US2982667A

US2982667A - Method of reorienting fibers and bonding the fibers into a nonwoven fabric

Info

Publication number: US2982667A
Application number: US619855A
Authority: US
Inventors: Irving S Ness; Ronald V Lints
Original assignee: Chicopee Manufacturing Corp
Current assignee: Chicopee Manufacturing Corp
Priority date: 1956-11-01
Filing date: 1956-11-01
Publication date: 1961-05-02
Anticipated expiration: 1978-05-02

Description

May 2, 1961 Filed NOV. 1, 1956 S. NEss ET A-L TJCIJ.

METHOD OF REORIENTING FIBERS AND BONDING THE FIBERS ONTO A NONWOVEN FABRIC 6 Sheets-Sheet 1 Rv/NG 5. NESS PON/LD V L1A/T5 ATTORNEYS fore-2id 91, WZ, f/

May 2, 1961 METHOD OF RERIENTING FIBERS AND BONDING THE FIBERS ONTO A NONWOVEN FABRIC Filed Nov. l, 1956 I S. NESS ETAL 6 Sheets-Sheet 2 I I I I I I I I I I I I I I I I INVENTORSI I R v/NG 5. N555 ATTO R N EYS.

NESS ET Al. METHOD OF REORIENTING FIBERS AND BONDING May 2, 1961 THE FIBERS ONTO A NONWOVEN FABRIC 6 Sheets-Sheet 3 Filed Nov. l, 1956 @WLF May 2, 1961 1. s. NEss ETAL 2,982,667

METHOD oF REORIENTING FIBERs AND BoNDING THE FIBERS oNTo A NoNwovEN FABRIC Filed Nov. l, 1956 6 Sheets-Sheet 4 INVENTORS? IINII 657 3 1m@ m, M r l l. S. NESS ET AL METHOD OF REORIENTING FIBERS AND BONDING THE FIBERs oNTo A NoNwovEN FABRIC :c rm

May 2, 19.61

Filed Nov. l, 1956 1 ATTORNEYS.

May 2, 1961 l. s. NEss ET AL 2,932,567

, METHOD oF REORIENTING FIBERS AND BoNnING THE FIBERS oNTo A NoNwovEN FABRIC Filed Nov. 1, 1956 6 Sheets-Sheet 6 TYP/TCH B'FORE CROSS- STRETCH/NG L 'f'v'f m9 75 7%/ 7&7 @RONALD /NTS Y long and cross directions.

-METHOD F REORIENTIN G FIBERS AND BOND- ING THE FIBERS INTO A NONWOVEN FABRIC yIrving S. Ness, Princeton, NJ., and Ronald V. Lints,

Hatboro, Pa., assignors to Chicopee Manufacturing Corporation, a corporation of Massachusetts Filed Nov. 1, 1956, Ser. No. 619,855

17 Claims. (Cl. 117-7) This application is in part a continuation of our copending application Serial Number 367,656, filed July 13, 1953, now abandoned, which in turn is in part a continuation of application Serial Number 280,966, filed April 7, 1952, now Patent No. 2,697,678.

The present invention relates to so-called nonwoven fabrics, i.e., fabrics produced from textile fibers without the use of conventional spinning, weaving, knitting, or felting operations.

Nonwoven fabrics are conventionally manufactured at the present time by producing a more or less Itenuous web of loosely associated textile bers disposed in sheet form (using any one of a variety of well-known procedures) and then bonding the sheet or web, to anchor or bond the individual bers together. The conventional base material for such nonwoven fabrics is a web cornprising any of the common textile-length fibers or mixtures thereof, the bers varying from approximately onefourth to one-third of an inch as the lower limit to approximately two or more inches in staple length. These fibers are customarily processed into web form by one of two general techniques, i.e., carding, or the like, to form an oriente web, or air-laying to form an isotropic web.

"Oriented webs are made by passing the bers through a conventional card to form a web or sheet of loosely associated bers, and then superposing a plurality of these webs to provide a laminated web weighing approximately from 100 to 5000 grains per square yard. This web or sheet of fibers is produced continuously with most of the fibers substantially parallelized or oriented in the machine direction, i.e., in the direction inwhich the product moves continuously from the sheet-forming machine. A web possessing substantially uniform density, wherein the fibers are distributed substantially uniformly throughout the area of the web, can be produced at relatively high speeds by this technique.

In a web produced as just described it is difficult to measure fiber orientation directly because the individual fibers thereof are curled and bent, with various segments of the fibers extending in various directions. However, a kind of average orientation may be ascertained which is helpful in describing the physical characteristics of the web. This characteristic is called the degree of ber orientation. The degree of ber orientation is determined by bonding the web uniformly with a material such as starch, drying the bonded web, measuring tensile strengths lengthwiser and crosswise of the resulting fabric, and then computing the percentage of lengthwise or long strength of the fabric to its total strength. Total strength, for this purpose, is the sum of the tensile strengths in the Thus, when longA and cross tensile strengths are equal the degree of ber orientation is 50 percent.

Something more can be said generally about the positions in which the various bers lie in the plane of the web. In a web wherein most of the fibers are substantially parallelized along the longitudinal axis of the web,

i United States Patent:

2,982,667 Patented May 2, *1961 the average angle between that axis and most of the individual bers of the web is substantially zero. When an individual fiber is reoriented by the method of this invention, it is generally moved into a new position in which the angle it makes with the longitudinal axis of the web is increased. Thus the combined effect of the movement of all the bers that are reoriented in the web is to increase the average angle between the longitudinal axis of the rearranged web and` all the various fibers contained in the web.

The bonding operation by which an oriented web is converted into a fabric may be accomplished in one of several different ways. For example, one method is to impregnate the web over its entire width with various well-known bonding agents such as natural or synthetic resins. Another method is to print nonwoven webs with continuous straight or wavy lines of binder extending transversely or obliquely across the web. Still another method is to imprint on the web a discontinuous binder pattern, consisting of discrete, physically separated areas of binder, arranged in a staggered pattern.V

Regardless of the bonding method used in producing a fabric directly from a web of oriented textile fibers, fabrics so formed have been subject to a major disadvantage; i.e., the starting web, and thus also the resulting fabric, are nonisotropic in respect to their physical properties. In particular, the tensile strength of the fabric transverse to the direction of ber orientation (its cross strength), is very much less than the tensile strength of the fabric in a direction parallel to the fiber orientation (its long strength). As a result, oriented nonwoven fabrics heretofore have been characteristically weak in the cross direction, tending to rip or tear when the web is subjected to even a moderate cross extensional stress.

Various techniques have been proposed for forming` webs wherein the ber orientation is more or less random. These webs may be bonded to form isotropic nonwoven fabrics wherein the long and cross strengths are approximately equal. Conventionally, the bers are dispersed in an air stream which is flowed through a conn tinuously moving foraminous collecting member which in turn separates and removes the fibers from the stream. The bers are deposited on the collecting member in the form of a web or layer which may be removed therefrom for bonding purposes.

Since, in air-laying, positive mechanical control of the fibers is not maintained during the time they are being carried in a stream or projected to the collecting member, considerable diiculty has been experienced in attempting to obtain a web having a uniform vber distribution. This is particularly true of light-weight webs wherein lack of uniformity will result in serious local weaknesses and even holes. While attention has been given to this difficulty in connection with the methods and apparatus disclosed in Plummer et al. United States Patents 2,676,363 and 2,676,364, the basic problem of controlling web uniformity is inherent in air deposition systems, particularly at normal economical production speeds for fabrics of this type.

In accordance with the present invention, an unbonded web having a substantially uniform density throughout the area thereof formed of loosely associated textile bers, such as a carded web made from a multiplicity of superposed conventional card Webs, which carded web Weighs from approximately to 5000 grains per square yard, in which the fibers are predominately parallelized or oriented in the long direction, is subjected to a combined i The. cross-stretching is effected in a direction substantially normal to the original direction of ber orientation while the shrinking is eiected in the said original directionof ber orientation, i.e., the length of the web. This operation 4results in a deformation ofthe web in the plane thereof, 'increasing its dimensions transverse'tolthe direction ofthe originally parallelized bers and decreasing its dimensions in the long dimension.

`During this web deformation, the bers in the web are moved into reoriented positions, but in their new positionsthey still remain individually intermingled, overlapping and crossing other individuall bers in the web in frictional and mechanical engagement therewith.

The reoriented webV formed bythecornbi-nedfcrossstretching Vand long-shrinking 'operation of `thepres'e'nt invention and then bonded to forrn the `reoriented, inonwoven fabric of the present invention', brings Aabout in the said fabric an increase in the-strength' of thefabric inr the cross direction (the width),`i.`e'., transverse to the direction of the originally parallelized bers in the' web.

' In other words, the reoriented web' has the potential of being converted by bonding into a nonwoven'fabric having an increased tensile strength in the cross direction as compared to the oriented nonwoven fabrics of the prior art.

The termv potential tensile strengthas applied to a web in the following description refers to the tensile strength of the fabric formed by bonding the bers of a web into a unitary structure. The cross strength of the fabric is increased to the extent that the originally parallelized bers in the web are moved or oriented away from the parallel.

In the reoriented web the density is substantially uniform throughout therarea thereof regardless of the thickness of the web or the speed at which it is produced. The preferred reoriented web is one wherein the average angle between individual bers and the longitudinal axis of the web is increased to the point where the degree of ber orientation is reduced to approximately 50 percent. Aweb Vapproaching this preferred form in structure is capable when bonded of providing `a long-to-cross tensile strength ratio of approximately one. web-is herein called a pseudo-isotropic web, because its potential tensile strength is of the same general order of magnitude in 'all directions, being in fact substantially equal when measured along the two major axes at 90 to each other, i.e., the longitudinal and transverse axes ofthe web. Thus therearranged ber web acts very much like a true isotropic web, and is for this reason referred to as a pseudo-isotropic web.

As the bers of the original oriented web are reoriented toy reduce the degree of ber orientation, the increased Width of the web tends to be more or less compensated for by the accompanying long shrinking thereof, with the result that the reoriented pseudo-isotropic web may have an area substantially the same as the area of the starting conventional card web..

Theratio of the long strength to cross strength of a bonded reoriented Web formed from an initially oriented web, such as a card web laminate, may be varied within Wide limits in accordancewith the invention. As the Web is 4cross stretched and reduced in length, the long tensile strength of the bonded web decreases while the cross tensile strength increases. The stretching can be carried out to such as extent that the starting web which initially has a substantially weaker potential strength in the cross direction than it has in the long direction, is made stronger in the cross direction than in the long direction. The invention thus makes possible the production of a web of rearranged bers having a predetermined potential longto-cross tensile strength-relationship from an initially oriented web which has a relatively weak potential strength in the cross direction.

The cross-stretchingaccompanied by the long shrinking of the web is effected in accordance with therinvention by engaging, preferably frictionally, the unbonde'd This preferred oriented textile ber web vwith an extensible carrierwhich is capable of undergoing extension in a direction normal to the original direction of ber orientation, and extending (stretching) the carrier in the said direction while the web is in engagement therewith. It is preferred that the web be saturated with Water or an aqueous emulsion of `a binder such as polyvinyl acetate, for example,` at the time of the cross-stretching operation since the aqueous medium aids in maintaining the engagement of the* web with the carrier and .also assists the bers in moving to the desired rearranged relationship duringV the crossstretching operation.

The extensible carrier may take `any desired form. Thus, for example, it may be a knitted fabric, a rubber sheet, rubber sheathed, laterally extensible spring belt elements spaced one from the other and assembled in continuous belt form, or an island bonded oriented nonwoven fabric wherein the binder coversnot substantially more than about 30% of the total surface ofthe fabric, etc., as hereinafter set forth in greatendetail.

The pseudo-isotropic web produced in accordance with the present invention, while similar to an isotropic web formed by r'air laying in accordance with prior art procedures in having potential strength properties of the same order of magnitude in all'directions in the plane of the web, is nevertheless distinguishable therefrom. During the cross-stretching of the web, especially when wet with water, the bers are'straightened considerably as they are being reoriented to their new positions. As a result, in the reoriented web, the fibers are substantiallyl straight over segments of their lengths.

ln contrast, in an air-formed isotropicweb, made by disposing bersl from an air stream onto a yforaminous conveyor, the bers are relaxed and are `positioned in their normal random relationship. f These bers, especial ly cotton bers, have a considerable amount of crimp and curl and they thereby impart a substantial loft to the web. In fact, the air-formed isotropic web has, a considerably higher loft for 4a given weight Vthan has the pseudoisotropic web made in accordance with the present invention.

After the reoriented web ofthe present invention is formed, the bers therein are xed in their reoriented relationship as by a bonding medium appliedin any desired manner to the web. The resulting product is the oriented, nonwoven fabric of the present invention.

The inventionY and the advantages thereof will be `understood from` the; following general description and theA detailed descriptions ofthe illustrative embodiments of the invention illustrated and lshown in the drawings wherein:-

Figure l is a flow sheet diagrammatically showingthe type of operations by which the present invention maybe carried into practice, theextensible-carrier used, in these operations being in the form of a laterally extensible sheetr material;

Fig. 2 is another ow sheet diagrammatically showing one method of practicing the type of operations outlined in Fig. 1;

Fig. 3 is a diagrammatic representation showing an illustrative arrangement of equipment by means of which one aspect of the present invention may be carried out continuously on a commercial production basis;

Fig. 4 is a perspective view of a nonwoven fabric the bers of which have been reoriented in accordance with the invention; i

Pig. 5 is a perspective view of a fragment of a two-ply pseudo cross-lay nonwoven fabric-made from the product of Fig. 4 in accordance with another aspect of the present invention;

Fig. 6 is a similar view of a three-ply fpseudocrosslay nonwoven fabric made from the product Of- Fig. 4 in accordance vvwith'still another aspect of the present vinvention; Y

Fig. r7 is a top planyiew oftamachi embodyinga preferred fornof 'h'enens'fr cross-s etchi'g'ia web in accordance with the invention, ,the extensible carrier elements and associated mechanism positioned in the lower portion of the machine being omitted for the sake of clarity;

Fig. 8 is a side elevational view of the machine shown yard) and the type of operations subsequently performed on the starting material depend in part on the end product to be produced. Generally speaking, however, a basic operation used in producing therefrom all types of products in accordance with our invention involves, in the case of an extensible carrier in the form of a laterally extensible sheet material, causing the unbonded oriented web (box l, Fig. l) to cohere to the laterally extensible sheet material (box 2) while the latter is undergoing extension in a direction normal to the original direction of orientation of the cohering web. Thus, for example, we have found that by cross-stretching a laterally extensible carrier sheet while an oriented web coheres thereto (the direction of cross-stretching being normal to the original direction of fiber orientation), the originally parallelized fibers of the cohering web may be caused to move into a rearranged relationship with the average angle of the fibers to the longitudinal axis of the web being increased, producing in the preferred form a pseudo-isotropic web of substantially uniform iiber distribution.

In carrying the invention into practice, various means may be used to cause the base web to cohere to the ca'rrier sheet. Thus, the Ybase web may be held under slight pressure between two laterally extensible carrier sheets, for example by maintaining it under tension over a cylindrical surface, while both carrier sheets are undergoing lateral extension. We prefer however a much simpler means for effecting such coherence, this being diagrammatically shown in Fig. l. This involves plying the base web (box l) and the carrier sheet (box 2) to form a two-ply structure (box 3), and maintaining the base web in wet contact with the carrier sheet, for example, by saturating or wetting-out the two-ply structure (box 4) with an aqueous medium such as water. Under the coheiing forces brought about presumably by the surface tension of the aqueous medium and the frictional engagement of the web by the carrier sheet, as the carrier sheet is cross-stretched (box 5), the carrier sheet drags or pulls the supported web in a substantially uniform manner in the direction in which the carrier sheet is being extended. lf this direction is substantially normal to the original direction of fiber orientation of the cohering web, the fibers of Ithe latter move from their initially parallelized condition into a reoriented relationship (box 5), producing substantial .symmetry in potential tensile strength along the long and cross axes of the web. In this reorientation process, the aqueous medium appears yto act in part as a lubricant facilitating the movement of the fibers. In `any event, regardless of the theoretical explanation of the phenomenon, the originally parallelized bers are effectively rearranged, and a web of substantially uniform fiber distribution is obtained.

`The thus reoriented web is sufficiently self-supporting to permit it to be lifted, peeled olf, or otherwise separated from the laterally extended carrier sheet (box 6). The separated web may then be used for any desired purpose or treated in any desired manne-r, for example by bonding (box 7), in order to convert it into a nonwoven fabric. Depending on the extent of the cross-draft applied in the foregoing process, the long-to-cross tensile strength ratio of the resultant fabric will differ substantiallyl from the corresponding ratio of a fabric made from the original oriented web by prior art procedures. Fabrics that have a long-to-cross tensile strength ratio of approximately one can readily be. produced by this process.

If desired, of course, the reoriented web may be bonded to the carrier sheet to' form a laminated fabric (boxes 5 and 7). Alternatively, the reoriented web may be separated or peeled from the carrier sheet (box 6) and then bonded to an oriented web (boxes 9 and 10).

The carrier sheet utilized in the foregoing process may comprise any suitable material capable of undergoing lateral extension when cross-stretched. We prefer however to use amaterial, the total surface area of which remains substantially constant during the cross-stretching operation Vdue to contraction in long direction as it expands in the ,cross direction. Knitted fabrics behave in this manner and 'afford a simple, readily available carrier sheet material for carrying out our process. Where the carrier sheet is intended to be reused repeatedly in carrying out the process, knitted fabrics made from synthetic filaments may be utilized.

Referring now to Fig. 2, another type of carrier sheet useful in carrying out the process of the present invention comprises island bonded oriented nonwoven fabrics wherein the binder covers not substantially more than about 30% of the total lateral surface of this fabric. A particularly useful fabric of this type (because of vits great capacity for lateral expansion) is described, for example, in tNess, Lints, and Petterson Patent 2,705,688.

As shown in Fig. 2, the process may be effected by plying unbonded card web (box 20) with an island bonded nonwoven fabric of high lateral extensibility (box 21) toform a two-ply structure (box 22). The two-ply structure is then wet-out (box 23) with a potential rebounding composition (i.e.,'one which can be softened by heat and then resetby cooling) such as anv aqueous emulsion of a heat softenable binder (e.g., polyvinyl acetate, polyvinyl chloride or rubber latex). The wet impregnated plied structure is then crossstretched by pulling on the nonwoven fabric carrier sheet (box 24). Thereafter, if desired, the stretched two-ply fabric may be dried in its extended condition to form a reoriented nonwoven fabric (box 27). Alternatively the stretched two-ply fabric while still wet may be plied with unbonded card web (box 25) and tne resultant three-ply fabric permitted to dry to form what we term a "pseudo cross-lay nonwoven fabric (box 26). The properties of the resulting three-ply fabric are similar to those of cross-laid oriented webs that have been bonded together.

fFig. 3 illustrates one method of carrying out the invention on a continuous production line basis. The card web 32, from card line 30 is continuously delivered to a continuous, laterally extensible carrier sheet 34. The advancing web 32 supported on the carrier sheet 34 passes through the wet-out 38 and thence through a suitable cross-stretching device, diagrammatically indicated at 4t), where the carrier sheet with the cohering web are crossstretched. After the cross-stretching operation, the wet reoriented web 321' is carried forward on the stretched carrier sheet 34s to a point where a second card web of suitable width 44, from the card line 42, is laid upon it. The carrier sheet 34s then passes around the separatingroller 45, where it is separated from the webs 44 and 32r. The two webs 32r and 44, after separation from the carrier sheet, pass through a continuous impregnating device 48 and thence into the dryer 50 where the water is removed, and finally onto the wind-up roll 52. The carrier sheet, after separation from the web at the separating roller 45, passes around the dancer rolls 26 which long-drafts the sheet to its original width and takes up the slack. It is then recycled continuously in the operation.

Fig. 4 shows -a typical reorientedcard web 60 produced'as described in any of theforegoing operations. The original .oriented card web was stretched Yabout 100 percent, i.e., to twice its original width. The finished product had a grain weight of 1500 grains per square yard. Its potential long tensile strength was l1 pounds and its potential cross tensile strength was` 18 pounds. Acomparable product of similar grain weight, produced as described above but without the reorientation step, would have a potential long tensile of about 30 pounds, and` a potential cross tensiie of about :3 pounds.

Fig. 5 shows a typical laminatedrfarbric producedby plying an orientedcard web 61 with the reorientedcard webv60 and then bonding the two together. In atypical example, the card web vwas stretched Q percent, plied with an equal weight of un-reoriented card web, impregnated with polyvinyl acetate emulsion and then dried. The long strength of the product (19 pounds) equals itsA cross strength, thus giving a` crossflay effect; we therefore term such a product alpseudocrosslay fabric. The product on the lower surface 61 looks like an impregnated card web, while the upper surface 66 looks like the fabric of Fig. 4. Y

Fig. 6 illustrates the three-ply laminated fabric resulting from the process of Fig. Y2 (boxes 20-26, 27). The fabric comprises a cross-stretched island bonded nonwoven fabric 62, sandwiched between a reoriented card web l6() andan oriented card web 61, the three ,plies being bonded linto a unitary fabric by the impregnant (not shown).

In carrying our process into practice, Ythe degree of elongation effected inthe cross-stretching step may be varied within wide limits. Generally speaking, substantial benets in fiber reorientationmay be obtained ,with as little as 30 percent stretch (i.e., the width of the stretched .product being 130 percent of the original width of the unstretched starting material). In the usual case, with about 8O percent to 100 percent stretch, the ratio of `long to cross tensile strength of the finished (bonded) product approaches unity; i.e., when thewidth of the stretched fabric is about 16.0 percent to about 200 percent that of the original web, the long and cross tensile strengths are about equal. With still higher degrees of stretch, the ratio of long to cross tensile strength of the end (bonded) product is generally smaller than unity.

The manner in which the unbonded oriented web is caused to cohere to the carrier sheet during the crossstretching step is not limited to the method hereinbefore described. A differential air pressure (eg, by suction below an air-permeable carrier sheet, or air pressure applied above such a carrier sheet) may be used in lieu of wet cohesion. We may also use physicalpressure at separated points, for example, using two laterally extensible metal fabric sheets with the web under slight pressure therebetween as the metal fabric sheets are crossstretched. Various other expedientsv for effecting coherence will readily be apparent to those skilled in the art. We prefer, however, to effect coherence by using an aqueous medium, preferably one containing a wetting agent.

In addition to the type of carrier sheets described above, it is possible to use many other alternative carrier sheets, including, forexample, a rubber or elastomeric sheeting.

In Figs. 7 to 10 there is shown an embodiment of a machine suitable for commercial use, wherein the crossstretching is effected by rubber-sheathed coil spring Vbelt elements. This machine is fully` disclosed and claimed in application Serial No. 621,490, led October v3 l, 1956, in the` name of Frank Kalwaites. Y

In vthe Kalwaites machine the springbelt elements are assembled *in spaced relationship intoan endless belt and a vpair of lsuch belts aredpositionedone above therother with the" belt elements extending transyersely/of the machine and stretchahle in that direction. The belts are driven so that @the direction oftravel ofthe; upper reach of.Y the lower endlessv belt is the same as that of the lower reach of the upper endless belt, from the inlet vtoithe outlet end ofthe machine. The -belt .elements ,ofthe upper endless vbelt are offset with respect to those ofthe lower endless belt and the vertical displacement of the endless belts is such that the belt elements of the respective endless belts mh alternately as the belt elements move from the inlet to the outlet end of the machine. It is preferred in this machine that the vertical displacement of the endless belts be such that the belt elements mesh to vthe greatest extent at or near the inlet end of the machine and move progressively into decreasing mesh as they approach the outlet end. As shown in Figs. Sand 9, at the outlet end of the machine the belt elements of the respective endlessbelts are still in alternating relationship but are no longer in meshing relationship. At this point the belt elements move away from each other and are carried back to the inletend of the machine.

The unbronded oriented web tobe cross-stretched is introduced between the endless belts .at the inlet'end of the machine. At the point where the web enters between the endless belts the belt elements move vinto meshing relationship and-engage the web therebetween. The belt elements are then stretched transversely of the machine and stretch the web therewith. The stretching of the meshing belt elements, and the engaged web, is eifected progressively as the web is carried by the belt elements through the machine.

The relationship between the progressive increase of lateral stretchvof the belt elements and the progressive decrease of the extent of meshing between the belt elements as the belt elements carry a web through the machine is, preferably, such lthat any portion of the web between any two adjacent belt elements `in one endless belt will always have substantially the same total surface area, regardless of the specific location of the two belt elements when the web is measured. Also, the frictional engagement between the web and the cooperating belt elements insures uniform distribution of the stretch forces. throughout all areas of the web.

Referring to Figs. 7 and 8 of the drawings, the machine has a base plate 65 having an upstanding angle iron 66 at each end of the front orinlet end of the machine, and similar angle irons 67 at each end of the rear or outlet end of the machine. An angle iron 68, similar to

angle irons

66 and 67, extends upwardly from base 65 a short distance forwardly of each angle iron 67. Longitndinalframe members 69 extend between

angle irons

66 and 67 ateach side of the machine. Frame members 69 are preferably `channel irons but may be ofany suitable shape. Transverse frame members (not shown) are secured to channel members 69 at each end thereof to provide a rigid rectangular supporting frame structure.

Triangular corner plates 70 reinforce the joints between angle iron 66 and` channel members 69 at each end of the front portion of the frame, and similar corner plates 71 reinforce the joints between angle iron67 and channel members 69 at each end of the rear portion of the frame. Angle irons 72 extending upwardly from each corner plate 70 have their upper ends tied together by a transverse rod 73, and angle irons 74 extending upwardly from each corner plate 71 have their upper ends tied together by a similar rod 75. A longitudinally extending'bar 76 is secured to corresponding ends of

angle ironsv

72 and 74 at each side of the frame.

A flanged plate 77 is secured to theunderside of each bar 76 adjacent its front end by bolts 78 which extend throughslots (not shown) in bar 76 or plate 77 to permit a limited slidable movement of plate 77 relative to bar 76 for a purpose hereinafter disclosed. An angular bracket 79 rigidly secured tothe underside of bar 76 by a bolt 78has a'flange 80 disposed parallel to a ange 81 depsndnswmllths'adjacent end 0f Plats '77-f 'Amadiusting screw 82 extends'f'throu'gh apertures (not shown) in flanges 80 and S1 to control the sliding movement of plate 77 relative to bar 76. A flanged plate 83 is secured to the top surface of each channel 69 adjacent its front end in the same manner plates 77 are secured to bars 76.

An angle member 84 disposed vertically between channel member 69 and bar 76 at each side of the frame has its upper end secured to plate 77 and its lower end secured to plate 83. A plate 85 is secured to the underside of each bar 76 adjacent its rear end and a similar plate 86 is secured to the top of each channel member 69 adjacent its rear end. Plates y85 and 86 are similar to plates 77 and 83, except that they are not movable relative to bar 76 and channel 69. An angle member 87, similar to angle member 84,'is secured between each pair of plates 85 and 86 at opposite sides of the frame. The open side of the V of each of the vertical angle members 84 faces in the opposite direction from the open side of the V of the vertical angle member 87.

Two vertically spaced sleeve members are slidably mounted on each

vertical angle member

84 and 87. The upper sleeve members are designated by the reference numeral 88, and the lower ones are designated 89. As shown in Fig. 7, each

sleeve member

88 or 89 comprises a pair of V-shaped

plates

90 and 91 screwed together at their outer edges. One of the plates 91 is offset to allow

angle member

84 or 87 to fit in the space provided between

plates

90 and 91 by the offset. A bracket 92 is secured to the back of each

sleeve member

88 or 89 by means of screws 93 which extend through apertures in V-shaped plates 90 to engage the rear edge of the

angle members

84 and 87.

A vertical shaft 94 extends through apertures (not shown) in bar 76, plates 77 and 83, and channel member 69 adjacent the open side of the V-shaped angle o'r each member 84 at the front or inlet end of the machine. The apertures in either plates 77 and 83 or in channel 69 and bar 76, are elongated slightly, so that if angle members 84 are moved relative to the frame, shafts 94 will be movable therewith.

The lower end of each shaft 94 projects below channel member 69 and has a worm gear (not sho-wn) rigidly secured thereto. A shaft 95 extends through corner plates 70 and has a hand wheel 96 secured thereto. Worm wheels (not shown) are mounted on shaft 95 in engagement with the worm gears. Accordingly, manual rotation of wheel 96 in either direction causes both shafts 94 to rotate simultaneously in the same direction. Each shaft 94 is operatively connected to the upper and

lower sleeves

88 and 89, in any suitable manner, so that when shaft 94 is rotated in one direction,

sleeves

88 and 89 moves vertically towards each other. When shaft 94 is rotated in the opposite direction, the sleeves move vertically away from each other. The effects of the vertical movement of sleeves88 and 89 will be described later.

The vertical shaft 97, similar to shaft 94, is rotatably mounted at each side of the machine adjacent the rear end thereof. Shafts 97 are rotated by a hand wheel 96 in the same manner as shafts 94. A removable hand crank can be used instead of hand Wheel 96, to rotate either shaft if desired.

Each of brackets 92 has an opening that is aligned with the opening of another bracket at the opposite side of themachine. As shown in Fig. 8, a shaft 98 is journalled in the upper pair of brackets adjacent the front or feed side of the machine. A drive shaft 99 is journalled in the upper pair of brackets adjacent the rear end of the machine. A shaft 100, similar to shaft 98, is journalled in the lower pair of brackets at the front end j of the machine, and-a second drive shaft 101 is journalled in the lower pair of brackets adjacent the rear end of the machine.

Drive shaft 99 has a sprocket 102 mounted thereon adjacent one end. A collar 103 keyed to shaft 99 holds sprocket 102 in position. Drive shaft 101 (Fig. 8) has a sprocket 104 held in place -by a collar v105 keyed to the shaft. Both shafts-99` and 101 arev driven by an endless chain 106 which extends around the top of each

sprocket

102 and 104 and is looped around an idler sprocket 107 rotatably mounted on corner plate 71, and a sprocketl 108 (Fig. 7 mounted on the shaft 109 of a reducing gear 110 driven -by a suitable motor 111. The travel of chain 106A over the upper edges of both sprockets 102 and` l104 makes these sprockets travel in opposite directions. The motor and reducing gear housing are mounted on base 65.

Shaft 109 also drives another sprocket 112 mounted thereon. As shown, an endless chain 113 extends around sprocket 112 and another sprocket 114 mounted on one endof a shaft `115. Shaft 115 is supported in bearings 116 mounted on the front or feed end of the machine. A sprocket 117 mounted on the other end of shaft 115 has an endless chain 118 extending around it. Chain 118 drives the feeding mechanism by means of a sprocket 119 mountedon a sha-ft 120 which carries the lower rollV of a wet-out device.

The lower roll of the wet-ou is partially immersed in a pan or trough 121 containing water 122. The pan is supported on a transverse channel member l123 which is in turn supported on a pair of upright standards 124 `spaced forwardly of the machine. Shaft is rotatably mounted -in a pair of spaced plates 125 extending upwardly from opposite ends of channel member 123. Plates 125 also support a shaft 126 which carries the upper roll 127 ofthe wet-out. The apertures in plates 125 for shaft 126 are slightly elongated to permit slight vertical movement of roll 127 relative to the lower roll.

An arm 128 pivoted intermediate its length to a stud 129 projecting inwardly from one platelZS also has an aperture fitting around shaft 126. Arm 128 is connected at one end to a piston rodv 130 extending from one end of an air cylinder 131 which is pivotally supported on a standard 124, as indicated at 13-2. The air cylinder regulates the pressure of roll 127 relative to the lower roll to provide the desired moisture content fo-r the web 133 as it is fed through the nip between the rollsof the wet-out to the web stretching mechanism. The lower roll constantly picks up Water on its peripheral surface as it rotates through pan 121 and applies it to the web to keep the web saturated to the desired extent, say about 200 percent to 300 percent. Roll 127 presses the fibrous nonwoven web at the nip or the rolls to squeeze any exless moisture from the web as it passes between the ro s.

Web 133 is fed from a supply roll 134 over an idler roll 135 before it passes between the rolls of the wetout. Supply roll 134 is mounted on a rod 136 supported in arms 137 extending forwardly from standards 124. Roll 134 is preferably rotatable on rod 136, but, if desired, the rod 136 may be rotatably mounted in arms 137. Idler roll 135 is similarly mounted on a rod 138 supported at its ends by ears 139 extending upwardly from each plate 125. A gear 140, mounted on shaft 120 meshes with a -gear 141 mounted on shaft 126 to rotate roll 127 simultaneously with the rotation of the lower roll of the wet-out. The positive drive on both rolls of the wet-out rotates them in opposite directions so as to pull web 133 from the supply roll, around the idler roll and between the rolls of the wet-out in the desired saturated condition. Idler roll 135 is positioned above roll 127 to hold the portion of web 133 being fed to the wet-out up against the'forward portion of the periphery of roll 127. This arrangement tends to prevent the water from the lower roll from reaching the web forwardly of the nipand facilitates feeding the web without tearing.

The web is introduced between inter-meshing rubbersheathed coil spring belt elements 146 of a pair of rotatable endless belts 146A and 146B positioned one abovel the other with the belt elements extending transversely of the machine. The web is engaged lby the intermeshmeneer ing belt elements' at the feed end ofthe machine carried thereby through the machine. The ,belt elements are stretched transversely of the machine and progressively in their travel from the feedto the outlet end of the machine and in doing so effect a simultaneous cross-stretch of the web. In the return travel of the belt elements, from the outlet to the feed end of themachine, the belt elements are permitted to retract to their unstretched `or relatively unstretched posit-ion for engagement with and cross-,stretching of succeeding portions of the web. This portion of the `apparatus will now be described.

The upper endless belt 146A and its associated mechanism is shown in detail inFig. 7 and will be described. The lower endless belt l146B and its associated mecha.- n ism is not shown in detail but it is to be understood that they substantially duplicate belt 146A and its associlated mechanism. For convenience hereafter reference will be made to upper level mechanism and lower level mechanism in referring, respectively, to the upper and lower endless belts and their associated mechanisms.

At each side of the upper level mechanism is a pair of spaced

endless chains

142 and 143 mounted on sprockets 142' which are carried by

shafts

98 and 99. rthe outer chain is designated 142 and the inner Vchain 1.43.

A vertically disposed cam track 144 extends diagonally between each pair of

chains

142 and 143. Each cam track is close to inner chain 143 adjacent the feed end .ofthe machine and close to outer chain 143 adjacent the-rear end of the machine. The cam tracks thus are in a divergent relationship when viewed from the front end of the machine.- The ends of the cam tracks are. secured to'hubs (not shown) on each( of the

shafts

98 and 99 so that the cam tracks remain stationary while the shafts and the endless chains rotate. Each link vof chain 142 is connected to a corresponding link of the adjacent chain 143 by a rod 145.

A plurality of longitudinally extensible belt elements 146 are mounted in spaced'relationship between Ychains M2, transversely of the machine. Each belt elementcomprises a coil spring 147 having its opposite ends secured to a-conical member 148 positioned inside the end members 149 of the belt element. A tubular sheath 150 of stretchable material, such as rubber, encases coil spring 147 and is secured at its ends to end members `149. Each conical member 14S is rigidly secured to one end of a rod 151. The outer end of each rod 1511's secured to a yoke 152. Each yoke is secured to a pair of sleeves 153 slidably mounted on adjacent rods 145. Each yokeA has a cam element 152 which engages the `outer surface of one of thecam tracks 144. As chains 142and 143 are driven around

shafts

93 and 99" the yokes 152 are moved from the feed end ofthe machine towards the discharge end and are moved outwardly by engagement of camelements 152 with the cam'tracks. As the .yokes are moved outwardly they stretch the coil springs `147. As the

chains

142 and 143 reach the limit of theirtravel towards the discharge end of the machine and start back towards the feed end of the machine, springs 147 contract and pull the cam elements inwardly against the outer surface of cam tracks 144.

The vertical disposition of the

sleeves

88 and 89 by operation of hand wheels 96, controls the positions of the upper and lower level mechanisms. It ispreferred that the vertical disposition of

sleeves

88 and 89 be controlled so that the upperand lower level mechanisms are closer together at the feed end of the machine than they are at the discharge end, as shown in Fig. 8, By positioning the upper and lower level mechanismsf` as in Fig. 8, the lower reach of belt elements of vtheupper level mechanism and the upper reach of beltelements of, the lower level mechanism intermesh, substantially ,at the feed end of the machine and the meshingp relationship diminishes progressively from the feed =erd'to the dischargeend, ,as shownin Fig. 9,' until at the discharge-end' thegbelt elementsA alternate but no longer mesh.

The .web 133, saturated with water to the desired extent, say about 200 percent to 300percent, is fed between the extensiblebelt elements of the lower reach of the upper level mechanism and the extensible belt elements ofv the upper reach of the lower level mechanism, and is cross-stretched as it is carried through the machine by the' progressively stretched belt elements. As seen in Figs. 8 and 9, adjacent belt elements of the upper and lower level mechanisms are spaced uniformly from each other.

It has been found that one preferredcondition for successfully stretching a saturated web is that the surface area for a length of `web represented by the linear dimen sion of the web between two corresponding points on adjacent belt elements-of the same series, be kept substantially uniform throughout its passage from the feed end of themachine to the discharge end. To this end the web is puckered transversely at the feed end ofthe machine-,by meshing the belt elements of the upper and lower series with one another as described hereinbefore and the `depth of the transverse puckering is decreased by decreasing the amount of mesh as the belt elements and the web frictionally adhered'thereto pass towards the discharge end of the machine.

The graduated vertical relationship between the belt elements of thefupper and lower level mechanisms is regulated dependent upon the extent to which web 133 is`- to be stretched in the transverse direction. vTo keep the web area subtsantially constant, the amount of long shrinking effected by the machine simultaneously with the cross stretching of the web must be larger for larger amounts of cross stretching. Thus, in general, the more the web is to be cross-stretched in a single pass through the machine, the more the belt elements should be intermeshed at the feed end of the machine.

Another preferred condition for successfully stretching a saturated web is that the stretch be uniform throughout the area of the web. By encasing the coil springs in rubber sheaths, and positioning the saturated web in contact with the rubber sheaths, as described, it has been found that equal pull on the ends of the ,springs produces a uniform stretching effect, so that the web is stretched uniformly throughout its width.

The operation of the cross-stretching machine may be summarized as follows. A fibrous nonwoven web is lsaturated with water, by means of a Wet-out device, say to about 200% to 300%, and is then passed between and in frictional engagement with transversely disposed, alternately meshing'extensible belt elements of an upper and lower endless belt. The longitudinal spacing of thelbelt elements is uniform from the feed end of the machine to the discharge end, but the amount of mesh is vdecreased uniformly from the vfeed'end to the discharge end.l The web is puckered longitudinallyV to a considerableextent at the feed end of the machine by the meshing of -alternate belt elements while at the discharge end ofthe machine the belt elements are vertically displaced out of mesh to an extent sufficient to allow the web to travel in a straight line.

As the extensible belt elements are moved, by

chains

142 and 143, from-the feed'endtowards the discharge end of the machine, the web is maintained in frictional engagement with the belt elements and is uniformly stretched transversely as the belt elements are stretched. As the transverse width of the web increases, the transverse puckering of the web decreases at such a rate that the surface area of thev web measured between two points on any two adjacent belt elements of the same endless'belt is approximately the same whether .measured near .the inlet end or discharge ,end vof the machine, regardlessof the difference in the width `of the web at these points. The overall decrease in the amount of puckeringcompensate's for the over-al1 increase in width so that the 13 area of the web leaving the machine is substantially the same as the area of the web entering the machine.

In addition to the change in the width of the web, the travel of the web through the cross-stretching machine also effects an important change in the Yorientation of the individual fibers of the web. At the feed end of the machine about 70 percent to 90 percent of the fibers are oriented in a general longitudinal direction. As the web moves through the machine the orientation of the fibers is gradually changed so that at the discharge end the fibers are disposed with their average angle with respect to the longitudinal axis of the web increased. This change in the direction of the fibers results in a very substantial increase in cross strength of the web and a less than proportional decrease in the long strength thereof.

The web is comparatively narrow as it enters between the first meshing pair of belt elements adjacent the feed mechanism. At this point the fibers of the web are generally oriented in the longitudinal direction of the web. The web remains in frictional engagement with the rubber sheathing of the belt elements and is gradually stretched transversely as the belt elements are stretched. As the web travels to the discharge end of the machine the fibers are gradually moved towards transverse orientation. The

lsurface of the web, no portion of the web is subjected to strain sufficient to tear it. Although the stretching may be continued until the fibers are generally oriented more in a transverse than in a longitudinal direction, it is preferred to limit the stretching to a point where the degree of ber orientation is approximately 50 percent, as this arrangement provides maximum tensile strength for the fabric made by bonding the cross-stretched web.

In order more clearly to disclose the invention, several specific examples will now be described. It should clearly be understood, however, that this is done solely by way of example and not for the purpose of delineating the breadth or scope of the invention.

Example I In this example, the carrier sheet comprised an island bonded nonwoven fabric of 550 grains per square yard. The carrier sheet was bonded with a staggered pattern of doughnut-shaped binder areas covering about 30 percent of the total lateral surface of the fabric. The carrier sheet had a long-to-cross tensile strength ratio of about 7 to l to l() to l, and was made as described in the aforesaid Ness, Lints, and Petterson Patent 2,705,688.

On top of this carrier sheet was placed a heavy web of carded rayon and cotton fibers, weighing about 450 grains per square yard. The composite structure was impregnated with an aqueous dispersion of latex of polyvinyl chloride copolymer sold by the B. F. Goodrich Company under the trademark Geom Thereafter the carrier sheet with the wet cohering web thereon was cross-stretched 80 percent, or until the width of the stretched `fabric was 180 percent of that of the unstretched fabric. The carrier sheet was then separated from the -reoriented card web, the carrier sheet was discarded and the separated web was dried and bonded.

The resulting product had a substantially uniform appearance and a long-to-cross tensile strength ratio of 1 to 1.

YExample Il In this example, the procedure was the same as that of Example I, except that'the card web was 100 percent shoddy cotton fibers. The long-to-cross tensile strength ratio of the finished product was 1 to 1.

. 14 Example Ill In this example, the carrier sheet consisted of a knitted fabric. The same card web as that used in Example I vwas placedon top of the knitted fabric, the two were impregnated with polyvinyl chloride latex (Geon) and stretched percent. The reorientedcard web while still wet was separated by peeling it ofi of the carrier sheet. The reoriented web was then dried and bonded.Y The long-to-cross tensile strength ratio of the bonded product was l to 1.

Example IV Example V The process was the same as that of Example IV except that the card web consisted of shoddy. After 80 percent stretch, the reoriented and bonded card web had a long-to-cross tensile strength ratio of 1 to 1.

Example VI In this example, the procedures was the same as that of Example IV, except that in the cross-stretching step, the stretch was 200 percent, so that the width of the ultimate fabric was 300 percent of that of the original card web. The long-to-cross tensile strength ratio of the finished fabric was l to 7 (the `reverse of the ratio that would have resulted if the original card web has been impregnated in the same way, but without the crossstretching step).

l Example VII I In this example, the procedure was similar to that of Example VI, except that after the wet reoriented card web was separated from the carrier sheet, it was laid on top of a 550 grain card web, the two were impregnated :with aqueous polyvinyl chloride latex ("Geon) and then dried and bonded. The product weighted 1500 grains per square yard. The long tensile strength and cross tensile strength of the fabric were equal (19 pounds per inch). The appearance and tear strength of the pseudo cross-lay product was excellent.

Example VIII yIn this example, we used a carrier sheet identical with that of Example I, except that it was an all-viscose fabric having weight of 750 grains/ square yard. On top of this carrier sheet was placed an all-viscose card web of 750 grains/square yard weight. The product was wet-ou with aqueous polyvinyl chloride emulsion (Geon) and stretched percent. The reoriented and impregnated card web was then peeled off of the carrier sheet and plied with 750 grain weight all-viscose card web. The dried product weighted 1800 grains/square yard. Its long tensile strength was 19 pounds per inch while its cross tensile strength was 30 pounds per inch. Thus, in this example, reversal of long to cross tensile strength ratio was effected at about 130 percent stretch (width of finished fabric, 230 percent that of starting material).

The fabric produced in all the above examples were excellent in uniformity and appearance.

In carrying the present invention into practice, we may use any of the conventional web-forming, bonding and drying operations and devices, well-known in the art, and any of the conventional binder media of the prior art. Typical procedures and binder media applicable inthe practice of the present invention include, for example, those disclosed in the Joshua Goldman Patent 2,039,312,

agsagsev 1:5 the Joseph Goldman Patent' 2,407,548, and the Ness, Lints, and Petterson Patent 2,705,687. These operations and media, being well-known and conventional, need not be described herein, since reference may readily be made' to the ,prior art, including the patents mentioned;

Having now described the invention in specific detail and exemplified the manner in which it may be carried into practice, those skilled in the art will readily appreciate that innumerable variations, ampliiications, modifications, and extensions of the basic principles involved may be made without departing from the spirit or scope of our concept. For example, although we have illustrated the application of the invention to the preparation of a relatively heavy fabric, various types of fabric produced as herein described may be made from webs ranging from lightweight webs (i.e., 100 to 500 grains per Vsquare yard) all the way to heavyweight webs (i.e., 500

`to 5000 grains per square yard). The resulting fabrics may be used in the manufacture of various types of surgical, medical, and iirst aid dressings and related products (including sanitary napkins), or in the manufacture of industrial fabrics, including artificial leather. These and many other modifications will be readily apparent to those skilled in the art. We therefore intend to be limited only in accordance with the appended patent claims.

The term textile fibers as used herein includes conventional textile fibers that are capable of being spun into yarn and woven into cloth. Generally speaking this includes fibers whose length vary from approximately one-fourth to one-third of an inch as the lower limit to approximately two or more inches in staple length. These iibers may be natural fibers, such as iibers of cotton, wool, jute, ramie, or abaca; or artificial fibers of viscose rayon, cuprammonium rayon, cellulose acetate, nylon, dynel or other materials, alone or in combination with lone another.

A wide variety of binders may be used to convert the reoriented web into a fabric. For example, water softenable materials including the following may be used: beaten cellulose jellies of woodpulp, caroa, ramie, etc.; natural gums including karaya, locust bean, gum arabic and others; starches; and synthetics, such as polyvinyl alcohol, carboxymethylcellulose, polyvinyl acetate, etc. Suitable binders, softenable by solvents other than water, are exemplified by polyvinyl chloride and polyvinyl butyral and their copolymers. Nonreversible binders such as urea-formaldehyde and melamine-formaldehyde resins may also be used.

The terms unbonded nonwoven web, unbonded nonwoven textile fiber web, and the like, when used in the Vspecification and claims, mean a web wherein the bers are substantially free to move with respect to one another under externally applied forces. This will include webs containing no bonding material at all, as well'as those containing bonding material which is not set or effective to prevent the fibers from moving with respect to one another. Thus a web of iibers, suitably an oriented web of iibers, may be impregnated lightly with an aqueous dispersion of binder and its fibers then may be reoriented 1n accordance with this invention before the binder becomes set.

We claim:

1. A method of reorienting the fibers of a textile iiber web which are oriented predominately in a given direction which comprises, cohering an unbonded oriented textile fiber web to an extensible carrier sheet material *in the direction transverse to the stretching direction, and thereafter separating the treated web from the carrier sheet.

2. `A method iof reorienting `the fibers of -a textile Iiber web which'jare oriented predominately in*v a given direction which comprises," cohering an unbonded oriented textile liber web to an extensible'carrier and stretching the carrier and with it the cohering oriented web in a direction normal to the original direction of liber orientation ofthe said web while permitting the carrier and the said web to shrink in the direction transverse to the stretching direction, and thereafter separating the web from the carrier.

3. A method of reorienting the fibers of a textile fiber web which are oriented predominately in a given direction which comprises, supporting an unbonded oriented textile fiber web upon and in cohering relation with a laterally extensible carrier sheet material while stretching said sheet material and the thereunto cohering oriented web in a direction normal to the original direction of liber orientation of the cohering web and at the same time permitting the said carrier sheet and thesaid web to shrink.

4. A method of reorienting the iibers of a textile iiber web oriented predominately in a given direction which comprises, maintaining said oriented web in wet coheringv contact with a laterally extensible sheet material while the latter is undergoing lateral extension in a direction normal to the original direction of fiber orientation of said oriented web; separating the cohering web from the supporting sheet material and adhesively anchoring the bers of the reoriented web to one another to form a nonwoven fabric therefrom.

5. A method which comprises supporting an `unbonded oriented textile fiber web upon and in cohering relation with a laterally extensible carrier sheet material, increasing the dimensions of said carrier sheet and with it the cohering web in a direction normal to the original direction of fiber orientation of the thereunto cohering web while decreasing the dimensions of said carrier sheet and the said web in the original direction of fiber orientation, whereby to reorient the iibers of the cohering web, and then separatingthe reoriented web from the carrier.

6. The method of claim 5 wherein said oriented web.

and said carrier are maintained in wet contact with each other.

7. The method of claim 5 wherein said oriented web in cohering contact with said carrier sheet is impregnated with an aqueous binder.

8. The method of claim 5 wherein the reoriented iibers in-said reoriented web, after separation of the latter from said carrier sheet, are adhesively bonded together to form a nonwoven fabric.

9. The method of claim 5 wherein the reoriented web, after separation from said carrier sheet, is impregnated with a binder and the binder then set.

l0. A method which comprises supporting an unbonded oriented textile fiber web upon and in cohering relation with va laterally extensible carrier sheet material while stretching said sheet material and the thereunto cohering web in a direction normal to the original direction of liber orientation of said cohering web and at the same time permitting the said carrier sheet and the said web to shrink, thereafter separating the cohering web from carrier sheet, plying the separated web with another web and cobonding the webs to form a composite nonwoven fabric.

11. A method which comprises applying a potential rebonding composition to an oriented, unbonded web of textile fibers, supporting said web upon a laterally extensible carrier sheet; deforming the carrier sheet, with the oriented web cohering thereto, in the plane of the sheet by increasing its dimensions transverse to the predominant iiber direction of the cohering web and decreasing the sheets dimensions parallel to the predominant fiber direction of the cohering web; separating the web from the carriery sheet; and developing the bonding properties of the potentialrebonding composition-in the web, whereby to anchor the bers of said web to one another.

12. A method of making a pseudo-isotropic fabric from a web comprising a major proportion o-f oriented textile fibers, which. comprises supporting said web upon a laterally extensible carrier sheet; stretching said carrier sheet in a direction transverse to the direction of b'er orientation of the thereon supported web, while the web is wet, to effect reorientation of the iibers of said web; separating the reoriented web from said sheet, applying to the web a binder; and setting the binder in the web to fix the libers in their reoriented state and produce a fabric that is substantially isotropic in its physical properties.

13. The method of claim 12 wherein said web is stretched to at least 150 percent of its original Width.

14. A method of reorienting the iibers of a textile ber web which are oriented predominately in a given direction which comprises, engaging an unbonded nonwoven oriented textile fiber web with an extensible carrier and stretching the carrier and with it the web in a direction normal to the original direction of fiber orientation of the engaged web While effecting shrinking of the web in the direction of the original direction of fiber orientation, and thereafter disengaging the treated web from the carrier.

15. A method of reorienting the fibers of a textile ber web which are oriented predominately in a given direction which comprises, engaging a wet unbonded nonwoven oriented textile fber web with an extensible carrier and stretching the carrier and with it the web in a direction normal to the original direction of fiber orientation of the engaged web while effecting shrinking of the web in the direction of the original direction of fiber orientation, and thereafter disengaging the treated web from the carrier.

16. A method of reorienting the fibers of a textile fiber web which are oriented predominately in a given direction which comprises, engaging a Wet nonwoven oriented textile fiber web with an extensible carrier and stretching the carrier and with it the web in a direction normal to the original direction of liber orientation of the engaged Web while effecting shrinking of the web in the direction of the original direction of iber orientation, and thereafter disengaging the treated web from the carrier.

17. A method of reorienting the iibers of a wet unbonded nonwoven textile fiber web wherein the fibers are oriented predominantly in a given direction which comprises, increasing the dimension of the said web in a direction normal to the original direction of fiber orientation and simultaneously effecting a corresponding decrease in the dimension of the Web in the original direction of liber orientation, so that the resulting reoriented web has an area substantially the same as the area of the starting web.

References Cited in the tile of this patent UNITED STATES PATENTS 2,171,551 Hannig Sept. 5, 1939 2,483,406 Francis Oct. 4, 1949 2,502,361 Zeigler Mar. 28, 1950 2,503,024 Boese et al. Apr. 4, 1950 2,528,793 Secrist Nov. 7, 1950 2,546,230 Modigliani Mar. 27, 1951 2,719,336 Stotler Oct. 4, 1955 2,777,787 Bragg Jan. 15, 1957 2,880,112 Drelich Mar. 31, 1959

Claims

1. A METHOD OF REORIENTING THE FIBERS OF A TEXTILE FIBER WEB WHICH ARE ORIENTED PREDOMINATELY IN A GIVEN DIRECTION WHICH COMPRISES, COHERING AN UNBONDED ORIENTED TEXTILE FIBER WEB TO AN EXTENSIBLE CARRIER SHEET MATERIAL AND STRETCHING THE CARRIER SHEET AND WITH IT THE COHERING ORIENTED WEB IN A DIRECTIONAL NORMAL TO THE ORIGINAL DIRECTION OF FIBER ORIENTATION OF THE SAID WEB WHILE PERMITTING THE SAID CARRIER SHEET AND THE SAID WEB TO SHRINK IN THE DIRECTION TRANSVERSE TO THE STRETCHING DIRECTION, AND THEREAFTER SEPARATING THE TREATED WEB FROM THE CARRIER SHEET.