US2353666A - Yarn and method of producing the same - Google Patents

Description

July 18, 1944. B. HATHORNE ET AL 2,353,666

YARN AND METHOD OF PRODUCING THE SAME Filed Aug. 24, 1940 IN BERKELEY LHAT VENTORS HORNE BY ROBERT w. SEEM WWZ WORNEY Patented July 18, 1944 YARN AND METHOD OF PBODUCIN G THE SAME Berkeley L. Hathorne, Delray Beach, Fla., and

Robert W. Seem,

11, Pa., assimors, by

direct and mesne assignments, to Crepe de Chine, Inc., a corporation of Pennsylvania Application August 24, 1940, Serial No. 354,064

26 Claims.

The present invention generally relates to yarns and the method of producing the same, as, well as to the fabric made therefrom. More particularly, the invention pertains to a method of producing twisted yarns so that the tendency to untwist is eliminated or controlled, thereby facilitating the processing of the yarns and the fabrication of fabric therefrom.

- The invention is particularly advantageous for the production of twisted natural silk yarns and synthetic yarns in which the tendency to untwist is eliminated, or so controlled as to facilitate processing in the manufacture of fabric, especially hosiery knitted from such yarns.

In the art of processing natural silk or synthetic yarns, it is common practice to set the yarn after twisting primarily for the purpose of imparting to the yarn a more or less permanent shape or form, to which the yarns tend to return after being subjected to deformation. Because of the inherent resilient characteristic of the yarn, the same tends to return to its normal shape after being deformed, and thus when the yarn is twisted, it tends to return to its untwisted form. Various methods of .;twist setting, such as heat, steam, water, water vapor, sizing, etc., or any combination of these methods, have been used to minimize the tendency of the yarn to untwist, especially in order to facilitate subsequent operations and to make practical or possible the production of fabrics otherwise most diffl- I cult and, in some instances, impossible to produce.

yarn important added characteristics, including a degree of permanent distortion and activeand latent torsions.

The active torsion is the torsional force which causes the twisted yarn to partly untwist when merely permitted to return to a state of rest as, for example, by allowing one end to hang free.

The latent torsion is the torsional force that is not evidenced until liberated after-the yarn has been disturbed as, for example, by subjecting it to water, stretching, bending, or a change in relative humidity or temperature.

The active torsion of the twisted yarn may be sumcient, for example, to cause the yarn to untwist flve turns per inch, but afterthe yarn has reached a state of rest, it may be caused to untwistten turns per inch additional by wetting, which liberates the latent torsion.

With certain types of twisted yarn, it is practical to reduce the active torsion by sizing and/or by twist setting methods, and with other types of yarn both the active and latent torsions may be reduced by certain twist setting methods. However, it is common knowledge in the art that natural silk and synthetic yarnshave a relatively high degree of active torsion even after the methods best suited for such yarns have been employed to set the twist. This characteristic of natural silk and synthetic yarns limits the amount of twist that can be used, since the tendency of the set yarn to untwist complicates subsequent operations necessary in the production of certain fabrics and gives a different appearance and eifect to the fabric, and adds materially to the cost of operation.

The active or perceptible torsion or tendency to untwist by the set yarn, or the latent torsional force when liberated, is evidenced in the subsequent operations and fabrication by diiiiculties such as snarling or kinking, and interference in the normal free delivery when the yarn is being drawn over end from a package, and in the fabric by kinking, crepeing, shrinking,- curling, and twisting on a bias. 1

It is, therefore, one of the most important objects of the invention to provide a twisted natural silk yarn, or a synthetic yarn, wherein the active torsion is eliminated or reduced, and the latent torsion so controlled as to overcome the defects and objectionable results above mentioned.

It is also an important object of the invention to make possible the production of twisted natural silk and synthetic yarns in which the tendency to untwist is eliminated or controlled, using as a means of eliminating or controlling the tendency to untwist, less or no previously known twist setting method or methods.

Another object of the invention is to make possible the production of twisted natural silk or synthetic yarns in which the tendency to untwist is eliminated or controlled, using as a means of eliminating or controlling the tendency to untwist, less or no opposite initial twist in the individual strands or combination of strands constituting the yarn.

Still another object of the invention is'to make possible and practical the production of improved fabrics from twisted natural silk or synthetic yarns in which the twist is greater than heretofore found possible or practical.

A further object of the invention is the production of a non-curling high twist yarn substantially free of torsional forces incident to the high twisting thereof, whereby high twist yarn may be more successfully utilized in the fabrication of textile fabrics of greater uniform texture and appearance, particularly knitted hosiery fabrics.

A still further object of the invention is the production of a finer type of yarn for the production of sheerer types of fabrics, while at the same time increasing the strength, snag-resisting and non-curling characteristics of the yarn.

We have discovered that the active and latent torsional forces of twisted natural silk or synthetic yarns can be eliminated or controlled by untwisting to a point sufficient to obtain the desired degree of balance. Said untwisting may be done before, but preferably after, setting the twist in the manner best suited for the yarn, and the untwisting may be progressed not only to a point where the tendency to untwist is brought to equilibrium, but by further untwisting, a-relatively small active and latent opposite torsion may be imparted to the yarn.

An example illustrating the useful benefit of the invention is found in the processing of socalled nylon" yarn, a synthetic polyamide fibre, such as disclosed in the United States Patents No. 2,157,116 and No. 2,071,250. Thirty denier nylon yarn twisted thirty turns left or Z-twist can 'be set after twisting by the use of hot water, heat, water vapor, or other known methods, sufficiently satisfactory to make possible and practical further processing, and knitting into nylon" hosiery. Such a yarn would have a size (30) a: twist (30) .1: strength (5 grams per denier) factor of 4500. However, if thirty denier ny1on" is twisted one way substantially more than thirty turns to give a "size a: twist a: strength factor" in excess of 4500, as, for example, fifty turns. it is impossible to set the yarn sufllciently satisfactorily by any practical means known in the art. The active and latent torsional forces contained in such a yarn after setting cause kinking, or snarling, and interfere with the uniform delivery of the yarn when drawn over end from any package in subsequent operations prior to knitting and, when knitting, the yarn will frequently kink and the knitted hosiery fabric or wales thereof will be on a bias to an undesirable extent.

An example of how thirty denier nylon yarn twisted fifty turns may be obtained by the use of this invention, said thirty denier fifty-turns nylon yarn being free from thedisadvantages herein mentioned, follows:

In accordance with the present invention, thirty denier "nylon" in which a finished twist of fifty turns Z-twist is desired is twisted, for example, sixty turns to the left. The twist is then set in the same manner as would be used for setting the twist in thirty denier thirty-turns nylon." The thirty denier "nylon set with sixty turns Z-twist will have a perceptible amount of active Z-twist torsion (the torsion resulting from twisting ,a. yarn Z-twist) and a very substantial amount of latent Z-twist torsion, the amount of torsion in both cases depending upon the thoroughness of the twist set. This yarn is then twisted ten turns S-twist, leaving the required fifty turns Z-twist in the yarn.

We have found it possible, with methods common in the art, to set the sixty turns of Z-twist in the thirty denier "nylon" yarn to an extent that I p less than five turns of twist need be removed to to a state of equilibrium, but by 75 bring the yarn removing ten turns, that is, twist thethirty denier sixty-turns Z-twist ten turns S-twist, the resultant thirty denier fifty-turns Z -twist nylon yarn will have some actual and latent S-twist torsion incorporated in it. After twisting ten turns 8- twist, the nylon yarn may again be set and thereafter processed in the usual manner.

In testing a cone of nylon yarn so processed, it will be found that, although the yarn actually contains fifty turns of Z-twist, it will tend to untwist in a direction resulting from the opposite or S-twist. This comparatively small amount of actual and latent S-twist torsion to offset the permanent Z-twist torsional aids in processing, in operations subsequent to twisting, and in actual knitting and, further, prevents the knitted fabric from assuming a detrimental bias formation.

It will be appreciated that this method of processing makes possible the use of yarns twisted substantially beyond the twist that produces a substantially higher size a: twist a: strength factor" heretofore found practical or used in the art and this, in turn, makes possible the production of yarns having a size a: twist a: strength factor of at least 5500 and of fabrics having such desirable characteristics as greater snag resistance and a more desirable hand or feel.

Another example illustrating the use of the invention is found in the twisting of natural silk yarns for hosiery manufacturing. In the art of full-fashioned hosiery manufacturing, it has been found impossible to knit satisfactorily three thread 1.3/ denier silk twisted more than thirty-five turns in one direction and having a degummed size (33.6) a: twist a: strength (3.8 grams per denier) factor of approximately 4500. When a three-thread 13/15 denier silk yarn is desired with, for example, forty-five turns of combining Z-twist, it is the general practice to twist with S-twist one or more of the three individual strands constituting the yarn sufficient to obtain the necessary balance for the forty-five turns of Z-twist with which three strands of 13/ 15 denier silk are to be combined. For example, the single strands of 13/ 15 denier silk are twisted fifteen turns S-twist and three such strands are then doubled (that is, assembled),

and twisted forty-five turns Z-twist.

In accordance with the present invention, it is possible and practical to knit into full-fashioned hosiery the three thread 13/ 15 denier silk with forty-five turns of Z -twist and having a. degummed size a: twist a: strength factor in excess of 5500, such as 6100, without the expense of twisting the single ends constituting the yarn and thus an economy in manufacturing, as well as improved fabrics, are made possible.

Hereinbefore it has been shown that it has been impossible to produce satisfactory twisted knitting or weaving yarns which, when tested by accepted methods of twist-testing, show a twist in.only one direction and which have a size as twist .1: strength factor" substantially in excess of 4500, such as in excess of 5500. By the instant invention, there is produced highly satisfactory compact, twisted knitting or weaving yarns which, when tested by accepted methods of twist-testing, show a twist in only one direction and which have a size :1: twist a: strength factor" of not less than 5500 and indeed-in excess of 5500. The yarns contemplated and made in accordance with this invention are straight and have substantially the same compactness and surface appearance throughout their length as that of a like yarn that has been twisted directly to the same finished twist. Herein, the term "straight yarn," or equivalent terminology, means a yarn which is free of crimps, curls or waves to substantially the same degree as possessed by a like yarn directly twisted to the same finished twist.

The compact yarn produced by the instant invention contains latent torsional forces resulting from subjecting the yarn to twisting operations in the Z- and s-directions as hereinbefore described. The latent torsional forces are released upon disturbance of said yarn with water, stretching, bending, change in relative humidity or temperature; and the degree of latent torsional forces released is dependent upon the degree of the disturbance applied. The yarns, in certain embodiments of the invention, also have active torsional forces resulting from twisting in the S-direction. The torsional forces substantially inhibit the yarn from curling, kinking, snarling or flying during operations subsequent to twisting, lmitting or weaving and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven therefrom. In certain embodiments of the yarn produced by this invention, the tendency to curl, kink, snarl or fly during operations subsequent to twisting, knitting or weaving and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is inhibited to substantially the same degree as that possessed by a like yarn directly twisted to a "size a: twist a: strength factor of approximately not more than 4500.

Herein, whenever reference to size is made, it is intended to refer to denier. Also herein, wherever reference is made to turnsf or "twists, it is intended to be turns per inch. Also herein, whereaver reference is made to strength," it is intended to refer to grams per denier. Also here- -in, the expressions "like yarn, a yarn of like kind or equivalent terminology are intended to mean a yarn of the same species and characteristics and alike in all commercial respects (except as to length) to the (antecedent) yarn to which the expression refers.

In order that the invention may be more clearly understood by those versed in the art, we have, in the accompanying drawing and in the detailed description based thereupon, set out possible embodiments of the invention.

In the drawing:

Figure 1 diagrammatically represents on a greatly enlarged scale an untwisted group of filaments;

Figure 2 diagrammatically represents the yarn twisted a predetermined number of turns in the 2 -direction; a

Figure 3 diagrammatically represents the yarn shown in Figure 1 with a certain number of turns removed by twisting in the opposite direction with the remaining twist being in the Z-direction;

Figures 4 and 5 diagrammatically represent the mode of constructing a muiti-thread yarn in accordance with this invention;

Figure 6 is a diagrammatic representation of a stocking knitted from the improved yarn; and

Figure '7 is an enlarged portion of astocking fabric showing the knitted construction thereof.

Referring more particularly to the drawing, there is diagrammatically shown inFigure 1 a length of an untwisted group of filaments III. In accordance with this invention, when it is desired to impart to the filaments III a certain twist to produce a yarn of the finished twist desired (say a yarn of fifty turns Z-twist), the filaments III are twisted in the direction to impart a Z- twist, this twisting being carried to a predetermined number of turns (say ten turns) beyond the fifty turns desired in the yarn. Thereafter, a certain number of turns (preferably equal to the number of turns beyond the desired twist in the yarn) are removed by twisting in the 8-"direction, which is opposite to the direction of the original twist. 'Ihe yarn may then be set according to any suitable method known in the art. The result is a relaxed yam I! with a Z- twist of fifty turns which, in its subsequent processing and knitting (for instance, into the fabric I, Figure 7), will not curl, kink, or tend to untwist unduly.

Also, according to the invention, it is preferable, although not absolutely necessary, to set the yarn after ithas been twisted in the Z-direction to the determined number of turns and before it is twisted in the S-direction. This intermediate setting assists in the relaxation of the final twisted yarn.

In certain instances (for example, if it is found desirable, or necessary to create in the yarn a compensating Z and S-twist torsional force for the purpose of equalizing the tendency of the yarn to curl or kink), the yarn may be twisted in the S-direction for a certain number of turns in excess to'the number of turns beyond the fifty turns in the Z-direction.

As an example, the yarn may be twisted up to ten turns beyond the final number of turns desired in the yarn, then untwisted ten turns to eliminate the inherent active torsion in the yarn due to the twisting thereof, and then further untwisted five turns to impart to the yarn atendency to twist in a direction opposite to the direction of untwisting, thus counteracting the latent torsion in the yarn occasioned by the twisting thereof.

As hereinbefore stated, the invention is also applicable to twist a plurality of threads which are doubled, that is, assembled together. As an example, there is diagrammatically shown in Figure 4 three untwisted groups of filaments Ilia twisted together. Assuming that it is desired to impart a Z -'twist to the yarn, the three untwisted groups of filaments Ilia are twisted together to give a Z-twist having a number of turns beyond the finished Z-twist desired, said excess number of turns being thereafter removed by S-twisting the yarn. The resulting yarn is a relaxed multiple thread twisted yarn I2a. Here again, the multiple thread twisted yarn I20. may be 8- twisted for a certain number of turns in excess to the number of turns beyond the finished twist desired and may be set before and after its 8- twisting to assist in the relaxation of said yarn. The yarn may then be knitted (for instance, into fabric ll of the stocking IS) without kinking, snarling, or curlingI It is pointed out that although under ordinary conditions it is found that by twisting the yarn I! or l2a to an average of twenty percent beyond the finished twist desired and then untwisting the yarn for substantially the same average percentage, satisfactory results are obtained, experiments have shown that this average percentage may vary from 'three percent to sixty percent. Therefore, it is to be understood that the invention is not limited to the specific example or examples given, but embraces such variances as come within the scope of the subioined claims.

What we claim is: 1. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a number of turns per inch of twist of from approximately 3% to 60% beyond the twist desired in the final yarn, setting the twist, subjecting the yarn to a twisting operation in the opposite direction a number of turns suflicient to produce a yarn having the said desired number of turns per inch of twist and substantially free of the objectionable active and latent torsional forces which normally result from subjecting a yarn of like kind directly to the same twist in the final yarn and normally remaining after the setting of said direct twist, whereby the tendency of the yarn to curl, kink, snarl or fly during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is substantially inhibited.

2. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a number of turns per inch of twist of from approximately 3% to 60% beyond the twist desired in the finual yarn, setting the twist, subjecting said yarn to a twisting operation in the opposite direction a number of turns sufilcient to create in the yarn an active torsional force in the desired direction, and setting the twist sufficiently to maintain said active torsional force in the yarn and to substantially inhibit the yarn from curling, kinking, snarling or flying during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn.

3. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a number of turns per inch of twist of from approximately 3% to 60% beyond the twist desired in the final yarn, setting the twist, subjecting said yarn to a twisting operation in the opposite direction a number of turns suflicient to not only eliminate the active torsional forces normally resulting from the twisting of a like kind of yarn directly to the same twist in the final yarn and normally remaining after setting of the direct twist but also to create in the yarn an inherent tendency to twist in the direction of the first-named twist, and setting the twist suiflcintly to maintain in the yarn a tendency to twist in the direction of the first-named twist and to substantially inhibit the yarn from curling, kinking, snarling or flying during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn.

4. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a yarn having a size a: twist a: strength factor of from approximately 3% to 60% in excess of 5500, setting the twist, subjecting the yarn to a twisting operation in the opposite direction a number of turns sucient to produce a yarn having a "size a: twist a: strength factor" not less than 5500 and substantially free of the objectionable active and latent torsional forces which normally result from subjecting a yarn of like kind directly to the same twist in the final yarn and normally remaining after the setting of said direct twist, whereby the tendency of the yarn to curl, kink, snarl or fly during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is substantially inhibited.

5. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a yarn having a size a: twist a: strength factor of from approximately 3% to 60% in excess of 5500, setting the twist, subjecting said yarn to a twisting operation in the opposite direction to produce a yarn having a "size a: twist .1: strength factor not less than 5500 and also to create in the yarn an active torsional force in the desired direction, and setting the twist sufliciently to maintain said active torsional force in the yarn and to substantially inhibit the yarn from curling, kinking,- snarling or flying during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn.

6. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a yam having a "size a: twist .r strength factor of from approximately 3% to 60% in excess of 5500, setting the twist, subjecting said yarn to a twisting operation in the opposite direction to produce a yarn having a size a: twist :c strength factor not less than 5500 and to eliminate the active torsional forces normally resulting from the twisting of a like'kind of yarn directly to the same twist in the final yarn and normally remaining after setting of the direct twist and also to create in the yarn an inherent tendency to twist in the direction of the first-named twist, and setting the twist sufllciently to maintain in the yarn a tendency to twist in the direction of the first-named twist and to substantially inhibit the yarn from curling, kinking, snarling or flying during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn.

'7. A method of producing straight, compact, twisted yarns which comprises subjecting a yarn to a twisting operation in the one direction to produce a yarn having a size a: twist a: strength factor of from approximately 3% to 60% in excess of 5500, setting the twist, subjecting the yarn to a twisting operation in the opposite direction a number of turns suflicient to produce a yarn having a "size a: twist a: strength factor not less than 5500 and active and latent torsional forces which normally result from twisting a yarn of like kind directly to a size so twist a: strength factor of 4500 or less and normally remaining after the setting of said direct twist, whereby the tendency of the yarn to curl, kink, snarl or fly during operations subsequent to twisting, knitting or weaving and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is substantially the same as that possessed by a like yarn directly twisted to a size .1: twist a: strength factor" of approximately not more than 4500.

8. A method of producing straight, compact, twisted yarns which comprises subjecting a 30 denier nylon yarn to a twisting operation to produce sixty turns per inch of Z-twist, setting the twist, twisting the yarn ten turns. per inch in the S-direction to produce a nylon yarn having fifty turns per inch of Z-twist and substantially free of the objectionable active and latent torsional forces which normally result from subjecting a nylon yarn of like kind directly in the fifty turns Z-twist and normally remaining after the setting of said direct twist and create an active torsional force in the Z-direction, whereby the tendency of the yarn to curl, kink, snarl or fiy during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is substantially inhibited.

9. A method of producing straight, compact, twisted yarns which comprises subjecting a 30 denier nylon yarn to a twisting operation to produce sixty turns per inch of Z-twist, setting the twist, twisting the yarn to not over five turns per inch in the S-direction to produce a nylon yarn having not over fifty-five turns per inch of Z- twist and substantially free of the objectionable active and latent torsional forces which normally result from subjecting a nylon yarn of like kind directly to the final Z-twist and normally remaining after the setting of said direct twist, whereby the tendency of the yarn to curl, kink, snarl or fly during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling, or twisting on a bias of the fabric knit or woven from said yarn is substantially inhibited.

10. A method of producing straight compact, twisted yarns which comprises subjecting silk yarn having a degummed size of 33.6 denier to a twisting operation to produce a Z-twist of about 20% higher than the desired final twist of fortyfive turns per inch of Z-twist, setting the twist, subjecting the yarn to a twisting operation in the S-direction to produce a silk yarn having forty-five turns per inch of Z-twist and substan- 1 tially free of the objectionable active and latent torsional forces which normally result from subjecting a silk yarn of like kind directly in the forty-five turns Z-twist and normally remaining after the setting of said direct twist and create an active torsional force in the Z-direction, whereby the tendency of the yarn to. curl, kink, snarl or fiy during operations subsequent to twisting, knitting or weaving thereof and the crepeing, shrinking, curling or twisting on a bias of the fabric knit or woven from said yarn is substantially inhibited.

11. A straight, compact, twisted yarn resulting from the process defined in claim 1.

12. A straight, compact, twisted yarn resulting from the process defined in claim 2.

13. Astraight, compact, twisted yarn resulting from the process defined in claim 3.

14. A straight, compact, twisted yarn resulting from the process defined in claim 4.

15. A straight, compact, twisted yarn resulting from the process defined in claim 5.

16. A straight, compact, twisted yarn resulting from the process defined in claim 6.

17. A straight, compact, twisted yarn resulting from the process defined in claim 7.

18. A straight, compact, twisted yarn resulting from the process defined in claim 8.

19. A straight, compact, twisted yarn resulting from the process defined in claim 9.

20. A straight, compact, twisted yarn resulting from the process defined in claim 10.

BERKELEY L. HATHORNE. ROBERT W. SEEM.

CERTIFICATE OF CORRECTION.

Patent No. 2,555,666. y 8, 9 1

BERKELEY L. mmomm, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correctionu follows: Page .2, first column, lines 58 and 39. strike out the words and come "es, for example,

fifty turns and insert the same after "turns" in line 57, some col- Page 5, first column, line 57, for "whereaver' read --vherever--- page L first column, line 2;, forfltinuel read '-1 ina1--; lines 50-51,

for "sufficintly" reed --.euriciently--; line 66, for "ancient" read --euI- ficient--; same page, same column, lines 1, 21, 38, 61, and second. column, line-8 L and +7, before "one" strike out "the"; and that the said. Letters Patent should be read with this correction therein that theeame may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of September, A. D. 19%.

Leslie Frazer (Seal) Acting Commiseioner of Patents.

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