US 3867242 A
Fabric simulating woven fabric comprising conventional warp threads disposed in the longitudinal direction and a "filling" comprising monofilaments laid transversely of the warp threads but not woven over-and-under therewith. By extruding the monofilaments onto the warp threads as these latter advance past an extruding nozzle the warp threads and "filling" threads are caused to cohere or coalesce at their points of intersection to provide a fabric having enhanced tensile strength and flexibility in both directions. Moreover, the fabric may be produced at substantially lower cost than fabrics woven by conventional methods, e.g. on a needle loom or shuttle loom or by braiding, all of which are regarded as uneconomically slow. In one aspect the junctions of the "filling" threads and the warp threads at the selvages are so united as to yield a smooth edge. In still another aspect the invention is ideally suited to fabrics which are to have stretch characteristics either in the longitudinal or transverse direction, or both.
Description (OCR text may contain errors)
United States Patent 191 Miller 1 Feb. 18, 1975 I SIMULATED WOVEN FABRICS  Appl. No.: 428,324
 U.S. Cl 161/57, 161/55, 161/60, l61/70,161/78,161/86, 161/92,161/143,
161/149, 264/167, 264/DIG. 75
 Int. Cl B321) 5/12  Field of Search 161/55, 57, 60, 70, 143, 161/147, 149,78, 86, 92, DIG. 6; 264/103,
167, DIG. 75, DIG. 76, DIG. 81
 References Cited UNITED STATES PATENTS 2,738,298 3/1956 David et al. 161/143 3,140,973 7/1964 Johnson 161/92 3,419,456 12/1968 Tenney [61/78 3,597,300 8/1971 Miller 161/147 3,753,842 8/1973 Pittman 161/57 3,759,782 9/1973 Bleuer 161/57 Primary ExaminerWilliam J. Van Balen Assistant ExaminerWilliam R. Dixon, Jr.
57 ABSTRACT Fabric simulating woven fabric comprising conventional warp threads disposed in the longitudinal direction and a filling comprising monofilaments laid transversely of the warp threads but not woven overand-under therewith. By extruding the monofilaments onto the warp threads as these latter advance past an extruding nozzle the warp threads and filling" threads are caused to cohere or coalesce at their points of intersection to provide a fabric having enhanced tensile strength and flexibility in both directions. Moreover, the fabric may be produced at substantially lower cost than fabrics. woven by conventional methods, e.g. on a needle loom or shuttle loom or by braiding, all of which are regarded as uneconomically slow. In one aspect the jlLlIlCtlOllS of the filling threads and the warp threads at the selvages are so united as to yield a smooth edge. In still another aspect the invention is ideally suited to fabrics which are to have stretch characteristics either in the longitudinal or transverse direction, or both.
17 Claims, 19 Drawing Figures SIMULATED WOVEN FABRICS BACKGROUND OF THE INVENTION Where, in the following description and claims, I employ the terms filling" or weft" the same are in-.
tended to refer to plastic filaments laid transversely of the warp threads by extrusion but not interwoven therewith under-and-over in a conventional manner. However, depending upon the viscosity of the extruded material the monofilaments may become merged or coalesced with the warp ends in varying degree. In accor dance with the invention some degree of embedment of one thread with another at the points of intersection is necessary in order that acceptable interlock of the warp and filling over the entire area of the fabric may be achieved.
Present methods of producing narrow fabrics, such as woven tapes and especiallly elastic tapes, often are uneconomical and are far from commercially acceptable. In cases where the filling is resilient, e.g. nylon filaments, horsehair and the like, reversal of the lays of filling at the selvages produces distinct arches which, due to the stiffness of the yarn, constitute rough edges. To counteract this the manufacturer introduces a cushioning material which has the effect of filling in and covering the arches. However, the cost of production is materially increased thereby.
Additionally, in the case of stiff threads in the filling, breakage may readily occur and the broken end then protrudes beyond the selvage, obviously an objectionable resultv The same is true of the end of the yarn wound on a shuttle when it runs out.
The principal object of the present invention resides in the provision of'a fabric, particularly a narrow fabric such as a tape which may be produced at substantially reduced cost and has enhanced versatility. For convenience of nomenclature, a fabric in accordance with the invention is referred to herein as a simulated woven fabric.
Another object is to provide a fabric as aforesaid wherein the warp threads may be conventional yarns,
twisted or untwisted, natural or synthetic, monoor polyfilaments, elastic or non-elastic. Since the filling is c. those thermosetting plastic materials or mixtures thereof with thermoplastic materials, which are capable of extrusion;
d. wet spinnable materials, such as viscose, cuprammonium cellulose or protein material (e.g. from soya beans), capable of extrusion and setting by immersion in or spraying with a coagulant as the plastic emerges from the die.
SUMMARY OF THE INVENTION Material in accordance with the invention comprises a plurality of warp threads which are spaced apart some selected distance and are maintained in such spaced re lation by a plurality of transverse plastic filaments extruded onto the warp threads as these latter advance past an extruding die. The extrusion process is so regulated that the warp threads and filling threads coalesce or cohere at their points of intersection whereby the flexibility of the fabric both longitudinally and transversely may be regulated.
Since it is desirable to attain a smooth aspect at the selvages, flow of the plastic material in such regions is necessarily controlled in a manner which avoids discontinuities or irregularities at the edges of the fabric.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a strip of fabric embodying the principles of the invention;
FIGS. 2, 3 and 4 are cross sections transversely of the fabric strip taken on the lines indicated compositely as 2-2, 3-3, 4-4;
FIGS. 5, 6, 7 and 8 are details in perspective of por tions of the weft filaments to show various cross sec tions the same may assume;
FIG. 9 is asomewhat magnified, perspective view of a portion of the fabric showing the coalescense of the warp ends and weft filaments at the selvage. In this figure the weft filaments are shown smaller than the selvage warp end;
FIG. 9a is a cross section taken on the line 9a-9a of FIG. 9;
FIG. 9b is a cross section taken on the line 912-912 of FIG. 9. In this figure the weft filaments are the same size as the selvage warp end;
FIG. 10 is a perspective view similar to FIG. 9 except that here the plastic forming the weft filaments is al' lowed to flow around and completely cover the selvage weft thread;
FIG. 10a is a cross section taken on the line 10a 10a of FIG. 10;
FIG. 11 is a perspective view similar to FIG. 9 except that in this case the plastic forming the weft filaments does not flow axially along the selvage warp end but embraces it over an angle on the order of from 180 to FIG. 11a is a cross section taken on the line lIa--l la of FIG. 11;
FIG. 11b is a cross section similar to FIG. except that in FIG. 11a the depth of the weft filament is greater than the diameter of the selvage warp end, while in FIG. 11b the depth of the weft filament is smaller;
FIG. 110 is a perspective view to show the relation of the selvage end and filling of FIG. 1111;
FIG. 12 is a perspective view showing a variation of FIG. 11 except that the weft filamentscompletely surround the selvage warp end; and
FIG. 12a is a cross section taken on the line 12a-12a of FIG. 12 to illustrate a condition wherein the portion of the Weft filament surrounding the selvage warp end is made quite thin.
DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to the drawing there is shown a section 15 of fabric embodying the principles of the invention illustrated, by way of example, as a strip comprising longitudinally extending warp ends of any conventional form and material, monoor multifilaments and classified somewhat more specifically in the foregoing portion of this description. In the description and claims such warp ends may sometimes be referred to as threads constituting a warp.
At this juncture it will have become apparent that the terms warp and filling are not used in the traditional sense but analogously thereto in that the threads fed in the direction of movement of the web of fabric function similarly to the warp of a woven fabric and the transversely disposed filaments function in somewhat the same way as the conventional weft or filling threads which are interwoven with the weft in an over-andunder orientation.
In FIG. 1 the spacing of the filaments 16 is exaggerated for clarity of exposition, it being understood that, in a practical construction, this spacing is on the order of H32 inch. However, the disclosure is not intended to be limited to any specific spacing of the filaments constituting the filling. The ensuing description will be devoted largely to particulars of the fused joints between the filling and warp, with special reference to the attainment of a smooth edge at the selvage. Such requirement becomes important when the invention fabric has rubbing contact with an adjacent fabric; for otherwise significant abrasion of the latter can readily result.
Since, at the moment of extrusion, the plastic forming the filaments l6 flows readily it is possible to control the coalescense of the filaments and warp ends in a manner to reliably unite the two groups at their points of intersection and to avoid any roughness or discontinuities at the zones of junction, and as will now be described.
FIGS. 2, 3 and 4 illustrate some ways in which the aforesaid union may be produced. FIG. 2 shows a condition in which the warp ends 17b disposed intermediate the selvage warps 17a are only slightly embedded in the filaments 16. FIG. 3 shows embedment in various degrees in order to obtain various characteristics in the finished product. FIG. 4 shows embedment of the warp ends to a somewhat greater depth than is shown in FIG.
2. Further, from FIGS. 2, 3 and 4 it will be seen that the filaments 17 have a cross section which is smaller than the mean diameter of the selvage warps 17a.'However, as will appear, the filaments may have a cross section which is larger than the mean diameter of the selvage warps or may be equal. Moreover, as shown in FIGS. 5 to 8 the cross section of the filaments may take various shapes e.g. circular, rectangular, triangular, or U- shaped. These and other cross sections are readily obtained by providing suitable transverse channels in a die into which, in one form of apparatus, the plastic may be extruded.
Since, in accordance with the principles of the invention, narrow fabrics may be produced without a shuttle or oscillating needle and the consequent mechanical problems incident upon the behaviour of reciprocating parts, the expense of maintenance and repair is materially reduced.
In order to provide a smooth or non-abrasive selvage various expedients may be availed of. Where, in this description and the claims, I employ the word selvage" I refer to the edge of the fabric as produced by the method referred to herein and not to the nonraveling selvage of a fabric woven by conventional techniques.
It will be understood that the apparatus for producing fabric embodying the principles of the invention will be provided with suitable means for controlling flow of the plastic in its molten state. If not regulated, overflow may occur at the ends of the filaments and a corresponding saw tooth edge produced. However, by proper choice of nozzle dimensions and accurate control of the temperature, rate of flow and initiation and interruption of flow, the edges of the fabric may take any of several forms now to be described.
Adverting to FIGS. 9, 9a and 9b the filaments 16 are, at their ends, caused to flow to terminate in what may be termed a claw 21, embracing the selvage warp ends 17a over an angle of from to 270 more or less, the
primary desideratum being to ensure that the extent of embrace be sufficient to preclude separation of the selvage warp end and the filaments. Thus, the nonembraced area, indicated as X in these figures, is the warp thread itself and, being smooth, will not abrade an adjacent fabric (not shown).
From FIGS. 9a and 9b it will be seen that the filaments 16 may be less than, equal to or greater than the selvage warps and of any cross section (FIGS. 5 to 8).
Although the claw formations 21 are shown as fused at their adjacent ends 20, it will be comprehended that slight separation is tolerable without introducing undesirable roughness at the selvage.
FIG. 10 illustrates a construction wherein the parameters regulating flow of the plastic are so selected as to result in complete coverage of the selvage warps. In this case a continuous edge 25 is presented to the adjacent fabric (not shown). FIG. 10a shows the cross-sectional aspect.
The modification of FIG. 11 depicts a construction in which flow of the plastic is regulated in a manner similar to that of FIG. 9 except that, here, flow along and around the selvage warp end is restricted to the area of abutment between the filaments 16a and the selvage warp. Although, in FIG. 11 the filaments 16a are illustrated as being of rectangular cross section, these may, as previously pointed out in connection with FIGS. 5 to 8, be of any desired cross section.
FIGS. 12 and 12a depict a modification which is similar to FIG. 11 except that the portion of a weft filament shown as embracing the selvage warp is extremely thin in order not to produce objectionable lack of smoothness at the edges of the strip.
It is to be understood that the joint between the filament and warp ends may encompass more than one end. Necessarily, this mode of joining should be confined to a zone closely adjacent to the edge of the fabric, for otherwise undesirable stiffness may be imparted.
It will be appreciated that either thermoplastic or thermal curing resins may be utilized for the weft filaments in accordance with this invention. Further, that a wide variety of resins may be used such as, vinyl chloride, vinyl acetate, vinylidene chloride, phenol, melamine, or urea aldehyde condensates, styrene and its copolymers with butadiene, acrylonitrile, acrylic resins, acrylonitrile resins, polyethylene, natural rubber, neoprene, and various other elastomers.
Where the fabric is to be longitudinally stretchable, elastomers are particularly advantageous for the warp ends. If two-way stretch is required, both the warp ends and weft filaments will be elastomeric. As an alternative, elastomeric warps may be alternated with nonelastomeric warps which are fed under little or no tension. In one commercial form the warp ends were a spun polyester. However, the warps may be a monofilament fed singly or in multiple, twisted or untwisted. It is possible to combine elastic weft filaments with nonelastic warp ends, both selvage and intermediate. Elastomeric warp ends will, necessarily, be fed to the point of extrusion under tension.
The invention also comprehends a fabric wherein the weft filaments intersect the warps at an angle other than 90. Moreover, the weft filaments may be welded to the warp threads by heat or ultrasonic radiant energy to supplement coherence naturally occurring by reason of the plasticity of the extruded material. In connection with any of these steps the warps may be preheated to improve the bond.
In producing one form of the invention on an experi mental basis the selvage warp ends comprised twisted polyester fibers. A die was provided with two grooves spaced apart the same distance as the selvage warp ends which latter were fed from sources of supply, e.g. bobbins. The warp ends were each received in respective grooves and carried beneath an extrudinghozzle having an exit opening of narrow, elongated form, the longer dimension of which was less than the distance between the selvage warp ends. The die was also provided with a set of transverse grooves meeting the other series of grooves and the plastic was extruded intermittently in timed relation with the relative movement of the transverse grooves past the nozzle exit whereby to form the weft filaments. By reason of the pressure applied to the plastic issuing from the nozzle the plastic is forced toward the selvage warp ends to improve the union of the weft filaments therewith and as described in connection with FIGS. 11, 11c and 12. The excess of molten plastic deposited in the transverse grooves was wiped flush with the die by a doctor blade. Following this the warp ends intermediate the selvage warp ends were laid across the still plastic weft filaments and roller pressure applied to insure positive cohesion at the points of meeting and intersection.
Where, herein, I employ the term intersection in relating the weft filaments to the warp ends I intend, in the interest of conciseness, to refer not only to intersections in the sense ofcrossing but the meeting of the filaments with the warp ends in a butt joint.
1. In a fabric simulating woven fabric comprising a plurality of parallel threads disposed in one direction to constitute a warp including a selvage warp thread at each edge of the fabric and a plurality of parallel filaments of plastic material disposed in a direction intersecting said threads to constitute a filling, said respective pluralities being joined at their points of intersection, the improvement wherein the juncture of the filling filaments with the selvage warp threads are constituted as a butt joint and are smoothly merged into the selvage warp threads whereby the selvages are substantially free of irregularities.
2. Fabric in accordance with claim 1 plastic material is thermoplastic.
3. Fabric in accordance with claim 1 plastic material is thermosetting.
4. Fabric in accordance with claim 2 thermoplastic is a polyamide.
5. Fabric in accordance with claim 1 warp threads comprise a polyester.
6. Fabric in accordance with claim 1 warp ends comprise an elastomer.
7. Fabric in accordance with claim 1 wherein the filling threads comprise an elastomer.
8. Fabric in accordance with claim 1 wherein the warp ends and filling threads comprise an elastomer.
9. Fabric in accordance with claim 6 further characterized in that the elastomer is wrapped with a conven' tional yarn.
10. A fabric simulating woven fabric comprising a plurality of parallel threads disposed inone direction to constitute a warp including a selvage warp thread at each edge of the fabric and a plurality of parallel filaments of plastic material constituting a filling disposed in a direction intersecting said threads, said respective pluralities being joined at their points of intersection, the filling threads at the points ofjuncture with the selvage warp threads being smoothly merged into the selvage warp threads, the place ofjuncture constituting a butt joint, whereby the portions of the filling filaments at the selvages are free of irregularities.
11. Fabric in accordance with claim 10 wherein the plastic material is thermoplastic.
12. Fabric in accordance with claim 10 wherein the plastic material is thermosetting.
13. Fabric in accordance with claim thermoplastic is a polyamide.
14. Fabric in accordance with claim warp threads comprise a polyester.
15. Fabric in accordance with claim warp ends comprise an elastomer.
16. Fabric in accordance with claim filling threads comprise an elastomer.
17. Fabric in accordance with claim 10 wherein the warp ends and filling threads comprise an elastomer.
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