about 88.3, an index of about 522, a MD Gurley stiffness of about 1965 milligrams and a LED score test result of about 51 degrees.
Examples 246 and 247 used the media of example 245. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 246 and 247 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of these Examples are illustrated on Table 6.
Tackified Nonwoven Filtration Media 6
Examples 248 to 252 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 80% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 20% 3 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers.
Foams were prepared by mixing the reported amounts of tackifier and water. The tackifier and water mixture was wisked forcefully for about 60 seconds to entrain air into the mixture and form a foam. The foam was applied to the media in a uniform fashion using a flat blade applicator.
The aqueous based foam of Hystretch V-60 tack agent was applied to one side of Examples 248 to 252 to provide the add-ons shown in Table 6 in percentage by weight. Examples 248 to 252 were dried for about four hours at a temperature in the range of about 60° F. to about 80° F. Physical properties of these Examples are illustrated on Table 6.
For a nonwoven, self supporting media a minimum basis weight is required to achieve a desired efficiency. A nonwoven, self supporting, non-tackified MERV 6 efficiency filtration media will typically require a basis weight of about 0.4 osf. To increase the efficiency of that media to MERV 8, the basis weight will have to be increased to about 0.6 osf. Surprisingly, if a tackifier is added to a nonwoven, self supporting, MERV 6 efficiency filtration media having a basis weight of about 0.4 osf the resulting tackified filtration media can achieve a MERV 8 efficiency. Further surprisingly, adding a tackifier to a self supporting filtration media appears to increase stiffness of the resulting tackified media. Thus, adding a tackifier to a self supporting media provides surprising increases to efficiency and stiffness without increasing base media weight.
While preferred embodiments of the foregoing invention have been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention.

TABLE 2

Examples

staple fibers

	4 denier			2.25		10 denier			3 denier
	bico fiber	15 denier	0.9 denier	denier	3 denier	bico fiber	1599 fibers	45 denier	chargeable	4 denier
Example	note 1	polyester	polyester	polyester	polyester	note 2	note 3	polyester	polypropylene	polyester	kenaf

1	50%			25%				25%
2	70%			15%				15%
3	70%			15%				15%
4	60%	20%						20%
5	60%	25%		15%
6	80%				20%
7	50%			25%				25%
8	80%		10%	10%
9	80%	20%
10	80%				20%
11	60%	20%	20%
12	70%	15%	15%
13	70%	15%	15%
14	50%				25%			25%
15	50%			25%				25%
16	50%	25%						25%
17	50%	25%						25%
18	50%									25%	25%
19 note 12	70%	15%
20	50%	25%	25%
21	70%									15%	15%
22	50%	25%						25%
23	70%			15%				15%
24	40%		20%					40%
25	60%	25%		15%
26 note 12	70%	30%
27	50%	35%	15%
28	60%	20%			20%
29	70%		15%				15%
30	70%						30%
31	50%	25%		25%
32	60%	15%		25%

			Thickness	Frazier
	Weight	Weight	(inches)	perm.	Gurley - MD	Gurley - CD	LED		dP	PFE
Example	(OSF)	(gsm)	note 4	(CFM/sq. ft.)	(mg)	(mg)	Score test	range	note 5	note 6	comments

1	0.56	171	0.07	499	3316	3153	85.8	A	0.106	50.3
2	0.58	177	0.07	321	3266	3155	62.2	A	0.184	57.5
3	0.55	168	0.06	334	3225	2991	72.5	A	0.162	61.5
4	0.54	165	0.08	377	3187	2624	81.7	A	0.141	61.6
5	0.59	180	0.09	353	3056	3064	64	A	0.129	46.7
6	0.57	174	0.07	339	3054	3044	79.7	A	0.168	66.1
7	0.51	156	0.07	432	3038	2495	70.0	A	0.098	46.9
8	0.49	149	0.05	409	2912	2975	90.8	B	0.117	50.2
9	0.54	165	0.09	361	2864	2099	67.3	B	0.133	49.8
10	0.57	174	0.07	331	2855	2943	83.7	B	0.067	30.9
11	0.57	174	0.09	411	2810	2333	60.2	B	0.107	45.5
12	0.57	174	0.11	420	2797	3301	68.7	B	0.134	55.5
13	0.57	174	0.11	420	2797	3301	68.7	B	0.117	54.1
14	0.61	186	0.09	511	2789	1991	66	C	0.089	44.2
15	0.54	165	0.08	491	2786	2339	79.0	C	0.095	48.1
16	0.58	177	0.09	594	2749	2764	58.2	C	0.063	20.9
17	0.59	180	0.11	615	2629	2461	66	C	0.054	35.6
18	0.54	165	0.09	457	2585	2916	64.5	C	0.099	52.2
19 note 12	0.55	168	0.09	532	2583	2634	74	C	0.071	40.8	note 12
20	0.56	171	0.07	340	2520	2949	69.5	C	0.165	61.5
21	0.55	168	0.07	433	2516	2879	69.7	C	0.08	47.8
22	0.66	201	0.11	559	2494	2483	61.3	C	0.07	36.5
23	0.51	156	0.07	349	2485	2694	67.8	C	0.135	60.8
24	0.52	159	0.1	456	2423	1682	61.3	C	0.094	51.9
25	0.53	162	0.06	398	2314	2181	71.5	D	0.13	47.1
26 note 12	0.50	153	0.09	539	2298	2113	86.7	D	0.07	44.4	note 12
27	0.48	146	0.08	541	2283	2601	62.6	D	0.077	44.8
28	0.57	174	0.08	456	2283	2057	62.3	D	0.103	42.2
29	0.62	189	0.08	288	2209	2054	63.3	D	0.211	66.3
30	0.66	201	0.1	330	2195	1755	53	D	0.161	72.9
31	0.57	174	0.1	379	2183	2259	51.3	D	0.134	62.4
32	0.50	153	0.09	465	2136	1800	58	D	0.119	52.7

staple fibers

	4 denier			2.25		10 denier			3 denier
	bico fiber	15 denier	0.9 denier	denier	3 denier	bico fiber	1599 fibers	45 denier	chargeable	4 denier
Example	note 1	polyester	polyester	polyester	polyester	note 2	note 3	polyester	polypropylene	polyester	kenaf

33	50%	25%		25%
34 note 7	70%							30%
35	30%			35%				35%
36	60%	20%						20%
37	50%				25%			25%
38	52%		5%	43%
39	50%	25%						25%
40 note 8	50%	25%						25%
41	60%	15%		25%
42	50%				25%			25%
43	60%	25%		15%
44	70%	30%
45	70%	15%	15%
46	40%	20%		40%
47	60%	25%		15%
48	60%	15%		25%
49	40%		20%					40%
50	50%			25%				25%
51	60%		10%		30%
52	60%	15%		25%
53	50%		20%	30%
54	50%	25%			25%
55	50%	25%						25%
56	50%		20%	30%
57	70%	15%	15%
58	50%	25%	25%
59 note 12	70%							30%
60	60%	15%		25%
61	40%									35%	25%
62 note 9	50%	25%						25%
63 note 11	60%	15%							25%
64	52%		5%	43%
65	60%	15%		25%

			Thickness	Frazier
	Weight	Weight	(inches)	perm.	Gurley - MD	Gurley - CD	LED		dP	PFE
Example	(OSF)	(gsm)	note 4	(CFM/sq. ft.)	(mg)	(mg)	Score test	range	note 5	note 6	comments

33	0.48	146	0.1	477	2117	1697	52.3	D	0.106	59.4
34 note 7	0.76	232	0.11	279	2102	1477	67.3	D	0.196	63.1	note 7
35	0.55	168	0.09	365	2035	1640	60.3	D	0.142	67.5
36	0.40	122	0.07	474	2021	2013	94.7	D	0.094	52.8
37	0.51	156	0.1	595	2020	2098	63.7	D	0.067	39.3
38	0.59	180	0.08	340	2013	1806	40	D	0.165	62.2
39	0.38	116	0.09	778	1998	1695	73.2	D	0.031	28.6
40 note 8	0.74	226	0.12	348	1983	1365	60.3	D	0.12	51.5	note 8
41	0.53	162	0.07	427	1981	1935	63.8	D	0.11	46.1
42	0.42	128	0.07	656	1958	1517	66.3	D	0.056	30.6
43	0.52	159	0.08	447	1946	1926	63	D	0.107	47.4
44	0.56	171	0.1	409	1935	2139	78	D	0.122	53
45	0.53	162	0.09	414	1935	1904	49.5	D	0.139	56.2
46	0.56	171	0.09	309	1839	1394	49.5	D	0.205	60.8
47	0.56	171	0.1	442	1780	1795	41.2		0.099	49.3
48	0.44	134	0.06	490	1776	1734	55.5	E
49	0.46	140	0.09	538	1776	1753	84.3	E	0.07	50.0
50	0.43	131	0.07	579	1772	1909	85.2	E	0.076	44.1
51	0.60	183	0.09	348	1761	1611	67.2	E	0.216	64.6
52	0.51	156	0.09	462	1757	1736	59	E	0.108	50
53	0.54	165	0.07	316	1747	1628	61.3	E	0.179	66.9
54	0.59	180	0.1	466	1718	1689	57.2	E	0.114	49.7
55	0.67	204	0.14	571	1715	1783	68.3	E	0.058	41.2
56	0.53	162	0.08	287	1710	2213	70.3	E	0.194	71.5
57	0.48	146	0.09	429	1710	1602	55.8	E	0.105	58.4
58	0.49	149	0.08	379	1695	1614	57.5	E	0.15	53.6
59 note 12	0.44	134	0.09	512	1671	1537	94	E	0.074	45.4	note 12
60	0.52	159	0.09	456	1660	1653	54.2	E	0.102	46.1
61	0.53	162	0.09	525	1650	2129	64.5	E	0.084	53.8
62 note 9	0.62	189	0.11	412	1577	1170	57.7	E			note 9
63 note 11	0.47	143	0.07	492	1572	1313	64.5	E	0.095	42.6	UNC
64	0.48	146	0.11	406	1558	1451
65	0.50	153	0.08	478	1554	1443	53.5	E	0.096	47.4

staple fibers

	4 denier			2.25		10 denier			3 denier
	bico fiber	15 denier	0.9 denier	denier	3 denier	bico fiber	1599 fibers	45 denier	chargeable	4 denier
Example	note 1	polyester	polyester	polyester	polyester	note 2	note 3	polyester	polypropylene	polyester	kenaf

66	80%	10%		10%
67	50%	25%			25%
68	60%	20%			20%
69	30%			35%				35%
70	60%	15%		25%
71	50%	25%	25%
72 note 11	50%								50%
73	60%	20%			20%
74	70%				30%
75 note 11	65%		20%						15%
76	50%		15%	35%
77 note 11	40%	30%							30%
78	50%	25%	25%
79	50%		15%	35%
80	40%	20%		40%
81	55%				50%	10%
82	30%									35%	35%
83	60%	20%			20%
84	40%	20%		40%
85	35%		30%			35%
87	40%	30%		30%
88	52%		5%	43%
89	60%	15%		25%
90	80%	10%		10%
91	50%	35%	15%
92	52%		5%	43%
93	70%	15%	15%
94	60%	25%		15%
95	50%	15%	35%
96 note 10	70%							30%
97	50%	25%	25%
98	40%	20%		40%
99	50%		20%	30%

			Thickness	Frazier
	Weight	Weight	(inches)	perm.	Gurley - MD	Gurley - CD	LED		dP	PFE
Example	(OSF)	(gsm)	note 4	(CFM/sq. ft.)	(mg)	(mg)	Score test	range	note 5	note 6	comments

66	0.46	140	0.07	514	1550	1844	74.3	E	0.083	49.1
67	0.53	162	0.09	442	1543	1650	63.7	E	0.106	47.8
68	0.52	159	0.1	504	1539	1576	57.7	E	0.08	41.6
69	0.46	140	0.08	418	1532	1517	60.2	E	0.121	63.5
70	0.48	146	0.08	472	1495	1371	67.3	E	0.098	44
71	0.53	162	0.1	360	1477	1410	51.5	E	0.14	50.2
72 note 11	0.50	153	0.07	405	1453	1298	54.7	E	0.12	61	UNC
73	0.49	149	0.08	521	1441	1424	62.8	E	0.088	48.9
74	0.48	146	0.1	490	1430	1415	45.2	E	0.087	45.4
75 note 11	0.38	116	0.05	418	1411	1581	66.5	E			UNC
76	0.71	217	0.1	263	1403	1347	42.5	E	0.241	84.3
77 note 11	0.52	159	0.09	514	1371	1531	50.8	F	0.079	40.7	UNC
78	0.51	156	0.09	387	1354	1252	63.2	F	0.14	50.7
79	0.53	162	0.07	312	1351	1275	43.5	F	0.173	65.2
80	0.56	171	0.1	325	1328	1188	49.2	F	0.152	60.2
81	0.45	137	0.09	488	1322	1299	68	F	0.08	47.4
82	0.51	156	0.09	533	1297	1561	63.5	F	0.078	48.2
83	0.51	156	0.11	519	1266	1140	64.7	F	0.087	52.5
84	0.65	198	0.12	321	1261	1241	45.5	F	0.089	66.3
85	0.38	116	0.06	502	1258	1173	59.5	F	0.1	47.8
87	0.50	153	0.09	464	1258	1270	55.3	F	0.097	48.9
88	0.52	159	0.08	356	1243	1386	45	F	0.156	67.8
89	0.39	119	0.08	569	1228	1314	55.7	F	0.071	39.5
90	0.42	128	0.07	548	1212	1384	67.3	F	0.068	40.9
91	0.37	113	0.08	649	1206	1421	42	F	0.06	31.3
92	0.67	204	0.09	258	1193	1280	44.8	G	0.23	72.7
93	0.35	107	0.06		1188	1232	60.7	G
94	0.47	143	0.1	538	1167	1409	54	G	0.078	40.8
95	0.47	143	0.08	432	1164	1414	60	G	0.106	52.2
96 note 10	0.86	262	0.12	246	1159	1521	60.7	G			note 10
97	0.47	143	0.1	475	1147	1105	39.3	G	0.101	50.4
98	0.58	177	0.11	310	1099	995	43.3	G
99	0.40	122	0.06	394	1095	1225	53.3	G	0.137	56.5

staple fibers

	4 denier			2.25		10 denier			3 denier
	bico fiber	15 denier	0.9 denier	denier	3 denier	bico fiber	1599 fibers	45 denier	chargeable	4 denier
Example	note 1	polyester	polyester	polyester	polyester	note 2	note 3	polyester	polypropylene	polyester	kenaf

100	50%	15%	35%
101	70%				30%
102 note 12	70%	30%
103	60%		10%		30%
104	55%				50%	10%
105 note 11	60%	15%							25%
106	50%	25%	25%
107	50%	25%			25%
108 note 11	50%								50%
109	50%		35%	15%
110	50%		15%	35%
111 note 11	40%	30%							30%
112	50%	15%	35%
113	40%	20%		40%
114	52%		5%	43%
115		25%						25%	50%
116		25%						25%	50%
117 note 11	50%								50%
118 note 11	60%	15%							25%
119 note 11	60%	15%							25%
120 note 11	40%	30%							30%
121 note 11	40%	30%							30%
122 note 11	65%		20%						15%

			Thickness	Frazier
	Weight	Weight	(inches)	perm.	Gurley - MD	Gurley - CD	LED		dP	PFE
Example	(OSF)	(gsm)	note 4	(CFM/sq. ft.)	(mg)	(mg)	Score test	range	note 5	note 6	comments

100	0.39	119	0.06	394	1069	1007	55	G	0.119	57.1
101	0.42	128	0.09	530	1040	1051	52.5	G	0.079	43.6
102 note 12	0.41	125	0.08	527	1032	1173	too curled	G	0.077	43.8	note 12
103	0.38	116	0.06	405	977	944	64.8	G	0.135	49.9
104	0.40	122	0.08	563	960	1041	68.2	G	0.078	38.1
105 note 11	0.37	113	0.07	613	955	1063	65	G			UNC
106	0.39	119	0.09	543	874	829	52	G	0.077	49.3
107	0.40	122	0.08	608	866	810	63.2	G
108 note 11	0.40	122	0.06	483	821	722	49	G			UNC
109	0.52	159	0.07	229	820	912	49	G	0.246	72
110	0.40	122	0.06	388	803	864	55.3	G	0.139	62.2
111 note 11	0.40	122	0.09	632	637	710	56.7	G			UNC
112	0.39	119	0.08	421	622	710	52	G	0.116	60.8
113	0.36	110	0.07	448	577	548	42.7	G	0.114	50
114	0.41	125	0.07	464	522	458	47.8	G
115	0.61	186	0.12	232	328	2422	68.8	G
116	0.56	171	0.1	413	140	798	73.3	G
117 note 11		0							0.119	56.6	CHGD
118 note 11		0							0.083	34.2	CHGD
119 note 11		0							0.057	38.7	CHGD
120 note 11		0							0.089	39.8	CHGD
121 note 11		0							0.056	25.7	CHGD
122 note 11		0							0.136	47.3	CHGD

note 1 - this fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber
note 2 - this fiber is a 10 denier, high melting point PET core, low melting point PET sheath bicomponent fiber
note 3 - this fiber is a polycotton thread shodde or blend of staple length, recycled polyester fibers and cotton fibers
note 4 - thickness is measured on a 12 inch square sample subjected to a compression of 2 grams per square inch.
note 5 - pressure drop
note 6 - particle filter efficiency, ASHRAE 52.2-1999
note 7 - this is a multilayered composite material comprising a 0.5 osy spunbond layer @ 320/a HPR25LB2DPR layer/a polyester bicomponent fiber comprising staple fiber nonwoven layer
note 8 - this is a multilayered composite material comprising a spunbond layer/a HP29LG2DPR layer @ 375/a polyester bicomponent fiber comprising staple fiber nonwoven layer
note 9 - this is a multilayered composite material comprising a spunbond layer/a HP27LB2DPR layer @ 375/a polyester bicomponent fiber comprising staple fiber nonwoven layer
note 10 - this is a multilayered composite material comprising a 0.5 OSY spunbond layer @ 320/a HP29LG2DPR layer/a polyester bicomponent fiber comprising staple fiber nonwoven layer
note 11- UNC is uncharged, CHGD is charged
note 12 - this is a multilayered composite material comprising a 0.5 osy spunbond layer

TABLE 3

Examples

staple fibers

		10 den	15 den						Thickness
	4 den bico	bico	bico				Weight	Weight	(inches)
Example	note 1	note 2	note 3	0.9 den	3 den	45 den	(OSF)	(gsm)	note 5

123	55%	10%			50%		0.4	122	0.08
124	35%	35%		30%			0.38	116	0.06
125	55%	10%			50%		0.45	137	0.09
126	25%		50%			25%	0.49	149	0.1
127	50%		30%		20%		0.5	153	0.08
128	10%		65%			25%	0.54	165	0.1
129	50%		30%		20%		0.49	149	0.09
130	25%		50%			25%	0.56	171	0.08
131	25%		50%			25%	0.56	171	0.08
132	25%		50%			25%	0.57	174	0.1
133	35%	35%		30%

	Frazier
	perm.	MD Gurley -	CD Gurley -	LED	Pleat	dP	PFE		MERV,
Example	(CFM/sq. ft.)	mg	mg	Score test	Memory	note 6	note 7	Index	est.

123	563	960	1041	68.2		0.078	38.1	488	6
124	502	1258	1173	59.5		0.1	47.8	478	6
125	488	1322	1299	68		0.08	47.4	593	6
126	569	1569	2083	94.5	5.75	0.081	43.2	533
127	466	2598	2609	82	6.25	0.094	55.7	593
128	671	2615	2223	101.5	4	0.033	17.8	539
129	472	3005	2809	94.2	7.38	0.089	51.8	582
130	590	3382	3334	101.7	8.88	0.055	41.1	747
131	546	3498	3683	94.7	6.63
132	561	3574	3584	94.2	9.31
133

note 1 - This fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber.
note 2 - This fiber is a 10 denier, high melting point PET core, low melting point PET sheath bicomponent fiber.
note 3 - This fiber is a 15 denier, high melting point PET core, low melting point PET sheath bicomponent fiber.
note 4 - 15 percent binder resin.
note 5 - thickness is measured on a 12 inch square sample subjected to a compression of 2 grams per square inch.
note 6 - pressure drop.
note 7 - particle filter efficiency, ASHRAE 52.2-1999.

TABLE 4

Examples

staple fibers

	4 denier			2.25		15 denier	1599		3 denier
	bico	15 denier	0.9 denier	denier	3 denier	bico fiber	fibers	45 denier	chargeable
example	note 1	polyester	polyester	polyester	polyester	note 2	note14	polyester	polypropylene

134	60%	20%			20%
135	80%		10%	10%
136 note 11	70%	15%
137	50%	25%						25%
138	50%	35%		15%
139	70%	15%			15%
140	35%				30%	35%
141	60%	30%			10%
142	65%				20%			15%
143	55%	25%			20%
144	55%	25%			20%
145	60%	20%			20%
146 note 13	60%	30%
147	70%	30%
148	70%	20%	10%
149	50%	30%		20%
150	80%		5%	15%
151	80%		5%	15%
152	80%		5%		15%
153	80%				20%
154	60%	30%			10%
155	70%						30%
156	70%						30%
157	70%						30%
158	65%				20%			15%
159	65%				20%			15%
160	60%				15%			25%
161					15%	50%		35%
162					35%	50%		15%
163					35%	50%		15%
164	50%				15%			35%
165	60%				15%			25%
166	60%				15%			25%

			Frazier						1 to 3	3 to 10
			perm						micron	micron
	Weight	Thickness	(CFM/sq.			LED		dP	PFE	PFE
example	(OSF)	note 3	ft.)	MD Gurley	CD Gurley	Score test	Memory	note 4	note 5	note 5	Index	MERV

134	0.4	0.08	608			50		0.066		41.6	630	6
135	0.37	0.05	502			93.7		0.094		42	447	6
136 note 11	0.43	0.09	551	1452	1378	75.1		0.067		34.7	518	5
137								0.037		28.6	773	5
138	0.49	0.09	511	1846	2498	66.2		0.083		45.7	551
139	0.36	0.08	599	896				0.061		40	656	6
140	0.41	0.08	498	1517				0.081		28.3	349	5
141	0.53	0.1	500	2326	2335	63		0.072		47.8	664	6
142	0.53	0.1	463	2167	2470	69		0.089		53.1	597	7
143	0.5	0.1	488	1946	2032	61.5		0.08		49.5	619	6
144	0.51	0.1	465	2101	2733	49.3		0.095		50	526	6
145	0.51	0.09	469	1678	2304			0.085		51.6	607	7
146 note 13	0.49	0.08	506	2338	2372	68.7		0.097		56.3	580	7
147	0.52	0.07	523	3005		71		0.075		51.6	688	7
148	0.5	0.09	441	2401	2737	53.3		0.104		55.9	538	7
149	0.48	0.08	488	2241	2303	39.7		0.086		56.1	652	7
150	0.39	0.05	489	1874	1420	69		0.075		43.8	584	6
151	0.44	0.05	425	2690	2435	70		0.094		42.0	447	6
152	0.38	0.06	487	2179	1804	71.7		0.081		47.3	584	6
153	0.38	0.06	468	2265	2125	63.3
154	0.5	0.08	476	2839	2921	85.3		0.099		62.0	626	7
155	0.47	0.09	383	1354	1343	66		0.122		63.0	516	7
156	0.55	0.1	319	1695	1835	58.3
157	0.41	0.09	428	1459	1261	74.8		0.094		52.0	553	7
158	0.53	0.08	428			83.7
159	0.51	0.08	468	2740	2620	87		0.099		63.5	641	7
160	0.49	0.08	514	2173	2106	63.3		0.069		60.5	877
161	0.51	0.11	818	2269	2120	83.7	4.25	0.035		55	1571
162	0.49	0.09	587	1453	1463	70.7		0.062		35.7	576
163	0.46	0.09	615			55.7	5.5	0.059		50.1	849
164	0.52	0.07	528	2992	3009	79.7	5.13	0.083		53.7	647
165	0.49	0.08	498	2302	2134	62		0.078		59.4	762
166	0.51	0.11	509	3301	2473	79.2		0.083		50.1	604

	4 denier			2.25		15 denier	1599		3 denier
	bico	15 denier	0.9 denier	denier	3 denier	bico fiber	fibers	45 denier	chargeable
example	note 1	polyester	polyester	polyester	polyester	note 2	note14	polyester	polypropylene

167	60%				15%			25%
168	60%				15%			25%
169 note 12	50%				25%			25%
170					15%	50%		35%
171					15%	50%		35%
172				15%		50%		35%
173				15%		50%		35%
174						50%	30%	20%
175	80%		10%	10%
176	80%		10%	10%
177
178
179
180				15%		50%		35%
181				15%		50%		35%
182				15%		50%		35%
183	10%					65%		25%
184	50%				20%	30%
185	45%					40%			15%
186	45%					40%			15%
187	45%					40%			15%
188	65%	15%							15%
189	70%	15%		15%
190					15%	50%		35%
191					20%	50%		30%
192				20%		50%		30%
193				15%		50%		30%
194					35%	50%		15%
195	35%					50%		15%
196				25%		60%		15%
197						70%		10%
198				15%		85%
199				20%		80%
200	50%		15%					35%

			Frazier						1 to 3	3 to 10
			perm						micron	micron
	Weight	Thickness	(CFM/sq.			LED		dP	PFE	PFE
example	(OSF)	note 3	ft.)	MD Gurley	CD Gurley	Score test	Memory	note 4	note 5	note 5	Index	MERV

167	0.52	0.15	561	3121	2219	78		0.07		51.4	734
168	0.51	0.18	580	2753	2027	56		0.061		46.2	757
169 note 12	0.49	0.13	496	2300	1709	73		0.075		45.4	605
170	0.54	0.1	669	2005	2321	72		0.052		42.7	821
171	0.58	0.1	620	2074	2547	69.7	8.25	0.078		59.4	762
172	0.56	0.08	615	2276	2216	70.2	11.25	0.064		51.1	798
173	0.43	0.08	708			81.2		0.071		42	592
174	0.51	0.1	549	1047		64.5		0.071		45.1	635
175	0.9	0.06	163	7000	6800			0.083		80.6	971	8
176	0.9	0.06	163	7000	6800		79.7	0.083		78.3	943	8
177								0.32		75.9	237
178							96.7	0.1		83.4	834
179								0.2		78.3	392
180	0.47	0.1	577	1965	1501	94.3	5.25	0.041		30.5	744
181	0.54	0.08	587	3508	3463	96.7	7.79	0.064		43.5	680
182	0.55	0.1	574	2941	2539	104.2	8.13	0.08		40.4	505
183	0.54	0.11	719	2362	2216	82	5.63	0.069		33.7	488
184	0.48	0.1	523	1983		69.5	5.5	0.075		41.7	556
185	0.49	0.1	545	1261	1710	62.8	6.5	0.078		42.9	550
186	0.48	0.1	581	1593	1993	59.3	7.75	0.062		40.1	647
187	0.48	0.1	542	1280	1500	59.8	6.38	0.067		45.1	673
188	0.47	0.09	508	1608	1473	64.2	7.1	0.08		46.7	584
189	0.52	0.07	419	3737	2945	96.2	7.9	0.112		43.2	386
190	0.52	0.11	794	1872	1857			0.031		36.1	1165
191	0.5	0.11	713	1332	1292			0.037		43.1	1165
192	0.5	0.1	573	1499	1354			0.059		48	814
193	0.51	0.1	743	1593	1891			0.043		43.2	1005
194	0.49	0.12	614	1371		72.2
195	0.43	0.08	642	2067		84.8
196	0.52	0.08	600	2047		77.8		0.054		33.1	613
197	0.47	0.08	561	1248	1459	77.2		0.082		47.5	579
198	0.43	0.06	647	2253	1868	105.3		0.065		35.9	552
199	0.48	0.06	627	2519	2448	98.5		0.065		34	523
200	0.46	0.07	512	2237	2193	76.5		0.085		46.6	548

	4 denier			2.25		15 denier	1599		3 denier
	bico	15 denier	0.9 denier	denier	3 denier	bico fiber	fibers	45 denier	chargeable
example	note 1	polyester	polyester	polyester	polyester	note 2	note14	polyester	polypropylene

201	50%		25%			25%
202					15%	50%		35%
203
204
205
206 note 7
207
208 note 8
209 note 9
210 note 10
211	10%					65%		25%
212	25%					50%		25%
213	25%					50%		25%
214	25%					50%		25%
215	25%					50%		25%
216	50%				20%	30%
217	50%				20%	30%

			Frazier						1 to 3	3 to 10
			perm						micron	micron
	Weight	Thickness	(CFM/sq.			LED		dP	PFE	PFE
example	(OSF)	note 3	ft.)	MD Gurley	CD Gurley	Score test	Memory	note 4	note 5	note 5	Index	MERV

201	0.41	0.06	400	1919	1467	75.7		0.116		47.6	410
202	0.37	0.09	957	903	1066	77
203	0.64	0.14	366	1279	912	52
204	0.45	0.11	886	1285	1436	75.3
205	0.67	0.14	467	1428	1712	51.7
206 note 7	0.57	0.08	574	3064	3543	94.7		0.067		35.2
207								0.069		34.8
208 note 8	0.49	0.14	560	481		68.3		0.057	59.2	87.8	10
209 note 9	0.7	0.16	259	492		48.8		0.167	71.4	93.3	11
210 note 10	0.74	0.16	323	559		45.7		0.141	62.9	85.8	10
211	0.54	0.1	671	2615	2223	101.5	4	0.033		17.8	539
212	0.49	0.1	569	1569	2083	94.5	5.75	0.081		43.2	533
213	0.56	0.08	546	3498	3683	94.7	6.63
214	0.57	0.1	561	3574	3584	94.2	9.31
215	0.56	0.08	590	3382	3334	101.7	8.88	0.055		41.1	747
216	0.5	0.08	466	2598	2609	82	6.25	0.094		55.7	593
217	0.49	0.09	472	3005	2809	94.2	7.38	0.089		51.8	582

note 1 - this fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber.
note 2 - this fiber is a 15 denier, high melting point PET core, low melting point PET sheath bicomponent fiber.
note 3 - thickness is measured on a 12 inch square sample subjected to a compression of 2 gms per square inch.
note 4 - pressure drop.
note 5 - particle filter efficiency, ASHRAE 52.2-1999.
note 6 - UNC is uncharged, CHGD is charged.
note 7 - 25% 2.25 denier, high melting point PET core, low melting point PET sheath bicomponent fibers; 50% 15 denier, high melting point PET core, low melting point PET sheath bicomponent fibers; 25% 45 denier fibers.
note 8 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.12 osy triboelectric fibers.
note 9 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.06 osy triboelectric fibers.
note 10 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.07 osy triboelectric fibers.
note 11 - this is a multilayered composite material comprising a 0.5 osy spunbond layer.
note 12 - this is a multilayered composite material formed from two layers of carded fibers.
note 13 - also includes 10% rayon fibers.
note 14 - this fiber is a polycotton thread shodde or blend of staple length, recycled polyester fibers and cotton fibers.

TABLE 5

	Number
	heated	Web	Heated
Example	rolls	Heated on	roll temp F.	Nip

1			370
2	2	one side	375	open
3	2	one side	375	open
4			375
5
6	2	one side		open
7			370
8	2	one side	380	open
9			350
10	2	one side		open
11			310
12	2	one side	365	open
13	2	one side	365	open
14	2	one side		open
15			370
16	2	one side		open
17	2	one side	320	closed
18	2	one side		open
19	2	one side	320	closed
20		two sides		closed
22	2	one side		open
23			345	open
24			375
25		two sides		closed
26			335
27	2	one side	395	open
28	2	one side		open
29	2	one side	380	open
30	2	one side	400	open
31			375
32		one side	370	open
33			375
34			320
35			370
36			375
37	2	one side		open
38	2	one side		open
39			375
40			375
41	2	one side	370	open
42	2	one side		open
43		one side		open
44			350
45	2	one side	375	open
46	2	one side	400	open
47	2	one side		open
48		two sides	370	closed
49			375
50			370
51	2	one side		open
52	2	one side	395	open
53	2	one side	380	open
54	2	one side		open
55	2	one side	320	closed
56	2	one side	380	open
57	2	one side	365	open
58		one side		closed
59	2	one side	320	closed
60	2	one side		open
62			375
63	2	one side	345-360	open
65	2	one side	370	open
66	2	one side		open
67	2	one side		open
68	2	one side		open
69			370
70		one side	370	closed
71		two sides		open
72	2	one side		open
73	2	one side		open
74	2	one side	395	open
75	2	one side		open
76	2	one side		open
77	2	one side	345-360	open
78		one side		open
79	2	one side	380	open
80	2	one side		open
81	2	one side		open
83	2	one side		open
84	2	one side		open
85	2	one side	395	open
87	2	One side	380	open
88	2	one side	397	open
89	2	one side	395	open
90	2	one side	395	open
91	2	one side		open
92	2	one side	380	open
93	2	one side	365	open
94	2	one side	395	open
95	2	one side	395	open
96			320
97	2	one side	395	open
98	2	one side		open
99	2	one side	380	open
100	2	one side		open
101	2	one side	395	open
102			335
103	2	one side		open
104	2	one side		open
105	2	one side	345-360	open
106	2	one side	395	open
107	2	one side		open
108	2	one side		open
109	2	one side	395	open
110	2	one side	380	open
111	2	one side	345-360	open
112	2	one side	395	open
113	2	one side		open
114	2	one side	397	open
117	2	one side		open
118	2	one side		open
119	2	one side		open
120	2	one side		open
121	2	one side		open
122	2	one side		open
134	2	one side	395	open
135	2	one side		open
136	2	one side	320	open
137	2	one side	320	open
138	2	one side		open
139	2	one side		open
140	2	one side		open
141	2	one side	370	open
142	2	one side	370	open
143	2	one side	370	open
144	2	one side	370	open
145	2	one side	350	open
146	2	one side	370	open
147	2	one side	370	open
148	2	one side	370	open
149	2	one side	370	open
150	2	one side	365	open
151	2	one side	355	open
152	2	one side	355	open
153	2	one side	355	open
154	2	one side	360	open
155	2	one side	360	open
156	2	one side	360	open
157	2	one side	350	open
158	2	one side	350	open
159	2	one side	350	open
160	2	one side	320	open
161	2	one side	340	open
162	2	one side	340	open
163	2	one side	360	open
164	2	one side	340	open
165	2	one side	340	open
166	1	one side	340	closed
167	1	one side	340	open
168	1	one side	350	open
169	1	one side	370	open
170	2	one side	350	open
171	2	one side		open
172	2	one side	350	open
173	2	one side		open
174	2	one side	350	open
175	2	one side		open
176	2	one side		open
177	2	one side		open
178	2	one side		open
179	2	one side		open
180	1	one side	345	open
181	1	one side	360	open
182	1	one side	360	open
183	1	one side	345	open
184	2	one side		open
185	2	one side	340	open
186	2	one side	340	open
187	2	one side		open
188	2	one side	340	open
189	2	two sides	310	open
190	2	one side	380	open
191	2	one side	380	open
192	2	one side	380	open
193	2	one side	380	open
194	1	one side	350	open
195	1	one side	375	open
196	2	one side		open
197	2	one side	395	open
198	2	one side		open
199	2	one side		open
200	2	one side	395	open
201	2	one side	395	open
202	2	one side		open
203	2	one side		open
204	2	one side		open
205	2	one side		open
206	2	one side		open
207	2	one side		open
208	2	one side		open
209	2	one side		open
210	2	one side		open
211	1	one side	345	closed
212	1	one side	345	closed
213		two sides	350	closed
214		one side	350	closed
215		two sides	350	closed
216	1	one side	330	closed
217	1	one side	320	closed

TABLE 6

Examples

staple fibers

Tribo

nonwoven

	4 den	15 den	15 den	0.9 den	2.25 den	3 den	45 den	Tribo	mod		filtration
example	bico	bico	polyester	polyester	polyester	polyester	polyester	propylene	acrylic	Layers	media

218	63		17			20					1
219	63		17			20					1
220	63		17			20					1
221	63		17			20				1	1
222	63		17			20				1	1
223	63		17			20				1	1
224	63		17			20				1	1
225	63		17			20				1	1
226	63		17			20				1	1
227	63		17			20				1	1
228	63		17			20				1	1
229	63		17			20				1	1
230	63		17			20				1	1
231	63		17			20				1	1
232		50			15		35				2
233		50			15		35				2
234		50			15		35			1	2
235		50			15		35			1	2
236		50			15		35			1	2
237		50			15		35			1	2
238		50			15		35			1	2

				tack		Frazier
				material	sides	perm.					3 to 10
	Weight	thickness		addon	tack	(CFM/sq.	Gurley -	LED			micron
example	(gsm)	(mm)	tack material	(%)	applied	ft.)	MD (mg)	Score	Range	dP	PFE	Index

218	153	2.5	none	0	0	540	2331	57	D	0.063	47.7	757
219	159	2.5	none	0	0	479	2203	69.3	D	0.073	50.5	692
220	159	2.5	none	0	0	468	2945	72	B	0.084	57.1	680
221	162	2.5	V-60	1.4	1	464	2535	67	C
222	153	2.3	V-60	2.5	1	464	2730	64.3	C
223	171	2.8	V-60	11.5	1	510	2834	55	B	0.064	62.2	972
224	162	2.3	V-60	3.3	2	464	2919	66.3	B
225	168	2.5	V-60	5.7	2	473	2903	60	B	0.083	69.1	833
226	183	2.8	V-60	16.2	2	496	3256	66.3	A	0.071	62.6	882
227	183	2.5	V-60	22.6	2	425	2893	67	B	0.092	67.5	734
228	186	2.8	V-60	23.8	2	464	2612	53.3	C	0.084	66.6	793
229	171	2.5	Flexacryl 1625	11.4	2	450	3730	94	A	0.083	67.3	811
230	165	2.3	Spar Cryl 102	7.9	2	431	2930	80.3	B	0.086	66.6	774
231	165	2.3	Spar Cryl 102	7.9	2	431	2930	80.3	B	0.086	66.6	774
232	162	2.3	none	0	0	608	2078	86.3	D	0.056	48.7	870
233	156	2.0	none	0	0	634	1665	71	E	0.046	37.9	824
234	201	2.3	V-60	7.9	1	568	2368	93	D	0.07	59.4	849
235	207	2.3	V-60	12.3	1	561	2819	74.7	B	0.068	57.6	847
236	201	2.3	V-60	4.6	2	569	2205	78	D	0.062	53.1	856
237	198	2.3	V-60	11.7	2	572	2220	80.7	D	0.066	58.8	891
238	177	2.0	V-60	13.0	2	638	1866	83.7	D	0.05	51.8	1036

									Tribo		nonwoven
	4 den	15 den	15 den	0.9 den	2.25 den	3 den	45 den	Tribo	mod		filtration
example	bico	bico	polyester	polyester	polyester	polyester	polyester	propylene	acrylic	Layers	media

239		37.8			11.4		26.5	12.2	12.2		3
240		37.8			11.4		26.5	12.2	12.2	1	3
241		37.8			11.4		26.5	12.2	12.2	1	3
242		37.8			11.4		26.5	12.2	12.2	1	3
243	50					25	25				4 note 2
244	50					25	25			2	4 note 2
245	50			8	43						5
246	50			8	43					1	5
247	50			8	43					1	5
248	80					20				1	6
249	80					20				1	6
250	80					20				1	6
251	80					20				1	6
252	80					20				1	6

				tack		Frazier
				material	sides	perm.					3 to 10
	Weight	thickness		addon	tack	(CFM/sq.	Gurley -	LED			micron
example	(gsm)	(mm)	tack material	(%)	applied	ft.)	MD (mg)	Score	Range	dP	PFE	Index

239	159	2.0	none	0	0	505	1731	65.3	E	0.077	77.9	1012
240	165	2.5	V-60	7.0	2	463	1672	70	E	0.09	68.9
241	180	2.8	Flexacryl 1625	10.0	2	471	2153	97	D	0.87	75.9
242	183	3.0	Spar Cryl 102	5.9	2	475	1569	98.3	E	0.079	70.4
243	149	3.3	none	0	0	496	2300	71.6	D	0.075	45.4	605
244	165	3.6	V-60	6.0	2	434	3099	62.1	A	0.098	62.1	634
245	174	3.0	none	0	0	230	1965	51	D	0.169	88.3	522
246	174	3.0	V-60	5.0	2	230	1965	51	D	0.169	88.3	522
247	204	3.0	V-60	17.5	2	261	2720	94.3	C	0.16	85.4	534
248			V-60	1.8	1	482	2479	63.3	C
249			V-60	2.4	1	458	3345	67	A
250			V-60	3.5	1	509	1753	56.3	E
251			V-60	5.1	1	440	3123	61	A
252			V-60	6.4	1	509	2035	73.7	D

note 1 - tack material Tg: V-60, −60° C.; Flexacryl 1625, −48° C.; Spar Cryl 102, −35° C.
note 2 - nonwoven material 4 is a 2 layer material

Claims

1. A tackified air filtration media comprising a thermally bonded nonwoven web comprising a generally homogeneous mixture of fiber types, the web comprising about 10% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 10% to about 90% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm; the media having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 150 CFM/square foot to about 1000 CFM/square foot; and a combination of MD Gurley stiffness and LED score results selected from one of the following ranges:

range Gurley Stiffness (mg) LED score (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 55.0 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 108.2 E 1400 to 1800 41.2 to 98.3 F 1200 to 1400 77.0 to 86.0 G 800 to 1200 39.3 to 68.2 H Under 800 42.7 to 68.8

and;

0.5 percent by weight of nonwoven web to about 30 percent by weight of nonwoven web of a tackifier on fibers of the air filtration media.

2. The tackified air filtration media of claim 1, wherein the first thermoplastic polymeric material is polyester.

3. The tackified air filtration media of claim 1 being a single layer.

4. The tackified air filtration media of claim 1, wherein the first thermoplastic polymeric material is polyester and the second thermoplastic polymeric material is polyester.

5. The tackified air filtration media of claim 1, further comprising kenaf fibers having a length of about 0.6 cm to about 20 cm.

6. The tackified air filtration media of claim 1, comprising about 1.5% to about 15% of the tackifier on fibers of the air filtration media.

7. The tackified air filtration media of claim 1, wherein one fiber type has a denier in the range of about 0.9 to about 6 and the other fiber type has a denier in the range of about 8 to about 45.

8. The tackified air filtration media of claim 1, further being a self supporting media.

9. The tackified air filtration media of claim 1, having a MD Gurley stiffness over 1700.

10. The tackified air filtration media of claim 1, wherein:

the first fiber type is selected from at least one of about 10% to about 85% 4 denier conjugate fibers comprising polyester first and second fiber portions or about 10% to about 85% 15 denier conjugate fibers comprising polyester first and second fiber portions;

the second fiber type is selected from at least one of about 5% to about 30% monocomponent polyester fibers having a denier in the range of about 0.9 to about 45; about 15% to about 50% 3 denier chargeable polypropylene fibers; about 15% to about 30% polyester/cotton blend fibers; or about 15% to about 35% cellulosic fibers;

at least one fiber type has a denier greater than 10; and

about 1.5% to about 6% tackifier.

11. The tackified air filtration media of claim 1 further comprising a cured, non-fibrous binder resin between the fiber types.

12. The tackified air filtration media of claim 1 having a combination of Gurley stiffness and LED score results selected from one of the following ranges:

range Gurley Stiffness (mg) LED score (degrees) A over 3,000 60.2 to 85.8; B 2,800 to 3,000 60.2 to 90.8; C 2,400 to 2,800 58.2 to 79.0; D 1,800 to 2,400 40.0 to 94.7; E 1,400 to 1,800 42.5 to 94.0; F 1,200 to 1,400 43.3 to 64.8; G 800 to 1,200 39.3 to 63.3; H under 800 42.7 to 68.8.

13. A method of making a tackified air filtration media comprising:

forming a fiber mixture, comprising about 10% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 10% to about 90% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm;

forming the fiber mixture into a nonwoven matt;

bonding the fibers in the nonwoven matt, the bonded nonwoven matt having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 150 CFM/square foot to about 1000 CFM/square foot; and a combination of MD Gurley stiffness and LED score results selected from one of the following ranges:

range Gurley Stiffness (mg) LED score (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 60.2 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 105.3 E 1400 to 1800 41.2 to 94.5 F 1200 to 1400 42.0 to 86.0 G 800 to 1200 39.3 to 68.2 H Under 800 42.7 to 68.8

and;

applying 0.5 percent by weight of nonwoven web to about 30 percent by weight of nonwoven matt of a tackifier to fibers of the bonded nonwoven matt to form the tackified air filtration media.

14. The method of claim 13 wherein the step of forming comprises carding the fiber mixture to form the nonwoven matt.

15. The method of claim 13 wherein the step of forming comprises carding the fiber mixture to form a web and cross lapping the web to form the nonwoven matt.

16. The method of claim 13 wherein the step of bonding comprises thermal bonding of the fibers in the nonwoven matt.

17. The method of claim 13 wherein the step of applying comprises spraying a tackifier on a surface of the bonded nonwoven matt.

18. The method of claim 13 further comprising the step of folding the media to form a self supporting structure.

19. A non-tackified air filtration media comprising a thermally bonded nonwoven web comprising a generally homogeneous mixture of fiber types, the web comprising about 30% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 5% to about 70% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm; the media having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 45,000 LSM to about 260,000 LSM; and a combination of Gurley stiffness and LED score results selected from one of the following ranges:

20. The non-tackified air filtration media of claim 19, wherein one fiber type has a denier less than about 6 and the other fiber type has a denier greater than about 8.