WO1997032805A1 - Readily replaceable roll covers - Google Patents

Abstract

A textile pull roll cover (20) is disclosed which has a plurality of surface stems (28) projecting outwardly from one side thereof. The surface stems are uniformly shaped and disposed on the pull roll cover, and the surface stems collectively define an operative contact surface for a textile web. A plurality of hooking stems (55) project from an opposite side of the pull roll cover. The hooking stems are adapted to releasably affix the pull roll cover to a cylindrical pull roll having loop structure material (45) adhered thereto. A method for making a textile pull roll is disclosed, as well as a method for changing the outer textile engaging surface of a textile pull roll using the hook-and-loop opposed fastening arrangement, with the loop material being disposed on the outer cylindrical surface of the pull roll. Also disclosed is a textile pull roll cover which has an exterior side (251) with desired frictional characteristics for engagement with an advancing textile web. On its opposite side, the pull roll cover is affixed to a cylindrical outer surface of a textile pull roll by a repositionable pressure sensitive adhesive disposed therebetween. A method for making a textile pull roll is disclosed, as well as a method for changing a pull roll cover using repositionable pressure sensitive adhesive.

Description

READILY REPLACEABLE ROLL COVERS

BACKGROUND OF THE INVENTION The present invention relates to apparatus for selective engagement with an advancing web In particular, the invention relates most specifically to apparatus and methods for the assembly and ready replacement of covers for rolls used to engage advancing webs

It is well known to provide a cylindrical roll with specifically desired frictional characteristics on its exterior surface for use in web advancement and treatment processes In the textile industry, the use of rolls to convey, pull and hold back fabric is very common, and these rolls are referred to as pull rolls For instance, weaving machines, inspection machines, finishing lines, napping lines, sueding Iines and dye lines all contain numerous pull rolls to aid m performing such operations Steel or aluminum rolls themselves do not provide surfaces with sufficient frictional forces to keep fabric from slipping in most applications Such rolls are thus covered or coated with a material which aids in gently guiding the fabric through the textile processing machinery without distorting its weave, yet keeping the fabric relatively uniform in advancement and spread The cover on a pull roll may have a low or high coefficient of friction, depending upon the particular fabric, process characteristics and desired engagement or traverse of the pull roll with the fabric Numerous materials have been used to define the frictional interaction between the roll surface and the fabric. Typical prior art pull roll cover materials include cork, rubber, modified cork, smooth rubber, sandpaper and bristle- bearing materials During use of such materials, their frictional characteristics can change. For instance, cork and bber-based materials tend to glaze over as they wear and become smoother, presenting a change in friction level to the fabric web over time This can result in a slow deterioration of fabric quality or increased motor power usage due to slipping, which are both difficult to detect In addition, abrasives such as sandpaper do not wear evenly, because of their random surface textures Further, while abrasives such as sandpaper present higher frictional characteristics for a pull roll cover, they are non-unifoπn by design and thus are unsuitable for some fabric webs because their non-uniformity results in damage to the fabric. Pull roll covers based on a bristled structure (such as the BRUSHLON™ brush material of Minnesota Mining and Manufacturing Company, St Paul, Minnesota), are also random in bristle dispersion and alignment.

A pull roll cover material is typically applied by helically wrapping a 5 to 7.5 cm (two to three inch) wide strip of the material down the length of the roll. Adhesion of the material to the roll surface has been accomplished by the use of contact cements, spray adhesives, and nonrepositionable pressure sensitive adhesives To remove such roll covers from a roll requires removal of the roll from the textile processing machinery, and in some instances the machining off of the covering These types of adhesion arrangements typically lead to build-ups of adhesive on the roll surface over time, contain flammable solvents in the adhesive, require long cure times on the roll surface, and in many cases require the use of flammable solvents for roll clean-up Environmental concerns and restrictions now prohibit the use of many of these adhesives in textile plants, thereby requiring the removal and application of roll surfaces by outside parties and at locations other than the textile processing facility

One type of pull roll cover fonns a cylindrical brush, as disclosed in Dupre U S Patent 4,627, 127 In Dupre, a fabric strip containing bristles on an outer peripheral surface thereof is wrapped in a helix about a cylinder The fabric strip is adhered to the cylinder by means of an adhesive such as polyurethane Through use, the bristles wear down and the remaining covering must be replaced To remove such a covering bonded to the cylinder by an adhesive requires the use of solvents This can be messy, relatively time consuming (resulting in machine downtime) and, as mentioned above, the use of solvents to remove adhesives creates undesirable hazardous waste removal issues

In an effort to address these environmental concerns, and also to form a more readily replaceable pull roll cover, mechanical fastening schemes (such as hook-and-loop fastener staictures) have been used instead of adhesives to bond the cover material to the roll One roll cover material currently available for this purpose has 3mm (1/8") trim nylon 6, 12 bristle BRUSHLON™ brush material (available from Minnesota Mining and

Manufacturing Company, St Paul, Minnesota) on one side of a support substrate, with a loop structure material on its other side. A hook structure material (having projecting hooks or capped stems thereon) is bonded to the exterior surface of the cylindrical roll, typically in strip form wrapped thereabout in a helix. The bristle/loop structure assembly is also wrapped in strip foπn in a helix about the cylindrical roll, with the loop structure interengaging with the hook structure to affix the bristle/loop structure assembly to the pull roll cylinder While this arrangement allows for ready removal of the exterior bristle bearing fabric, and replacement thereof with an alternative roll exterior material having a loop structure backing, it also is not ideal The combination of the bristles, support substrate and hook-and-Ioop fastener form a pull roll cover assembly having a relatively high profile. Further, if the pull roll cover material is wrapped in an imperfect helix along the roll, one or more hooks may be inadvertently exposed from the hook structure material mounted on the cylindrical roll These exposed hooks can damage the fabric web being traversed by the roll by picking or tearing at fabric fibers, creasing the fabric, scuffing its surface or by causing some other similar surface phenomenon. A typical textile pull roll will have a diameter in the range of 10 to 30 cm (4-12 inches), but can be smaller or larger. A high profile (relatively thick) pull roll cover increases the effective diameter of a pull roll, and this effect is even more significant on a smaller diameter pull roll e.g., a 2.5 - 7.5 cm ( 1 -3 inch) diameter pull roll. It is an undesirable necessity that drive roll speeds be adjusted if a significant change in roll diameter results from the application of a roll cover, and thus a pull roll cover should be as thin as possible.

The pickup or transfer of particulates or fluids by a pull roll cover is also undesirable A cover material is also unacceptable if it allows lint and fiber build-up thereon during use. In addition, in some applications the roll or fabric web will be wet. For example, a roll cover must not pick up and hold fabric dyes from the manufacturing process Color changes are common and the transfer of dyes from one fabric lot to another is unacceptable.

In view of the disadvantages associated with the various pull roll cover schemes of the prior art, it is desirable to provide a pull roll that has a changeable exterior covering, wherein the covering is relatively inexpensive, reusable or replaceable, easily and securely attachable to the cylindrical pull roll and which, in use, does not allow undesirable contact or damage to the web traversed thereby Other desirable features in a replaceable pull roll cover are that the cover assembly have a relatively low profile, that it not collect lint or fibers, and that it not transfer dyes between webs In addition, an exterior material for a pull roll cover is desired that has a long life, and provides the desired frictional characteristics, or range of frictional characteristics for customer flexibility

SUMMARY OF THE INVENTION In one embodiment, the present invention includes an engagement apparatus for selective engagement with an advancing web The engagement apparatus includes a base having an outer surface with hook-engaging structures disposed thereon, and a surface substrate sheet having first and second major surfaces The second surface of the substrate sheet has desired characteristics for frictional engagement with an advancing web A plurality of hooking stems are provided on and project from the first surface of the substrate sheet The hooking stems include means for hooking the hook- engaging surfaces on the outer surface of the base to releasably affix the surface substrate to the base

In another embodiment the present invention includes a low profile engagement apparatus for use on a roll having a cylindrical outer surface The engagement apparatus comprises a surface substrate sheet having first and second sides, with the second side thereof having desired characteristics for frictional engagement with an advancing web. A repositionable pressure sensitive adhesive is disposed between the cylindrical outer surface of the roll and the first side of the surface substrate sheet to releasably adhere the surface substrate sheet to the cylindrical outer surface of the roll for replacement or realignment

In another embodiment, the second surface includes means for defining a frictional engagement surface for the advancing web The defining means includes a plurality of surface stems projecting outwardly from the second surface of the surface substrate sheet, with the surface stems collectively defining an operative contact surface for contacting the advancing web Preferably, the surface stems are disposed in a selected arrangement on and formed integrally with the second surface of the surface substrate sheet

The present invention further includes a method of making a textile pull roll, which includes pi oviding a base having an outer cylindπcal surface, and providing a s substrate sheet having first and second major sides The first side of the substrate sheet is releasably bonded to the outer cylindπcal surface of the base A plurality of surface stems are provided on and project outwardly from the second side of the substrate sheet, with the surface stems being formed integrally with the surface substrate and having outer ends which are generally uniform in height The surface stems collectively define

10 an operative textile contact surface for contacting a textile web The bonding of the substrate sheet to the outer cylindrical surface of the base includes adhering the first side of the substrate sheet to the outei cylindncal surface by opposed hook-and-loop fasteners with the loop fasteneis being on the outer cylindrical surface of the textile pull roll

] The present invention also includes a further method of making a roll, which includes providing a base having an outer cylindrical surface and providing a substiate sheet having fiist and second major sides The second side of the substrate sheet has the desired chaiacteπstics for frictional engagement with an advancing web The method furthei includes releasably bonding the first side of the substrate sheet to the

20 outer cylindncal surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the substrate sheet relative to the base Preferably, the inventive method furthei includes positioning the repositionable pressure sensitive adhesive on the first side of the substrate sheet pnor to the bonding thereof to the base The invention is furthei embodied in a method of changing the outer textile engaging surface of a textile pull roll In this process, a pull roll is provided having a cylindπcal pull roll base, a loop fastenei structuie secured to the pull roll base, and an initial substrate sheet releasably affixed to the loop fastener structure The initial substrate sheet has first and second ma|oι sides, with the second side of the substrate 0 sheet being defined bv a textile engagement material and the first side thereof being defined bv a hook fastenei structuie which is releasably engaged with the loop fastener structure on the pull roll base The initial substrate sheet and textile engagement material thereon are removed from the pull roll base by disengaging the hook fastener structure on the initial substrate sheet from the loop fastener structure on the pull roll base A replacement substrate sheet having first and second major sides is provided, with its second side being defined by a replacement textile engagement material and its first side being defined by a hook fastener structure The replacement substrate sheet is affixed to the pull roll base by adhering the hook fastener structure thereon to the loop fastener structure on the pull roll base

In another embodiment of the above process, a pull roll is provided having a cylindrical pull roll base, with an initial substrate sheet releasably affixed to the pull roll base The initial substrate sheet has first and second major sides, with the second side of the initial substrate sheet being defined by a textile engagement material and the first side thereof being bonded to the pull roll base by a repositionable pressure sensitive adhesive The initial substrate sheet and textile engagement material thereon are removed from the pull roll base by overcoming the adherence force of the repositionable pressure sensitive adhesive A replacement substrate sheet having first and second major sides is provided, with its second side being defined by a replacement textile engagement material. The replacement substrate sheet is affixed to the cylindrical pull roll base by means of a repositionable pressure sensitive adhesive disposed therebetween to permit replacement or realignment thereof on the cylindrical pull roll base

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further explained with reference to the drawing figures referenced below, wherein like structure is referred to by like numerals throughout the several views

FIG I is an isometric view of a textile web being advanced over a pull roll cover of the present invention

FIG 2 A is a top plan view of one preferred embodiment of the exterior pull roll cover of the present invention having upwardly projecting surface stems. FIG 2B is a sectional view as taken along lines 2B--2B in FIG 2A FIG 3 is a schematic illustration of an apparatus and process for forming the pull roll cover of FIGS 2 A and 2B

FIG 4 is a schematic view of a strip of loop fastener structure partially wound about the cylindrical base of a pull roll FIG 5 is a schematic view of a strip of pull roll exterior cover material partially wound over the first strip and cylindrical base of a pull roll

FIG. 6 is a sectional view as taken along Iines 6-6 in FIG 5. FIG 7 is a sectional view of an alternative pull roll cover assembly FIG 8 is a sectional view of an alternative pull roll cover assembly. FIG 9 is a schematic view of a strip of another preferred embodiment of a pull roll exterior cover material partially wound about the cylindrical base of a pull roll FIG 10 is a sectional view as taken along Iines 10-10 in FIG 9 FIG 1 1 is an enlarged sectional view of a portion of FIG 10 FIG. 12 is a sectional view of an alternate pull roll cover of the present invention

While the above-identified drawing figures set forth several preferred embodiments, other embodiments of the present invention are also contemplated, as noted in the discussion This disclosure presents illustrative embodiments of the present invention by way of representation and not limitation Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention The drawing figures have not been drawn to scale as it has been necessary to enlarge certain portions for clarity

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG I illustrates a textile or fabric web 10 being processed along a web travel path which is defined, at least in pan, by textile pull rolls such as pull rolls 12, 14 and 16 Such rolls may be driven or idler rollers, depending upon the processing application The surfaces of the rolls are coated or covered with materials having the desired frictional characteristics for the application and for the fabric web being processed The pull rolls are intended to keep the fabric web taut and uniformly disposed as it is processed Depending upon the requirements for a specific pull roll, a high degree of friction may be required between the pull roll and fabric web to prevent slippage, or a low degree of friction may be required to allow a controlled degree of slippage of the fabric web over the pull roll

FIGS. 2A and 2B illustrate the inventive pull roll cover material of the present invention Functionally, the inventive pull roll cover 20 has a substrate 22 with a first side 24 adapted to be mounted onto a pull roll, and a second side 26 defining a frictional engagement surface for a fabric web which may be traversed or advanced over the pull roll This engagement surface is further defined by a plurality of surface stems 28, which are disposed in a selected arrangement (it is preferred that this arrangement be a predetermined pattern) across the second surface 26, and are formed to have a generally unifoπri height projection from the substrate sheet 22 The selected arrangement for surface stem dispersal is preferably a uniform array, although any arrangement of surface stems is possible (including even a randomly designed dispersal of surface stems within a given area) In a preferred embodiment, the surface stems 28 are arrayed in staggered rows across the substrate 22, such as row a, b, c, d in FIG 2 Preferably, each surface stem 28 projects at a right angle relative to the second side 26 of the substrate 22, but alternatively angled stem orientations are also contemplated

Preferably, the surface stems 28 and substrate 22 are formed integrally as a stem web, and the substrate requires no additional support layer or backing material As shown, the surface stems 28 of the preferred embodiment are equally spaced apart and each is round in lateral cross section, having a generally uniform diameter along its height, from its outer end 30 to the second side 26 The surface stems 28 collectively serve to define an operative region or contact surface for the pull roll cover which contacts the advancing fabric web With a pull roll cover material 20 of this design (e , FIGS 2A and 2B), the surface stems 28 provide a very uniform frictional engaging surface for presentation to the advancing fabric web, both initially, and as the surface stems 28 wear down during usage The surface stems 28 wear uniformly, and since the diameter of the surface stems 28 is generally uniform along their height in the preferred embodiment, the surface area of stem ends 30 does not change because of changing stem structure along the entire height of the surface stems 28 as the surface stems 28 wear down The inventive

x - pull roll cover material thus presents a frictional engaging surface that is resistant to glazing and maintains a constant friction level during its useful life

The use of uniformly disposed and formed surface stems as the engaging surface of a pull roll cover results in a highly controllable and predictable frictional engagement relationship between the pull roll cover and web In addition to opposed roll and web material-to-material frictional interengagement characteristics, the precisely formed nature of the pull roll cover surface introduces a significant mechanical engagement component into the frictional engagement relationship The upstanding surface stems on the pull roll cover penetrate interstices on the web surface (e , between the crossed fibers of its weave for a woven web) to engage the web mechanically Testing suggests that such surface stems disposed on a pull roll cover do not damage many woven fabrics, as otherwise might be expected Outer end portions of the surface stems actually engage the threads of a woven fabric web to mechanically engage with the woven web as it is advanced past the pull roll While such mechanical interengagement is a facto i in the frictional relationship of prior art pull roll cover materials and woven webs (e , bristle based covers or abrasive material covers), those cover materials are not entirely uniform in the dispersement of their bristles or abrasive particles (as well as being less than fully uniform in teπns of the size, height and diameter of their bristles or particles) As a result, the web engagement surfaces presented by those prior art cover materials to the web were not as uniform frictionaily as desired The uniformly shaped, sized and disposed surface stems of the present inventive pull roll cover present a homogeneous frictional surface for contacting the web The surface stems of the inventive pull roll cover are particularly useful and effective in this regard when the web has a relatively uniform surface structure (e , woven or knitted), although the mechanical engagement characteristics are evident in relation to other web structures as well (e g . spun bonded, nonwoven, etc )

The inventive pull roll cover 20 illustrated in FIGS 2A and 2B is resistant to the pickup of lint and fiber during use Further, it is possible to use materials to fabricate the inventive pull roll cover 20 so that the cover 20 is resistant to dye pickup and transfer from the fabric web In one embodiment, the inventive pull roll cover 20 is molded from

SRD7-560 impact copolymer resin available from Shell Polypropylene Company, Houston, Texas Other possible materials for forming the pull roll cover 20 include Prevail™ 3050, available from Dow Chemical Company, Midland, Michigan, Himont KS084P, Montell-Himont, Atlanta, Georgia, and Hytrel™ 5526 or Surlyn™ 1702, both available from E 1. du Pont de Nemours & Co., Inc., Wilmington, Delaware

The nature of the inventive cover 20 is described by its combination of stem height, stem diameter, stem spacing and number of stems per square inch. The frictional characteristics of the cover 20 presented to the fabric web are altered by changing stem density, stem diameter, stem height or stem spacing, which in turn affect the surface area presented by the stem ends 30 of the surface stems 28 to the fabric web, and also affect the mechanical engagement relationship between the weave of the fabric web and the surface stems 28 (e.g , a change in stem height may affect stem flexibility) Four examples of these parameters for the cover 20 are listed in Table I below

TABLE I

Stem Density Substrate Stem Height Stem Stem

Item Thickness Diameter Spacing

50 0 127 mm Approx 0 4 mm 1 4 mm

Al stems/cm² 0.94 mm

50 stems/cm^" 0 127 mm Approx 0 38 mm 1 4 mm

A2 0 64 mm

150 stems/cm² 0 1 mm Approx 0 13 mm to 0 8 mm

A3 0 15 mm 0 18 mm

355 stems/cm^" 0 076 mm Approx 0 13 mm to 0 53 mm

A4 0 15 mm 0 18 mm

The stem spacing is the distance between centers of two adjacent stems As shown in FIG 2A, in a preferred embodiment the stems are uniformly spaced apart in all directions across the second surface 26 of the substrate 22

The parameters listed in Table 1 are not meant to be limiting, and numerous variations in those parameters are possible for a particular cover For instance, the stem densitv is preferably greater than 12 stems/cm^", and more preferably greater than 15 stems/cm Table 1 presents specific stem density examples of 50, 150 and 355 stems/cm², but stem web stem densities greater than 355 stems/cm² are also possible Further, the surface stems may have a height giadient aci oss the pull roll (e g , shorter in centei than near its ends) in ordei to facilitate web handling, the stems may not be round in cioss-section, and the stem density and/or stem spacing may vary across the pull roll In some applications, it may even be desirable that adjacent stems have different heights, or to have stems which change in profile (1 e , cross-section) along their height (e g , a cylindπcal stem having an enlarged, tapered stem base)

In the pull toll cover 20 just descnbed, and the methods of making such pull roll covei mateπals descnbed below, the cover mateπal is typically foπned by molding a flowable mateπal The flowable material can be any suitable mateπal, such as a polymei, a metal or a ceramic precursor It is also within the scope of this invention to use two or more different flowable materials to make the surface stems The flowable material is a foamed or solid polymeric mateπal (such as that descnbed above), such as a thermoplastic material or a thei mosettmg mateπal Othei suitable mateπals include thermoplastic polyui ethanes, polyvinyl chloπdes, polyamides, polyimides, polyolefins (e g , polyethylene and polypropylene), polyesters (e g , polyethylene terephthalate), polystv renes, nylons, acetals, block polymeis (e g , polystyrene mateπals with elastomenc segments, available from Shell Chemical Company of Houston, Texas, undei the designation Kiaton™), polycarbonates, thermoplastic elastomers, and copolymers and blends thereof The flowable mateiial mav also contain additives including but not limited to fillei s, fibei s, antistatic agents, lubπcants, wetting agents, foaming agents sui factants, pigments dyes coupling agents, plasticizers, suspending agents and the like

FIG 3 illustrates one embodiment of an apparatus and process for forming the inventive pull roll covei This process generally involves molding surface stems in a substrate sheet fiom which the surface stems project Substrate sheet 22 is formed, bearing a pluiality of pιo|ectιng surface stems 28 on one maioi surface thereof The molding step may include any suitable molding apparatus as known in the molding art Foi example the surface stems and substrate sheet could be n ection molded, molded by compressing a heated sheet membei against a molding surface, or molded by molding a flowable matenal over and into the cavities of a mold, winch may be stationary or moving (e , a belt, a tape oi a drum) As illustrated schematically in FIG. 3, the process includes an extruder 35 adapted for extruding a flowable material, such as an impact copolymer resin, into a mold 37. The surface of the mold 37 includes a plurality of arranged cavities 39, which are adapted to form a like plurality of surface stems from the flowable material. The cavities 39 may be aπanged, sized and shaped as required to form a suitable surface ste structure from the flowable material. Typically, a sufficient additional quantity of flowable material is extruded onto the mold 37 to form substrate sheet 22 concurrently with the formation of surface stems 28. The mold 37 is rotatable and forms a nip, along with an opposed roll 41. The nip between the mold 37 and opposed roll 41 assists in forcing the flowable material into the cavities 39 of the mold 37, and provides a uniform substrate sheet 22. The temperature at which the foregoing process is carried out depends on the particular flowable material used. For example, the temperature is in the range of 140° to 260° C. for an impact copolymer resin available from Shell Polypropylene Company, Houston, Texas, under the designation SRD7-560. The mold 37 may be of the type used for either continuous processing (such as a tape, a cylindrical drum or a bell), or batch processing (such as an injection mold), although the former is preferred. The cavities 39 of the moid 37 may be formed in any suitable manner, such as by drilling, machining, laser drilling, water jet machining, casting, etching, die punching, diamond turning and the like The placement of the cavities 39 determines the spacing and orientation of the surface stems 28 on the substrate sheet 22, and thus on the inventive pull roll cover. The mold cavities 39 can be open at the end of the cavity opposite the surface from which the flowable material is applied to facilitate injection of the flowable material into the cavity. If the cavity is closed, a vacuum can be applied to the cavity so that the flowable material fills substantially the entire cavity Alternatively, closed cavities can be longer than the lengths of the stems being formed so that the injected material can compress the air in the cavities The mold cavities should be designed to facilitate release of the surface stems therefrom, and thus may include angled side walls, or a release coating (such as a Teflon™ material layer) on the cavity walls The mold surface may also include a release coatim> thereon to facilitate release of the substrate sheet from the mold. The mold can be made from suitable materials that are rigid or flexible The mold components can be made of metal, steel, ceramic, polymeric materials (including both thermosetting and themioplastic polymers) or combinations thereof The materials forming the mold must have sufficient integrity and durability to withstand the thermal energy associated with the particular molten metal or themioplastic material used to form the substrate sheet and surface stems. In addition, the material forming the mold preferably allows for the cavities to be formed by various methods, is inexpensive, has a long service life, consistently produces material of acceptable quality, and allows for variations in processing parameters The flowable material is flowed into the mold cavity, and over the surface of the mold to form the substrate sheet To facilitate flow of the mateπal, the material typically must be heated to an appropriate temperature, and then coated into the cavities This coating technique can be any conventional technique, such as calendar coating, cast coating, curtain coating, die coating, extrusion, gravure coating, knife coating, spray coating or the like

After the themioplastic material has been coated into the mold cavities and over the mold surface, the material is cooled to solidify and form the surface stems The flowable material is solidified in and on the mold to form the surface stems and substrate sheet, w hich are then separated from the mold The flowable material will often shrink when it is solidified, which facilitates release of the surface stem and substrate sheet from the mold Part or all of the mold may be cooled to aid in solidifying the surface stems and substrate sheet Cooling can be effected by the use of water, forced air, liquid nitrogen or other cooling processes

When thermosetting resins are used as the flowable material, the resin is applied to the mold as a liquid in an uncured or unpolymerized state After the resin has been coated onto the mold, it is polymerized or cured until the resin is solid Generally, the polymerization process involves either a setting time, or exposure to an energy source, or both, to facilitate the polymerization The energy source, if provided, can be heat or radiation energy such as an electron beam, ultraviolet light or visible light After the resin is solidified, it is removed from the mold In some instances, it may be desired to further polymerize or cure the thermosetting resin after the surface stem if removed

- 1: from the mold. Examples of suitable thermosetting resins include melamine, formaldehyde resins, acrylate resins, epoxy resins, urethane resins and the like. The formation of a substrate having upstanding stems on one side thereof is further detailed in U.S. Patent No 5,505,747 and in WIPO International Patent Application Publication No. WO 95/19242.

The frictional characteristics of the inventive pull roll cover 20 have been established through both static and dynamic testing procedures. The dynamic friction was measured between a cloth and a selected pull roll cover surface by the following procedure A pull roll cover was formed by helically wrapping a 5 cm (two-inch) wide strip of the designated cover material on a 12.5 cm (five-inch) diameter roll or core, providing a minimum of a 10 cm (four-inch) wide covered surface for evaluation purposes The 12.5 cm (five-inch) core, end flanges and a 2.5 cm (one-inch) shaft were mounted on a free wheeling supporting shaft. A 5 cm (two-inch) wide strip of untreated jeans cloth (specifically, 96x64 jeans cloth, 1.943 yds/lb, Tencel™ fibers, available from Milliken Company, Spartanburg, South Carolina) was anchored at one end and placed over the designated pull roll cover material with approximately 180 degrees of wrap. A spring scale and wire were used to rotate the core and measure the amount of force (in ounces) necessary to move the pull roll cover material against the fixed cloth. The spring scale was a Chatillon scale, gauge R, Catalog No. 719-5 (0-5 lb. force gauge) (available from Chatillon, New York).

The results are tabulated in Table II below, and demonstrate the range of friction values provided by the various pull roll cover test materials The values are in ounces of force required to produce smooth travel between the designated pull roll cover material and the 5 cm (two-inch) wide strip of cloth

TABLE II

Item Pull Roll Material Measured Load (ounces)

0

B l Scotcli ' ^l PTFE (Teflon ' ^l) Film Tape 54 1 Extruded ,

Smooth Back ol^'Slcm Web (Stem Height approx 0.030". Stem Dia.

B2 0 01 ". Stem Spacing 0 050". Slc Dcnsilv 325 stems/in². Substrate Thickness 0.005") ₂ 0

B3 1

Safclx -Walk^{1 M} TN JC 220 Fine Resilient Treads i

B4 Stem Side of Stem Web (same parameters as Item A2 from Table I) 10

B5 Guill id 18904 Loop Cloth ₄ 17

B6 Sa(ct> -Walk ^I

370 Medium Rcsihcnl Treads ι 48

B7 BRUSHLON ' bnish material. No 3 1 B 0 005" x ϋ 1875" Trim 56

BR BRUSHLON ^{■ l} brush material. No 331 B 0 003" x 0 125" Tπ 64

Notes 1 Available as identified from Minnesota Mining and Manufacturing

Company, St Paul, Minnesota 2 The back side (no stems) of the inventive pull roll cover material formed from impact copolymer resin available from Shell Polypropylene Company, Houston, Texas, under the designation SRD7-560 3 The front (surface stem) side of the inventive pull roll cover material formed from impact copolymer resin available from Shell Polypropylene Company, Houston, Texas, under the designation SRD7-560 4 Available as identified from Guilford Mills. Inc , Greensboro, North Carolina

The majority of these items were secured to the core using hook-and-loop mechanical attachment structures The pull roll cover test material was laminated to a hook staicture backing, with the hooks projecting oppositely from the frictional engaging surface of the pull roll cover test material A corresponding loop structure was secured about the core for engagement with the loop structure backing on the pull roll cover test materials The hook structure in this example constituted either Velcro™ 81 1 , Velcro™ 887 (both available from Velcro USA, lnc , Manchester, New Hampshire) or the polyolefin "mushroom" hook fastener portion of the 3M Mechanical Fastener Diaper Closure System (available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota) The loop structure was Guilford 18904 loop cloth, available from Guilford Mills, Greensboro, North Carolina

Since a pull roll cover is typically intended to prevent slippage of the fabric web and pull roll surface, a measurement of the static friction or the force required to create a slip between a fabric and a variety of pull roll cover test materials was performed This analysis measured the horizontal force required to cause movement of a two-inch by four-inch surface of 14 oz. denim cloth against a pull roll cover material at two separate normal forces or weights on the two-inch by four-inch surface The cloth was tested with its lighter colored (back) side facing the pull roll cover surface The cloth was anchored to a metal block which was placed on top of a pull roll surface attached to a table top The coefficient of friction was then calculated by dividing the horizontal force to cause slippage by the weight on the two-inch by four-inch surface area The horizontal force was measured with a Chatillon force gauge Model DPP-50 (available from Chatillon, John & Sons, lnc , Greensboro, North Carolina) The measured horizontal forces and resultant coefficients of friction (COF) are presented in Table III below at both normal forces Theoretically, the coefficient of fiiction is independent of surface area of contact and the normal force applied (for friction considered on a microscopic scale— i e , a "smooth" surface against a "smooth" surface) In the present case, the frictional effect must be considered on a macroscopic sale (i e., including the effect of the penetration of the stems into the weave of the web), so the expected independence of COF on suiface area and normal force may not hold true

Notes

1 Available as identified from Minnesota Mining and Manufacturing Company, St Paul, Minnesota

2 The back (no stems) side of the inventive pull roll cover material, formed from impact copolymei resin available from Shell Polypropylene Company, Houston,

Texas, under the designation SRD7-560

3 Available as identified from Guilford Mills, lnc , Greensboro, North Carolina

4 The front (surface stem) side of the inventive pull roll cover material, formed from impact copolymer resin available from Shell Polypropylene Company, Houston, Texas, under the designation SRD7-560

The inventive pull roll cover (such as Items C7 and C8 in Table III) exhibits a particular frictional performance, as lecognized by the above testing That performance can be varied, not only by varying certain design parameters of the pull roll cover (e g , stem height, dia etei , density or spacing) but also by varying the mateπal itself

Alternative mateπals foi foπning the pull roll cover have been mentioned above, and the frictional properties of those mateπals can be further altered by the use of additives (e g , a fillei ) or coatings (e g , a lubncious coating)

The significance of the mechanical intei engagement component of the frictional charactenstics of the inventive pull I oil covei is illustrated by the results of further static friction testing in the mannei detailed above The hoi izontal force required to cause movement of a two-inch by foui-inch surface of 14 oz denim cloth or steel against a pull i oil cover matei ial at a noi mal force of 8 344 lbs on a surface was measured The cloth was tested with its lighter coloied (back) side facing the pull roll cover surface The cloth was anchored to a metal block which was placed on top of a pull roll surface attached to a table top Items D 1 , D2 and D3 weie tested on separate occasions for the cloth, hence the additional test data The coefficient of friction was then calculated by dividing the horizontal foice to cause slippage by the weight on the two-inch by four- inch surface atea The hor izontal foice was measured with a Chatillon force gauge Model DPP-50 (av ailable fiom Chatillon, John & Sons, lnc , Greensboro, North

Carolina) The measui ed hoi izontal foice and calculated coefficients of friction (COF) aie presented in Table IV below TABLE IV

Ilcm Pull Roll Cover Test Surface Horizontal Force COF Material Malerial (lbs), at Normal Force = 8.344 lbs

Smooth Back of Sicni Web Siccl 1 77 0.2117

DI (back side of Item D2)

Cloth - Isi \ .1.1 0.3994

Cloth - 2nd 2 3 0.2756

Stem Side of Slcni Web Steel 1.8 0.2157

D2 (same parameters ofltcm A2 from Table I herein)

Clolh - Isl 6 03 0.7231

Cloth - 2nd 6 07 0.7275

Slcm Side of Ste Web Siccl 1 9 0.2277

D3 (same parameters of Ilcm A3 from Table 1 herein)

Clolh - Isi 6.13 0.7351

Cloth - 2nd 5 76 0.6903

D4 (same parameters o ltcm Steel 1.9 0.2277 A4 from Table 1 herein)

Clolh 6.03 0.7231

The pull roll cover test materials in Table IV are either the back side (Item DI - no stems) of the inventive pull roll cover material, or its front side (Items D2, D3 or D4 - surface stems), and all were formed from an impact copolymer resin available from Shell Polypropylene Company. Houston, Texas, under the designation SRD7-560. The coefficient of friction for each of the different pull roll cover test materials in Table IV is much lower for the steel surface than the coefficients of friction for that same material in relationship to the cloth surfaces The difference is believed to be the result of the mechanical interengagement of the surface stems and weave of the cloth, and its contribution to the frictional interrelationship between those two materials. As can be seen by a comparison of the steel coefficients of friction and the cloth coefficients of friction in Table IV, this contribution is significant.

In addition to the inventive pull roll cover 20 itself, the present invention relates to the apparatus and method for use of a readily replaceable and repositionable pull roll cover The invention allows relatively quick changeover from one cover to another on a pull roll by a simple and efficient arrangement that results in low machine downtime. In addition, the present invention does not require special handling or expertise (e.g , hazardous waste disposal) in the pull roll cover replacement process Previously, opposed hook-and-loop fastener structures have been used to secure pull roll covers to pull rolls In all such instances, however, the hook structure material was mounted onto the pull roll The pull roll cover then had loop structure material on its back side, and was helically wrapped about the pull roll with hook structure material mounted thereon Occasionally, one or more hooks protruded (because of an imperfect helical wrap of the pull roll cover) from the pull roll exterior to contact the fabric web in use, picking and tearing at the fabric web as it traversed the pull roll cover Any change to the surface of the cloth or its weave produced by the pull roll is considered to be damage to the cloth and is thus to be avoided

The pull roll cover attachment of the present invention involves securing the loop material on the pull roll instead of the hook material The loop material is bonded around the cylindrical outer surface of the pull roll The loop material is preferably secured to the pull roll by a non-repositionable adhesive, since the loop material would rarely be removed or need replacement once secured onto the pull roll The loop material, even if exposed by an imperfect spiral wrap of the pull roll cover over it, does not pick at the fabric traversing the pull roll, and thus significantly minimizes the possibility of damage to the fabric weave The hook material used to secure the pull roll cover to the pull roll now projects a ay from the textile web, thereby preventing the possibility of picking or tearing the textile as it traverses the pull roll

FIG 4 illustrates the preferred method for the application of a strip of loop structure material 45 about the cylindrical outer surface of a pull roll 47 The loop structure material 45 is applied in a narrow strip e g., 2 5 to 10 cm (one to four inches) wide wrapped helically about a cylindrical outer surface 49 of the pull roll 47 The entire cylindrical outer surface 49 of the pull roll 47 (or at least that portion of the pull roll that contacts the textile web) is covered in this manner with the loop structure material 45 An adhesive (such as a pressure sensitive adhesive) is used to secure the loop material 45 to the pull roll 47 The exterior pull roll cover material is bonded to a hook structure fastener material such that one major side of the pull roll cover (its inner side) has fastening hooks projecting therefrom while the other side (its outer side) has the desired frictional engaging surface projecting therefrom (for engaging and traversing a fabric web), 5 thereby defining a pull roll cover assembly for application to the pull roll. The pull roll cover assembly is also preferably applied as a long narrow strip (e.g , one to four inches wide) which is helically wrapped around the pull roll. FIG 5 illustrates the application of a strip of a pull roll cover assembly 50 about the pull roll 47 The pull roll cover assembly 50 is helically wrapped about the loop fastener structure 45, and can be l o oppositely wound relative to the winding of the loop fastener structure 45 (as illustrated in FIG 5) if desired The use of hook-and-loop fastening structures allows some slight axial or side to side play of the pull roll cover assembly 50 as it is being helically wrapped This allows for the efficient achievement of fairly precise edge-to-edge wrapping, without the necessity for continued removal and repositioning of the pull roll

1 cover assembly 50 to properly and completely cover the pull roll 47

While a preferred embodiment includes the application of narrow strips of loop structure material 45 and pull roll cover assembly 50 in a helical wrap about the pull roll, other application configurations are possible. For instance, one or more longitudinally aligned strips may be adhered to the pull roll 0 FIG 6 illustrates, in more detail, the nature of the pull roll cover assembly 50 and its mounting to the pull roll 47 (which has a backing substrate sheet 51 of the loop structure material 45 adhered to its cylindrical outer surface 52) The pull roll cover assembly 50 has its exterior side defined by the inventive pull roll cover 20 As such, the surface stems 28 of the cover 20 project outwardly from the substrate 22, with the outer 5 ends 30 of the surface stems 28 defining the cylindrical textile engaging surface of the pull roll 47

On its opposite side, the cover assembly 50 has means for hooking the loop structuie material 45. In FIG 6, the hooking means is illustrated as a sheet of hook structure material 53 having a supportive substrate 54 with an array of projecting hook 0 stems 55 on one side thereof, with each stem having at least one head 56 thereon for interengagement with the looped and intermingled hook-engaging filaments of the loop structure material 45.

The opposed substrates 22 and 54 are bonded together to define the cover assembly 50 as a surface substrate sheet, with surface stems 28 projecting from one side and hook stems 55 projecting from its other side. A suitable adhesive for laminating the inventive pull roll cover 20 to the hook staicture material 53 is Scotch™ 9851 laminating adhesive, available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota. An alternative adhesive is Scotch™ 919 laminating adhesive, also available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota. The particular laminating adhesive used depends upon the characteristics of the compositions used to form the pull roll cover 20 and hook structure material 53. In any event, the lamination is intended to be permanent and no separation of the facing substrates of the two materials, once bonded together, is desired Webs of the pull roll cover 20 and hook structure material 53 (which may or may not be formed from the same material) are laminated by feeding those webs from rolls, removing and winding up any necessary adhesive liners, and bringing the laminating surfaces together in a rolling nip under controlled tension and pressure. The joined materials are then slit with a rolling knife and wound on cores to produce strip rolls of the pull roll cover assembly 50 The width of each pull roll cover assembly strip roll preferably ranges from 2.5 to 10 cm (one to four inches) and, more preferably, from 5 to 7.5 cm (two to three inches).

As mentioned above, in a preferred embodiment, the pull roll cover used with a particular pull roll should not be so thick as to significantly modify the effective diameter of the pull roll. Thus, in a preferred embodiment, a low profile hook-and-loop fastener structure assembly is desired so that the attachment means for the exterior pull roll cover surface is as thin as possible. The hook structure material 53 and the loop structure material 45 are thus mated in terms of their characteristics and structure to provide sufficient bonding strength but maintain a relatively low profile.

The loop staicture material 45 can be either knitted loop, warp knitted loop fabric, stitched loop fabric, woven or nonvvoven loop fabric The loop structure material 45 presents intermingled fibers for engagement by the hooks 55 of the hook structure material 53 Preferably, the loop structure material 45 includes a plurality of loops 60

~>-> . comprising filaments anchored to the loop structure substrate 54 at each end. The hook stems 55 thus become entangled in the loops 60 to attach the cover assembly 50 to the pull roll 47.

The loop structure material 45 should be such that it is easy, i.e., without much effort on the operator's part, to engage the hook stems 55 into the loop structure material 45. Likewise, when the cover assembly 50 is to be replaced, the operator should be able to easily remove the cover assembly 50 from the pull roll 47 by disengagement of the opposed hook-and-loop structure materials.

If the loop height is too high, it can lead to shifting of the cover assembly 50, which could lead to non-uniform contact with the advancing fabric web and scuffing or marring thereof If the loop height is too low, there may be insufficient interengagement and attachment of the hook stems 55 and loops 60. In general, the height of the loops should be of the same order of magnitude as the height of the hook stems. Additionally, the loop dimensions and orientations may depend upon the shape and height of hook stems provided.

The loop density may also be selected to provide suitable performance characteristics For example, the density of the loops can be the same as or different from the density of the hooks. If the loop density is too high, this increases the cost of the loop staicture material, and it may be difficult to disengage the opposed hook staicture material If the loop density is too low, there may be insufficient peel and shear strength to maintain the cover assembly 50 in place during use

The loop staicture material 45 includes a plurality of loops 60 comprising filaments which are intermingled together, as illustrated in FIG 6 The filaments may either be individual filaments, or yarns comprising a group of twisted filaments. The filaments should be relatively strong lo effectively hold the hook stem and not prematurely release the hook stem Examples of such materials include inorganic fiber filaments, such as metal (including aluminum or steel), ceramic (including glass and fiberglass) and the like The fiiament may also be a combination of different materials. The filament may be straight, curved or twisted, and may contain a surface treatment of some type, such as an antistatic coating, lubricious coating, etc. Examples of organic based filaments include both thermoplastic and thermosetting materials like polyamides,

- polyolefins, polyurethanes, aramides, polyester, cellulosic materials and the like. In general, it is preferred that the filament diameter be one-half the distance that the head 56 overhangs from the stem of the hook stem 55

The loop staicture material 45 can be bonded directly to the exterior surface of the cylindrical pull roll 47 (i.e., thermoplastic loops can be melt bonded thereto)

Alternatively, a laminating adhesive can be used to secure the loop structure material to the pull roll Examples of laminating adhesives include polyolefins, polyesters, polyurethanes, polyamides, hide glue, rubber based adhesives, urea-formaldehyde adhesives, epoxy adhesives, acrylate adhesives and the like. A preferred loop material is Guilford 18904 loop cloth, available from Guilford

Mills, lnc , Greensboro, North Carolina This knitted loop cloth has a low profile (approximately 0 3 mm (0.012 inch) thick) A scrim has loop fibers on one side thereof, and is provided with an acrylic pressure-sensitive adhesive on its other side, which allows easy bonding of the loop cloth to the exterior cylindrical surface of the pull roll A suitable adhesive for this purpose is A210 pressure sensitive adhesive film, available from illbruck, inc , Minneapolis, Minnesota

The hook structure material 53 for the pull roll cover assembly 50 also has a relatively low profile, and preferably is formed from hook stem materials such as those disclosed in Melbye et al U S Patent 5,077,870; Chesley et al U S Patent 5,505,747, and WIPO International Patent Application Publication No WO 95/19242. One version of such material is the 3M Mechanical Fastener Diaper Closure System (available from Minnesota Mining and Manufacturing Company, St Paul, Minnesota) In a preferred embodiment, the hook structure material 53 is formed with the following characteristics stem height = approximately 0.5 mm (0.020 inches), stem diameter = 0.4 mm (0 016 inches), head diameter = 0 76 mm (0 030 inches), stem spacing =

1.4 mm (0.055 inches), and stem density = 50 stems cm² (325 stems per inch²) The hook stems 55 are foπned integrally with substrate 54 (which is 4 5 to 5 mil thick), preferably of S D7-560 impact copolymer resin, available from Shell Polypropylene Company. Houston. Texas Alternative hook structure material formations are also contemplated As used herein, hook stem means a stem having a free end that is spaced from the surface to which the stem is attached and a structure that enables the hook stem to releasably hook the features of the engaging surface (loop structure material) In FIG. 6, each hook stem 55 is illustrated as having a head 56 shaped in the form of a nail head. Alternative hook stem and head configurations will function to suitably engage the loop structure material For instance, the head may have any suitable three-dimensional shape, such as a hemisphere, sphere, mushroom cap, cube, pyramid, etc Preferably, the head has at least one undercut portion that extends radially away from the stem at a right angle, such as the heads 56 shown in FIG 6, to hook loop filaments of the loop structure material 45 Also, while the arrangement and formation of hook stems on the hook structure material 53 are illustrated as generally uniform, alternative stem patterns, such as non- uniform stems and stem array arrangements, will suffice

A pull roll cover assembly, such as described above and illustrated in FIG 6, combined with the preferred loop and hook materials described above, preferably has a thickness of less than 0 50 inch, more preferably less than 0 25 inch, and most preferably less than 0 09 inch, thus defining a relatively low profile covering for the pull roll The low loft of the Guilford 18904 loop cloth was significant in its selection as a preferred loop structure material for this purpose.

The embodiment illustrated in FIG 6 uses both the low profile pull roll cover 20 having upstanding surface stems 28, and the disclosed low profile pull roll cover attachment means. The pull roll cover assembly 50 is readily replaceable relative to the pull roll 47 bearing the loop staicture material 45 on its exterior cylindrical surface 52 When a change in pull roll covers is desired, the pull roll cover assembly 50 can be removed by disengaging the hook ste s 55 on the hook structure material 53 from the loops 60 of the loop staicture material 45 A replacement pull roll cover assembly, having one side defined by a replacement textile engaging material and the other side defined by a suitable hook fastener structure, is then affixed to the pull roll by adhering the hook fastener structure thereon to the loop fastener staicture on the pull roll. The replacement pull roll cover assembly is also typically applied as a thin strip, helically wrapped about the pull roll, as illustrated in FIG 5 Replacement can be performed simply to replace a worn pull roll cover with another having the same frictional and mechanical engagement properties, or to replace a pull roll cover with another pull roll cover having different frictional and mechanical engagement properties. For instance, with respect to the inventive pull roll cover 20 illustrated in FIGS. 2A, 2B and 6, different frictional and mechanical engagement characteristics may be achieved by substituting a different pull roll cover of the same general structure, but having different surface stem densities, spacings, heights or diameters, or being formed from a different

(i.e., less lubricious) material.

The use of the inventive hook-and-loop fastener aπangement of the present invention thus provides for a wide range of pull roll cover options for the same pull roll. The different pull roll cover materials can be readily replaced because of the ease and effectiveness of the inventive attachment arrangement where the loop structure material is essentially permanently attached to the pull roll, while the hook structure material is adhered or foπned on the back of the pull roll cover. This is illustrated, for example, by FIG. 7, wherein a pull roll cover assembly 150 has a pull roll cover 120 formed from an alternative material. This could include any of the types of pull roll cover materials mentioned herein, such as cork, aibber, sandpaper, bristle brushes, films, cloths,

Teflon™ substrates, polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, smooth or textured polymeric films, glass coatings, paper, foam, nonwoven materials, metal foils, and other materials, such as those listed in Tables 11 and 111 Another pull roll cover material is a microreplicated surface, such as a structural abrasive article, available under the trade designation 207EA structured abrasive article, from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota The possible pull roll cover materials are limited only by the desired frictional characteristics of such materials, and their suitability for use in a particular textile pull roll application. The alternative pull roll cover assembly 150 has a cover 120 with an exterior textile engaging surface on one side, and on its opposite side, it bears a hook structuie material or structure such as hook structure material 153. This hook structure material 1 3 in turn is releasably engageable with loop staicture material 145, which is bonded to cylindrical outer surface 152 of pull roll 147. The cover assembly 150 can thus be removed for replacement or change with another pull roll assembly haviim the same or different frictional engauement characteristics, as desired. FIG 8 illustrates yet another embodiment of a pull roll cover assembly 250 In this embodiment, no separate or disci ete exteπor pull roll cover is provided The exteπoi (pull roll) surface of the pull roll assembly 250 is defined by the side or surface 251 of hook structui e mateπal 253 opposite its hook stems 2^ The hook structure material 253 is again releasably e gageable with loop structure material 245 adhesively bonded to cylindrical outei surface 252 of pull roll 247 The exterior surface 251 of hook structure mateπal 253 itself serv es as the textile engagement surface of the pull roll cover The frictional charactei istics for two versions of this type of pull roll cover assembly are listed in Table II (Item B2), Table III (Item C2), and Table IV (Item DI ) The inventive pull i oil cover 20 of the inventive embodiments descnbed above ovei comes many of the disadvantages of the prior art It provides a pull roil cover having initially unilbi m and extremelv consistent frictional engagement characteπstics, which includes conn oiled and non-abiasive mechanical engagement with a textile web traversed thereby The inventive pull roll covei 20 has a low profile and maintains its engagement properties unifoπnly duπng wear of its surface stems The pull roll cover surface stems do not pick oi tear at a textile web, it is resistant to the transference of dye from one textile web lot to another , and it does not exhibit a buildup of lint and fibers duπng use The inventive pull i oil cover 20 when combined w ith the inventive hook- and-loop fastenei means toi attaching a pull i oil covei to a pull roll (with the loop staicture mateπal bonded to the pull i oil), l esults in a superior, low profile, inexpensive and easy to use pull i oil cover replacement arrangement The unique and inventive attachment aπ angement eliminates the possibility of damage or picking of the web by the attachment components themselves

The pi esent invention furthei lelates to an apparatus and method for use of a readily replaceable (oi repositionable), low pi ofile pull l oil covei The invention allows relatively quick changeover fi om one cover to another on a pull l oll by a simple and efficient ai rangement that t esults in low machine downtime In addition, the present invention does not requn e special handling oi expertise (e , hazardous waste disposal) in the pull roll cover replacement piocess, and it provides for an extiemely low profile pull roll cover attachment The present inv ention simplifies the cover application and replacement process, since it does not necessarily require the application of a fastener material onto the pull roll prior to application of the pull roll cover itself

While the inventive embodiments described above with respect to FIGS. 4-8 provide many advantages and are particularly well suited for many applications, such two-part fastening arrangements require additional material and add depth to the pull roll cover.

The pull roll cover attachment of the embodiment described with respect to FIGS. 9- 12 involves securing the pull roll cover directly onto the pull roll by means of a repositionable pressure sensitive adhesive (PSA). A repositionable pressure sensitive adhesive is a low tack adhesive, having sufficient adhesive qualities to maintain an article in place once applied to a surface, but allowing the adhesive to be overcome if it is desired to reposition or remove the article. The repositionable adhesive leaves no appreciable residue once removed, and retains sufficient tack to be re-adhered once repositioned on a mounting surface Repositionable pressure sensitive adhesives are further described in U.S. Patent Nos. 3,691 , 140 and 4, 166, 152 This attachment arrangement for a pull roll cover does not appreciably add to the radius of the pull roll cover, thus creating a very low profile pull roll cover assembly. Further, no undesirable residue is left on the pull roll when covers are changed

FIG 9 illustrates the preferred method for the application of a strip of pull roll cover 320 about the cylindrical outer surface of a pull roll 47 The pull roll cover 320 is preferably applied in a narrow strip, e.g., 2.5 to 10 cm (one to four inches) wide wrapped helically about a cylindrical outer surface 49 of the pull roll 47. The entire cylindrical outer surface 49 of the pull roll 47 (or at least that portion of the pull roll that contacts the textile web) is covered in this manner with the pull roll cover 320. While a helical application is shown, other alignments are also possible.

FIG. 10 illustrates, in more detail, the nature of the pull roll cover 320 and its mounting to the pull roll 47. When mounted as shown, the surface stems 328 of the pull roll cover 320 project outwardly from the second side 326 of the substrate 322 The surface stems 328 thus define the cylindrical operative textile contact surface of the pull roll 47

2S On its opposite side (first side 324), the substrate 322 of the pull roll cover 320 is bonded to the cylindrical outer surface 49 of the pull roll 47 This bond is preferably achieved by a laminating adhesive assembly, as more specifically illustrated in FIG. 1 1 (as mentioned above, the drawing figures are not to scale, portions being enlarged for clarity). A sheet or scrim 69 has its first side 71 bonded by a nonrepositionable pressure sensitive adhesive layer 73 to the second side 324 of the substrate 322. The particular nonrepositionable adhesive selected depends upon the characteristics of the compositions used to form the substrate 322 of the pull roll cover. In any event, the lamination of sheet 69 to substrate 322 is intended to be permanent. On its second side 75, the sheet 69 is bonded to the cylindrical outer surface 49 of the pull roll 47 by a low tack pressure sensitive adhesive layer 77. This lamination is intended to be repositionable in nature, so that the pull roll cover 320 may be repositioned (or removed) relative to the pull roll 47 by release of the low tack repositionable pressure sensitive adhesive from the cylindrical outer surface 49. In a preferred embodiment, these low tack adhesive properties are provided by

Scotchmark™ 9870 High-Low Tack Laminating Adhesive, available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota The Scotchmark™ 9870 laminating adhesive has a polyester scrim or carrier (sheet 69) This prevents any bleed through of nonrepositionable adhesive toward the cylindrical outer surface 49 of the pull roll 47. and thus lessens the likelihood of any nonrepositionable adhesive residue being left on the surface 49. Webs of the pull roll cover and laminating adhesive are laminated by feeding those webs from rolls, removing and winding up any necessary adhesive liners, and bringing the layer 73 of nonrepositionable adhesive together against the second side 324 of the pull roll cover substrate 322 in a rolling nip under controlled tension and pressure. The joined materials are then slit with a rolling knife and wound on cores to produce strip rolls of the pull roll cover. The width of each pull roll cover assembly strip roll ranges from 2.5 to 10 cm (one to four inches), and preferably from 5 to 7.5 cm (two to three inches) A liner remains over the layer 77 of low tack pressure sensitive adhesive, to be removed upon application of the pull roll cover to the cylindrical outer surface 49 of a pull roll 47. As mentioned above, in a preferred embodiment, the pull roll cover used with a particular pull roll should not be so thick as to significantly modify the effective diameter of the pull roll The thickness of the Scotchmate^{l vl} 9870 laminating adhesive is approximately 2 5 mil, and thus provides an attachment means for the exterior pull roll cover which adds no appreciable increase to the pull roll diameter Any change in diameter between pull roll covers on a single pull roll thus depends on the thickness of the pull roll covers themselves, and not on their repositionable pressure sensitive adhesive attachment means The pull roll cover, such as described above and illustrated in FIG 5, preferably has a thickness of less than 1 27 cm (0 500 inches), more preferably less than 6 4 mm (0.250 inches), and most preferably less than I 3 mm (0.050 inches), thus defining an extremely low profile covering for the pull roll

Other suitable pressure sensitive adhesive aπangements are contemplated For instance, a nonrepositionable pressure sensitive adhesive can be laminated on the second side 324 of the substrate 322, with a low tack pressure sensitive adhesive laminated over the high tack adhesive Suitable pressure sensitive adhesives for this purpose are

Scotch ¹ 9] Laminating Adhesive and Scotch ^{I M} 9449 Laminating Adhesive, respectively, both available from Minnesota Mining and Manufacturing Company, St Paul, Minnesota Again, this adhesive arrangement is extremely thin, preferably accumulating to less than 0 050 mil For this specific arrangement, over time (e.g , 30 days), the nonrepositionable adhesive will bleed through to the low tack adhesive, and the repositionable characteristics of the low tack adhesive will deteriorate

The embodiment illustrated in FIG 10 uses both the low profile pull roll cover 320 having upstanding surface stems 328. and the disclosed very low profile pull roll cover attachment means When a change in pull roll covers is desired, the pull roll cover 320 is simply peeled away from the cylindrical outer surface 49 of the pull roll 47 to separate the repositionable (low tack) pressure sensitive adhesive layer 77 from the cylindrical outer surface 49 of the pull roll 47 A replacement pull roll cover, having one side defined by a replacement textile engaging material and the other side bearing repositionable pressure sensitive adhesive, is then applied to the pull roll 47 by wrapping it about the pull roll 47 and pressing it thereto The replacement pull roll cover is also typically applied as a thin strip, helically wrapped about the pull roll as illustrated in FIG 9 Replacement can be perfbi med simply to replace a wom pull roll cover with another having the same fi ictional and mechanical engagement pioperties, or to replace a pull toll co er with another pull toll cover hav ing different desired fi ictional and mechanical engagement pioperties Foi instance with respect to the inventive pull roll cover 20, 320 illustrated in FIGS 2 A, 2B and 10, different desired frictional and mechanical engagement characteristics may be achieved by substituting a different pull roll cover of the same general structure, but having different surface stem densities, spacings, heights or diameters, or being formed from a dif eient (I e , less lubπcious) mateπal There is no appreciable adhesive residue buildup from one cover to the next on a pull roll, so that the initial diametei of that pull roll is maintained ovei time and vanous pull roll cover applications

The use of the inventiv e repositionable piessui e sensitive adhesive pull roll fastening aπ angement of the piesent invention thus provides for a wide range of pull roll covei options foi the same pull roll The different pull roll cover mateπals can be readily replaced (or leposmoned if initially misaligned duπng application) because of the ease and effectiveness of the i entive attachment arrangement This is illustrated, for example by TIG 12, w hei em a pull I oil cover 420 is formed from an alternative matenal oi stiuctuie The covei 420 could include any of the types of pull roll cover materials mentioned heiein, such as cork, rubbei, sandpaper bπstle brushes, films, cloths Teflon ¹ substrates, polymenc coatings, polymei ic coatings containing additives, coated abi asives nonwoven abrasives polymenc films glass coatings, paper, foam, nonwoven materials, metal foils textuπzed polvmers and other mateπals, such as those listed in Tables I I and 111 Anothei pull roll covei matenal is a microreplicated surface, such as a structured

e article available undei the trade designation 207EA staictuied abiasive article av ailable fiom Minnesota Mining and Manufactuπng

Company St Paul Minnesota The possible materials aie limited only by the desired frictional characteπstics of such matenals. and their suitability for use in a particular textile pull roll application The alternative pull roll cover 420 has an exteπor textile engaging surface 421 on one side and on its opposite side 422, it bears a layer of lepositionable pressui e sensitive adhesive hich is bi ought into adheπng contact with the cylindncal outei surface 49 of pull roll 47 The pull i oil cover 420 can thus be easily and efficiently removed for replacement with another pull roll cover having the same or different frictional and mechanical engagement characteπstics, as desired

The pull roll cover of the inventive embodiments of FIGS 9-12 overcomes many of the disadvantages of the prior art It pi ovides a pull roll cover having initially unifoim and extiemelv consistent frictional engagement characteristics, as well as the possibility for conti oiled and non-abrasive mechanical engagement with a textile web traversed thereby The inventive pull i oil covei has a low profile and maintains its engagement properties unifoimly during weai of its surface stems The pull roll cover surface stems do not pick or tear the textile web, it is resistant to the transference of dye from one textile web lot to anothei, and it does not exhibit a buildup of lint and fibers during use The pull roll cover, when combined with the inventive repositionable pressuie sensitive adhesive foi attaching a pull roll cover to a pull roll, results in a supeπoi exti emelv low pi ofile inexpensive and easy to use pull roll cover replacement aπangement The unique and inventiv e attachment aπangement eliminates the possibility of damage oi picking of the textile web by the pull roll cover attachment arrangement

Although the present in ention has been described with reference to preferred embodiments, woi kers skilled in the art will lecognize that changes may be made in foim and detail without departing fiom the spirit and scope of the invention For instance the base structure foi application of the invention has only been descnbed with l espect to cylindncal pull i oils The inventive cover and the novel cover attachment method disclosed heiem can be applied lo othei base structures such as an endless belt or other surface which mav come into contact with an advancing textile web m a textile processing oi manufacturing facility Further, the invention is also applicable in applications other than textile pull rolls Any surface which contacts a web or sheet or othei substi ate workpiece is a candidate for the inventive cov ei and inventive cover attachment aπ angement of the piesent invention For instance the roll cover can be applied to a one-inch diameter tiansfer roll m a photocopy machine In this regard, possible web mateπals may include but aie not limited to wo\ en, nonwoven, knitted, needle tacked, wet laid stitch bonded and spun bonded mateπals as well as papers, films foils and metal sheets or stπps Furthei moie, the oπentation of the laminating

- J- adhesives described with respect to FIG. 1 1 may be reversed such that the nonrepositionable adhesive faces the pull roll surface and the repositionable adhesive is exposed on the pull roll (so that the repostionable adhesive is on the pull roll rather than the on the replaceable cover) Alternatively, a discrete sheet having repositionable pressure sensitive adhesive on both its sides may be disposed between the roll and roll cover

Claims

WHAT IS CLAIMED IS:

1. An engagement apparatus for use on a roll having a cylindrical outer surface which traverses an advancing web, the engagement apparatus comprising: a surface substrate sheet having first and second sides, the second side of the sheet having a plurality of surface stems projecting outwardly therefrom, the surface stems being disposed in a selected arrangement on and formed integrally with the surface substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative eb contact surface; and means for releasably securing the first side of the surface substrate sheet to the cylindrical outer surface of the roll

2 The engagement apparatus of claim 1 wherein the securing means comprises opposed hook and loop fasteners on the first side of the surface substrate sheet and at least a portion of the cylindrical outer surface of the roll, with the loop fasteners being on the cylindrical outer surface of the roll and the hook fasteners being on the first side of the surface substrate sheet

3 The engagement apparatus of claim I wherein the selected arrangement is a uniform array.

4. The engagement apparatus of claim 1 wherein the surface stems are uniformly shaped.

5. The engagement apparatus of claim 1 wherein the roll is a textile pull roll

6. The engagement apparatus of claim 1 , wherein the securing means comprises: a repositionable pressure sensitive adhesiv e disposed between the cylindrical outer surface of the roll and first side of the surface substrate sheet to releasably adhere the surface substrate sheet to the cylindrical outer surface of the roll for replacement or realignment

7. A engagement apparatus for selective engagement with an advancing web, the engagement apparatus comprising: a base having an outer surface with hook-engaging structures disposed thereon; a surface substrate sheet having first and second major surfaces, the second surface having desired characteristics for frictional engagement with an advancing web; a plurality of hooking stems provided on and projecting from the first surface, the hooking stems including means for hooking the hook-engaging structures on the outer surface of the base to releasably affix the surface substrate sheet to the base

8. The engagement apparatus of claim 7 wherein the outer surface of the base is cylindrical

9 The engagement apparatus of claim 8 wherein the hook-engaging structures disposed on the exposed surface of the base are foπned from a loop structure material and wherein the loop structure material is helically wrapped around the cylindrical exposed surface of the base.

10. The engagement apparatus of claim 8 wherein the surface substrate sheet is helically wrapped around the cylindrical outer surface of the base

1 1 The engagement apparatus of claim 6 wherein the hook-engaging structures disposed on the outer surface of the base are formed fiom a loop structure material 12. The engagement apparatus of claim 7 wherein the second surface of the surface substrate sheet has a plurality of surface stems projecting outwardly therefrom, the surface stems collectively defining an operative contact surface for the advancing web.

13. The engagement apparatus of claim 12 wherein the surface stems are generally uniform in height.

14 The engagement apparatus of claim 13 wherein the surface stems are selected from the group consisting of thermoplastic polyurethanes, polyvinyl chlorides, polyamides, polyimides, polyolefins, polyesters, polystyrenes, nylons, acetals, block polymers, polycarbonates, themioplastic elastomers, and copolymers and combinations thereof

15 The engagement apparatus of claim 12 wherein the surface stems directly adjoin and are integral with the second surface of the surface substrate sheet.

16 The engagement apparatus of claim 12 wherein the surface stems are generally uniform in shape.

17. The engagement apparatus of claim 12 wherein the surface stems are uniformly disposed across the second surface of the surface substrate sheet

18. The engagement apparatus of claim 7 wherein the second surface of the surface substrate sheet includes an exterior layer selected from the group consisting of teflon substrates, polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, bristles, brushes, smooth or textured polymeric films, glass coatings, cloth, rubber, paper, foam, nonwoven materials, and metal foils.

1 . The engagement apparatus of claim 7 wherein the second surface of the surface substrate sheet is resistive to dye transfer from the advancing web in engagement therewith

- J - 20 The engagement apparatus of claim 7 wherein the surface substrate sheet comprises a laminated composite including a first composite sheet having its outer side defining the first major surface and a second composite sheet having its outer side defining the second major surface, with inner sides of the two composite sheets being bonded together.

21 A surface cover assembly for releasabie affixation to an opposed surface having hook-engaging structures, comprising a cover substrate having a first major surface, and an opposite second major surface, a plurality of surface stems disposed in a selected arrangement to project outwardly from the second major surface of the cover substrate, the surface stems collectively defining an operative contact surface for the surface cover assembly; and a plurality of hook projections extending outwardly from the first major surface of the cover substrate, wherein the hook projections each include means for hooking the hook-engaging structures to releasably affix the surface cover assembly to the opposed surface

22 The surface cover assembly of claim 21 wherein the surface stems are integrally formed ith the second major surface of the cover substrate

23 The surface cover assembly of claim 21 wherein the selected arrangement is a uniform array

24 The surface cover assembly of claim 21 wherein the surface stems are generally uniform in shape

25 The surface cover assembly of claim 21 wherein each surface stem is cylindrically shaped 26. The surface cover assembly of claim 2 1 wherein the cover substrate comprises: a first sheet bearing the surface stems; and a second sheet adhered to the first sheet and bearing the hook 5 projections.

27 An engagement apparatus for use on a textile pull roll having a cylindrical outer surface, the engagement apparatus comprising: a loop structure material bonded to the cylindrical outer surface 0 of the pull roll, the loop staicture material having a plurality of projecting loops; and a surface substrate formed from a laminated composite including. a first composite sheet having first and second 5 sides, the second side of the first sheet having a plurality of hooking stems projecting outwardly therefrom, the hooking stems including means for hooking the projecting loops on the loop structure material to releasably affix the surface substrate to the pull roll, and o a second composite sheet having first and second sides, the first side of the second sheet being bonded to the first side of the first sheet, the second side of the second sheet having a plurality of surface stems disposed in a selected arrangement to project outwardly 5 therefrom, with the surface stems collectively defining an operative textile engaging surface

28 The engagement apparatus of claim 27 wherein the tirsi and second composite sheets are constructed from the same material 0 29 The engagement apparatus of claim 27 wherein the hooking stems are formed integral with the first composite sheet

30 A method of making a textile pull roll, comprising the steps of providing a base having an outer cylindrical surface; providing an inner sheet having first and second major surfaces, the second major surface being defined by a loop structure material, bonding the first major surface of the inner sheet to the outer cylindrical surface, providing an outer sheet having first and second major surfaces, the second major surface of the outer sheet defining an engaging surface for contacting a textile web, and the first major surface of the outer sheet including means for hooking the loop structure material, and releasably affixing the means for hooking on the first major surface of the outer sheet to the loop structure material of the second major surface of the inner sheet

31 The method of claim 30 wherein the outer sheet is an initial outer sheet, and further comprising providing an alternative outer sheet having first and second major surfaces, the first major surface of the alternative outer sheet including means for hooking the loop structure material, and the second major surface of the alternative outer sheet having an exterior surface that defines an alternative textile engaging surface for contacting the textile web, separating the means for hooking on the first major surface of the initial outer sheet from the loop structuie material bonded to the base; and releasably affixing the means for hooking on the first major surface of the alternative outer sheet to the loop structure material of the second major surface of the inner sheet

32. A method of making a roll, comprising the steps of. providing a base having an outer cylindrical surface; providing a substrate sheet having first and second major sides; releasably securing the first side of the substrate sheet to the outer cylindrical surface of the base, and providing a plurality of surface stems projecting outwardly from the second side of the substrate sheet, with the surface stems being disposed in a selected arrangement on and formed integrally with the substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative workpiece contact surface for the roll

33 The method of claim 32 wherein the securing step includes adhering the first side of the substrate sheet to the outer cylindrical surface by opposed hook and loop fasteners, with the loop fasteners being mounted on the outer cylindrical surface of the roll

34. The method of claim 32 wherein the substrate sheet is an initial substrate sheet, and further comprising providing an alternative substrate sheet having first and second major sides, the second side of the alternative substrate sheet having an exterior surface that defines an alternative operative workpiece contact surface; separating the first side of the initial substrate sheet from the outer cylindrical surface of the base, and releasably bonding the first side of the alternative substrate sheet to the outer cylindrical surface of the base J? The method of claim 32 wherein the selected arrangement is a uniform array

36 A method of changing the outer textile engaging surface of a textile pull roll, the method comprising the steps of providing a pull roll having a cylindrical pull roll base, a loop fastener staicture secured to the pull roll base, and an initial substrate sheet releasably affixed to the loop fastener structure, the initial substrate sheet having first and second major sides, w ith the second side of the substrate sheet being defined by a textile engagement material and the first side thereof being defined by a hook fastener structure which is releasably engaged with the loop fastener structure on the pull roll base, removing the initial substrate sheet and textile engagement material thereon from the pull roll base by disengaging the hook fastener staicture on the initial substrate sheet from the loop fastener staicture on the pull roll base, providing a replacement substrate sheet having first and second major sides, with its second side being defined by a replacement textile engagement material and its first side being defined by a hook fastener structure; and affixing the replacement substrate sheet to the pull roll base by adhering the hook fastenei" staicture thereon to the loop fastener structure on the pull roll base

37 The method of claim 36 wherein the replacement textile material on the replacement substrate sheet has the same textile frictional engagement properties as the textile enuauement material n the initial substrate sheet 38 The method of claim 36 wheiein the replacement textile mateπal on the replacement substrate sheet has ditieient textile frictional engagement properties than the textile engagement material on the initial substrate sheet

39 A low profile engagement apparatus foi use on a roll having a cylindncal outer surface which travel ses an advancing web, the engagement appaiatus compπsing a surface substrate sheet having first and second sides, the second side having desired characteπstics foi fiictional engagement with an advancing web, and a leposmonable piessuie sensi e adhesive disposed between the cylindncal outei surface of the toll and fu st side of the surface substrate sheet to leleasably adhere the surface substrate sheet to the cylindncal outei surface of the roll for replacement or lealignment

40 The engagement appaiatus of claim 39 wheiein the second side of the surface subsuate sheet has a pluiality of surface stems pioiecting outwardly therefrom, the surface stems being disposed in a selected aπangement on and formed integrally with the surface substrate sheet, and the surface stems being generally uniform in height and collectively defining an opeiative web contact surface

41 T he engagement appaiatus ol Jaim 40 wheiein the selected aπangement is a uniform an ay

42 The engagement appaiatus of claim 40 wheiein the surface stems are selected from the gioup consisting of themioplastic polyui ethanes, polyvinyl chloπdes, polvamides. polyimides, polyolefins, polvesteis, polystvienes, nylons, acetals, block polvmei s polvcaibonates, themioplastic elastomeis, and copolv mers and combinations 43 The engagement apparatus of claim 40 wherein the surface stems are uniformly shaped

44 The engagement apparatus of claim 39 wherein the second side of the surface substrate sheet includes an exterior layer selected from the group consisting of teflon substrates, polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, bristles, baishes, smooth or textured polymeric films, glass coatings, cloth, rubber, paper, foam, nonwoven materials, and metal foils

45 The engagement apparatus of claim 39 wherein the surface substrate sheet is helically wrapped around the cylindrical outer surface of the pull roll

46 The engagement apparatus of claim 39 wherein the repositionable pressure sensitive adhesive is carried on the first side of the surface substrate sheet

47 A method of making a roll, comprising the steps of providing a base having an outer cylindrical surface, providing a substrate sheet having first and second major sides, the second side ha ing desired characteristics for frictional engagement with an advancing web, and releasably bonding the first side of the substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the substrate sheet relative to the base

48 The method of claim 47 wherein the bonding step includes helically wrapping the substrate sheet around the outer cylindrical surface of the base

49 The method of claim 47 wherein the substrate sheet is an initial substrate sheet, and furthei comprising providing an alternative substrate sheet having first and second major sides, the second side of the alternative substrate sheet having an exterior surface that defines an alternative engaging surface for contacting an advancing web, separating the first side of the initial substrate sheet from the outer cylindrical surface of the base, and releasably bonding the first side of the alternative substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the alternative substrate sheet

50 The method of claim 49 wherein the desired frictional characteristics on the second side of the alternative substrate sheet are the same as the desired frictional characteristics on the second side of the initial substrate sheet

51 The method of claim 49 wherein the desired frictional characteristics on the second side of the alternative substrate sheet are different from the desired frictional characteristics on the second side of the initial substrate sheet

52 The method of claim 47, and further comprising positioning the repositionable pressure sensitive adhesive on the first side of the substrate sheet prior to the bonding step

53 The method of claim 47, and further comprising providing a plurality of surface stems projecting outwardly from the second side of the substrate sheet, the surface stems being disposed in a selected arrangement on and formed integrally with the substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative contact surface for contacting an advancing web 54 The method of claim 47 wherein the selected arrangement is a uniform array.

55. A method of changing the outer textile engaging surface of a textile pull roll comprising providing a pull roll having a cylindrical pull base with an initial substrate sheet releasably affixed to the pull roll base, the initial substrate sheet having first and second major sides, with the second side of the initial substrate sheet being defined by a textile engagement material and the first side thereof being bonded to the pull roll base by a repositionable pressure sensitive adhesive, removing the initial substrate sheet and textile engagement material thereon from the pull roll base, providing a replacement substrate sheet having first and second major sides, with its second side being defined bv a replacement textile engagement material; and affixing the replacement substrate sheet to the cylindrical pull roll base by means of a repositionable pressure sensitiv e adhesive disposed therebetween to permit replacement or realignment thereof on the cylindrical pull roll base t>

56. The method of claim 55 wherein each substrate sheet bears the repositionable pressure sensitive adhesive for the bonding thereof to the outer cylindrical surface of the base.