US3531363A - Nonwoven fabric - Google Patents

Description

Sept. 29, 1970 c. SHAMBELAN uonwovnu FABRIC 3 Sheets-Sheet 1 Filed Jan. 6, 1967 FIG.

CHARLES SHAMBELAN WATER SUPPLY ATTORNEY p 29, 1.970 c. SHAMBELAN 3,531,363

NONWOVEN FABRIC Filed Jan. 6, 1967 3 Sheets-Sheet 2 F l G 3 l G 4 LAYER l E Sl 3 LAYER L g /WER 2 E Q Q @ZLAYER 5 L ,fiw N W Y LAYER e 7-aono s TEs Wm Y\ R I LAYER 4 J I i Y m WQY V w L aw LAYER 5 F Y G. 6 n n m' H m mus w 4 I Y R LAY-ER 3 INVENTOR CHARLES SHAMBELAN ATTORNEY BOND Q I x snIEs-m Y LA ER l p 29, 1970 c. SHAMBELAN 3,531,333

NONWOVEN FABRIC Filgd Jan. 6, 1967 3 Sheets-Sheet 3 F G 7 F i G. 8 N fiT E M Z ZLAYEFYI m o N M i LAYER 9 LAYER 5 L Y /?J BOND l LAYER7,

I /l S|\TE L\ E N 9 b/m LAYERs a. N K 1 LAYER K) LAYER4 LAYER 6 LAYERZII LAYER a I F I A 9 Z V 2 R5 2:3

C C BOND SITE 1\ Y Z L&/ JZ/E /2Z INVENTOR CHARLES SHAMBELAN BY MZM ATTORNEY United States Patent 3,531,363 NONWOVEN FABRIC Charles Shambelan, Chattanooga, Tenn., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Jan. 6, 1967, Ser. No. 607,842 Int. Cl. D04h 3/04 US. Cl. 16172 ABSTRACT OF THE DISCLOSURE Nonwoven fabric having conformability and drape similar to woven fabrics is provided by an assembly of three or more layers of warp-like arrays of filaments or yarns. At least two layers are arranged with the filaments or yarns in superimposed relationship and at an angle to those of one or more other layers, preferably crossing at a 90 angle. The superimposed filaments or yarns are united between the intersections with crossing filaments, or yarns, to hold the assembly together, whereas mobility is provided at the intersections of crossing filaments or yarns. The union between intersections may be accomplished by self-bonding or adhesive-bonding, or by fiberinterentangling with fine streams of liquid jetted at high pressure.

Background of the invention This invention relates to drapeable nonwoven fabrics made from intersecting warp-like arrays of yarns and/ or filaments.

Nonwoven fabrics have been prepared in the past by assembling intersecting arrays of filaments or yarns and bonding the arrays together, either by application of an adhesive or by fusion of thermoplastic fibers present in the assembly. The bonding techniques and yarn arrangements employed resulted in products wherein the filaments or yarns were rigidly bonded at their intersections, the binder often also being present throughout the product, including the interstices thereof. As a result, the prior art nonwoven fabrics were still, inflexible and generally harsh to the touch so that they were unsuited for use as apparel.

Summary of the invention The present invention provides a nonwoven fabric comprising intersecting filaments or yarns which are integrally united in the fabric but are free to move with respect to one another at their intersections, whereby the nonwoven fabric has bias stretch properties like those of a woven fabric when subjected to in-plane shear. These nonwoven fabrics are particularly desirable for apparel and other uses which require conformability and drape. The present invention also provides nonwoven fabrics wherein little or no adhesive or other binder is used, whereby the fabrics have a soft, aesthetically pleasing hand. The present invention also provides for the production of nonwoven fabrics having the behavior characteristic of a woven fabric without the costly step of weaving. These and other advantages of the invention will become apparent from the following disclosure.

The products of the present invention are nonwoven fabrics comprising at least 3 layers of warp-like arrays of yarns and/or filaments, hereinafter referred to simply as strands, arranged so that the strands of adjacent layers intersect at an angle, while the strands of selected nonadjacent layers (for example, the strands of the top and bottom layers of the fabric) are parallel and in superimposed relationship with respect to one another, the strands in the selected layers being united to one another only in the regions where these strands overlie one another, i.e., in the spaces between crossing strands of inter- 2 Claims Patented Sept. 29, 1970 mediate layers. Selection of the layers, which are to be in register and united between intersections in the fabric, is arbitrary with the exception that at least those layers are chosen which, when bonded, will hold all the remaining layers together in the fabric. For a simple 3-layered assembly, the selected layers must be the top and bottom layers. For other assemblies having an odd number of total layers, at least the top and bottom layers must be selected. For assemblies having many layers, various arrangements are possible as may be seen in the examples. Since the strands of the nonwoven fabric are not rigidly united to one another at their intersections, individual strands of the fabric are free to slide along one another when the fabric is pulled in the bias direction. Furthermore, the nonwoven fabric exhibits the same trellis-like behavior which is responsible for the drape and conformability of woven fabrics, when subjected to a shearing stress in the plane of the fabric. Preferably the strands of adjacent layers intersect at a angle to provide an appearance like that of woven fabric.

By Warp-like array, as used herein, is meant a layer of strands which lie substantially in one plane, are laterally spaced from one another, and are substantially parallel to one another.

The term strand as used herein includes any type of continuous fibrous element used in making up the warplike array. The strand may be a single filament or a yarn composed of continuous filaments or staple fibers.

Bonding of the strands of alternate layers to one another may be accomplished by any means, including adhesive bonding, self-bonding, e.g., by treatment with heat, solvent or softening agent for the binder strands. However, bonding is not necessary as the strands can be united by stitching and/or entanglement of strand fibers with one another. Fabric preparation, however, must be carried out so as to preclude rigid bonds or unions at strand intersections in the final products.

Brief description of the drawing F for accomplishing this in high-speed, continuous production of nonwoven fabrics of this invention,

FIG. 3 is a schematic top view of a three-layer fabric prepared from bulk yarns as described in Example I,

FIGS. 4 and 5 are schematic top views of a four-layer v fabric to illustrate Example II,

FIGS. 6 and 7 are schematic top views of a five-layer fabric to illustrate Example III, and

FIGS. 8 and 9 are schematic top views of an eight-layer fabric to illustrate Example IV.

Description of specific embodiments In one embodiment of the present invention, the warplike arrays are formed from continuous filaments and/ or yarns and a special self-bonding or adhesive-bonding technique is employed to cause the strands of the selected layers to adhere between strand intersections. Self-bonding may be achieved by hot-embossing of the layered assembly, using an embossing plate having the bosses or projections thereof programmed to touch the strand assembly at locations between strand intersections. Bonding may also be accomplished by treating the strand assembly at the selected locations with a suitable adhesive, for example, by the use of a roll applicator programmed to print-bond the assembly only at intervals corresponding to the locations between strand intersections.

As illustrated in the examples, three or more warplike arrays of continuous filament yarns or staple fiber a yarns can be assembled in layers with warp-like arrays formed from binder filaments. The warp-like arrays are placed one on top of the other, adjacent layers being at 90 to each other. A warp-like array of binder filaments is employed between the selected layers, the binder filaments being so situated that upon application of heat and pressure, they are melted to thereby bond the yarns of the selected yarn layers between yarn intersections. By use of this bonding method, strong products having a very low binder content are obtained, whereby the nonwoven fabric has a pleasant, soft texture with none of the disadvantages associated with high binder content.

In a preferred embodiment, the nonadjacent layers of warp-like arrays to be united are formed from bulk yarns, i.e., bulky, textured and stretch yarns as defined by A.S.T.M. Dl23-63 Standard Definitions of Terms Relating to Textile Materials. These yarns have a fiber arrangement which provides free length or crimp along the fibers of the yarn and/or a number of free ends, loops, kinks, curls, and/or twists capable of interentanglement with one another. The layered assembly of three or more warp-like arrays is treated to entangle fibers of the bulk yarns, in the selected layers of the assembly, between intersections with crossing strands. Entanglement is preferably achieved by treating the assembly with fine columnar streams of a liquid, such as water, jetted at 200 p.s.i.g. or higher pressure. When using a suitable supporting member, the streams will automatically align the bulk yarns and unite them so securely that binder is not required.

When the layered assembly comprises strands in two major directions of the fabric at 90 to one another, the nonwoven product may be treated in the bias direction to achieve the desired uniting in both major directions at the same time. If high pressure streams of liquid are used to entangle the strands of the selected layers, the assembly is passed under the streams in the bias direction and the streams are spaced so as to strike the assembly at intervals between strand intersections. Adhesive or binder fibers may similarly be applied at spaced intervals between strand intersections in the bias direction of the assembly after which the asembly may be treated to set the adhesive or to activate the binder fiber. Methods of achieving the desired bonding are discussed in more detail in connection with the illustrations.

The warp-like arrays may be prepared and assembled by any suitable conventional means. Suitable apparatus for cross-laying of warp-like arrays is described in Slayter et al., U.S. Pat. No. 2,797,728, issued July 2, 1957.

A relatively simple form of equipment for treating the yarn assembly with fine streams of water jetted at the required high pressure is illustrated in FIG. 1. Water at normal city pressure of approximately 70 pounds per square inch (p.s.i.) (4.93 kg./cm. is supplied through valve 1 and pipe 2 to a high-pressure hydraulic pump 3. The pump may be a double-acting, single-plunger pump operated by air from line 4 (source not shown) through pressure-regulating valve 5. Air is exhausted from the pump through line 6. Water at the desired pressure is discharged from the pump through line 7. A hydraulic accumulator 8 is connected to the high-pressure water line 7. The accumulator serves to even out pulsations and fluctuations in pressure from the pump 3. The accumulator is separated into two chambers 9 and 10 by a flexible diagragm 11. Chamber 10 is filled with nitrogen at a pressure of one-third to two-thirds of the desired operating water pressure and chamber 9 is then filled with water from pump 3. Nitrogen is supplied through pipe 12 and valve 13 from a nitrogen bottle 14 equipped with regulating valve 15. Nitrogen pressure can be released from system through valve 16. Water at the desired pressure is delivered through valve 17 and pipe 18 to manifold 19 supplying orifices 20. Fine, essentially columnar streams of water 21 emerge from orifices and iimpinge on the yarn assembly 22 supported on member 23.

The streams are traversed over the assembly by moving the member 23 and/or the manifold 19, until all parts of the assembly to be treated are entangled. In general, it is preferred that the assembly be treated by moving member 23 under a number of fine, essentially columnar streams, spaced apart across the Width of the assembly being treated. Rows or banks of such spacedapart streams can be utilized for more rapid, continuous production. Such banks may be at right angles to the direction of travel of the assembly, or at other angles, and may be arranged to oscillate to provide more uniform treatment. Streams of progressively increasing pressure may be impinged on the assembly during travel under the banks. The streams may be made to rotate or oscillate, may be of steady or pulsating flow, and may be directed perpendicular to the plane of the assembly or at other angles, provided that they impinge on the assembly at sufl'iciently high pressure.

Apparatus suitable for use in continuous production is shown schematically in FIG. 2. A pump 25, which may be one of the types used for supplying water to high pressure steam boilers, is used to provide liquid at the required pressure.

A yarn ansembly 29, prepared by conventional means such as the cross-laying apparatus as described for example in Slayter et al. US. Pat. No. 2,797,728 issued July 2, 1957, is supplied continuously to a moving carrier belt 31 of flexible foraminous material, such as a screen. The carrier belt is supported on two or more rolls 32 and 33 provided with suitable driving means (not shown) for moving the belt forward continuously. Six banks of orifice manifolds are supported above the belt to impinge liquid streams 34 on the yarn assembly at successive positions during it travel on the carrier belt. The assembly passes first under orifice manifolds 35 and 36, which are adjustably mounted. Orifice manifolds 37, 38, 39 and 40 are adjustably mounted on frame 41. One end of the frame is supported for movement on a bearing 42, which is fixed in position. The opposite end of the frame is supported on oscillator means 43 for moving the frame back and forth across the fibrous layer to provide more uniform treatment.

High pressure liquid is supplied from the pump 25 to the orifice manifolds through pipe 18. Each manifold is connected to pipe 18 through a separate line which includes flexible tubing 44, a needle valve 45 for adjusting the pressure, a pressure gage 46, and a filter 47 to protect the valve and jet orifices from foreign particles. As indicated on the gages in the drawing, the valves are adjusted to supply each successive orifice manifold at a higher pressure, so that the assembly 29 is treated at increasingly higher pressure during travel under the liquid streams 34.

The invention will be better understood from the following examples of specific embodiments of nonwoven fabrics provided in accordance with this invention. The examples are not intended to be limitative.

Example I This example illustrates the preparation of a nonwoven fabric from three warp-like arrays of bulk yarns, the yarns being mobile at the yarn intersections in the finished 7 fabric, uniting of the yarns being achieved by entanglement with water streams, in an arrangement shown in FIG. 3.

Three warp-like arrays are prepared from highly crimped, bulk stretch yarn prepared from continuous filament nylon yarn having a total denier of 40 and containing 13 filaments. These arrays are assembled on a screen of plain weave, 6 x 6 wires/inch (2.38 x 2.38 wires/cm.) and mil diameter wire (2 mm. diameter), having a surface characterized by intersecting channels or grooves located between the wires. The first layer of highly crimped yams placed on the screen is a 0.5 oz./ yd. warp-like array of the yarns; the second layer is a warp-like array, weighing 1 oz./yd. and placed on the first array perpendicular to the yarns thereof; the third layer is a 0.5 oz./yd. array like the first layer and is placed on top of the second layer, with its yarns parallel to the yarns of the first layer.

The yarn assembly is kept on the screen during treatment and is passed under essentially columnar streams of 50 C. water issuing from a line of 0.005 inch orifices arranged in a manifold. Treatment is done with the assembly approximately in contact with the orifices. The assembly is passed under the streams using water pressures and passes as follows: passes at pressures from 500 to 1900 p.s.i.g. (35 to 133 kg./cm. gauge) using a top screen to help keep the yarns in place during treatment, followed by treatment at 500 to 1900 p.s.i.g. (35 to 133 kg./crn. gauge) Without the top screen. The assembly is passed under the manifold with the yarns of the top and bottom layers being perpendicular to the axis of the manifold. This treatment results in alignment of the yarns of each layer in the grooves, spaced 6/ inch in each direction of the screen, to form a final fabric having 6 yarns/inch in each direction. The treatment also preferentially results in interentanglernent of the fibers of the bulk yarns in the top and bottom layers, where two yarns overlie one another, but not in the intersections where 3 thicknesses of yarns are present.

The assembly is then removed and dried, The yarns are free to slide along one another at the intersections when the fabric is pulled in the bias direction and, as a result, the fabric has particularly good conformability and drape.

Another sample was prepared in a similar fashion and physical property determinations were made after steaming to fully relax and crimp the nonwoven and to produce a final basis weight of 7.5 oz./yd. The physical properties were:

Tensile strength:

MD lb./in./oz./yd. 6.2

XD lb./in./oz./yd. 5.0 Elongation:

MD percent 150 XD do 217 Modulus, 5% secant:

MD lb./in./oz./yd. 0.22

XD lb./in./oZ./yd. 0.17

The 5% secant modulus is determined in accordance with ASTM Standards E6-61, part 10, page 1836.

Example II This example illustrates preparation of a 4-ply nonwoven fabric with its yarns bonded between intersections by use of binder.

A four-ply nonwoven fabric is prepared from a six layer arrangement of yarns and binder filaments. The first and fifth layers are composed of Warp-like arrays of yarns, which run in a longitudinal direction and are in register. Warp-like arrays of yarns, which run transversely, make up the second and sixth layers, the yarns of both layers being in register. A warp-like array of binder filaments running longitudinally, makes up the third layer. The fourth layer consists of a warp-like array of binder filaments, running transversely. The following table, taken with FIG. 4, summarizes the initial arrangement of the filaments and yarns.

When the initial strand assembly is viewed in plan, as in FIG. 4, it may be seen that each binder filament is evenly spaced between the yarns which run in the same direction but are located in the layers above and below the binder filaments.

All yarns in this example are continuous filament yarns, having 34 filaments of polyethylene terephthalate With a total denier of 70. They are evenly spaced in each layer at 25 yarns per inch. The binder filaments, which are also spaced in each layer at 25 filaments per inch, are of 10 denier per filament and are made from an 80/20 copolymer of poly(ethylene terephthalate)/poly(ethylene isophthalate).

The assembly of layers is placed in a Pasedena press where bonding is effected at a temperature of about 195 C. and a pressure of about 1500 p.s.i. The duration of the bonding step is approximately 5 minutes. During this step the identity of the binder filaments is lost; the binder flows primarily to the locations where the in-register yarns crossed the binder filaments in the initial assembly. Thus the in-register yarns are bonded to each other, while the intersections between longitudinal and transverse yarns are left relatively free of binder. After the press is cooled and pressure released, the fabric is removed from the apparatus. The final product is made up of 4 layers of yarns bonded together as shown in FIG. 5.

To assure that the finished fabric is bonded primarily between yarn intersections, rther than at intersections, tension is applied to the fabric in the longitudinal and transverse directions successively, and at a 45 angle to the yarns. This treatment preferentially breaks any bonds that may have formed at yarn intersections as a result of undesired binder flow to these locations. The treatment is preferential because the bonds at the intersections are weaker than those between intersections and because the stress placed on the intersections is greater than at the sites between intersections. In other words, when bias stretching loads are placed on the fabric, bonds at yarn intersections are in torsion and therefore break; bonds located between the intersections readily carry the load because they are under simple tension. The final nonwoven fabric is substantially free of bond sites at yarn intersections.

The fabric made by the above procedure exhibits a high degree of three-dimensional conformability, good cover and excellent dimensional stability. The unit weight of the fabric prepared in this example is one oz./yd. Yarn-direction tensile-strength is about 35 lb./in.//oz./ yd. with an elongation below 20%. The fabric exhibits the desired free-shear trellis-type action at yarn intersections which provides it with the bias-stretch properties possessed by woven fabrics. Total binder content of the structure is only 6.7% based on yarn weight.

Example III This example illustrates preparation of a 5-ply fabric, the yarns of which are bonded between intersections by use of binder filaments.

A five-ply assembly is prepared by layering warp-like arrays of denier, 56 filament polyethylene terephthalate yarns, and 2-filarnent binder strands of 3 d.p.f. polyethylene terephthalate/isophthalate (/20) copolymer. A plan view of the initial assembly of yarns and filaments is shown in FIG. 6 and the following table summarizes the arrangement of the layers.

Strands in Strands in Register Register Strand Strand with Those Strand Strand vs itn Those Layer Direction Type of Strand Spacing of Layer No. 70 Layer Direction Type 01 Strand Spacing of Layer N o.

1 Longitudinal. Yarn 25/ineh 5 1 Transverse Yarn 24/ineh 5 2... Transverse .;do 25/ineh.. 6 .d

LongitudinaL... Binder filament. 25/inch Transverse o 25/ineh 5 Lcngitudinal.-. Yarn 25/inch. 1 G Transverse do 25/inch. 2

ib/inch 5 Transverse Sam 24/1neh. 1

The assembly is prepared as follows: Transverse yarns are spaced 24 per inch in the first layer. A second layer of yarns spaced at 24 per inch is placed perpendicular to the first layer, thereby forming a longitudinal layer. The yarns of the third layer are transverse yarns that are evenly spaced at 24 per inch, and offset by A of an inch from the yarns of layer 1. The fourth layer comprises both yarns and filaments oriented longitudinally. First the longitudinal yarns layer 4a) are placed at 24 per inch offset of an inch from the longitudinal yarns of layer 2. Then the longitudinal binder filaments of layer 4b, offset A of an inch from the longitudinal yarns of layers 2 and 4a, are evenly spaced at 48 per inch. Thus, the binder filaments (4a) and yarns (4b) lie in essentially the same plane. The fifth layer is of transverse yarns, spaced at 24 per inch and in register with the transverse yarns of layer 1. Thus, the transverse yarns of layers 1 and 5 sandwich the entire arangement.

The assembly of yarn and filament layers is placed in a Pasedena press and bonding is effected as in Example II. During the bonding treatment the binder flows primarily to locations where the binder filament is initially sandwiched between yarns of layers 1 and 5. Because the binder filaments lose their form as filaments, the final fabric is a 5-ply structure bonded as shown in FIG. 7. A light tensioning treatment, as in Example II, assures that the bonds are located primarily between yarn intersections and not at them.

The final nonwoven weighs one oz./yd. exhibits the desired trellis-like action at the yarn intersections, and has a high degree of drapeability, excellent cover, and good dimensional stability. Tensile strength in the yarn direction is about 35 lb./in.//oz./yd. with an elongation below 20%. Total binder content of the fabric is only about 4%, based on yard weight.

Example IV This example illustrates preparation of an 8-ply nonwoven fabric with its yarns bonded between intersections by use of binder filaments.

The 8-ply fabric is prepared from a IO-layer arrangement of yarns and filaments. The same polymers as used in Example II are used for the fabric yarns and binder filaments of this example. FIG. 8 is a plan view showing the initial assembly of yarn and filament layers, which are arranged as tabulated below. The strand spacing in each layer is 28/inch.

Referring to FIG. 8, it may be seen that the first and ninth layers comprise transverse, in-register yarns. The second and tenth layers comprise longitudinal, in-register yarns. The third and fifth layers comprise transverse yarns that trisect the lateral distance between the pairs of inregister yarns of layers 1 and 9. Thus, in plan view, there is the repetitive pattern of equally spaced transverse yarns: those of layers 1 and 9 (which are in register), followed by those of layer 3, followed by those of layer 5. The longitudinal yarns of layers 4 and 6 are located in relation to the in-register longitudinal yarns of layers 2 and 10 in the same manner as the transverse yarns of layers 3 and 5 are located in relation to the in-register, transverse yarns of layers 1 and 9. Layer 7 and layer 8 are composed, respectively, of transverse and longitudinal 8 binder filaments which are located equidistant from successive parallel, in-register yarns.

This arrangement of yarn and filament layers is then bonded in a Pasadena press as in Example 11. During bonding, the binder filaments lose their identity and binder flows to the locations where the binder filament is initially sandwiched between the in-register yarns, whereby the eight-layer bonded nonwoven fabric structure of FIG. 9 is obtained. As in Example II a tensioning treatment assures that the bonds are located primarily between yarn cross-over points.

The fabric of this example weighs 1.9 oz./yd. and contains only about 3% binder based on yarn weight. The fabric exhibits the desired trellis-like characteristic, has a high degree of drapeability, excellent cover, and good dimensional stability. Tensile strength in the yarn directions is about 35 lb./in.//oz./yd. with an elongation of less than about 20%.

In the foregoing examples, the tensile properties are measured on an Instron tester at 70 Fjand 65% relative humidity. Strip tensile strength is determined for a sample 0.5 inch wide, using a 2-inch sample length and elongating at per minute.

The nonwoven fabrics of the present invention may be used in any of the conventional uses for which woven or knitted fabrics are commonly employed. Their drape and conformability makes them particularly suitable for use in clothing-upholstery materials, and the like, which require fabric having the ability to yield in response to stress and to recover substantially to its original shape when the stress is removed. The nonwoven fabrics which are made from bulk yarns and entangled or stitched between yarn intersections are particularly desirable for applications which require softness combined with high bulk, such as in blankets, insulated linings, and the like. Preferred bulk yarns are continuous filament yarns which have been treated to impart a random loopiness or fuzziness to the surface of the yarns. Such yarns may be of the type having crunodal loops as described in Breen US. Pat. No. 2,783,609, issued March 5, 1957. Also suitable are the bulky crimped bior multicomponent composite filaments of the type described in Breen US. Pat. No. 2,931,091, issued April 5, 1960, or the yarns of helically crimped composite filaments of the type described in French Pat. No. 1,442,768, granted May 9, 1966. Another type of yarn which is suitable is yarn having two types of crimp superimposed upon each other as described in Claussen US. Pat. No. 3,167,845, issued February 2, 1965. Boucle yarns and bulky spun yarns, especially of low twist, are also suitable. For the preparation of nonwoven fabrics resembling broadcloth, printcloth and the like, it is preferred to use continuous filament yarns having little or no crimp and optionally twisted and effecting the bonding between the selected layers by use of a binder filament. The continuous filament yarn may be of any material such as polyamide, polyester, polyurethane, polyhydrocarbon and the like. Preferably the yarns are continuously spun, layered in the desired arrangement, and bonded in one continuous operation. The binder filaments are preferably of a related polymer or copolyrner having a lower melting or softening temperature than that of the yarns of the nonwoven fabric. The individual filaments, employed alone or in yarns in the fabrics of this invention, may be of any cross-sectional shape including round, trilobal, or ribbon-like.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood the invention is not limited by the specific illustrations except to the extent defined in the following claims:

I claim:

1. A nonwoven fabric comprising at least three layers of warp-like arrays of bulk yarns, the yarns of adjacent layers intersecting at an angle, said adjacent layers being substantially free from unions at the yarn intersections 9 10 in the fabric, and the yarns of selected nonadjacent layers References Cited being parallel and supeirintnpzvsed rglationtsiiip, th; su- UNITED STATES PATENTS pernnpose yarns o e se ec e nona acen ayers eing united by intertangled yarn fibers with each other only in 3,479,244 11/1969 Burnett 161-58 the spaces between intersections with yarns of adjacent 5 layers to hold all of the layers together as a fabric having ROBERT F BURNETT Pnmary Exammer conformability and drape similar to a woven fabric. Assistant Examiner 2. The nonwoven fabric defined in claim 1 wherein the U S C1 X R yarns of adjacent layers intersect at a 90 angle to provide an appearance like that of a Woven fabric. 10 150

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