US3493452A - Apparatus and continuous process for producing fibrous sheet structures - Google Patents

Description

Ml Am Am m% h s 2 3, 1970 P. M. COLE APPARATUS AND CONTINUOUS PROCESS FOR PRODUCI FIBROUS SHEET STRUCTURES Filed June 28, 1968 BATT CONVEYOR CROSSER- LAPPER FIBER WEB COMPRESSION & SLITTER ROLL INVENTOR PAU L MORRISON COLE I "III nuw ATTORNEY Feb. 3, 1970 P M. COLE APPARATUS AND CONTINUOUS PROCESS FOR PRODUCI FIBROUS SHEET STRUCTURES Filed June 28. 1968 2 s t s 2 PAUL MORRISON COLE I ATTORNEY United States Patent O US. Cl. 156254 13 Claims ABSTRACT OF THE DISCLOSURE Continuous process for forming fiber-on-end sheet products which involves providing a fibrous batt in which the fibers are oriented in its width dimension, compressing the batt in its height dimension and cutting it longitudinally to form a series of strips, placing the strips under compression then rotating them about their longitudinal axes to orient the fibers vertically, then permitting the strips to engage one another to form an integral coherent sheet. Apparatus for performing this process including means for compressing and cutting the batt, a series of pairs of belts for placing the strips under compression, means for rotating the belts and strips individually about their longitudinal axes, and means for separating the strips from the belts.

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation in part of application Ser. No. 456,421, filed May 17, 1965, and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a process for making fibrous sheet products having a generally fiber-on-end orientation.

Various methods have been proposed for making pile fabrics and other textile articles by aligning fibers in a preferred longitudinal orientation, slicing sections therefrom transversely to the longitudinal orientation, and thereafter combining the sections in one way or another, frequently by adherence to a backing, to provide a pile fabric. These methods are advantageous in that they avoid the customary weaving, knitting, tufting, and like textile operations, but are frequently uneconomical from the standpoint that they are difficult to perform as a continuous process on a commercial scale. Even so the products have often lacked a high degree of uniformity as is required for most textile applications.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a continuous process for producing fibrous sheet products having a generally fiber-on-end orientation. This process comprises the steps of:

(alt Forwarding along a predetermined path a wide, elongated, porous, resilient batt of fibers having fiber orientation predominantly in its width dimension;

(b) Compressing said batt in its height dimension While cutting it longitudinally, transversely of said width dimension, to form a series of generally parallel moving compacted fibrous strips;

(c) Placing each strip under compression in its height dimension between surfaces parallel to the direction of fiber orientation;

(d) Causing the forwardly and generally parallel moving strips while under compression to individually rotate substantially 90 about their longitudinal axes; and

(e) Separating the strips from the compression sur- 3,493,452 Patented Feb. 3, 1970 faces and permitting the strips to engage adjacent strips at their edges to form an integral coherent sheet Whose major faces are defined by fiber ends.

The present invention also provides apparatus for carrying out the above process, Which apparatus comprises:

(a) Means for forwarding along a predetermined path an elongated, porous, resilient batt of fibers having fiber orientation predominantly in its width dimension;

(b) Means for compressing said batt in its height dimension;

(c) Means for cutting said batt longitudinally, transversely of its width dimension, to form a series of generally parallel moving compacted fibrous strips;

(d) A pair of parallel spaced-apart rolls positioned on opposite sides of said moving strips in contact with the upper and lower surfaces thereof;

(e) A series of pairs of endless ribbon belts, one belt of each pair being trained to run about the upper of said rolls and at least one additional roll and the other of each pair being trained to run about the lower of said rolls and at least one additional roll, the belts having a width essentially the same as the width of the moving strips, the belts being positioned across said first two rolls so that each strip is engaged by a pair of belts as it passes through the nip of said rolls and is held between the belts by compressive force;

(if) Means for individually rotating said moving strips and associated belts through substantially about their longitudinal axes while maintaining them in generally parallel relationship with the strips still under compression from said belts;

(g) Means for separating said moving strips from said belts, whereupon each strip engages adjacent strips to form an integral coherent sheet whose major faces are defined by fiber ends.

As will be seen from the above, the present invention enables the continuous manufacture of a highly useful fibrous sheet product of generally fiber-on-end orientation from a starting material comprising a batt of fibers having their orientation predominantly in a side-to-side direction. The latter starting batt is readily obtainable by well known types of textile converting equipment. Hence, the relative ease with which, according to this invention, such a batt can be transformed into the fiber-on-end sheet product, offers distinct advantages as a commercial manufacturing procedure. Moreover, this invention enables not only the production of a Wide range of product dimensions and properties, but also a high degree of uniformity in those products. The process of the invention is thus well suited to the provision of pile layers for a great number of textile applications.

In one embodiment of this invention, there is produced a fibrous sheet product in which the fibers are bonded together at spaced contact points by a binder. In this respect it is especially advantageous in the production of porous, flexible materials, including laminates thereof, as described in Koller US. Patent 3,085,922. These materials are of a porous character and have a plurality of contorted, e.g. crimped, filamentary structures which overlap, are aligned generally in the same direction, are interconnected throughout the three dimensions of the material, e.g. by a binder.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 illustrates schematically in perspective view an apparatus for forming the initial elongated fibrous batt in which the fiber orientation runs from side-to-side.

FIGURE 2 illustrates schematically in perspective view a simplified version of apparatus for transforming the batt produced in FIGURE 1 into one having a fiber-on-end orientation and then slicing the product into two sheets.

FIGURE 3 is a partial and detail view of the compression and slitter rolls of the arrangement shown in FIG- URE 2.

FIGURE 4 is a schematic side elevation view of a preferred form of apparatus for converting a batt of sidet-o-side fiber orientation into elongated strips, rotating the strips and recombining them into a sheet product having a generally fiber-on-end orientation.

FIGURE 5 is a schematic side elevation view of a belt arrangement for recombining the rotated strips and may be used as an alternate to the roll arrangement shown in FIGURE 4.

FIGURES 6 through 10, inclusive, are partial section views of the fibrous batt and sheet product, along with associated apparatus elements, at various stages of the process illustrated in FIGURE 4.

DETAILED DESCRIPTION The apparatus of FIGURE 1 employs a carding machine and crosser-lapper, both of the type commonly used in the textile industry, in order to provide from a supply of staple or other fibers an initial elongated, porous resilient batt of fibers having fiber orientation predominately in the width dimension. A Wide web of fibers, formed by the carding machine, is conveyed to the crosser-lapper which comprises a pair of belts pivotally mounted at the top so as to swing back and forth and thereby deposit the fibers transversely of a batt conveyor. The speed of the various conveyors may be adjusted to give a batt of the desired thickness. Additionally, two or more assemblies of carding machine and crosser-lapper may be used in tandem so as to deposit a thick batt upon a single conveyor. The formation of this batt of predominately side-to-side orientation constitutes no part of this invention since a wide variety of suitable arrangements will be apparent to those skilled-in-the-art for accomplishing this purpose.

FIGURES 2 and 3 illustrate sschematically the formation of a fiber-on-end product from the batt such as that produced in FIGURE 1. According thereto the initial batt of side-to-side fiber orientation is compacted and severed into a series of parallel moving fibrous strips by means of a rotary gang slitter with blade spacings, in one preferred embodiment, at least as great as twice the thickness of the desired final product. The initial batt, the thickness of which is selected to be greater than the blade spacing, is compressed perpendicular to its face and to the transverse orientation of fibers while it is being slit by the multiple rotary blades. FIGURE 3 shows the spacing of the circular knives on the slitter roll and their relation to grooves on the lower roll.

In lieu of that shown in FIGURES 2 and 3, other forms of cutting mechanism such as vertical knife blades or multiple horizontally reciprocating knives may be used for the multiple longitudinal slicing step. Similarly, the compacting may be accomplished by other means and may be performed either before or after the slicing step.

The fibrous strips while still under compression in the height dimension, for example by means of belts or other restraining surfaces, not shown, are then caused to individually rotate substantiall 90 about their longitudinal axes. One method for rotating or turning the longitudinal strips through an angle of 90 involves the use of a series of pairs of ribbon belts made of polyethylene terephthalate plastic film having a thickness on the order of 0.0075 inch (.019 cm.). These then, along with a fibrous strip sandwiched between each pair, pass through a square metal tube of the type shown having a minimum wall thickness and an outside dimension approximating the spacing between adjacent blades of the slitter. A convenient width for the two belts is slightly less than the space between adjacent knife blades. In going through the tubes the plastic belts are guided from a horizontal to a vertical position so as to turn the fibrous strips to the desired orientation.

When the turning of the fibrous strips has been completed they will, because of already possessing suflicient internal stresses due to the prior compression, effect union with one another at their edges merely upon release of the compression. When these longitudinal ribbons laterally engage one another at a spacing less than the original batt thickness, they tend to lose their identity and thus create a continuous uniform fibrous sheet product having essentially vertical or fiber-omend orientation.

If desired, the fibrous sheet product may be then compacted in its longitudinal dimension to achieve a desired fiber density. Also it can be sliced in the manner shown in FIGURE 2 to provide two or more separate sheets of pile fibers.

FIGURE 4 illustrates a preferred form of apparatus for accomplishing the cutting of strips from a batt, such as that produced in FIGURE 1, and then rotating and recombining the strips to form a sheet product having a fiber-on-end orientation. A batt 12 of side-to-side fiber orientation, shown in FIGURE 6 across 6--6 of FIG- URE 4, is fed between upper and lower forwardly driven rolls 13 and 14. A series of circular slitter knife blades, 15 and 16, is fixedly mounted along the length of those rolls at predetermined spacings from one another. The cutting operation is shown in FIGURE 7 across 77 of FIGURE 4. Each knife blade on the upper roll engages in scissor-like fashion a corresponding knife blade on the lower roll to cut perpendicularly through the batt continuously along its length.

A series of pairs of thin plastic belts 20 and 21, of the type described hereinbefore, are guided by various rolls in the manner shown to engage the upper and lower faces of the severed batt strips 22 to transport those strips in a compacted condition beyond the rolls 13 and 14 for eventual rotation. In the vicinity of guide roll 25, provided with a series of circular spacers 26, the fibrous strips 22 have been rotated about 45 from their original plane. A view of the various fibrous strips and taken along line 88 is shown in FIGURE 8. Beyond guide roll 25 the fibrous strips 22, each of which are still compressed between a. pair of plastic belts 20 and 21, continue to rotate unti at take-01f roll 27 they have become fully perpendicular to their original plane. As the fibrous strips 22 tangentially contact the outer surface of take-off roll 27, the belts 20 and 21 slip into guide grooves 28 forcing the strips to divert downwardly and into contact with one another along their lateral edges. A view along line 9-9 is shown in FIGURE 9. Thereafter the joined fibrous strips, an integral sheet product 29 now having been formed with a fiber-on-end orientation, are sandwiched between belts 30 and 31. A view, along line 1010, of the product in this form is shown in FIGURE 10. By reducing the rate of forward travel of belts 30 and 31 relative to speed of belts 20 and 21, the fibrous sheet product can in this operation be longitudinally compacted to a desired density.

The fibrous product 29 may be then wound up into a package or sliced into layers of the desired thickness. If it has been provided with a binder composition, e.g. as a spray of particles upon the fibers or by the inclusion of low-melting binder fibers, it can be forwarded to an oven for heat bonding fibers prior to windup or slicing. As a part of the same operation, whether or not the fibers have been bonded together, the entire product or sheets sliced therefrom can be provided with an adhesive on one or both faces and adhered to a backing in the conventional manner.

In lieu of using take-off roll 27 of FIGURE 4, a series of belts 35 may be used as shown in FIGURE 5 to engage the upper faces of the various fibrous sections to divert them downwardly between belts 30 and 31. In a further embodiment, not shown, a stationary deflector plate having a series of narrow slots to receive belts 20 and 21 may he used to divert the fibers sections downwardly.

As will be apparent from the foregoing, numerous variations can be made to produce a fibrous sheet product of the desired dimensions. The initial batt may be quite wide,

having a width up to feet or more. Its thickness, preferably less than 10% of its width, can also vary considerably depending upon the width desired in the final product. Ordinarily it will be advantageous for the crosssectional batt dimensions, the number of knife blades, as well as the spacings therebetween, and the compression applied to the batt to be so selected as to provide a series of generally parallel moving compacted fibrous strips having a greater width than height dimension. The strips need not then be spread apart to enable their rotation and, upon release of the compression, a sheet product will be obtained having a thickness which approximates that of the initial batt. In any case it will be apparent that only nominal compression upon the strips is required, usually at least 5% but preferably or more. Thus following rotation of the strips mere partial release of compression will cause them to unite. However, the mere removal of the belts 20 and 21 will alone cause the strips to join at their edges even though full compression is retained. The retention of a considerable amount of the compressive stress is preferred to provide a uniform integral product.

It will be understood that the fiber-on-end or vertical orientation in the fibrous product does not necessarily mean that the fibers intersect the major faces at an average angle of 90. The average angle of intersection may be considerably less, i.e. as low as 10, and the product will still contain upstanding fibers and have major faces defined by filament ends.

The initial batt of fibers having the fibers aligned predominantly in a side-to-side or transverse dimension may be prepared by a variety of known methods. The fibers may be composed of any synthetic fibers, natural fibers, glass, metal or ceramic fibers, or blends of two or more fibers, depending upon the properties desired in the finished product. The fibers may also have any denier or length and may be staple fibers, continuous filaments cut to the desired size, tow, top, fibers cut in a Pacific converter or Turbo machine, sliver, roping, roving, yarns and the like. One satisfactory form of starting material for this process is a carded Web of crimped staple fibers. A group of carded webs may be then cross-lapped as shown in FIGURE 1 to give the starting batt. Crimped fibers are highly preferred for forming the porous resilient starting batt. Synthetic fibers which are useful include polyamide, polyester, and polyacrylic fibers.

The fibers in the batt may be bonded at this initial stage or they may be bonded after longitudinal slicing or even after formation of the continuous sheet product having fiber-on-end orientation, In some instances it may be desirable to bond the fibers at more than one stage in the process. For some end uses it may be desirable to avoid any bonding between the fibers; that is, in the case where a pile fabric having no binder in the pile layer is to be obtained. However, for many products for which the present process is useful, it will be desirable to use some form of interfiber bonding at one or more stages in the process. Either a permanent binder of a fugitive binder may be used to bond the fibers together to provide some greater form of batt stability for purposes of processing, or for achieving certain predetermined properties in the final textile product. The selection of a permanent or fugitive binder composition may be made from a wide variety of well-known resinous and elastomeric compositions, typical examples of which include natural and synthetic rubbers, polyurethanes, polyamides, polyesters, acrylic polymers, copolymers and terpolymers, natural gums and resins, starches, cellulose derivatives, such as carboxymethylcellulose, and the like. The permanent or fugitive binder may be a thermoplastic composition or a thermosetting composition. Examples of thermosetting compositions include neoprene, phenol-formaldehyde resins, ureaformaldehyde resins, melamineformaldehyde resins, polyurethane resins, and the like. The binder composition may be incroporated into the fiber mass by any suitable method such as spraying, dipping, padding, vacuum means and the like.

Other suitable methods of providing interfiber bonding may be used besides the incorporation of liquid binder compositions. A solvent or partial solvent for the fibers may be selected for spraying, or otherwise incorporating into the fiber mass, and then activated to bond the fibers. A binder fiber may be selected such as a lower melting fiber than the structural fiber or a more soluble or solventsensitive fiber than the structural fiber, The binder fiber may be incorporated in the desired proportion along with the structural fiber in forming the batt. At the proper time in the process the binder fiber is then activated by solvent, heat, or other means in order to attach the structural fibers together. Various heating means may be used for interfiber bonding such as steam, infrared heat, ultra high frequency heating, and the like.

An alternate means for applying a binder composition involves sifting a powdered binder composition into the sheet product or sliced wafers from one face followed by curing of the binder so that its density varies from a maximum at one face to essentially Zero or at least minimum at the other face. Similarly, and in the case where a binder has been uniformly distributed throughout the thickness the curing can be regulated, e.g. by application of heat to only one side, to confine the bonding to the lower one-third or one-half of the pile thickness, thus leaving the unbonded pile face having a very soft tactile hand. The uncured binder may either be left in place in a portion of the product or, if desired, may be removed by a liquid which is a solvent for the uncured binder but not for the fibers or the cured binder.

It will be apparent that the above described process is subject to a great number of modifications, all within the scope of the invention. One such modification involves allowing the rotated fibrous strips to unite at their edges upon a horizontal conveyor such as a Fourdrinier wire screen containing upstanding wire projections so as to engage and lend support to the vertically oriented fibers. This provides better control of any further processing operations to be performed on the sheet product without losing vertical fiber orientation.

If the sheet product obtained is unbonded but contains a binder, it may be passed through an oven for setting or curing the binder. Following cooling, the product may be passed through a band knife for slicing parallel to its major faces into two or more fibrous wafers having vertical fiber orientation, An adhesive coating may be applied to one or both faces either before or after it is sliced into the wafers. The adhesive applied to the surface of the web may be any suitable thermoplastic or thermosetting adhesive such as polyester resins, polyamide resins, polyethylene resins, natural and synthetic rubber compositions, and the like. The adhesive may be applied by spraying, dipping, doctoring, laminating, application of a film layer followed by melting, and the like.

The present invention may be also used to produce porous bonded fibrous sheets or wafers having a variation in fiber density through the thickness of the sheet. One method for accomplishing this is to subject the pile structure to a controlled thickness compression while the binder is being cured and at a time when a temperature gradient exists within the structure. The higher temperature portions of the pile will receive a disproportionate share of the compression, and the pile density of the total thickness of the sheet will become accordingly unequal. Heat may be applied in such a manner as to create temperature gradient from one face of the sheet to the other or from both faces to the center. In the latter case a final product can be obtained with a low density center, but if desired this can be sliced into two wafers each with a density gradient from one face to the other.

The process of this invention is particularly suitable for producing porous low density fiber sheets having a variety of patterning effects. Thus card webs may be rolled into slivers of 0.5-0.75 inch (1.27-1.90 cm.) diameter and these then assembled in parallel fashion to form an elongated transverse-oriented batt of two or three roll thickness and a programmed arrangement of color. The batt is then transformed into the vertical fiber structure by the process of this invention. The patterns can be modified as desired by controlling the relative longitudinal, lateral, and thickness compression. The component fiber rolls may be precolored or may have differet receptivities to post-coloration. Alternatively, two different fibers from two card webs may be rolled up into one sliver. Not only may color patterning be produced in this manner, but also texture, relief, and tone patterns may be created.

An advantage of the present invention is that it provides a continuous and economical process for producing porous, self-supporting fibrous products which have a number of uses as such, or can be converted into various textile materials. The process provides a great degree of freedom in controlling not only the speed of manufacture of pile fabrics and other textiles but also better control of the uniformity of the products. An almost infinite variety of styles and properties can be obtained in the products. Another advantage is that the process permits the manufacture of fibrous products having lower fiber densities than are possible by dipping blocks of aligned fibers into a binder composition. Such a dipping procedure frequently tends to collapse the blocks upon their removal from a solution of the binder composition because the fiber density is too low.

The present process is useful for manufacturing not only porous self-supporting sheets having small thicknesses from about Mr inch down to 0.05 inch (0.127 cm.) for use in making pile fabrics and other apparel and industrial textile products, but also for making thicker sections of porous self-supporting low density products which are useful in manufacturing pillow, upholstery, cushions, and similar products. The process is especially suitable for manufacturing high quality, lowcost pile fabrics such as carpets, blankets, apparel interlinings, apparel outer wear, bed spreads, bath robes, insulation and the like. Porous fibrous products can be made in accordance with this invention having fiber densities ranging from 02-3 pounds per cubic foot (3.248.1 g./'l.), although higher and somewhat lower fiber densities may be possible by varying some of the conditions of the process.

The following examples are illustrative of the present invention.

EXAMPLE I Polyethylene terephthalate staple fibers, 1.5 denier per filament, 2 inches (5.08 cm.) long, having a stutter-box type of crimp were procesed through a commercial garnett machine equipped with a conventional textile crosserlapper. The garnett opened the fiber bundles and provided a predominance of longitudinal fiber orientation in the web discharged to the crosser-lapper. The crosser-lapper delivered the fibers to a coveyor in transverse orientation as shown in FIGURE 1. Fifteen passes were made to build a 1 /2 inch (3.81 cm.) thick batt of transversely oriented fibers on the conveyor.

A fibrous sheet product was then obtained using an apparatus similar to that shown in FIGURES 4 and 5. The fiber batt was fed into a commercial gang slitter which had been modified for simultaneous compression and slitting into ribbons followed by rotation of the ribbons from transverse to vertical fiber orientation in formation of a vertically oriented fiber layer. The slitter had two driven cutter mandrels with four sets of blades of 2.75 inches (6.98 cm.) outside diameter and .021 inch (0.53 cm.) thickness. The blades on both mandrels were separated by .4815 inch (1.22 cm.) wide cylindrical steel spacers. The mandrels were positioned one above the other so that the blades overlapped approximately .030 inch (.076 cm.). the mandrels being axially loaded to provide a cutting relationship. The spacers on the top mandrel had an outside diameter of 2.31 inches (5.87 cm.) while the bottom mandrel spacers had a 2.63 inches (6.67 cm.) outside diameter, providing a gap of .251 inch (.637 cm.). A continuous belt of .375 inch (.950 cm.) width and .0075 inch (.019 cm.) thickness polyethylene terephthalate film passed through each blade spacing and was tensioned against the cylindrical spacer for driving action by the mandrel. The direction of belt departure was normal to a plane through the tWo mandrel axes. The belts were guided by distant spacers to twist from a horizontal to a vertical orientation in the horizontal path of departure, all belts simultaneously rotating the 90 in the same direction so that the belts in passing around the top and bottom mandrels formed cooperating pairs with vertical spacing at the point of cutting and horizontal spacing a short distance beyond the cutters. A 2-inch (5.1 cm.) fabric conveyor wider than the total of all ribbons, Was mounted below the departing small belts and moved at the same speed with the parallel path just clearing the small belts. The wide conveyor belt beyond the point of small belt rotation was diverted downwardly approximately 35 around a support pulley to part company with the small belts.

The above described fiber batt with fibers oriented parallel to the mandrel axes was fed into the gang slitter and cut into ribbons of .5025 inch (1.28 cm.) width. At the time of cutting, the fiber assembly was vertically compressed from the original 1.5 inches (3.8 cm.) dimension to the .236 inch (.60 cm.) dimension of the mandrel gap reduced by two belt thicknesses. The belts continuous- 1y rotated the fibers from horizontal to vertical orientation and caused the fibers when in the vertical position to come into engagement with the Wide conveyor. At the point of downward belt divergence deflectors guided the fibers into leaving the small belts and moving with the wide belt, the small belts carrying each ribbon at this point being in vertical plane separated approximately .438 inch (1.11 cm.). The deflectors were continuous belts of .125 inch (.317 cm.) wide by .0075 inch (.019 cm.) polyethylene terephthalate film driven in a path tangential to the path of the extreme fiber ends, one belt contacting each ribbon and passing through the space between the .375 inch (.952 cm.) wide belts. Release from the narrow belts was accompanied by self-expansion in response to internal compression stresses so as to form a uniform sheet of fibers united from the three ribbons. The fibrous sheet had a thickness of 0.5 inch (1.27 cm.) and a width of 1.5 inches (3.81 cm.) when restrained at the selvages.

EXAMPLE II The procedure of Example I is repeated, except that polyhexamethylene adipamide crimped staple fibers (3 d.p.f. and 2 inches long) are substituted for the polyethylene terephthalate staple fibers. The resulting fiberon-end sheet is immersed in a 5 weight percent solution of a polyamide binder in ethanol/water (/20 by volume). The binder is a terpolymer formed by condensing together caprolactam, hexamethylene diamine, adipic acid and sebacic acid such that there are substantially equal proportions of polycaproamide, polyhexamethylene adipamide and polyhexamethylene sebacamide in the terpolymer. The excess binder solution is drained from the sheet and the fibers are dried with hot hot air at 212 F. until all the volatiles are removed. The well bonded sheet is passed by a band knife cutter such that the plane of the cut is perpendicular to the axes of the parallelized fibers. The sheet is sliced into two equal layers of 0.25 inch (.64 cm.) thickness. Each of the sheets is attached on one side only to a plain weave polyamide fabric by applying a layer of neoprene-based adhesive to one face of the bonded fiber sheet and one face of the backing fabric. The sheets are lightly pressed together, adhesive-coated side to adhesive-coated side, to laminate the bonded sheet 9 to the backing sheet. The fibers in the bonded sheet are firmly adhered to the backing. The binder holding the fibers of the sheet together is then removed with an ethanol/water (80/20) mixture, a non-solvent for the neoprene-based adhesive.

EXAMPLE III Bicomponent polyacrylonitrile staple fibers prepared according to U.S. Patent 3,038,237 having a 2 /2 inch staple length and 3 denier/filament are treated in hot (190 F.) water for 15 minutes and dried at 120 F. in a tumble dryer. The resulting fibers have a crimp frequency of 11 crimps per inch and a crimp index of 24%. Crimp frequency and crimp index are defined and measured as described in Koller U.S. Patent 3,293,105. The fibers are processed on a gamett machine equipped with a crosser-lapper as described in Example I, except that only seven passes are made so that the batt of transversely oriented fibers has a thicknes of about inch (1.9 cm.).

This batt is then slit into ribbons, the ribbons rotated 90, then the ribbons recombined to form a uniform fiber-on-end sheet, in the manner described in Example 1. Equipment used is the same as that described for Example I, except that the cutter mandrels have eight sets of blades, the blades on both mandrels are separated by 0.23 inch (0.585 cm.) wide spacers, the outside diameters of the spacers on both mandrels are 2.6 inches (6.6 cm.) so that the gap between mandrels is 0.12 inch (0.305 cm.), and the continuous polyethylene belt passing through each blade spacing is 0.175 inch (0.44 cm.) wide. Consequently, the individual ribbons are approximately /4 inch in width, and at the time of cutting, the ribbons are vertically compressed from the original inch thickness to 0.105 inch (0.27 cm.), which is the gap distance between mandrels reduced by two belt thicknesses. At the point where deflectors guide the ribbons into leaving the belts the belts are in vertical plane separated by about /5 inch. Thickness of the resulting fiber-on-end sheet is approximately inch; width is about 1% inches.

One surface of this sheet is spray-coated with a polyurethane adhesive, then bonded to a woven cotton fabric. The assembly is then wound under tension and heated (240 F. for 30 minutes) to bond the fiber ends in one face of the sheet to the cotton backing. The resulting laminate is a soft bulky fabric suitable for use as a pile lining for garments.

I claim:

1. Continuous process for producing fibrous sheet structures having a generally fiber-on-end orientation comprising the steps of:

(a) forwarding along a predetermined path a wide, elongated, porous, resilient batt of fibers having fiber orientation predominantly in its width dimension;

(b) compressing said batt in its height dimension while cutting it longitudinally, transversely of said width dimension, to form a series of generally parallel moving compacted fibrous strips;

(c) placing each strip under compression in its height dimension between surfaces parallel to the direction of fiber orientation;

(d) causing the forwardly and generally parallel moving strips while under compression to individually rotate substantially 90 about their longitudinal axes; and

(e) separating the strips from the compression surfaces and permitting the strips to engage adjacent strips at their edges to form an integral coherent sheet whose major faces are defined by fiber ends.

2. Process of claim 1 wherein said batt has a width dimension at least times its height dimension.

3. Process of claim 2 wherein the fibers are polyamide fibers.

4. Process of claim 2 wherein the fibers are polyester fibers.

5. Process of claim 2 wherein the fibers are polyacrylic fibers.

6. Process of claim 2 wherein the thickness of the resulting fiber sheet is no more than about A.

7. Process of claim 6 comprising the further step of laminating one side of the fiber sheet to a supporting sheet.

8. Process of claim 2 wherein the fibers are interbonded at contact points to form a self-supporting sheet.

9. Process of claim 8 comprising the further steps of slicing the resulting fiber sheet between major faces to make a thin wafer, then laminating one side of the wafer to a supporting sheet.

10. Process of claim 9 wherein the final wafer is no more than about A" thick.

11. Process of claim 10 comprising the further step of removing the binder interbonding the fibers whileleaving the binder adhering the wafer to the supporting sheet.

12. Apparatus for continuously producing fibrous sheet products having a generally fiber-on-end orientation which comprises:

(a) means for forwarding along a predetermined path an elongated, porous, resilient batt of fibers having fiber orientation predominantly in its width dimension;

(b) means for compressing said batt in its height dimension;

(c) means for cutting said batt longitudinally, transversely of its width dimension, to form a series of generally parallel moving compacted fibrous strips;

((1) a pair of parallel spaced-apart rolls positioned on opposite sides of said moving strips in contact with the upper and lower surfaces thereof;

(e) a series of pairs of endless ribbon belts, one belt of each pair being trained to run about the upper of said rolls and at least one additional roll and the other of each pair being trained to run about the lower of said rolls and at least one additional roll, the belts having a width essentially the same as the width of the moving strips, the belts being positioned across said first two rolls so that each strip is engaged by a pair of belts as it passes through the nip of said rolls and is held between the belts by compressive force;

(f) means for individually rotating said moving strips and associated belts through substantially about their longitudinal axes while maintaining them in generally parallel relationship with the strips still under compression from said belts;

(g) means for separating said moving strips from said belts, whereupon each strip engages adjacent strips to form an integral coherent sheet whose major faces are defined by fiber ends.

13. Apparatus as defined in claim 12 wherein the means of parts (f) and (g) for rotating then separating said strips and belts comprises a horizontal take-off roll having a series of longitudinally spaced-apart vertical grooves in its periphery, the distance between grooves being substantially equal to the original width dimensions of said strips, whereby said moving belts slip into said guide grooves with their width dimensions in a vertical position and said strips are diverted downwardly as they contact the face of the take-01f roll.

References Cited UNITED STATES PATENTS 2,521,831 9/1950 Cone et a1 156-254 X 3,092,203 6/1953 Slayter et al 156--254 X 3,140,220 7/ 1964 Walter 156271 X VERLIN R. PENDEGRASS, Primary Examiner U.S. Cl. X.R.

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