Патент USA US2411132код для вставки
Nov. 12, 1946- B: L. HATHORN‘E ETAL ' ARTIFICIAL YARN AND METHOD OF PRODUCING Filed Aug. 15, 1942 ‘ 2,411,132 SAME I . AND ROBE/P7’ 14/. SEEM ' W-u/WM 2,411,132 UNITED STATES PATENT OFFICE Fatent'ed Nov. 12, 1946_ 2,411,132 ARTIFICIAL YARN AND METHOD OF PRODUCING THE SAME Berkeley L. Hathorne, Delray Beach, Fla., and Robert W. Seem, United States Army, assignors, by direct and mesne assignments, to Crepe de Chine, Inc., a corporation of Pennsylvania Application August 13, 1942, Serial No. 454,679% 23 Claims. (Cl. 57—140) 1 This invention is a continuation-in-part of ap plication Serial No. 354,064, ?led August 24, 1940, greater than the desired ?nished twist, the twist set, the yarn subjected to a twisting operation and relates to arti?cial or synthetic yarns, par ticularly rayon yarns, the method of producing the same, and fabric made therefrom. An object of this invention is to, in some in in a direction opposite to the original twist to stances, substantially reduce, by counter-balance in the ?nal yarn. ing, the torsional forces in the yarn and, in other instances, to create in the yarn torsional forces in a direction opposite to that which results from claims. twisting a yarn directly to the same ?nished twist and opposite to that which would be ex pected from a twist determination, as determined by a standard twist tester. ' , produce the desired ?nished twist, and ?nally the twist set, the twists and the degree of setting thereof depending on the torsional forces desired , Other and further objects will become apparent from the’ following description and appended ' The above objects are broadly obtained by twisting a yarn beyond the ?nished twist desired, setting the twist, reverse-twisting the yarn to produce the desired ?nished twist, and setting 'Another object of this invention is to accu 15 the twist, the magnitude of the twist and the degree of setting the twist being such as to con rately control the torsional forces of knitting or trol the torsional forces of that yarn very accu weaving yarns whereby said yarns possess new rately. By appropriate twisting operations in the and useful characteristics. opposite directions and the degree of setting of Another object of this invention is to provide yarns having substantially reduced and/or con 20 the respective twists, the knitting orv weaving yarn can be made, as desired, to have (a) either trolled torsional forces to facilitateoperations subsequent to twisting, for example coning and/or quilling, and the knitting or weaving operations, by substantially eliminating and/or controlling or both the active and/or latent torsional forces practically eliminated or reduced to the desired or required degree, or (b) active torsional forces 25 resulting from S-twist in a yarn showing a Z-twist the curling, kinking or ?ying of the yarn. only by conventional twist-testing methods, to A further object of this invention is to provide gether with latent torsional forces practically yarns having the torsional forces substantially’ reduced and/or controlled, which makes possible I eliminated or reduced the desired or required degree. new knitted and woven fabrics. We have further discovered that when the , A still further object of this invention is to 30 aforementioned process is applied to rayon yarn, for best results the inherent characteristics of rayon that effect its resistance to twisting, its tendency to untwist after having been twisted, crepeing, shrinking, curling or twisting on a bias 35 and the amount of twist that may be inserted is substantially reduced and/or controlled. and set without having an objectionable degree Another object of this invention is to provide of tendency to untwist should be considered with yarns, and fabrics formed thereof, of increased respect to the various steps of the process. resiliency and elasticity. The term “rayon” employed herein is intended Another object of our invention is to provide provide yarns having the torsional forces sub stantially reduced and/or controlled, which makes possible knitted and woven fabrics in which the '~ more compact yarns with the torsional forces 40 to include all yarns formed of a cellulose or cellu losic material such as, for example, prepared by I the viscose, cuprammonium or.cellulose acetate Another object of this invention is to provide process, irrespective of whether the yarns are sheerer, duller, and more snag-resistant fabrics. formed of continuous ?laments or staple fibers. Another object of this invention is to provide yarns of the maximum compactness and mini 45 If rayon were perfectly elastic, then the torsion reduced and/or controlled. in a twisted rayon yarn would follow Hook's law, i. e. the torsion is proportional to the turns. However, rayon being far from perfectly elastic, a method of making the yarns having the afore the torsion of twisted rayon yarn varies consid mentioned characteristics. Another'object of this invention is to provide 60 erably from Hook's law. When referring to all of the many types of a. method in which rayon yarns have been twisted natural and arti?cial yarns, the “size >< twist >< beyond the ?nished twist desired, twist-set to the strength factor” (size in denier >< twist in turns necessary or desired degree and then untwisted per inch X strength in grams per denier) gives to the desired twist, and ?nally the twist set to produce yarns whose superficies do not differ from 55 a good over-all relative indication of the resist ance of a yarn to twisting and the tendency to that of a yarn that has been twisted directly to untwist after having been twisted and the amount the same ?nished twist. ' _ of twist that may be inserted and set, without Another object of this invention is to provide having an objectionable degree of tendency to a method wherein rayon yarns are twisted in one direction to impart a twist of from 3% to' 60% 60 untwist. Rayon, however, possesses certain pe mum torsional forces. Another object of this invention is to provide 2,411,132 3 4 culiar characteristics which must especially be , taken into consideration, said relevant character- ' istics being the elongation and plastic flow of the rayonv at stress .strain loads voi.’ spinning various amounts of twist under various percentages of relative humidity, and the degree of ductility, plastic ?ow or permanent’ elongation‘resulting from twist-setting. ' ' ‘ Rayon, being synthetic, can and\is_ being made ' to vary considerably in strength and elongation, 10 but of special importance inythe utilization of our invention is'the fact that the elongation does not always have approximately the same relationship to the strength, and for this reason it is necessary mula, the ‘numerical values resulting therefrom are necessarily of a different magnitude than when the "size X, twist X strength factor" is used. In connection with this formula, it is im portant to consider ,‘the atmospheric conditions under which the twisting load is applied, since ' rayon generally elongates up to 50% more when wet than when dry and- consequently more twist may be evenly inserted under a given twisting load it the atmospheric conditions cause the rayon yarns to absorb more moisture, and the more moisture present in a rayon yarn being twisted under a given twisting load, the less tendency there will be to untwist from a given amount of to include the elongation of the yarn in any for 15 twist. In other_ words, the elasticrecovery of mula dealing with the resistance of various rayons rayon after the removal of various stress strain to twisting and the tendency to untwist after hav loads varies considerably with the moisture con ing been twisted. ' tent of the rayon when being twisted. Tensile strength is the measure 01’ the resistance It‘ is also important, when considering the tor of a yarn to elongation at the breaking point and, 20 sion to be expected from a twisted rayon yarn, to since no single or multi-?lament yarn can be take into consideration the degree of setting of twisted without elongating the ?ber in a helical the twist, since it is customary in the art of rayon form around its axis, it is quite evident that the , yarn manufacturing to set the twist for the de strength or resistance to elongation is an im liberate purpose of reducing the active torsion re portant factor when dealing with torsion of a 25 sulting from twisting. It can readily be appre yarn. However, since the elongation of various ciated that the degree of twist-setting, including rayon yarns varies so considerably under the same the time that the yarn is exposed to the arti?cial atmosphere or to water, has a considerable effect upon. the production of twisted rayon yarns. stress strain load, the factor of the elongation at the stress strain load of twisting must also be taken into consideration. 30 However, there are de?nite limitations tov the A comparison of stress strain load curves of control by twist-setting of the torsional forces of both conventional and high tenacity continuous a twisted rayon yarn. We can best illustrate this ?lament rayon of the several types, such as vis by the following examples; ' cose, cuprammonium, and acetate process, and A IOO-denier continuous ?lament viscose proc from various producers, readily shows the marked 35 ess rayon yarn was twisted 20 turns per inch and difference in elongation under the same stress strain load. It is true that these curves show the elongation as a result of load strain applied longi the twist set in a conventional manner, with the resultant yarn being a practical knitting yam from the standpoint of being capable of being knit without kinking, snarling or ?ying of the sists elongation in a helical form around its axis, 40 yarn while knitting. A more improved knitting. tudinally along the yarn's axis, butleach yarn re necessarily resulting from twisting, approximately yarn was then produced by utilizing the very best the same as it resists longitudinal elongation. The known method of twist-setting, but still this im marked differences mentioned above, between var proved yam was found to be inferior, as hereaf ious kinds of continuous ?lament rayons are also ter set forth, to the same IOU-denier rayon yarn present in rayon staple ?ber yarns of various 45 which we produced, in accordance with this in kinds. 1 I vention, by twisting the yarn 30 turns per inch Generally speaking, the elongation at the break in one direction, then setting the twist, by the ing point of various rayon yarns is proportional to same very best known method of twist-setting, the elongation at lower stress strains, such as con then twisting the yarn in the opposite direction ventional spinning loads, but for more accurate 10 turns per inch, and then setting the twist determination of the resistance of various rayon just su?'iciently to leave in the yarn a decided yarns to twisting and the tendency to untwist, the I tendency to turn on its own axis in a direction elongation at the twisting load must be speci?cally opposite to that of the last twisting, i. e. though considered. It is customary in the art of rayon it contained Z-twist ‘only when tested by con yarn processing not to use a twisting load in excess ventional twist-testing methods, it also possesses of 1/3 of that required to break the yarn. but gen S-twist active torsional forces. This latter yarn, erally the twisting load is 15% to 25% of the produced in accordance with this invention, can breaking strength, and it is therefore the elonga be knit with‘ greater tension without kinking and tion at these stress strain loads that particularly the knitted fabric knit therefrom shrunk less, concerns us. , 60 had less bias, and was more resilient and elastic We have found that a very practical formula to than the prior art yarns and fabrics formed use in comparing the relative torsion to- be ex thereof, respectively. ‘ pected from various twisted rayon yarns is the _ In certain embodiments of this invention, we have found it to be very advantageous for a knit “size >( twist” ting or weaving rayon yarn to have substantial strength X % elongation at stress strain load of I twisting active or visible torsional forces in a direction opposite to that which would result from twist For accurate comparisons, the elongation at the ing ‘a yarn directly to a given twist. This can stress strain load of twisting is necessary, but in be accomplished in a yarn in which there is ply most instances a good practical formula has been twist only in no other way than by the principles found to be of this invention, i. e. by ?rst twisting the neces “size X twist” . strength >< % elongation (at the breaking point) sary degree beyond the ?nished twist desired, ' setting the twist the required degree, and sub Since the property of elongation has been neces sequently twisting in the opposite direction, and sarily introduced into the aforementioned for 75 thereafter setting the twist'the required degree 9,411,182 5 6 . means a yarn which is free of crimps; curls or waves to substantially the same degree as pos sessed by a like yam directly twisted to the same - to produce the desired torsional forces in the ?nal twisted yarn. In a one-way prior art twist ed yarn, as for example a yarn twisted directly to the desired Z-twist, the torsional forces re finished twist. , ' Rayon yarn can be directly twisted to produce sulting from the twisting causes the yarn to tend a to fly in an S-direction and any disturbance of the set of the twist, such as by stretching, change in atmospheric conditions, etc.,'adds to this tend size X twist strength X elongation ) ency to fly in an S-direction. Also, since any contact with the spiral formation of the yarn 10 factor” of 60 without encountering the serious di?lculties due to the torsional forces resulting surface mechanically tends to untwist the yarn, from twisting, whereby such rayon yarn can be the frictional contact with said yarn while knit used for many purposes. However, when rayon ting or weaving exaggerates this tendency to fly. yarn is directly twisted to produce a In a yarn contemplated by the instant inven tion, and particularly that embodiment wherein 15 _ the yarn contains S-twist active torsional forces _ size X twist ) strength X elongation even though the yarn shows‘ Z-twist only, when factor in excess of 60, such as, for example, 75, the yarn has a. decided tendency to curl, kink, any disturbance of the set 'of the twist as previ snarl or fly during operations subsequent to ously mentioned will counter-balance the S 20 twisting, knitting or weaving of the fabric knit twist torsional forces and the yarn will be pre or woven therefrom and said yarn cannot be vented from ?ying in the S-direction, and indeed satisfactorily used for many purposes. Accord in any direction, either 2 or S. . ing to the instant invention, there can be readily As is shown from the foregoing, the principles obtained a twisted rayon yarn having a of this invention are applicable to the produc¢ 25 tested by conventional twist-testing methods, tion of rayon yarns having either a ?nished low or high twist or indeed a twist higher than that which could be obtained by the prior art pro- ‘ cedures. For purposes of this invention, a twist ed rayon yarn having a sizeXtwist strength X elongation , I sizeXtwist strengthX elongation ) factor in excess of 60, such as, for example 75, and in which the tendency to curl, kink, snarl or 30 ) ?y' during operations subsequent to twisting, knitting or weaving of thefabric therefrom is inhibited to substantially the same degree as that. possessed by a rayon yarn twisted directly to a factor in excess of 60, such as '75 or more, is con- » size)( twist V ) sidered a highly twisted rayon yarn. The em 35 strength X elongation bodiment of the invention which contemplates a twisted yarn having a high twist or twist higher factor of 60 or less. Further, according to this than the prior art yarn, in addition to possessing invention, there can be obtained a twisted rayon the aforementioned properties, will, when formed yarn having a ‘ - into fabrics,,woven or knitted, result in fabrics 40 having greater sheerness, dullness, snag resist strength X elongation ance, resiliency and elasticity when compared to prior art fabrics formed of the prior art rayon factor of 60 or less and which is substantially free of many of the undesirable and unavoidable yarns. We have discovered that, by twisting beyond 45 features which characterize a directly twisted ( the ?nished/twist desired, then‘ setting the twist and then untwisting to the desired twist, and ?nally setting the twist to the desired degree, rayon yarns, due to their generally poor elas ‘ tic recovery, will become substantially more per size X twist ) yarn of the same factor. *With rayon yarn, we have found in practice that with any degree of twisting, certain desirable bene?ts, as hereinbefore and hereinafter'men 50 tioned, result from our method of counterr balancing and/or controlling the torsional forces to various degrees. For example, in some in manently elongated and thus the fabrics pro duced therefrom will have substantially less op portunity 0r tendency to become further per stances on high, medium or low twisted rayon manently elongated or baggy during use. We yarns, it may be desired to merely slightly mini have also found that the greater permanent 55 mize the active torsion to enable the twist setting elongation of yarn produced by our method re to be minimized and/or to facilitate further sults in a closer relationship of the rayon micells. processing; in other instances, it may be desired thus further adding resiliency to the yarn and to create an opposite torque force just sufficient fabrics made therefrom. to enable the twist-setting to be minimized and/ or The mechanical formation of higher twist in 60 to facilitate processing; but in still other in rayon yarn causes greater elasticity due to the ‘ stances, it may be the chief object to control the spring-like effect of the twist formation, but . crepeing, or the shrinking, or the curling; or the we have discovered that due to the greater per twisting on a bias of the fabric knit or woven manent elongation of rayon yarns produced by therefrom, while at the same time counter our method, much of the plastic ?ow is removed 65 balance the torsional forces resulting from twist ing to a degree that will inhibit the yarn from and any further stretch of the yarn per se or curling‘, kinking, snarling or ?ying during op in the fabric produced therefrom will result, in erations subsequent to twisting or while knitting greater recovery or elasticity. , or weaving. It can thus readily be appreciated The yarns contemplated and made in accord ance with this invention are straight and have 70 that the degree of counter-balancing desirable or necessary varies greatly depending upon the substantially the same compactness and surface further processing or eventual use to which the appearance throughout their length as that of yarn is to be put. alike rayon yarn that has been twisted directly to the same ?nished twist. _Herein, the term “straight yarn,” or ‘.equivalent'" terminology, 75 ‘The ccrrelationship between the twisting in the Z-direction, the degree of setting of the Z 2,411,182 . _ 7 I twist, the twisting in the S-direction, and the degree of setting of the resultant yarn depends _ Example B Purp0se.—-To produce a high twist rayon woven fabric, which entailed a sumcient reduction in on the ‘torsional forces required in the ?nal product. It will be clear to those familiar with the art that the embodiments of our invention for a given purpose and/or given effect, or various the active torsion of a rayon yarn having a (strength sizeXXelongation twist ) _ combinations thereof, are enumerable. For any given purpose, the above relation of > twist, degree of setting, counter-twisting, and factor of 150, in order to facilitate the cupping degree of setting to produce the desired torsional 10 and weaving after .using normal twist-setting forces may be determined by simple empirical experiments. Experiments have shown that the Satisfactory results are obtained by (a). twist methods. ‘ . ' twisted rayon yarn can be counter-twisted, from ing a loo-denier rayon yam of 1.8 grams per 3% to 60% of the original twist, depending on denier strength and 20% elongation to a ' the nature of the twist setting and the torsional m, forces desired in the ?nal product. ( strengthX size Xtwist )’ elongation In the drawing: Figure 1 is an enlarged diagrammatic elevation factor of approximately 155 and (b) then‘set-' of a multi-filament rayon yarn resulting from ting the twist in a normal manner, and (c) then twisting in the Z-direction 3% to 60% in excess of 20 twisting in an opposite direction to a the desired. ?nal twist and setting; and Figure 2 is an enlarged diagrammatic elevation of the rayon yarn shown in Figure 1 after twist v strengthXelongation ( sizeXtwist ) mg in the S-direction to the desired ?nal twist ‘ factor of 150, and (d) then copping the yarn and and with or without setting. 25 (e) then weaving the yarn.v Enumerable examples could be given to illus In this example, the yarn was counter-twisted to an amount approximately 3% of the original twist, but it can readily be appreciated that to trate the many useful embodiments of our in vention hereinbefore and hereinafter referred to. It is to be ‘understood that the several em ' bodiments hereinafter set forth are merely illus trative and in no way limitative of the invention. ' meet some conditions or combination of condi 30 tions, a very much greater degree of counter twisting may be desirable or necessary and, in Example A fact, we have ‘found certain combinations of con Purpose.—To substantially reduce the degree of twist-setting of a rayon-yarn having a / ditions that required as much as 60% counter twisting. 35 ( strength sizeXXelongation twist ) ‘ Example 0' Purpose-To produce a rayon hosiery welt im proved in resiliency and reduced in bagginess by factor of 50, while the the same time have no greater torsional forces than is characteristic of 40 the utilization of higher than conventional twist, , but without the creases, etc., at the upper edge of the same yarn twisted directly to a the stocking, characteristic of rayon hosiery welts (strength sizeXXelongation twist ) knit from rayon yarns having a ( strength sizeXXelongation twist ) factor of 50, and then thoroughly set by con ventional twist-setting methods. Highly satisfactory results were obtained by (a) twisting a 100-denier rayon yarn of 2 grams factor of approximately 60; A highly satisfactory welt yarn having a final per denier strength and 20% elongation to 22% turns per inch, and (b) then setting the twist (strength sizeXXelongation twist ) to a low degree, 1. e. in an atmosphere of 120° F. factor of approximately 60 was produced by (a) dry with temperature at 110° F. with bulb tem twisting a, ISO-denier rayon yarn of 2 grams per perature for 30 minutes, and (c) then twisting denier strength and 18% elongation to a ‘in an opposite direction 2‘turns per inch, and (d) then coning the yarn without any further 55 twist—setting. ( strength sizeXXelongation twist ) -In this example, the yarn was counter-twisted approximately 10% to the ?nal size X twist strength X elongation ' factor desired. 60 factor of approximately 90, and (b) then set ting the twist, and (c) then counter-twisting to the required twist, and (d) then setting the twist in an atmosphere of 170° F. dry bulb tempera ture and 160° F. wet bulb temperature for 2 hours, However, to meet some conditions, including and (e) then coning the yarn. reduction in twist-setting. we have found that In this example, the yarn was counter-twisted counter-twisting to an amount of as little as 3% 65 to an amount approximately 331/2% of the orig of the original twist gave the most bene?cial re inal twist. sults, especially in rayon yarns of a high It is to be noted that we cannot utilize ex tremely high twisted rayon yarns in wells even size X twist ) though such yarns are perfectly balanced when strength X elongation ' 70 dry because the twisted condition of the welts factor, such as 150. while wet, caused by the swelling of the yarn, . To meet other conditions, such as when prac prevents the welt from drying smoothly on the tically no twist-setting was to be used, we have hosiery forms when boarding in a conventional found that counter-twisting as high as 60% of manner, even though the welts when dried loose the original twist gave the most beneficial results. 76 return to a perfectly smooth condition. 2,411,182 10 Example D tion yarn separately, and (h) weavingvwith a plain weave with 50 picks per inch using a suit Purpose-To produce Isubstantially shrink proof rayon.“crepe" fabric, processing the prop ' able warp of approximately 3200 ends, and (i) boiling off and dyeing as usual (due to the con erties normally associated with “crepe,” and also trol of the torsional forces,.the_ fabric can be dyed on a continuous machine, thus substantially re having the torsional forces so controlled that after washing and drying the fabric is substan ducing production costs), and (:i) then drying tially the same in‘size and appearance‘ as before _ and framing as usual. ' washing. Highly satisfactory results were obtained by .10 ’ Example F Purpose.-To produce a rayon hosiery yarn of 1.8 grams per denier strength and ‘20% elonga maximum compactness, sheerness, lack of longi-' tion to a ' " _ ' tudinal waviness, and having the active torsional forces practically eliminated and the latent ‘tor _ sizeXtwist ) (a) twisting a 100-denier viscose rayon yarn of strengthXelongation sion substantially reduced.‘ ' Very satisfactory'results were obtained by (a) factor of 208, and (b) then setting the twist in an atmosphere of 175° F. dry bulb temperature and 165° F. wet bulb temperature, and (c) then twisting in an opposite direction to a z-twisting various kinds and sizes of rayon to a ' 20 (strength sizeXtwist ) >< elongation ~factor of 180, and (d) then setting the twist the same as used in step‘ (a) above, and (e) then copping the yarn and (1‘) then weaving the yarn strengthX elongation) factor of from 107 to 120, (b) setting the twist in an atmosphere of 180° F. dry ‘bulb temperature and 170° F. wet bulb temperature for 2 hours and (c) then S-twisting the ‘yarn to a v " size X twist as hereafter described. Two picks alternately of S-twisted and Z-coun- " strengthxelongation factor of from 75 to 8'7, (11) setting the twist for 1 hour in an atmosphere of 140° F. dry bulb tem yarn, prepared as described in the paragraph im perature and 130° F. wet bulb temperature, and mediately preceding, were woven into the ?lling 30 (c) then coning the yarn. of an acetate warp viscose-?lled crepe, for exam ‘In this example, the yarn was counter-twisted ple a fabric 45 inches in the greige containing approximately 30%. _ 6075 ends in the warp and 64 picks per inch in Itis, however, understood that to meet various the ?lling. The woven fabric was boiled off and conditions, considerably more or less counter dyed in a conventional manner. The boiled-off 85 twisting may be used as required. ter-twisted and Z-twisted and S-counter-twisted ' and dyed fabric was straightened and dried loose, after which it was framed. . Example G . Prior to drying loose, the fabric was especially Purp0se.—To produce a 75-denier; rayon ho well straightened out so as not to interfere with siery yarn of 40 turns per inch delivered Z-twist, action of the torsional forces in causing the fab-. (0 said yarn having a substantial amount ‘of active ric, which shrunk appreciably during boil-off and dyeing, to come back substantially toward its original width during drying, and thus producing the shrink-proof effect desired. ‘ Under one normal boil-off, dyeing, and drying S-torsion and the latent Z-torsion substantially reduced. Very satisfactory results were obtained by (a) 45 Z-twisting the 75-denier rayon yarn which had a strength of 1.8 grams per denier and an elon gation of 20% to a procedure, the fabric shrunk from 451/2 inches in the greige to 32 inches after dyeing, and recov size X twist ered to 371/2 inches during drying and was framed strength X elongation _ to 39 inches. 50 factor of 135, (b) settingthe twist for 1 hour in Example E an atmosphere of 180° F.‘ dry bulb temperature Purpose-To produce a substantially shrink and 170° F. wet bulb temperature and (c) coun proof combination “crepe” fabric, processing the ' other properties normally associated with com bination yarn fabrics. _ . I ter-twisting to a 55 , sizeX twist ) Satisfactory results were obtained by (a) S strength X elongation twisting a 100-denier rayon yarn of 1.8 grams per denier strength and 20% elongation to a factor of 83.3, (d) then setting the twist for 10 minutes in an atmosphere of 140° F. dry bulb sizeXtwist strengthXelongation ) 60 (e)' coning the yarn. 65 sizeXtwist ) st engthXelongation factor of 153, and’ (d) then setting the twist the _ In this example, the counter-twisting was ap proximately 38% of the original factor of 180, and (b) then ‘setting the‘ twist in an atmosphere of 175° F. dry bulb temperature and 165° F. wet bulb temperature, and (c) then Z-twisti'ng the yarn to a temperature and 130° F. wet bulb temperature, size X twist ) ’ s‘trength X elongation factor, but this percentage of counter-twisting may be increased or decreased substantially de pending upon the condition to be met, the char same as used in step (a) above, and (e) then 70 acteristics of the rayon, and the conditions under doubling and S-twisting, with 12 turns per inch, which it must be processed, as hereinbefore de scribed. ’ the yarn from (d) with 100-denier acetate yarn, In reference to the examples herein given, we and (e) then setting the twist, and (I) then re have found that when rayon of other sizes, peating (a) to (e) starting with Z-twist and end ing with S-twist, and (g) copping each combina 75 strength and elongation are to be used, very simi - i-r - a 4' I ‘ , 2,411,182 11 12 iar results may be obtained if said yarns are ( strengthXelongation sizeXtwist ) twisted and counter-twisted approximately to ~ ' - ' ‘ ’ the same ( strengthX sizeXtwist ) elongation ,‘ factor in excess of '75, setting said twist, subject ’ 0 ing‘ said yarn to a twisting-operation in the op posite direction to produce a twisted yarn having factors used in‘ our examples and otherwise simi larly processed. , a ' (strengthX sizeXelongation twist ) In this speci?cation, the expression “Z-twist" de?nes a twist resulting from twisting the yarn in one‘ (the left) direction, and the expression factor of approximately 75, and setting the re sulting yarn, the twisting operation in the said opposite direction and the setting of the twists ~ “S-twist” de?nes a twist resulting from subject ' ing the yarn to a twist in a direction opposite (i. e. right) to that of the Z-twist. Likewise,'the expressions “Z-direction” and “S-direction" used herein de?ne subjecting the yarn to a twisting operation in one (the left) direction and subject ing the twisted yarn to a twisting operation in being of such magnitude and degrees as to pro duce a twisted yarn in which the torsional forces ' are counter-balanced in accordance with the ultimate use of the yarn. 3..A method of producing a straight, compact, , the opposite (right) direction, respectively. It twisted rayon yarn which, when tested by con is, however, to be understood that the expression 20 ventional twist-testing methods, shows twists in “it-twist”v as appearing herein is not intended to one direction only, which comprises subjecting be ‘restricted thereto, since it will be obvious to a rayon yarn to a twisting operation in one direc ~ a person skilled in the art that the twist in the tion to produce a twisted yarn having a yarn as delivered may have an S-twist and sub ( jected to counter-twisting in the Z-direction in sizeXtwist ) accordance with this invention. In other words, strengthXelongation the ‘expressions “Z-twist” and “Z-direction” are used for convenience only and may de?ne an factor of. from 3% to 60% in excess of 75, setting said twist, subjecting said yarn to a twisting op eration in the opposite direction to produce a “S-twist" and “S-direction” respectively. ' , Herein, wherever reference to "size” is made, 30 twisted yarn having a it is intended to refer to denier., Also herein, wherever reference is made to “turns" or "twists," it is intended to mean turns per inch. strength sizeXtwist X elongation Also herein, wherever reference is made to factor of 75, and setting'the resulting yarn, the twisting operation in the said opposite direction “strength,” it is intended to refer to grams per denier. Also herein, wherever reference is made to “elongation,” it is intended to refer to the and the setting of the twists being of such mag as set forth in application Serial No. 354,064, _ twist of from approximately 3% to 60% beyond nitude and degrees as to produce a twisted yarn percent of elongation at the breaking point, as in which the torsional forces are counter-bal determined by conventional methods. As is apparent from the foregoing description, 40 anced in accordance with the ultimate use of the yarn. . the principles of the instant invention have been 4. A method of producing straight, compact, described in connection with arti?cial yarns, and twisted rayon yarns~ which comprises subjecting speci?cally rayon. /It is, however, to be under a rayon yarn to a twisting operation in one di stood that the principles of this invention are, rection to produce a number of turns per inch of equally applicable to natural and synthetic or arti?cial yarns other than rayon.v the twist desired in the ?nal yarn, setting/the twist, subjecting the yarn to a twisting operation in the opposite direction a number of turns suffi , Since it is obvious that various changes and modi?cations may be made in the above descrip~'v cient to produce a yarn having the desired num tion without departing from the nature or spirit 50 ber ofv turns per inch of twist and substantially thereof, this invention is not restricted thereto free of the objectionable active and latent tor except as set forth in the appended claims. sional forces which normally result from sub We claim: jecting a yarn of like kind directly to the same 1. A method of producing a straight, compact, twist in the ?nal yam,.and, normally remaining twisted rayon yarn which, when tested by con after the setting of said direct twist, to thereby ventional twist-testing methods, shows twists in substantially inhibit the tendency of the yarn to one direction only, which comprises subjecting curl, kink, sn‘arl or ?y during operations subse a rayon yarn to a twisting operation in one direc quent to twisting, knitting or weaving thereof and tion to produce a twist of approximately from 3% the creping, shrinking, curling, or twisting on to 60% in excess of the desired ?nished twist, 60 a bias of the fabric formed from said yarn. setting said twist, subjecting said yarn to a twist: 5. A method of producing straight, compact, ing operation in the opposite direction to produce twisted rayon yarns which comprises subjecting the desired ?nished twist, and setting the re a rayon yarn to a twisting operation in one di sulting yarn/the twisting operation in the said rection to produce a number of turns per inch of opposite direction and the setting of the twists 65 twist of from approximately. 3% to 60% beyond being of such magnitude and degrees as to pro; the twist desired in the ?nal yarn, setting the duce a twisted yarn in which the torsional forces twist, subjecting said yarn to a twisting operation are counter-balanced in accordance with the _ in the opposite direction a number of turns suffi ultimate use of the yarn. I cient to create in the yarn‘ an active torsional 2. A method of producing a straight, compact, 70 force in the desired direction,'and setting the twist su?iciently to maintain said active torsional twisted rayon yarn which, when tested by con ventional twist-testing methods, shows twists in - force in the yarn and to substantially inhibit the yarn from curling, kinking, snarling or ?ying one direction only, which comprises subjecting a rayon yarn to a twisting operation in one direc- I ' tion to produce a twisted yarn having a during operationssubsequent to twisting, knit 75 ting or weaving thereof and the crepeing, shrink r - . ' 2,411,182 ' 13 , prises subjecting a rayon yarn to a twisting oper-r ing, curling, or twisting on a bias of the fabric _ formed from said yarn. ation in one direction to produce a yarn having a Y 6. A method of producing straight, compact, ( twisted rayon yarns which comprises subjecting V a a rayon yarn to a twisting operation in one di ' sizeXtwist )I strengthXelongation , . factor of from approximately 3% to 60% in ex cess of 75, setting the twist, subjecting said yarn ' to a twisting operation in'the opposite direction to- produce a yarn having a -' rection to produce avnumber of turns per inch of twist of from approximately 3% to 60% beyond the twist desired in the ?nal yarn, setting the twist, subjecting said yarn to a twisting opera tion in the opposite direction a number of turns sufficient to not only eliminate the active tor ( strength sizeXtwist X elongation sional forces normally resulting from the twist factor not less than '15 and to eliminate the active ‘ ‘ing of a like kind of yarn directly to the same torsional forces normally resulting 'from the twist in the ?nal yarn and normally remaining twisting of a like kind of yarn directly to the after setting of the direct twist but also to create 15 same twist in the ?nal yarn and normally re- ' in the yarn an inherent tendency to twist in the maining after setting of the direct twist and also direction of the ?rst-named twist, and setting to create in the yarn an-inherent tendency to the twist suf?ciently to maintain in the yarn twist in the direction of the ?rst-named twist, .a' tendency to twist in the direction of the ?rst and setting the twist sufficiently to maintain in named twist and to substantially inhibit the yarn 20 the yarn a tendency to twist in‘ the direction of from curling, kinking, snarling or ?ying during. the ?rst-named twist and to substantially inhibit operations subsequent to twisting, knitting or the yarn from curling, kinking, snarling or ?ying weaving thereof and the crepeing, shrinking, during operations subsequent to twisting, knitting curling, or twisting on a bias of the fabric formed ‘or weaving thereof and the crepeing, shrinking, from said yarn. ‘ _ ' 25 curling, or twisting on a bias of the fabric formed 7- A method of producing straight, compact, from said yarn. twisted rayon yarns which comprises subjecting, > - ' 10. A method of producing straight, compact, a yam to a twisting operationin one direction to _ V twisted rayon yarns which comprises subjecting produce a rayon yarn having a ' ‘ . a rayon yarn to a twisting operation in one direc (a strength sizeXtwist ) X elongation 30 tion to produce a yarn having a ‘ strengthXelongation ' sizeXtwist factor of from approximately 3% to 60% in ex cess of 75, setting the twist, subjecting the yarn factor of from approximately 3% to 60% in ex to a twisting operation in the opposite direction 35 cess of 75, setting the twist, subjecting the yarn a number of turns sumcient to produce ,a yarn to a twisting operation in the opposite direction having a a number of turns su?icient to produce a yarn (strength sizeXtwist ) X elongation having a‘ Y ' ' (strength sizeXtwist ) X elongation factor not less than 75 and substantially free of 40 the objectionable active and latent torsional forces which normally result from subjecting a ‘ factor not less than 75 and active and latent torsional forces which normally result i’romtwist-lv yarn of like kind directly to the same twist in the ?nal yarn and normally remaining after the ing a yarn of like kind directly to a l (strength sizeXtwist X elongation setting of said direct twist, to thereby substan tially inhibit the tendency of the yarn to curl, kink, snarl or ?y during operations subsequent - ' , factor of 60 or less and normally remaining after the setting of said direct twist, to substantially to twisting, knitting or weaving thereof and the ' crepeing, shrinking, curling or twisting on a bias 50 inhibit the yarn from curling, kinking, snarling of the fabric formed from said yarn. or flying during operations subsequent to twist 8. A method of producing straight, ‘compact, twisted rayon yarns which comprises subjecting ing, knitting or weaving and the crepeing, shrink ing, curling, or twisting on a bias of the fabric a rayon yarn to a twisting operation in one direc formed fromsaid yarn to at least substantially tion to produce a yarn having a 55 the same as that possessed by a like yarn directly (strength sizeXXtwist ) elongation twisted to a ’ . (strength sizeXtwist ) X elongation factor of from approximately 3% to 60% in ex cess of 75, setting the twist, subjecting said yarn factor of approximately not more than ‘60. to a twisting operation in, the opposite direction 60 11. A method of preparing a straight, compact, to produce a yarn having a size X twist strength X elongation ( ) ‘ twisted rayon yarn which, when tested by con ventional twist-testing methods, shows twist in one direction only, which comprises twisting rayon yarn in one direction to produce a yarn factor not 1 ss than '75 and also to create in the 65 having a yarn an active torsional force in the desired di-' size X twist rection, and setting the twist suf?ciently to main strengthXelongation tain said active torsional force in the yarn and to substantially inhibit the yarn from curling, factor of approximately l35,'setting said twist in kinking, snarling or ?ying during operations sub 70 the yarn, subjecting the yarn to a twisting opera sequent to twisting, knitting or weavingthereof _ tion in thevopposite direction to produce. a yarn and the crepeing, shrinking, curling or twisting - ‘ having a on a bias of the fabric formed from said yam. 9. A method of producing straight, compact,‘ - twisted knitting or weaving yarns which come‘ - ( ‘ sizeXtwist strength X elongation I 2,411,182 .15 factor of approximately 83.3 and setting the twist. twist is‘ set by subjecting said yam' for two hours 12. A method as set forth in claim 11 wherein the original twist is set by subjecting the yarn . one hour in an atmosphere of 180° F. (dry bulb temperature) and 170° F. (wet bulb temperature) and the twist in the yarn after the second twist . to an atmosphere 0! 180° F. (dry bulb tempera ture) and 170° F. (wet bulb temperature) and the yarn resulting'rrom the second twisting oper- ' ation set by subjecting said yarn for one hour in an atmosphere of 140° F. (dry bulb temperature) ing operation is set by subjectingthe yarn for 10 and 130° F. (wet bulb temperature). 15. A‘ yarn resulting from the method de?ned minutes in an atmosphere of 140° F. (dry bulb I temperature) and 130° F. (wet bulb temperature). - in claim 1. I _ 13. A method of preparing a straight, compact, 10 16. A yarn resulting from'the method de?ned twisted rayon yarn which, when tested by con ‘ventional twist-testing methods, shows twist in one direction‘ only, which comprises twisting in claim 8. in claim 4., 15 ' si'zeXtwist ) strength X elongation factor of approximately from 107 to 120, setting said twist in the yarn, subjecting the yarn to a 20 ‘ twisting 'operationin the opposite direction to produce a yarn having a size X twist ‘ ' ' in claim 5. , ‘ 19. A yarn resulting from the method de?ned in claim 6. 20. A yarn resulting from the method de?ned in claim '7. , _ 21. A yarn resulting-from the method de?ned in claim 9. ' 22. A yarn resulting from the method de?ned in claim 11. ) g . 18. A yarn resulting from the method de?ned rayon yarn in one direction to produce a yarn having a ' _ 17. A yarn resulting from the'method de?ned . - 23. A yarn resulting from the method de?ned '25 in claim 13. factor of approximately from 75 to 87, and setting BERKELEY L. HATHORNE. the twist. ROBERT W. SEEM, ' strength X elongation _ 14. A method as set forth in claim 13 wherein the twist in the yarn resulting from the original By WARREN A. SEEM, Y Attorney in fact.