EP0412099A4 - Apparatus and method for hydroenhancing fabric - Google Patents

Abstract

An apparatus (10) and related process for enhancement of woven and knit fabrics through use of dynamic fluids which entangle and bloom fabric yarns. A two stage enhancement process is employed in which top and bottom sides of the fabric are respectively supported on members (22), (34) and impacted with a fluid curtain including high pressure jet streams. Controlled process energies and use of support members (22), (34) having open areas (26), (36) which are aligned in offset relation to the process line produces fabrics having a uniform finish and improved characteristics including, edge fray, drape, stability, abrasion resistance, fabric weight and thickness.

Description

Description APPARATUS AND METHOD FOR HYDROENHANCING FABRIC

Cross Reference To Related Applications

This application is a continuation-in-part of U.S. Serial Nos. 07/041,542 and 07/184,350, respectively filed April 23, 1987 and April 21, 1988.

Field of Invention

This invention generally relates to a textile finishing process for upgrading the quality of woven and knit fabrics. More particularly, it is concerned with a hydroentangling process which enhances woven and knit fabrics through use of dynamic fluid jets to entangle and cause fabric yarns to bloom. Fabrics produced by the method of the invention have enhanced surface finish and improved characteristics such as cover, abrasion resistance, drape, stability as well as reduced air permeability, wrinkle recovery, seam slippage, and edge fray.

Background Art

The quality of a woven or knit fabric can be measured by various properties, such as, the yarn count, thread count, abrasion resistance, cover, weight, yarn bulk, yarn bloom, torque resistance, wrinkle recovery, drape and hand.

Yarn count is the numerical designation given to indicate yarn size and is the relationship of length to weight. Thread count in woven or knit fabrics, respectively, defines the number ends and picks, and wales and courses per inch of fabric. For example, the count of cloth is indicated by enumerating first the number of warp ends per inch, then the number of filling picks per inch. Thus, 68 x 72 defines a fabric having 68 warp ends and 72 filling picks per inch.

Abrasion resistance is the ability of a fabric to withstand loss of appearance, utility, pile or surface through destructive action of surface wear and rubbing.

Cover is the degree to which underlying structure in a fabric is concealed by surface material. A measure of cover is provided by fabric air permeability, that is, the ease with which air passes through the fabric. Permeability measures fundamental fabric qualities and characteristics such as filtration and cover. Yarn bloom is a measure of the opening and spread of fibers in yarn.

Fabric weight is measured in weight per unit area, for example, the number of ounces per square yard.

Torque of fabric refers to that characteristic which tends to make it turn on itself as a result of twisting. It is desirable to remove or diminish torque in fabrics. For example, fabrics used in vertical blinds should have no torque, since such torque will make the fabric twist when hanging in a strip.

Wrinkle recovery is the property of a fabric which enables it to recover from folding deformations.

Hand refers to tactile fabric properties such as softness and drapability. It is known in the prior art to employ hydroentangling processes in the production of nonwoven materials. In conventional hydroentangling processes, webs of nonwoven fibers are treated with high pressure fluids while supported on apertured patterning screens. Typically, the patterning screen is provided on a drum or continuous planar conveyor which traverses pressurized fluid jets to entangle the web into cohesive ordered fiber groups and configurations corresponding to open areas in the screen. Entanglement is effected by action of the fluid jets which cause fibers in the web to migrate to open areas in the screen, entangle and intertwine.

Prior art hydroentangling processes for producing patterned nonwoven fabrics are represented by U.S. Patent Nos. 3,485,706 and 3,498,874, respectively, to Evans and Evans et al., and U.S. Patent Nos. 3,873,255 and 3,917,785 to Kalwaites. Hydroentangling technology has also been employed by the art to enhance woven and knit fabrics. In such applications warp and pick fibers in fabrics are hydroentangled at cross¬ over points to effect enhancement in fabric cover. However, conventional processes have not proved entirely satisfactory in yielding uniform fabric enhancement. The art has also failed to develop apparatus and process line technology which achieves production line efficiencies.

Australian Patent Specification 287821 to Bunting et al. is representative of the state of the art. Bunting impacts high speed columnar fluid streams on fabrics supported on course porous members. Preferred parameters employed in the Bunting process, described in the Specification Example Nos. XV — XVII, include 20 and 30 mesh support screens, fluid pressure of 1500 psi, and jet orifices having 0.007 inch diameters on 0.050 inch centers. Fabrics are processed employing multiple hydroentangling passes in which the fabric is reoriented on a bias direction with respect to the process direction in order to effect uniform entanglement. Data set forth in the Examples evidences a modest enhancement in fabric cover and stability.

Another approach of art is represented by European Patent Application 0 177 277 to Gilpatrick which is directed to hydro- patterning technology. Gilpatrick impinges high velocity fluids onto woven, knitted and bonded fabrics for decorative effects. Patterning is effected by redistributing yarn tension within the fabric - yarns are selectively compacted, loosened and opened - to impart relief structure to the fabric.

Fabric enhancement of limited extent is obtained in Gilpatrick as a secondary product of the patterning process. However, Gilpatrick fails to suggest or teach a hydroentangling process that can be employed to uniformly enhance fabric characteristics. See Gilpatrick Example 4, page 40.

There is a need in the art for an improved woven textile hydroenhancing process which is commercially viable. It will be appreciated that fabric enhancement offers aesthetic and functional advantages which have application in a wide diversity of fabrics. Hydroenhancement improves fabric cover through dynamic fluid entanglement and bulking of fabric yarns for improved fabric stability. These results are advantageously obtained without requirement of conventional fabric finishing processes.

The art also requires apparatus of uncomplex design for hydroenhancing textile materials. Commercial production requires apparatus for continuous fabric hydroenhancing and in¬ line drying of such fabrics under controlled conditions to yield fabrics of uniform specifications.

Accordingly, it is a broad object of the invention to provide an improved textile hydroenhancing process and related apparatus for production of a variety of novel woven and knit fabrics having improved characteristics which advance the art. A more specific object of the invention is to provide a hydroenhancing process for enhancement of fabrics made of spun and spun/filament yarn. Another object of the invention is to provide a hydroenhancing process having application for the fabrication of novel composite and layered fabrics.

A further object of the invention is to provide a hydroenhancing production line apparatus which is less complex and improved over the prior art. Disclosure of the Invention

In the present invention, these purposes, as well as others which will be apparent, are achieved generally by providing an apparatus and a related method for hydroenhancing woven and knit fabrics through dynamic fluid action. A hydroenhancing module is employed in the invention in which the fabric is supported on a member and impacted with a fluid curtain under controlled process energies. Enhancement of the fabric is effected by entanglement and interwining of yarn fibers at cross-over points in the fabric weave or knit. Fabrics enhanced in accordance with the invention have a uniform finish and improved characteristics, such as, edge fray, drape, stability, wrinkle recovery, abrasion resistance, fabric weight and thickness.

According to the preferred method of the invention, the woven or knit fabric is advanced on a process line through a weft straightener to two in-line fluid modules for first and second stage fabric enhancement. Top and bottom sides of the fabric are respectively supported on members in the modules and impacted by fluid curtains to impart a uniform finish to the fabric. Preferred support members are fluid pervious, include open areas of approximately 25%, and have fine mesh patterns which permit fluid passage without imparting a patterned effect to the fabric. It is a feature of the invention to employ support members in the modules which include fine mesh patterned screens which are arranged in offset relation with respect to the process line. This offset orientation limits fluid streaks and eliminates reed marking in processed fabrics.

First and second stage enhancement is preferably effected by columnar fluid jets which impact the fabric at pressures within the range of 200 to 3000 psi and impart a total energy to the fabric of approximately .10 to 2.0 hp-hr/lb.

Following enhancement, the fabric is advanced to a tenter frame which dries the fabric to a specified width under tension to produce a uniform fabric finish.

Advantage in the invention apparatus is obtained by provision of a continuous process line of uncomplex design. The first and second enhancement stations include a plurality of cross-directionally ("CD") aligned and spaced manifolds.

Columnar jet nozzles having orifice diameters of approximately 0.005 inches with center-to-center spacings of approximately .017 inches are mounted approximately .5 inches from the screens. At the process energies of the invention, this spacing arrangement provides a curtain of fluid which yields a uniform fabric enhancement. Use of fluid pervious support members which are oriented in offset relation, preferably 45°, effectively limits jet streaks and eliminates reed markings in processed fabrics.

Optimum fabric enhancement results are obtained in fabrics woven or knit of yarns including fibers with deniers and staple lengths in the range of 0.5 to 6.0, and 0.5 to 5 inches, respectively, and yarn counts in the range of .5s to 50s. Preferred yarn spinning systems of the invention fabrics include cotton spun, wrap spun, wool spun and friction spun. Other objects, features and advantages of the present invention will be apparent when the detailed description of the preferred embodiments of the invention are considered in conjunction with the drawings which should be construed in an illustrative and not limiting sense as follows: Brief Description of the Drawings

Fig. 1 is a schematic view of a production line including a weft straightener, flat and drum hydroenhancing modules, and tenter frame, for the hydroenhancement of woven and knit fabrics in accordance with the invention;

Figs. 2A and B are photographs at 10X magnification of 36x29 90° and 40x40 45° mesh plain weave support members, respectively, employed in the flat and drum enhancing modules of Fig. 1;

Figs. 3A and B are photomicrographs at 10X magnification of a fine polyester woven fabric before and after hydroenhancement in accordance with the invention; Figs. 4A and B are photomicrographs at 16X magnification of the control and processed fabric of Figs. 3A and B;

Figs. 5A and B are photomicrographs at 10X magnification of a control and hydroenhanced woven acrylic fabric;

Figs. 6A and B are photomicrographs at 10X magnification of a control and hydroenhanced acrylic fabric woven of wrap spun yarn;

Figs. 7A and B are photomicrographs at 10X magnification of a control and hydroenhanced acrylic fabric woven of wrap spun yarn; Figs. 8A and B are photomicrographs at 10X magnification of a control and hydroenhanced acrylic fabric including open end wool spun yarn;

Figs. 9A and B are photomicrographs at 16X magnification of a control and hydroenhanced wool nylon (80/20%) fabric; Figs. 10A and B are photomicrographs at 16X magnification of a control and hydroenhanced spun/filament polyester/cotton twill fabric; Figs. 11A and B are photomicrographs at 16X magnification of a control and hydroenhanced doubleknit fabric- Figs. 12A and B are front and back side photomicrographs at 16X magnification of a control wall covering fabric; Figs. 13A and B are front and back side photomicrographs at 16X magnification of the wall covering fabric of Figs. 12A and B hydroenhanced in accordance with the invention;

Fig. 14 is a photomacrograph at 0.09X magnification of a control and hydroenhanced acrylic fabric strips, the fabric of Figs. 7A and B, showing the reduction in fabric torque achieved in the invention process;

Figs. 15 A-C are photomacrographs at 0.23X magnification, respectively, of the woven acrylic fabrics of Figs. 5, 7 and 8, comprised of wrap spun and open end wool spun yarns, showing washability and wrinkle characteristics of control and processed fabrics;

Fig. 16 is a schematic view of an alternative production line apparatus for the hydroenhancement of woven and knit fabrics in accordance with the invention; and Fig. 17 illustrates a composite fabric including napped fabric components which are bonded into an integral structure employing the hydroenhancing process of the invention.

Best Mode Of Carrying Out The Invention With further reference to the drawings, Fig. 1 illustrates a preferred embodiment of a production line of the invention, generally designated 10, for hydroenhancement of a fabric 12 including spun and/or spun/filament yarns. The line includes a conventional weft straightener 14, flat and drum enhancing modules 16, 18, and a tenter frame 20.

Modules 16, 18 effect two sided enhancement of the fabric through fluid entanglement and bulking of fabric yarns. Such entanglement is imparted to the fabric in areas of yarn cross¬ over or intersection. Control of process energies and provision of a uniform curtain of fluid produces fabrics having a uniform finish and improved characteristics including, edge fray, torque, wrinkle recovery, cupping, drape, stability, abrasion resistance, fabric weight and thickness. Method and Mechanism of the Enhancing Modules

Fabric is advanced through the weft straightener 14 which aligns the fabric weft prior to processing in enhancement modules 16, 18. Following hydroenhancement, the fabric is advanced to the tenter frame 20, which is of conventional design, where it is dryed under tension to produce a uniform fabric of specified width.

Module 16 includes a first support member 22 which is supported on an endless conveyor means including rollers 24 and drive means (not shown) for rotation of the rollers. Preferred line speeds for the conveyor are in the range of 10 to 500 ft/min. Line speeds are adjusted in accordance with process energy requirements which vary as a function of fabric type and weight.

Support member 22, which preferably has a flat configuration, includes closely spaced fluid pervious open areas 26. A preferred support member 22, shown in Fig. 2A, is a 36x29 90° mesh plain weave having a 23.7% open area, fabricated of polyester warp and shute round wire. Support member 22 is a tight seamless weave which is not subject to angular displacement or snag. Specifications for the screen, which is manufactured by Albany International, Appleton Wire Division, P.O. Box 1939, Appleton, Wisconsin 54913 are set forth in Table I.

TABLE I Support Screen Specifications

Property 36x29 90° flat mesh 40x40 45° drum mesh Wire polyester stainless steel

Warp wire .0157 0.010

Shute wire .0157 0.010

Weave type plain plain

Open area 23.7% 36%

Module 16 also includes an arrangement of parallel and spaced manifolds 30 oriented in a cross-direction ("CD") relative to movement of the fabric 12. The manifolds which are spaced approximately 8 inches apart each include a plurality of closely aligned and spaced columnar jet orifices 32 which are spaced approximately .5 inches from the support member 22.

The jet orifices have diameters and center-to-center spacings in the range of .005 to .010 inches and .017 to .034 inches, respectively, and are designed to impact the fabric with fluid pressures in the range of 200 to 3000 psi. Preferred orifices have diameters of approximately .005 inches with center-to-center spacings of approximately .017 inches.

This arrangement of fluid jets provides a curtain of fluid entangling streams which yield optimum enhancement in the fabric. Energy input to the fabric is cumulative along the line and preferably set at approximately the same level in modules 16, 18 (two stage system) to impart uniform enhancement to top and bottom surfaces of the fabric. Effective first stage enhancement of fabric yarn is achieved at an energy output of at least .05 hp-hr/lb and preferably in the range of .1 to 2.0 hp-hr/lb. Following the first stage enhancement, the fabric is advanced to module 18 which enhances the other side of the fabric. Module 18 includes a second support member 34 of cylindrical configuration which is supported on a drum. The member 34 includes closely spaced fluid pervious open areas 36 which comprise approximately 36% of the screen area. A preferred support member 34, shown in Fig. 2B, is a 40x40 45° mesh stainless steel screen, manufactured by Appleton Wire, having the specifications set forth in Table I.

Module 18 functions in the same manner as the planar module 16. Manifolds 30 and jet orifices 32 are provided which have substantially the same specifications as in the first stage enhancement module. Fluid energy to the fabric of at least 0.5 hp-hr/lb and preferably in the range of .1 to 2.0 hp-hr/lb effects second stage enhancement.

Conventional weaving processes impart reed marks to fabrics. Illustrations of such markings are shown in Figs. 3A and 4A which are photomicrographs at 10X and 16X magnification of a polyester LIBBEY brand fabric style no. S/X-A805 (see Table II) . Reed marks in Figs. 3A and 4A are designated by the letter "R".

The invention overcomes this defect in conventional weaving processes through use of a single and preferably two stage hydroenhancement process. Advantage is obtained in the invention process by orienting the drum support member 34 in offset relation, preferably 45°, relative to machine direction ("MD") of the hydroenhancing line. See Figs. 2A and B.

Support members 22 and 34 are preferably provided with fine mesh open areas which are dimensioned to effect fluid passage through the members without imparting a patterned effect to the fabric. The preferred members have an effective open area for fluid passage in the range of 17 - 40%.

Comparison of the control and processed polyester fabric of Figs. 3A, B and 4A, B illustrates the advantages obtained through use of the enhancement process. Reed marks R in control polyester fabric are essentially eliminated through enhancement of the fabric. The offset screen arrangement is also effective in diminishing linear jet streak markings associated with the enhancement process.

Examples I-XIII

Figs. 3 - 15 illustrate representative woven and knit fabrics enhanced in accordance with the method of the invention, employing test conditions which simulate the line of Fig. 1.

Table II sets forth specifications for the fabrics illustrated in the drawings.

As in Fig. 1 line, the test manifolds 30 were spaced approximately 8 inches apart in modules 16, 18, and provided with densely packed columnar jet orifies 32 of approximately 60/inch.

Orifices 32 each had a diameter of 0.005 inches and were spaced approximately .5 inches from the first and second support members

22, 34. The process line of Fig. 1 includes enhancement modules 16,

18 which, respectively, are provided with six manifolds. In the

Examples, modules 16, 18 were each fitted with two manifolds 34.

To simulate line conditions, the fabrics were advanced through multiple runs on the line. Three processing runs in each two manifold module was deemed to be equivalent to a six manifold module.

Fabrics were hydroenhanced at process pressures of approximately 1500 psi. Line speed and cumulative energy output to the modules were respectively maintained at approximately 30 fp and 0.46 hp-hr/lb. Adjustments in the line speed and fluid pressure were made to accommodate differences in fabric weight for uniform processing and to maintain the preferred energy l vel.

Fabrics processed in the Examples exhibited marked enhancement in aesthetic appearance and quality including, characteristics such as cover, bloom, abrasion resistance, drape, stability, and reduction in seam slippage, and edge fray. Tables III - XI set forth data for fabrics enhanced in accordance with invention on the test process line. Standard testing procedures of The American Society for Testing and Materials (ASTM) were employed to test control and processed characteristics of fabrics. Data set forth in the Tables was generated in accordance with the following ASTM standards:

Fabric Characteristic ASTM Standard

Weight D3776-79

Thickness D1777-64 (Ames Tester)

Tensile Load D1682-64 (1975) (Cut strip/grab)

Elongation D1682-64 (1975) Air Permeability D737-75 (1980) (Frazier) Thread Count D3775-79 Ball Burst D3787-80A Seam Slippage D4159-82 Tongue^* Tear D2261-71 Wrinkle Recovery D1295-67 (1972) Abrasion Resistance D3884-80 Pilling D3514-81

Washability tests were conducted in accordance with the following procedure. Weight measurements ("before wash") were taken of control and processed fabric samples each having a dimension of 8.5"xll" (8.5" fill direction and 11" warp direction) . The samples were then washed and dried in conventional washer and dryers three consecutive times and "after wash" measurements were taken. The percent weight loss of the pre and post wash samples was determined in accordance the following formula:

% weight loss = D/B x 100 where, B = before wash sample weight; A = after wash sample weight; and D = B-A.

Photomicrographs of the fabrics, Figs. 4-15, illustrate the enhancement in fabric cover obtained in the invention. Attention is directed to open areas in the unprocessed fabrics, photographs designated A, these areas are of reduced size in the processed fabrics in the photographs designated B.

Hydroenhancement caused fabric yarns to bloom and entangle at cross-over points, filling in open areas to improve cover and reduce air permeability in the fabrics.

Figs. 12 and 13 are photomicrographs of a HYTEX brand wall covering fabric, manufactured by Hytex, Inc, Randoph,

Massachusets. A multi-textured surface appearance of the fabric is provided by yarns which are woven through discrete areas of the front fabric surface. Free floating weave stitches, designated by the letter "S" in Figs. 12B and 13B, are formed on the backside of the fabric.

Hydroenhancement of HYTEX wall covering fabric secured the free-floating stitches S to the fabric backside enhancing fabric stability and cover. See Figs. 12B, 13B. In wall covering applications, fabric enhancement and associated stabilizing effects reduces or eliminates the need for adhesive backcoatings. Enhancement of the fabric also limits wicking of wall cover application adhesives through the fabric. Further advantage is obtained when enhanced fabrics are used in accoustic applications; elimination of backcoating reduces sound reflectio and furthers efficient transmission of sound through the fabric.

TABLE II

Fabric Specifications Fiber Brand and Style Designation Figure(s)

NOMEX S/X-A805 .*' 3A,B, 4A,B

Fiber 2 denier-1.9 inch Yarn Open end cotton spun 17s

LIBBEY S/022 ** 5A,B Warp:

Fiber: 3 denier - 1.5 inch acrylic Yarn : Open end cotton spun 9s 28 ends per inch

Fill:

Fiber: 3 denier - 3 inch acrylic Yarn : Open end wool spun 4s

14, 16 or 18 picks per inch LIBBEY S/x-1160 6A,B

Fiber: 3 denier-3 inch acrylic Yarn : Wrap spun w/100 den textured polyester 4s 14 ends x 16 picks per inch

LIBBEY S/406 7A,B, 14A,B

Warp:

Fiber: 3 denier - 1.5 inch acrylic Yarn : Open end cotton spun 9s 28 ends per inch

Fill:

Fiber: 3 denier - 3 inch acrylic Yarn : Hollow spun 6 twists/inch 4s

14, 16 or 18 picks per inch Table II. continued

LIBBEY S/152 8A,B Warp:

Fiber: 3 denier - 2.5 inch acrylic Yarn : Open end cotton spun 4s 14 ends per inch

Fill:

Fiber: 3 denier - 3 inch acrylic Yarn : Open end wool spun 2.6s 14, 16 or 18 picks per inch

Guiiford Wool/Nylon 9A,B 80% wool/20% nylon

Polyester/cotton (53/47) 10A,B

Weight 10 ounces/yd²

Yarn Spun Filament

Weave 3x1 Twill

Thread Count: 120x38 50% Polyester/50% cotton Doubleknit 11A,B

Yarn: wrap spun with 100 denier polyester wrap HYTEX Wall covering *** 12, 13

LIBBEY is a trademark of W. S. Libbey Co., One Mill Street, Lewiston, ME 04240. **NOMEX is a trademark of E.I. Du Pont de Nemours and Company, Wilmington, Del. ***^HYTEX is a trademark of Hytex, Inc., Randoph, MA.

TABLE III

Nomex A805 - Fig. 4 Control Processed Chance

Weight (gsy) 195 197 +1.0

Thickness (mils) 42 42

Air Perm. (ft³/ft²/ 331 156 -52.9 min)

Strip Tensile (lbs/in) warp 115 132 +14.8 fill 59 47 -20.3

Elongation (%) warp 48 50 +4.2 fill 62 71 +14.5

TABLE IV

022/6075 (16 ppi) - Fig. 5

Control Processed % Change

Weight (gsv) 158 165 + 4.4

Thickness (mils) 48 49 + 2.1

Air Perm, (ft³/ft² 406 259 -36.2 min)

Strip Tensile (lbs/in) warp 34 36 + 5.9 fill 37 31 -16.2

Elongation (%) warp 33 27 -18.2 fill 27 28 + 3.7 Seam Slippage (lbs/in) warp 5 60 +1100.0 fill 7 55 + 685.7

Tongue Tear (lbs) warp 18 10 -44.4 fill 21 8 -61.9

Wt. Loss In Wash (%) 37 5 -86.5 Wrinkle Recovery 123 138° +12.2 (recovery angle)

Under ASTM test standards (D1295-67) improvements in the wrinkle recovery of a fabric are indicated by an increase in the recovery angle. TABLE V

Libbv S/x-1160 - Fig. 6 Control Processed % Change

Weight (gsy) 146.8 160.2 9.1

Thickness (mils) 38.1 52.7 38.3

Air Perm. (ft³/ft² 457.2 188.5 -58.8 min) Grab Tensile (lbs/in) warp 80.2 89. .3 11.4 fill 105.0 111. ,4 6.1

Elongation (%) warp 30, 34. ,0 13.3 fill 32. 46..0 43.8

Ball Burst (lbs) 190 157 ^■17.4

TABLE VI

40 6/6075 (16ppi) - Fig. 7

Control Processed % Change

Weight (gsy) 159 166 + 4.4

Thickness (mils) 48 50 + 4.2

Air Perm, (ft³/ft² 351 184 -47.6 min)

Strip Tensile (lbs/in] 1 warp 42 36 -14.3 fill 66 58 -12.1

Elongation (%) warp 23 31 +34.8 fill 49 33 -32.7

Seam Slippage (lbs) warp 29 36 +89.5 fill 21 76 + 261.9

Tongue Tear (lbs) warp 23 18 -21.7 fill 19 15 - 1.1

Wt. Loss In Wash (%) 28 4 -85.7

Wrinkle Recovery 140° 148° + 5.7

(recovery angle) TABLE VII

152/6076 (16 ppi) - Fiq. 8

Control Processed % Change

Weight (gsγ) 231 257 +11.3

Thickness (mils) 259 238 - 8.1

Air Perm. (ft³/ft²/ ' 204 106 -48.0 min)

Strip Tensile (lbs/in) warp 48 58 +20.8 fill 56 72 +28.6

Elongation (%) warp 33 33 0 fill 34 39 +14.7 Seam Slippage (lbs) warp 64 81 +26.6 fill 78 112 +43.6

Tongue Tear (lbs) warp 21 18 -14.3 fill 17 15 -11.8

Wt. Loss In Wash (%) Wrinkle Recovery 117' 136 +16.2 (recovery angle)

TABLE VIII

Guilford Wool (80% wool/20% nylon) - Fig. 9

Control Process % Change

A r Perm. ^•243 147 -39.5

TABLE IXA

Spun/Filament - Bottom Weights - Fig. 10

Sample #1 Sample #2 Sample #3 Sample #4 Control Proc Control Proc Control Proc Control Proc

Weight (gsy) 259.2 275.4 240.3 248.4 286.2 297.2 267.3 280.8 Thickness (mils) 39.7 39.2 35.0 35.3 44.2 41.5 40.0 38.0 Strip Tensiles (lbs./in.)

Warp 206.98 208.87 195.50 200.86 183.09 189.95 206,43 207.8

Fill 85.55 56.23 84.21 71.83 80.88 83.01 80.16 82.1

Normalized Tensiles (lbs./in. )

Warp 7.98 7.58 8.05 8.09 6.40 6.39 7.65 7.4

Fill 3.30 2.04 3.54 2.89 2.83 2.79 3.03 2.9

Elongation (%) Warp 42.0 55.3 36.5 39.1 40.9 43.5 46.1 51.2 Fill 23.6 25.6 24.0 20.0 23.5 20.3 22.9 22.4

Air Perm. (ft.³/ft.²/min) 50.9 27.3 43.5 28.8 45.8 21.8 51.4 25.4

Thread Count (wxf) 120 x 40 120 x 41 120 X 45 120 X 45 120 X 38 120 x 42 120 x 42 120 x

Mullen Burst (lbs.) 161.2 222.2 187.2 228.8 161.0 217.8 205.0 242.2

Normalized Burst (lbs./g x 10²) 62.2 80.7 77.9 92.1 56.2 73.3 76.7 86

TABLE IXB

Abrasion — Spun Filament-Bottom Weights Fig. 10

ASTM Standard - Twill side up; 500 cycles; 500 g weiiight; H-18 wheels

Weight Weight Weight % Improve¬

Sample Before (q) After(g) Loss(g) % Loss ment 1C 3.32 3.02 0.30 9.0 IP 3.36 3.13 0.23 6.9 23%

2C 4.64 4.16 0.48 10.4 2P 4.83 4.57 0.26 5.4 48%

3C 4.73 4.47 0.26 5.5

3P 4.91 5.13 0.22 4.5 18%

4C 4.47 4.18 0.29 6.5

4P 4.71 4.53 0.18 3.8 41%

TABLE X

Doubleknit - Fig. 11 Control Processed Change

Air Perm. (Ft³/ft² 113.1 95.1 -15.9 min) Abrasion 1.0 0.6 -40.0 ASTM (D-3884-80) : 250 Cycles, H-18 wheel Pilling (1-5 rating) 4.3 4.3

ASTM (D-3914-81) : 300 cycles

Figs. 14A, B are photomacrographs of control and processed acrylic vertical blind fabric, manufactured by W.S. Libbey, style designation S/406. Enhancement of the fabric reduces fabric torque which is particularly advantageous in vertical blind applications. The torque reduction test of Figs. 14A, B employed fabric strips 84" long and 3.5" wide, which were suspended vertically suspended without restraint. Torque was measured with reference to the angle of fabric twist from a flat support surface. As can be seen in the photographs, a torque of 90° in the unprocessed fabric, Fig. 14A, was eliminated in the enhancement process.

Figs. 15A-C are macrophotographs of control and processed acrylic fabrics, LIBBEY style nos. 022, 406 and 152, respectively, which were tested for washability. Unprocessed fabrics exhibited excessive fraying and destruction, in contrast to the enhanced fabrics which exhibit limited fraying and yarn (weight) loss. Table XI sets forth washability test weight loss data.

TABLE XI

022. 406, 152 - Figs. 15A-C

Percent Weight Loss (3 wash/dry cycles)

Sample Control Processed

022 36.5 5.0 406 28.0 4.0 152 28 1 7.2

Fig. 16 illustrates an alternative embodiment of the invention apparatus, generally designated 40. The apparatus includes a plurality of drums 42a-d over which a fabric 44 is advancement for enhancment processing. Specifically, the fabric 44 traverses the line in a sinuous path under and over the drums 42 in succession. Rollers 46a and b are provided at opposite ends of the line adjacent drums 42a and d to support the fabric. Any or all of the drums can be rotated by a suitable motor drive (not shown) to advance the fabric on the line.

A plurality of manifolds 48 are provided in groups, Fig. 16 illustrates groups of four, which are respectively spaced from each of the drums 42a-d. An arrangement of manifold groups at 90° intervals on the sinuous fabric path successively positions the manifolds in spaced relation with respect to opposing surfaces of the fabric. Each manifold 48 impinges columnar fluid jets 50, such as water, against the fabric. Fluid supply 52 supplies fluid to the manifolds 48 which is collected in liquid sump 54 during processing for recirculation via line 56 to the manifolds.

The support drums 42 may be porous or non-porous. It will be recognized that advantage is obtained through use of drums which include perforated support surfaces. Open areas in the support surfaces facilitate recirculation of the fluid employed in the enhancement process.

Further advantage is obtained, as previously set forth in discussion of the first embodiment, through use of support surfaces having a fine mesh open area pattern which facilitates fluid passage. Offset arrangement of the support member orientations, for example at 45° offset orientation as shown in Fig. 2, limits process water streak and weave reed marks in the enhanced fabric.

Enhancement is a function of energy which is imparted to the fabric. Preferred energy levels for enhancement in accordance with the invention are in the range of .1 to 2.0 hp- hr/lb. Variables which determine process energy levels include line speed, the amount and velocity of liquid which impinges on the fabric, and fabric weight and characteristics.

Fluid velocity and pressure are determined in part by the characteristics of ^'the fluid orifices, for example, columnar versus fan jet configuration, and arrangement and spacing from the process line. It is a feature of the invention to impinge a curtain of fluid on a process line to impart an energy flux of approximately 0.46 hp-hr/lb to the fabric. Preferred specifications for orifice type and arrangement are set forth in description of the embodiment of Fig. 1. Briefly, orifices 16 are closely spaced with center-to-center spacings of approximately 0.017 inches and are spaced 0.5 inches from the support members. Orifice diameters of .005 inches and densities of 60 per manifold inch eject columnar fluid jets which form a uniform fluid curtain.

The following Examples are representative of the results obtained on the process line illustrated in Fig. 17.

Example XIV A plain woven 100% polyester fabric comprised of friction spun yarns having the following specifications was processed in accordance with the invention: count of 16 x 10 yarns/in². weight of 8 ounces/yd², an abrasion resistance of 500 grams (measured by 50 cycles of a CS17 abrasion test wheel) and an air permeability of 465 ft³/ft²/min.

The fabric was processed on a test line to simulate a speed of 300 ft/min. on process apparatus including four drums 42 and eighteen nozzles 16 at a pressure of approximately 1500 psi. Energy output to fabric at these process parameters was approximately .46 hp-hr/lb. Table XII sets forth control and processed characteristics of the fabric.

TABLE XII

100% Polyester Friction Spun Fabric Fabric Characteristic Control Processed

Count (yarns/in.²) 16X10 17x10

Weight (ounces/yd.²) 8 8.2

Abrasion resistance (cycles) 50 85

Air permeability (ft³ft²/min. ) 465 181

Examples XV and XVI The process conditions of Example XIV were employed to process a plain woven cotton osnaburg and plain woven polyester ring spun fabrics yielding the results set forth in Tables XIV and XV. TABLE XV

Plain Woven Cotton Osnaburg Fabric Characteristic Control Processed Count (yarns/in.²) 32x26 32X32 ^■^^•brasion resistance (cycles) 140 344 Air permeability (ft³ft²/min.) 710 120

TABLE XIV

Plain Woven Polyester Ring Spun Yarn Fabric Characteristic Control Processed

Count (yarns/in.²) 44x28 48x32

^Abrasion resistance (cycles) 100 225

Air permeability (ft.³/ft²/min.) 252 63

Fabrics processed in Examples XIV-XVI are characterized by a substantial reduction in air permeability and increase in abrasion resistance. Process energy levels in these Examples were approximately .46 hp-hr/lb. It has been discovered that there is a correlation between process energy and enhancement. Increased energy levels yield optimum enhancement effects. The foregoing Examples illustrate applications of the hydroenhancing process of the invention for upgrading the quality of single ply woven and knit fabrics.

In an alternative application of the hydroenhancing process of the invention, fabric strata are hydrobonded into integral composite fabric. Fig. 17 illustrates a composite flannel fabric 60 including fabric layers 62, 64. Hydrobonding of the layers is effected by first napping a opposing surfaces 62a, 64a of each of the layers to raise surface fibers. The opposing surfaces 62a, 44a are then arranged in overlying relation and processed on the production line of the invention. See Figs. 1 and 16.

Enhancement of the layers 62, 64 effects entanglement of fibers in the napped surfaces and bonding of the layers to form a integral composite fabric 60. Exterior surfaces 62b, 64b are also enhanced in the process yielding improvements in cover and quality in the composite fabric.

Napped surfaces 62a, 62b are provided by use of conventional mechanical napping apparatus. Such apparatus include cylinders covered with metal points or teasel burrs which abrade fabric surfaces. Advantageously, composite fabric 60 is manufactured without requirement of conventional laminating adhesives. As a result, the composite fabric breaths and has improved tactile characteristics than obtained in prior art laminated composites. It will be recognized that such composite fabrics have diverse applications in fields such as apparel and footware.

Optimum enhancement (in single and multi-ply fabrics) is a function of energy. Preferred results are obtained at energy levels of approximately .46 hp-hr/lb. Energy requirements will of course vary for different fabrics as will process conditions required to achieve optimum energy levels. In general, process speeds, nozzle configuration and spacing may be varied to obtain preferred process energy levels.

Enhanced fabrics of the invention are preferably fabricated of yarns including fibers having deniers and lengths, respectively, in the ranges of 0.3 to 10.0 and 0.5 to 6.0 inches, and yarn counts of .5s to 80s. Optimum enhancement is obtained in fabrics having fiber deniers in the range of .5 to 6, staple fibers of .5 to 6.0 inches, and yarn counts in the range of .5s to 50s. Preferred yarn spinning systems employed in the invention fabrics include cotton spun, wrap spun and wool spun. Experimentation indicates that preferred enhancement results are obtained in fabrics including low denier, short lengths fibers, and loosely twisted yarns.

The invention advances the art by recognizing that superior fabric enhancement can be obtained under controlled process conditions and energy levels. Heretofore, the art has not recognized the advantages and the extent to which hydroenhancement can be employed to upgrade fabric quality. It is submitted that the results achieved in the invention reflect a substantial and surprising contribution to the art.

Numerous modifications are possible in light of the above disclosure. For example, although the preferred process and apparatus employ fluid pervious support members, non-porous support members are within the scope of the invention. Similarly, Figs. 1 and 16 respectively illustrate two and four stage enhancement process lines. System configurations which include one or more modules having flat, drum or other support member configuration may be employed in the invention. It will be recognized that the process of the invention has wide application for the production of a diversity of enhanced fabrics. Thus, the Examples are not intended to limit the invention.

Finally, although the disclosed enhancement process employs columnar jet orifices to provide a fluid curtain, other apparatus may be employed for this purpose. Attention is directed to the International Patent Application (RO/US) to Siegel et al., entitled "Apparatus and Method For Hydropatterning Fabric", filed concurrently herewith, assigned to Veratec, Inc. , which discloses a divergent jet fluid entangling apparatus for use in hydropatterning woven and nonwoven textile fabrics.

Therefore, although the invention has been described with reference to certain preferred embodiments, it will be appreciated that other hydroentangling apparatus and processes may be devised, which are nevertheless within the scope and spirit of the invention as defined in the claims appended hereto.

Claims

Claims 1. A method for enhancing and finishing textile fabrics including spun and/or spun filament yarns which intersect at cross-over points, and first and second sides, the fabric including yarn fibers having deniers and lengths in the range of 0.3 to 16.0 and .5 to 8 inches, respectively, and yarn counts in the range of .5s to 80s, the method comprising the steps of: supporting the fabric on a first support member, and traversing the first side of said fabric with a first continuous curtain of fluid for sufficient duration to effect entanglement of said yarns at the cross-over points, thereby enhancing fabric cover and quality, said curtain of fluid impacting the fabric with an energy in the range .1 and 2.0 hp-hr/lb. 2. The method of Claim 1, wherein said fluid curtain is provided by columnar fluid jet orifices having a diameter of approximately 0.005 inches, center-to-center spacing of approximately .017 inches, and spacing from said first support member of approximately .5 inches, said fluid jets impinging the fabric with fluids at pressure of approximately 1500 psi.

3. The method of Claim 2, wherein said support member includes a pattern of closely spaced fluid pervious open areas aligned in a first direction to effect fluid passage through said support member. 4. The method of Claim 3, wherein said open areas occupy approximately 17 to 40% of said support member.

5. The method of Claim 1, comprising the further steps of: supporting said enhanced fabric on a second support member, and traversing the second side of said enhanced fabric in a second enhancement stage with a second continuous fluid curtain for sufficient duration to further enhance fabric cover and provide a uniform fabric finish, said second enhancement stage impacting the fabric with an energy in the range 0.1 and 2.0 hp-hr/lb.

6. The method of Claim 5, wherein: said first and second fluid curtains are provided by columnar fluid jets each having a diameter of approximately 0.005 inches and center-to-center spacing of approximately .017 inches, said fluid curtains are spaced approximately .5 inches from said first and second members, and said fluid jets impinge the fabric with fluids at a pressure of approximately 1500 psi, said first and second support members each include a pattern of closely spaced fluid pervious open areas, respectively aligned in first and second directions, said open areas being dimensioned to effect fluid passage through said support members without imparting a patterned effect to the fabric.

7. The method of Claim 6, wherein said open areas occupy approximately 17 to 40% of each of said first and second support members.

8. The method of Claim 7, wherein said first and second support members respectively have flat and drum configurations.

9. The method of Claim 7, wherein said first and second support members have drum configurations. 10. The method of Claim 8, wherein said irst and second directions are offset approximately 45°.

11. The method of Claim 9, wherein said first and second directions are offset approximately 45°. 12. The method of Claim 6, comprising the further step, following said second stage enhancement, of drying the enhanced fabric to a specified width under tension.

13. An enhanced textile fabric made by the method of Claim 6, the fabric including yarn fibers having deniers and lengths in the range of 0.3 to 16 and 0.5 to 8 inches, respectively, and thread counts in the range of 0.5s to 80s, the yarn cross-over points in the fabric weave define interstitial open areas, wherein the process effects enhancement of the yarns in the interstitial open areas, thereby enhancing fabric cover. 14. An enhanced textile fabric made by the method of Claim 6, the fabric including yarn fibers having deniers and lengths in the range of 0.5 to 6 and 0.5 to 8 inches, respectively, and thread counts in the range of 0.5s to 50s, the yarn cross-over points in the fabric weave define interstitial open areas, wherein the process effects enhancement of the yarns in the interstitial open areas, thereby enhancing fabric cover, and yields a reduction in fabric air permeability in the range of 10 to 90%.

15. An enhanced woven polyester fabric made by the method of Claim 6, wherein the fabric includes 2 denier, 1.9 inch polyester fiber, open-end cotton spun yarn having a yarn number of 17s and count of 49x23 per inch, and the process yields an approximate 48% reduction in air permeability in the fabric.

16. An enhanced woven acrylic fabric made by the method of Claim 6, wherein the fabric includes 3 denier, 1.5 inch fiber, open-end cotton warp yarn having a yarn number of 9s, 28 ends per inch, and a 3 denier, 3 inch acrylic fiber, open-end wool spun fill yarn having a number of 4s, 16 picks per inch, and the process yields an approximate 36% reduction in air permeability in the fabric.

17. An enhanced acrylic wrap spun fabric made by the method of Claim 6, wherein the fabric includes 3 denier, 3.0 inch acrylic fiber, wrap spun with 100 denier textured polyester yarn having a yarn number of 4s and count of 14 x 16 per inch, and the process yields an approximate 65% reduction in air permeability in the fabric. 18. An enhanced woven acrylic fabric made by the method of Claim 6, wherein the fabric includes 3 denier, 1.5 inch acrylic fiber, open-end cotton spun warp yarn having a yarn number of 9s, 28 ends per inch, and a 3 denier, 3 inch acrylic fiber, hollow wrap spun fill yarn, 6 twists per inch having a number of 4s, 16 picks per inch, and the process yields an approximate 48% reduction in air permeability in the fabric.

19. An enhanced woven acrylic fabric made by the method of Claim 6, wherein the fabric includes 3 denier, 1.5 inch acrylic fiber, open-end wool spun warp yarn having a yarn number of 4s, 14 ends per inch, and a 3 denier, 3 inch acrylic fiber, open-end wool spun fill yarn having a yarn number of 2.6s, 16 picks per inch, and the process yields an approximate 48% reduction in air permeability in the fabric.

20. An enhanced woven fabric made by the method of Claim 6, wherein the fabric includes 80% wool/20% nylon in a 2x1 twill weave, and the process yields an approximate 49.5% reduction in air permeability in the fabric.

21. An enhanced 53% polyester/47% cotton fabric made by the method of Claim 6, wherein the fabric includes a 3x1 twill weave, a thread count of 120 ends x 38 picks, and the process yields an approximate 50.6% reduction in air permeability in the fabric.

22. An enhanced 50% polyester/50% cotton doubleknit fabric made by the method of Claim 6, wherein the fabric includes wrap spun yarn with 100 denier polyester wrap, and the process yields an approximate 16% reduction in air permeability in the fabric. 23. An enhanced woven or knit textile fabric which comprises: spun and/or spun filament yarns which intersect at cross-over points to define interstitial open areas, said yarns including fibers having deniers and lengths in the range of .5 to 6 and 0.5 to 5 inches, respectively, wherein said yarns are fluid entangled in said interstitial open areas by application of fluid energy in the range of .1 to 2.0 hp-hr/lb.

24. An enhanced woven or knit textile fabric according to Claim 23, wherein the yarn is cotton spun.

25. An enhanced woven or knit textile fabric according to Claim 23, wherein the yarn is wrap spun.

26. An enhanced woven or knit textile fabric according to Claim 23, wherein the yarn is wool spun. 27. A method for hydrobonding woven or knit fabric materials to form a composite textile fabric, the fabric including spun and/or spun filament yarns in a structured pattern including yarns which intersect at cross-over points, the method comprising the steps of: napping first and second surfaces of the fabric to raise surface fibers thereof, arranging said first and second surfaces in opposing and overlying layered relation, supporting the layered fabric on a support member, and traversing one side of said layered fabric with a first continuous curtain of fluid for sufficient duration to effect entanglement of said raised surface fibers in said first and second surfaces, said curtain of fluid impacting the fabric with an energy in the range .1 and 2.0 hp-hr/lb.

28. The method of Claim 27, wherein said fluid curtain is provided by columnar fluid jet orifices having a diameter of approximately 0.005 inches and center-to-center spacing of approximately .017 inches, said fluid curtain impinging the fabric with fluids at pressure of approximately 1500 psi.

29. The method of Claim 28, wherein said support member includes a pattern of closely spaced fluid pervious open areas aligned in a first direction to effect fluid passage through said support member.

30. The method of Claim 29, wherein said open areas occupy approximately 17 to 40% of said support member. 31. The method of Claim 27, comprising the further steps of: supporting said layered fabric on a second support member, and traversing the other side of said layered fabric in a second entanglement stage with a second continuous fluid curtain to effect a uniform composite fabric bond and finish, said second entanglement stage impacting the layered fabric with an energy in the range 0.1 and 2.0 hp-hr/lb. 32. The method of Claim 31, wherein: said first and second fluid curtains are provided by columnar fluid jets have a diameter of approximately 0.005 inches and center-to-center spacing of approximately .017 inches, said fluid jets impinging the fabric with fluids at pressure of approximately 1500 psi, said first and second support members each include a pattern of closely spaced fluid pervious open areas, respectively aligned in first and second directions, said open areas being dimensioned to effect fluid passage through said support members without imparting a patterned effect to the fabric.

33. An enhanced composite woven .or knit textile fabric which comprises: at least two fabric layers which each include spun and/or spun filament yarns in a structured pattern of yarns which intersect at cross-over points, said fabric layers including first and second napped surfaces which have raised surface fibers, said napped surfaces being arranged in overlying and opposed relation and bonded together by dynamic fluid energy through entanglement of said raised surface fibers in said first and second surfaces.

34. An apparatus for enhancing and finishing woven and knit fabric including spun and/or spun filament yarn by impacting the fabric with pressurized fluid jets, the fabric including yarns which intersect at cross-over points, and first and second sides, the apparatus comprising: conveyor means for conveying the fabric in a machine direction ("MD") through a production line including a first enhancing station, said conveying means supporting a first support member which underlies the fabric in said enhancing station; curtain means spaced from said first support member for directing a curtain of fluid onto the first side of the fabric, said curtain means including a plurality densely spaced orifices which eject high pressure fluid jets; said curtain means coacting with said first support member to entangle fabric yarns at the cross-over points, enhancing fabric cover and imparting a uniform finish to the fabric.

35. An apparatus as set forth in Claim 34, wherein said fluid orifices have a columnar configuration, a diameter of approximately 0.005 inches and center-to-center spacing of approximately 0.17 inches, and impart energy to fabric of approximately 0.1 to 2.0 hp-hr/lb.

36. An apparatus as set forth in Claim 35, wherein said fluid jets have a spray pressure of approximately 1500 psi. 37. An apparatus as set forth in Claim 34, further comprising a second enhancing station, a second support member which underlies the fabric and is supported for movement on the production line by said conveyor means, and a second curtain means spaced from said second support member for directing a curtain of fluid onto the second side of the fabric, said second curtain means including a second plurality of densely spaced orifices which eject high pressure fluid jets, thereby further enhancing the fabric. 38. An apparatus as set forth in Claim 37, wherein said first and second fluid curtains respectively impart energy to the fabric of approximately 0.1 to 2.0 hp-hr/lb.

39. An apparatus as set forth in Claim 38, wherein said second support member is fluid pervious and has open areas aligned on a bias relative to the machine direction of the line.

40. An apparatus as set forth in Claim 39, wherein said first and second curtain means are spaced approximately .5 inches from said first and second support members, said fluid jets have a spray pressure of approximately 1500 psi, and conveyor means speed is approximately 100 fpm.

41. An apparatus as set forth in Claim 40, wherein said first and second support members respectively have generally flat and cylindrical configurations.