US3842576A

US3842576A - Method and apparatus of making crimped yarn

Info

Publication number: US3842576A
Application number: US00352694A
Authority: US
Inventors: N Rosenstein
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-04-19
Filing date: 1973-04-19
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

A multiple filament yarn is crimped by sewing it onto a backing layer, with the yarn then being set in the sewn condition and thereafter de-sewn leaving sharp crimps therein. The yarn may then be bulked or texturized by tensioning the yarn or otherwise causing longitudinal translation of crimps of some of the filaments relative to crimps of others of the filaments.

Description

United States Patent 1 1 Rosenstein, deceased [4 1 Oct. 22, 1974 1 1 METHOD AND APPARATUS ()F MAKTNG CRIMPED YARN [76] lnventor: Nathan Rosenstein, deceased, late of 66 Foxcroft Rd.. West Hartford, Conn. 06119 by Rachael Rosenstein. administrator [22] Filed: Apr. 19, 1973 [21] Appl. No.: 352,694

[52] US. Cl. 57/1 R, 57/156 [51] Int. Cl D02g H00 [58] Field of Search 57/1 B. 34 B. 34 R, 34 HS. 57/36. 55.5, 156. 157 R, 157 J. 157 S. 157

TS. 157 MS, 28/72.]6

[56] References Cited UNITED STATES PATENTS 2.051.588 8/1936 Wilson 28/7216 X 2.950.521 8/1960 Wheat et a1. 28/7216 3.196.602 7/1965 Jenkins ct al. 57/157 TS 3.330.018 7/1967 Silver ct al. 57/157 MS X 3.358.345 12/1967 Daniel 57/34 HS X 3.469.387 9/1969 Chamberlain 57/157 MS X 3.605.225 9/1971 Gibson ct al 28/7216 FOREIGN PATENTS OR APPLICATIONS 2.007.285 9/1971 Germany 28/72.]6

Primary ExaminerDonald E. Watkins [57 ABSTRACT A multiple filament yarn is crimped by sewing it onto aacking layer, with the yarn then being set in the sewn condition and thereafter de-sewn leaving sharp crimps therein. The yarn may then be bulked or texturized by tensioning the yarn or otherwise causing longitudinal translation of crimps of some of the filaments relative to crimps of others of the filaments.

24 Claims, 8 Drawing Figures Ii ll '44 I 25 PATENIEB ZZW mints METHOD AND APPARATUS OF MAKING CRIMPED YARN BACKGROUND OF THE INVENTION Polymeric materials such as nylon, polyethylene, and other synthetic materials, generally of the thermoplastic type are normally formed into yarn by reducing them to the liquid state and by then extruding the liquid through orifices in a spinnerette, with a plurality of filaments that are extruded from the spinnerette being allowed to solidify in air, or some other solidification medium, in order to comprise a plurality of filaments which are then brought together to form a yarn. As extruded, the filaments are normally in a so-called amorphous condition, wherein the molecules of the polymer are randomly arranged and in which condition filaments do not have desirable strength characteristics. However, the strength is thereafter imparted to the filaments and to the yarn by a process of drawing, in which case the yarn is stretched, usually to several times its original length. This stretching produces an orientation of the molecules of the polymer and thus contributes the desired strength characteristics to the yarn.

However, the stretching procedure referred to above also leaves residual stresses in the filaments, and it has been determined that these characteristics plus the thermoplastic characteristics of the drawn filaments themselves leave the filaments in such a condition that if they are buckled and folded upon themselves in order to form crimps, as'in stuffer-box crimping, these crimps can be rendered substantially permanent by heat setting. In heat setting, the yarn is preferably heated to a temperature which is high enough to cause an internal molecular relaxation of the molecules in the polymers, and this relaxation results in a considerable degree of permanence in the crimp that has been applied to the yarn, after cooling of the heated yarn.

Heretofore, it has become common practice to provide some element of bulk to yarns, by subjecting them to stuffer-box crimping wherein the yarns are forced under a pressure into a confined chamber and are thereafter subjected to heat setting as disclosed in US. Pat. No. 3,271,836. Crimping in such a manner introduces a memory of the crimped condition into the yarns that may be useful in simulating natural fibers as opposed to the straight, linear fibers in the justextruded stage.

Separately, or in addition to stuffer-box crimping, yarns have been texturized in various other ways, also generally to provide an element of bulk, for example by false twisting as disclosed in the US. Pats. of Carruthers Nos. 3,091,908 and 3,192,697, and texturizing of the types disclosed in US. Pats. to Wyatt No. 3,488,936 and Berger No. 3,482,384.

While yarns produced in accordance with all of the procedures just referred to have been highly useful in the art, there is a need for yarn having special crimp characteristics and having an unusual degree of uniformity with respect to crimp level. Further, there is a need in the art for yarn which can be crimped at extremely low cost and with unprecedented convenience of operation, and especially with minimal outlays for specialized individual components of the apparatus.

In the art of stuffer-box crimping of yarn, consider-.

able difficulty was encountered because of nonuniformity of crimp level, because of the very nature of application of the crimp. Disclosures have been made of the desirability of effecting special control of the uniformity of crimp. For example, the US. Pat. to Shattuck et al. No. 3,000,060, purports to disclose, the control of the feed of the yarn into the chamber so that the yarn will meet uniform resistance within the crimping chamber.

Variations in resistance that yarn can encounter at different locations in stuffer-box crimping can, at some times produce a multiplicity of extremely high level crimps (short legs crimped at a high angle), and at other times, often only momentarily thereafter, produce crimp of a very low level (long legs crimped at a low angle).

In actual operation of stuffer crimpers of various kinds notwithstanding the extreme care that has been taken to control the yarn feed in some cases, generally stuffer-box crimping results in extreme variations of crimp level, for the most part not yet overcome by the art. Variations in crimp level can be extremely serious because the degree of crimp level has a profound affect upon the uniformity of dyeing of the yarn, or of dyeing a fabric into which the yarn has been incorporated. Variations in uniformity of crimp level in fabric being dyed can result in dye streaks, which so seriously affect the quality of the fabric that many fabrics are required to be down-graded and sold at sacrifice prices because of the presence of such streaks.

Some disclosures teach providing uniformity of crimp level. For example, the US. Pat. to Keen No. 2,857,651 is directed toward making crimps of the curled'type by tufting and then detufting, in order to form rounded loopy tufts. After the tufting operation and prior to de-tufting, the yarns are heat set. The result is yarn that is composed of rounded curls, as distinguished from sharp crimps.

Also gear crimping provides uniform crimps from crimp to crimp. However, again, crimps made thereby are generally characterized by gradual or rounded loops or reversals of the yarn, because of the very nature of the construction of gear teeth, which do not lend themselves to providing sharp crimps.

There is a need for crimped yarn having the sharpness of crimps that is sometimes obtained in the nonuniform yarn that has been stuffer-box crimped, but that also has the crimp uniformity of the rounded crimps of yarn that has been gear-crimped or tuftcrimped.

THE PRESENT INVENTION The present invention is directed toward providing crimped yarn, wherein the crimps are not only regular and extremely uniform, but which are very sharp and highly bent or angular, in a particular repetitious pattern of zig-zag configuration.

Such sharp bends in themselves may provide desired aesthetic and/or novelty characteristics of the yarn, either by themselves, or after further treatment, such as twisting. However, when the filaments of the yarn are of a synthetic type, not having their own natural bends, kinks, crimps and the like, or when the yarns are only partly constructed of natural fibers having such, with the other filaments of those yarns being synthetic, it becomes highly desirable to give the yarns a bulk or texturized appearance and feel. For the reasons set forth above, it becomes important that such yarns have favorable dyeing characteristics, and accordingly, uniformity is desired in the texturized yarns. By applying sharp crimp as discussed herein above, and by thereafter subjecting the crimp to a further process, preferably that tensions the yarn longitudinally such that of a given yarn length, some filaments are translated longitudinally of the yarn, to displace peaks or crimped portions of the filaments, from peaks or crimped portions of other, generally adjacent filaments, wherein such peaks or crimped portions were originally structured in the same crimp. By controlling the even application of such tensioning or stretching of the crimped yarns, an even distribution of crimped portions of the various filaments will be obtained, throughout a given yarn. Accordingly, the tensioning or stretching causes a slippage" of filaments relative to each other, thereby displacing the peaks or crimped portions of filaments that were once in the same crimp, relative to each other.

If the crimping has effected a sharp crimp in such a way that there are alternate shorter and longer spaces between crimps, measured longitudinally of the yarns, subsequent tensioning or stretching of the yarns easily causes a slippage or de-phasing of the zig-zag relationship of filaments of a given yarn to each other that gives a rapid de-phasing that is seemingly random, and which results in desirable bulked texturized qualities in the yarn.

This de-phasing is effected by using uniform sharply crimped yarns that have alternate long and short legs between the crimps prior to effecting the slipping or de-phasing thereof.

It has been found that the desired long leg short leg crimp with sharp bends and extremely high uniformity from crimp to crimp can be achieved by first sewing the yarn onto a backing layer, then heatsetting the yarn in its sewn condition, followed by a de-sewing of the yarn from the backing layer. Thereafter, the yarn may be tensioned to de-phase the sharp crimps longitudinally of the yarn.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed toward providing a novel yarn, having sharp crimps therein with uniformity from crimp to crimp, that may thereafter be further processed by tensioning or the like to have desirable bulk characteristics, wherein the yarn is first sewn onto a backing layer, heat set in the sewn condition, and thereafter de-sewn.

Accordingly, it is a primary object of this invention to provide a novel crimped yarn.

It is a further object of this invention to provide a novel bulked or texturized yarn.

It is another object of this invention to provide a novel process for crimping yarn.

It is a further object of this invention to accomplish the above objects, wherein the process employs sewing, heat-setting and then de-sewing.

It is another object of this invention to accomplish the two objects set forth immediately above, wherein the sewing operation effects a regular pattern adapted for providing crimp uniformity.

It is a further object of this invention to provide novel apparatus for producing yarns of the type described herein.

Other objects and advantages of the present invention will be readily apparent to those skilled in the art by a reading of the following brief descriptions of the drawing figures, detailed descriptions of the preferred embodiments, and the appended claims.

IN THE DRAWINGS FIG. 1 is a top perspective schematic illustration of apparatus for accomplishing the method of this invention, wherein a continuous belt is utilized, into which yarns from a creel or the like are sewn, and then delivered into a heat chamber, and which are then de-sewn and tensioned after leaving the chamber.

FIG. 2 is an enlarged schematic illustration of a multiple filament yarn that has just been de-sewn, and prior to tensioning or otherwise de-phasing filaments thereof, with the yarn being illustrated as it appears when it is disposed on a flat planar surface, as for example, between two sheets of glass, with the alternate shorter and longer legs disposed in a generally common plane.

FIG. 2a is an enlarged detail view of a pair of adjacent shorter and longer legs connected by a sharp crimp made in accordance with the present invention.

FIG. 2b is an enlarged schematic illustration of the yarn of FIG. 2a, as longitudinal tensioning is begun, but prior to any de-phasing.

FIG. 20 is an illustration similar to that of FIG. 2b, but wherein the yarn is illustrated after tensioning thereof has been effected, and after de-phasing has occurred, with some of the filaments being in slipped or longitudinally displaced positions relative to each other.

FIG. 3 is an enlarged fragmentary schematic illustration of a chain stitch, illustrated in full lines, being desewn from a backing layer (illustrated in phantom for the sake of clarity), with a portion of the de-sewn stitch being illustrated in a relaxed condition, in phantom, for demonstrating the alternate shorter and longer legs between crimps.

FIG. 4 is a schematic side elevational view of an alternative apparatus for accomplishing the method of this invention, wherein the sewing is done on a backing layer that is then roller up and placed into a batch autoclave, for subsequent removal therefrom and de-sewing and tensioning thereof.

FIG. 5 is a fragmentary illustration of an alternative tensioning mechanism for effecting the de-phasing of filaments of a given yarn, relative to each other, such mechanism being of the ring twister type.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail, reference is first made to FIG 1, wherein the apparatus generally designated by the numeral I0, is illustrated as comprising a continuous backing layer 11 of the belt type disposed about

rotatable rollers

13, 14, 15, l6, 17, I8, 20, 21, 22, 23, 24 and 25.

The belt 11 will preferably be continuous as shown, and may be of cloth or other construction, or may even be of paper construction, as might be preferable if a backing layer of the throw-away type is desired. The roller 15, may for example be a drive roller, with the others being idler rollers, although any suitable arrangement may be utilized.

Yarns such as those 26 may be delivered to a sewing machine 27 from cones such as that 28 carried on a creel, for sewing of the yarns 26 into the backing layer 11.

The sewing machine 27 may be of any standard commercial type, capable of providing a suitable stitch. The stitch provided will preferably be of a chain type, as illustrated in FIG. 3, for facilitating later removal of the yarn, with ease, rather than being of the locking-stitch type, which would substantially retard the de-sewing operation. It will also be noted that the stitch will provide alternate longer and shorter legs as is more fully discussed hereinafter in the specific discussion of the illustration of FIG. 3.

It will be seen that the backing layer 11, with the stitches 30 therein then passes into a heated chamber 31, with heat being provided from any suitable source, such as a hot box 32 with a fan therein blowing hot air upwardly through ports 33 thereof, of any alternative steam chest, autoclave of any type may be utilized. It will be understood that sufficient heat is applied to the generally thermoplastic yarns 26, within the chamber 31 to relax the stresses that would exist just previously in the sewn yarns, in order that the yarns take on a set, in their sewn orientation (for example as illustrated in FIG. 3), after leaving the chamber 31 and cooling thereof. The cooling that effects the final set of the yarns in their sewn condition may be provided by ambient air, a blower, or any other suitable means. The yarns 27 are de-sewn, by passing into the nip 34 of a pair of rolls 35, 36, one of which will generally be driven and the other being driven thereby. The tensioning of the yarns being de-sewn may be effected by the tension on the yarns between the backing layer 11 at the point that the yarns leave the backing layer and the nip 34, or alternatively, may be provided between the nips 34 and 37. The nip 37 will be provided by a pair of rollers similar to those 35, 36 if desired, or by any other suitable means. The yarn may then be delivered to a bin 38 or the like, suitable for delivery to a station of use, or as an alternative, the yarn may then be delivered directly to a loom, knitting machine, or the like.

With reference to FIG. 3, it will be clear that the backing layer 11 has the yarn 26 stitched thereinto in a chain stitch. The stitch illustrated in FIG. 3, is of a type that will provide alternate longer and shorter longitudinal portions between crimps of the yarn. It will be noted that, while the crimps are of exaggerated roundness in FIG. 3, for the sake of clarity, in a sewing operation in reality, the crimps for example, at locations a, b, c as illustrated in FIG. 3, will be sharp, and highly bent. Upon gripping of the yarn 26 in a nip such as that of rolls, or otherwise, the yarn will be tightly stretched as illustrated at the upper right portion of FIG. 3, but if relaxed at that point and maintained in a flat gener ally vertical plane, the yarn 26 would assume the phantom position illustrated schematically in FIG. 3, or one close thereto, wherein alternate longer (L) and shorter (S) yarn portions would exist between crimps a, b, c. It will be seen, for example, that the shorter S distance between locations a and b correspond to the distances between points a and b in the as yet stitched portion of the yarn at the left end of the illustration of FIG. 3. Similarly, the longer length L between locations b and c represents a portion of yarn that once assumed a disposition similar to that between points b and c illustrated in FIG. 3, in that portion of the yarn that is stitched into the backing layer 11.

With reference to FIG. 2, it will be seen that the yarn 26 is comprised of a plurality of adjacent alternate shorter S and longer L legs or portions between crimps 40 thereof. Occasionally, longer legs L and L" will appear, if the yarn 26 is placed in common plane, that seem to indicate that the zig-zag orientation of the yarn 26 reverses itself. What actually happens here, is that the yarn 26 rotates 180 on its axis, about that location, such that, when flattened out, it gives the appearance of two portions between crimped being back-to-back. FIG. 2 represents, in schematic form, a regular, uniform, zig-zag highly crimped yarn, in accordance with the techniques of the present invention.

In FIG. 2a, the yarn 26, having crimps 40 therein is seen to comprise a plurality of

filaments

41, 42, 43 and 44 (although in most instances, greater number of filaments will be utilized). Also, in the schematic illustration of FIG. 2a, the yarn is illustrated as being constructed of filaments that are all synthetic, of thermoplastic type, although in practice, each yarn could be made from a mixture of some natural and some synthetic fibers and filaments, respectively.

Upon slightly tensioning the yarn 26, as illustrated in FIG. 2b, the

points

45, 46, 47 and 48 of the respectively associated

filaments

41, 42, 43 and 44 that comprise a unitary crimp 40 have not yet been de-phased by tensioning.

In FIG. 2c, the filament crimps, apices, or points 45, 46, 47 and 48 have been de-phased, or translated or disposed longitudinally, relative to each other, and relative to the previous multiple filament crimp 40, now substantially nonexistent. It will be understood that the de-phasing that is effected by virtue of tensioning or the like may not always undergo the apparent uniform longitudinal translation for the points 45 to 48 illustrated in FIG. 20, because such illustration is of course schematic only. However, over many such points being translated, some more or less than others, over a yarn having a great many filaments therein, the translational movements will tend to average out, to give the appearance of uniformity in location or spacing of crimps of the filaments along the yarn, and uniformity of bulk.

With reference to FIG. 4, it will be seen that yarn 50 is being delivered from a cone 51 of a creel, and is sewn by a sewing machine 52 onto a backing layer 53, that is then wound-up into a reel 54 at station 55, for delivery in batch to an autoclave 56. In the autoclave, the yarn is heated for relaxation of its tensions, and for taking on a set, and may be cooled therein, after the heating has been done, or cooled upon removal, or subsequent thereto. In any event, the yarn is eventually delivered to a station 57, for unwinding thereof, as illustrated in FIG. 4, by winding-up the backing layer 53 at station 58, as the crimped yarns 50 are de-sewn from the backing layer 53, passing into the nip of a pair of

rotating rollers

61, 62 or the like. The tensioning may be effected between the point 63 at which the yarn 50 leaves the backing layer 53 and the nip 60, or if desired, between the nip 60 and a bobbin wind-up device 64 having a suitable longitudinally removable guide 65, for facilitating the winding of the de-sewn yarn therethrough, in a conventional manner.

It will be apparent, that in accordance with any of the methods, techniques, and apparatus of this invention, it may be desirable to utilize the de-sewn yarn, without tensioning it in such a way as to effect the de-phasing, particularly in those instances in which sharp crimps in the yarn, as illustrated in FIG. 2a are desired. In such instances, no longitudinal translation of points 45 through 48 will be made, and in order to accomplish this end, no substantial tensioning of the yarn will be provided at or downstream of the de-sewing location.

With reference to FIG. 5, an alternative tensioning mechanism is provided, whereby de-sewn yarn 70 is drawn from a backing layer 71, passed around a roller 72, and another roller or guide 73, will be delivered through a guide 74, to the ring 75 of a rotating ring twister 76. The ring twister 76 is of a conventional type, and may, for example, be constructed along the lines of that illustrated and disclosed in U.S. Pat. No. 3,530,656. either for merely winding the yarn onto a bobbin, or for providing the desired tensioning therefor.

It will be understood that the mechanism illustrated in FIG. may be applicable to tensioning or winding-up yarn coming from a batch process as illustrated in FIG. 4, or from a continuous process as illustrated in FIG. 1, as desired.

From the above, it will be clear that the desired ends of the invention will be accomplished, in providing a novel yarn, in providing a novel bulked or texturized yarn, in providing novel techniques for making crimped yarn and for making bulked or texturized yarn, and in providing novel apparatus for doing all of these things. Furthermore, it will be apparent that within the skill of the art, various changes may be made in the apparatus from the particular apparatus herein disclosed, as well as in the method of this invention, all within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer in a manner to form the yarn into regularly spaced sharp bends, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer.

2. The method of claim 1, wherein the setting of the yarn comprises the application of sufficient heat to the yarn to effect an internal relaxation of molecules thereof, followed by a cooling of the yarn.

3. The method of claim 1, with the yarn being thereafter wound, all in a continuous process.

4. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer, wherein the sewing step comprises engaging the yarn with the backing layer in such a way as to employ a repetitious pattern comprising alternate shorter and longer stitch portions between crimp-forming portions, and with the yarn setting comprising the setting of crimps in the crimp-forming portions.

5. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer, and with the yarn being thereafter longitudinally tensioned, all in a continuous process.

6. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer, wherein the sewing is of the type that places a plurality of sharp, tight bends in the yarn, that after setting and removal of the yarn from the backing layer, become sharp crimps.

7. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer, with the yarn being of the multiple filament synthetic type, and with crimped portions of filaments of the yarn being longitudinally translated relative to crimped portions of other filaments of the yarn to stagger the crimped portions along the yarn for bulking the yarn.

8. A method of producing textured multiple filament synthetic yarns having substantially uniform bulk characteristics, comprising the steps of sewing heat settable yarns into a backing layer in regular patterns of stitches that have sharp bends that comprise crimp-forming portions longitudinally of the yarns, heat setting the yarns to set crimps in the crimp-forming portions thereof while the yarns are in their stitched condition on the backing layer, with the yarns after cooling then being destitched from the backing layer and each being longitudinally tensioned to cause longitudinal displacement of crimps of filaments relative to crimps of other filaments of the same yarn.

9. The method of claim 8, wherein the stitching step comprises applying alternate shorter and longer stitch portions between crimp-forming portions of the yarns.

10. The method of claim 9, wherein the stitching step comprises applying a chain stitch.

11. The method of claim 8, wherein a plurality of yarns are sewn and later de-sewn substantially simultaneously.

12. The method of claim 8, wherein the yarns are sewn onto a continuous or belt type backing member in the sewing step.

13. The method of claim 12, wherein the step of heat setting the yarns comprises passing the backing member with the yarns sewn thereon through a heat zone and thereafter to a desewing station, then to the tensioning zone, all as part of a continuous process.

14. The method of claim 8, wherein the sewing step is effected with the backing layer comprising a windable sheet, with the sheet being then cylindrically wound and delivered to a heat chamber and thereafter to an unwind station, with the sheet then being unwound for facilitating the desewing operation.

15. The method of claim 8, wherein the tensioning step comprises passing the yarns over rollers that are spaced longitudinally of the yarns and operated at different rotational speeds.

16. The method of claim 8, wherein the tensioning step comprises twisting each yarn in a ring twister.

17. The method of claim 8, wherein the stitching step comprises applying alternate shorter and longer stitch portions between crimp-forming portions of the yarns, wherein the stitching step comprises applying a chain stitch, wherein a plurality of yarns are sewn and later de-sewn substantially simultaneously, wherein the yarns are sewn onto a continuous or belt type backing member in the sewing step, wherein the step of heat setting the yarns comprises passing the backing member with the yarns sewn thereon through a heat zone and thereafter to a desewing station, then to the tensioning zone, all as part of a continuous process.

18. The method of claim 8, wherein the stitching step comprises applying alternate shorter and longer stitch portions between crimp-forming portions of the yarns, wherein the stitching step comprises applying a chain stitch, wherein a plurality of yarns are sewn and later de-sewn substantially simultaneously, wherein the sewing step is effected with the backing layer comprising.

a windable sheet, with the sheet being then cylindrically wound and delivered to a heat chamber and thereafter to an unwind station, with the sheet then being unwound for facilitating the desewing operation.

19. Apparatus for use in texturing synthetic multiple filament yarn, comprising means for delivering yarn to a sewing means, sewing means for sewing yarn onto a backing sheet to have regularly spaced sharp bends in the yarn, means for carrying a backing sheet, heating means for applying heat to yarns sewn on the backing sheet to heat set sharp crimps in the filaments of the yarns at the yarn bends after cooling thereof, and means for de-sewing the yarn from the backing sheet and for tensioning the yarn to cause a displacement longitudinally of the yarn, of bends of filaments thereof.

20. The apparatus of claim 19, including the backing sheet in the combination.

21. The apparatus of claim 19, wherein the tensioning means is separate from, but disposed downstream of said de-sewing means.

22 The apparatus of claim 21, wherein said tensioning means comprises rotatably driveable rollers for engagement with the yarn at longitudinally spaced locations along the yarn, and with means being provided for driving the rollers at different relative speeds effective for tensioning the yarn.

23. The apparatus of claim 21, wherein the tensioning means comprises a ring twister.

24. The apparatus of claim 19, wherein said sewing and de-sewing means comprise respectively means for sewing and de-sewing a plurality of generally parallel yarns substantially simultaneously, with the means for delivering the yarn to the sewing means comprising reel means, and with the heating means comprising heating chamber means.

Claims

1. A method of making crimped yarn comprising the steps of sewing settable yarn into a backing layer in a manner to form the yarn into regularly spaced sharp bends, setting the yarn in that condition on the backing layer, and then removing the yarn from the backing layer.

18. The method of claim 8, wherein the stitching step comprises applying alternate shorter and longer stitch portions between crimp-forming portions of the yarns, wherein the stitching step comprises applying a chain stitch, wherein a plurality of yarns are sewn and later de-sewn substantially simultaneously, wherein the sewing step is effected with the backing layer comprising a windable sheet, with the sheet being then cylindrically wound and delivered to a heat chamber and thereafter to an unwind station, with the sheet then being unwound for facilitating the desewing operation.

20. The apparatus of claim 19, including the backing sheet in the combination.

22. The apparatus of claim 21, wherein said tensioning means comprises rotatably driveable rollers for engagement with the yarn at longitudinally spaced locations along the yarn, and with means being provided for driving the rollers at different relative speeds effective for tensioning the yarn.