Aug. 31, 1943. A, S, HUNTER 2,328,074 MANUFACTURE OF TEXTILE YARN Filed July 16, 1940

Archibald S. Huttervucintot Patented Aug. 31, 1943 2,328,074 UNITED STATES PATENT OFFICE MANUFACTURE of TEXTILEYARN Archibald Stuart Hunter, Kenmore, N. Y., as signor to E. I. duPont de Nemours & Company Wilmington, Del, a corporation of Delaware . Application July 16, 1940, Seria No. 345,778 2. Claims. (C. 18-54) This invention relates to the manufacture of Other objects of this invention will appear textile yarn. More specifically, it relates to a hereinafter. process of producing novelty yarn composed of The objects of this invention are accomplished, two or more strands of filaments, said strands in general, by Spinning several regenerated cellu having shrunk unequally during the production 5 lose yarns, or similar acid coagulated yarns, un thereof to form a pebbly yarn structure. der different tensions but without exceeding the Novelty yarns which are a composite of two or elastic limit of the yarn, combining the yarns more single yarns of different lengths are known while still in the gel state and twisting the sev to the art. Such multiple yarns are produced by eral yarns, for example, into a bucket in accord combining two or more single yarns having dif O ance, with the bucket spinning process. e ferent shrinkage characteristics and thereafter composite yarn is then dried while maintaining subjecting the yarn to a shrinking treatment. the same free from tension, w In U. S. Patent No. 1976,201, a method is de By a 'gel' yarn is meant a freshly spun co scribed for producing multiple yarn from cellu agulated yarn which has never been dried and lose acetate, wherein two yarns coming from a 5 which contains a large amount of water, Gel spinning machine are subjected to different de shrinkage of a yarn may be described as the grees of stretching, then are combined into one amount a gel yarn Will shorten when allowed to strand and finally thrown on a down-twister and dry while under no tension. When a yarn is collected on a bobbin. The degree of tension on . dried while under tension either in the form of a one of the yarns is such that the yarn is bucket cake or on a bobbin, it can shrink only to stretched beyond its elastic limits. The compos a small degree. Since after drying in this man ite yarn. On the bobbin is subjected to the custom ner, the yarn is still in a strained condition, it ary after-treatment procedure and then to, a still retains the capacity to shrink. It possesses, shrinking treatment. The filaments of the yarn therefore, residual shrinkage which may be . which was subjected to the higher tension, will 2 5 measured Or determined by subjecting the yarn shrink to a greater degree and will, therefore, be to a boil-off procedure which comprises, for ex shorter than those of the yarn which was sub ample, treatment of the yarn with a hot bath and jected to the lower tension. permitting the same to dry without restraint. Novelty or composite yarns made from cellu For convenience, the present invention will be lose acetate according to the method described in 3. described with particular reference to the pro U. S. Patent No. 1,976,201 do not possess a very duction of regenerated cellulose yarn from vis great difference in length of the single yarn cose. The present invention is not limited there members. Yarn produced in accordance with to, but is applicable generally to the production this process, therefore, does not exhibit a definite of yarn from aqueous cellulosie flament-form pebbly or rippled effect. It is important to note 5 ing solutions which may be coagulated in the acid that in yarns of this character, the component coagulating bath, for example, lowly etherified yarn which has been subjected to a tension be cellulose compositions such as ethyl cellulose. yond the elastic limit thereof exhibits the higher The invention is also applicable to the productio degree of shrinkage and becomes the core, or the of yarn by the cuprammonium process. shorter member, of the composite yarn. 40 Referring to the accompanying drawing where It is an object of this invention to provide a in Fig. 1 is a diagrammatic illustration of one . process for producing a rippled novelty yarn arrangement for carrying out the tension spin wherein the ripples are quite pronounced. : ning and doubling steps of this invention, and Another object of this invention is to provide a Fig. 2 is a diagrammatic illustration of an ar 45 rangement for carrying out the tension-free dry process for the production of a rippled, or pebbly, ing step, this invention may, for example, be car novelty yarn during the conventional steps of ried out as follows: Two yarns A and B freshly spinning and purification, without the necessity spun from spinnerets and 2 respectiyely, into of having additional shrinking and drying pro a spinning or coagulating bath are, while still 50 in the gel state, subjected to different tensions It is a further object of this invention to pro by passing one yarn over the enlarged portion, vide a yarn which when woven into fabric will and the other yarn over the reduced portion of give depth to the fabric, thereby eliminating the a conventional roll 4, and then passing both uninteresting flat appearance common to most yarns over a drawing roll 4 which is of the same fabrics, diameter as that of the enlarged portion of roll 2. 2,828,074 4 and which is driven at the same speed where shrinkage of 4.2%. A yarn effect similar to that by yarn B is subjected to the requisite stretch. of Example I was obtained. Thereafter the yarns are combined in guide 5 Eacample III and fed into bucket 6, preferably at equal rates of speed, during which procedure the two yarns 5 Yarn B of Example II while in the gel state are twisted together and collected as a cake 7. was combined on a downtwister with yarn made While the combined yarn is still in the gel state, as follows: A high salt index viscose, said index it is wound on reel 8 from cake to form skeins. being 8, modified with 5% sodium sulfate was The skeins are allowed to dry freely while under spun into a coagulating regenerating bath to give no; tension. The ripple develops as one compo O a yarn of 370-denier, 40-filament, using a 6-inch nent shrinks on drying more than the other. bath travel and collected on a bobbin. The Any other suitable expedient for spinning one combined yarns after purification were reeled to yarn at a higher tension than the other may of skeins and allowed to dry. The gel shrinkage of the yarn spun from the high index viscose was course be employed. 12.1%, while that of yarn B was 2%, giving a Surprisingly, the yarn which was spun at the 15 differential shrinkage of 10.1%. A yarn having lower tension shrank to a considerably greater a pronounced ripple effect was obtained, the ef degree than the other yarn. This component fect being produced by the long and short Com was, therefore, shorter in the shrunken yarn and ponents thereof. consequently constitutes the Core, While the other Eacample IV yarn Spun under the higher tension forms, the 20 ripples and gives the novelty effect. Two yarns having different filament sizes and The following examples illustrate several de spun under different tensions were produced as tailed processes for carrying out the present in follows. Yarn A which was a 370-denier, 10-fila vention. ment yarn was spun through a Spinneret having Eacample I 25 10 holes, each hole being 0.012 inch in diameter, Wiscose was spun through two identical spin using a 6-inch bath travel and collected on a nerets mounted side by side in a coagulating and bobbin. Yarn B which was a 70-denier, 40-fila regenerating bath to form yarns which were con ment yarn was spun through a spinneret having tinuously removed, combined into one strand, 40 holes, each hole being 0.0035 inch in diameter, and collected on a bobbin at a take-up speed of 30 using a 50-inch bath travel and collected on a 2,000 inches per minute. The Spinnerets con bobbin. The two yarns were washed and purified tained 40 holes each. The diameter of the holes on the bobbin and thrown on a downtwister was 0.0035 inch. The yarn from one of the spin which applied 3 turns per inch to the yarn. The nerets, yarn A, was a 370-denier, 40-filament yarn wet yarn was immediately reeled to skeins and and was spun with a 6-inch bath travel. The allowed to dry in a relaxed form. Yarn A which other yarn, yarn B, was a 370-denier, 40-filament contains the large filaments possessed a shrink yarn and was spun with a 90-inch bath travel. age on drying of 6.9%, while yarn B containing The combined yarn collected on the bobbin was filaments of small size spun under a higher ten washed acid-free on the bobbin and while still sion possessed a shrinkage on drying of 2.4%, in the wet gel state, thrown on a downtwister ..) giving a differential shrinkage of 4.5%. A yarn which applied 3 turns per inch to the yarn. The of the nature described in the previous examples gel yarn was immediately reeled to skeins and was obtained. while in a completely relaxed state, was allowed Preferably the component yarn which is spun to dry. During the drying, yarn component A with a high tension is spun with a tension two which was spun under low tension decreased in or more times the spinning tension of the length 9.8%, while yarn component B which other component yarn or yarns. The high dif was spun under a higher tension decreased in ferential shrinkage of the component yarns is length 4%. The differential shrinkage obtained believed due to the fact that they are com was therefore 5.8%. Because of the shrinkage bined to form a composite yarn while still in difference, yarn component A became shorter the wet gel state. The yarn according to this in than the other, said component becoming, the vention is distinguished from that of the prior base yarn, while yarn component B Was loosely art in that the base yarn or the short yarn is the twisted thereabout. one which was spun under the lower tension. Eacample II The present invention is further distinguished by . . .) the fact that the gel shrinkage between yarns Two yarns were spun as follows: Yarn. A which spun under different tensions differs to a greater was a 200-denier, 40-filament yarn was produced degree than the residual shrinkage of the same by spinning viscose...into a coagulating bath using yarn. By, this fact, it has been possible to obtain a 6-inch bath travel and winding the same on a novelty yarns having a more pronounced ripple bobbin by the conventional "bobbini-Spinning' effect than was produced by the prior art. For process. Yarn B which was a 300-denier, 120 the production of a satisfactory novelty yarn in filament yarn and which contained 4 S turns accordance with the present invention, it is es per inch was produced by spinning viscose into sential that the shrinkage difference between the a coagulating regenerating bath using 100 inches yarns must be in excess of 3%. For the best re bath travel and collecting in a bucket by the sults, the shrinkage differential between the two "bucket-spinning' process. The two yarns were yarns should be from 5% to 10%, or even higher. subjected to the usual after-treatments such as The gel shrinkage of a yarn increases with an washing, desulfuring and bleaching, in that form. increase in filament denier, an increase in the The two yarns were combined by twisting to total denier, and with a decrease of spinning ten gether on a downtwister while still in the wet gel sion. If two gel yarns are combined which have state. Tha combined yarn was then reeled to a wide difference in filament denier, a wide dif skeins and dried in the relaxed state. Yarn A ference in total denier, and which were spun un which was spun under low tension possessed a der widely different tensions, a high gel shrink gel shrinkage on drying of 6.2%, while yarn B age differential will be obtained. Two yarns, had a shrinkage of 2%, giving a differential 75 which are identical with the exception that one

2,828,074 3 has been spun under a much higher tension than The process of this invention makes it possible the other, will give a satisfactory shrinkage dif to produce a novelty rippled yarn during the ferential though not as high as when all con standard steps of spinning and purification. It trolling factors have been utilized. is not necessary, therefore, to provide more than In the above examples, several ways of pro s One drying, stretching or shrinking procedure, as ducing the novelty yarn of this invention have would be the case if the novelty effect were to been described. The invention is not to be lim be produced by the residual shrinkage of the ited to these examples since it is possible to vary yarn. the conditions of spinning the yarn and still ob The yarns may be knitted or woven in the cus tain yarns having different gel shrinkage values. () tomary manner to give fabrics having unusual For example, a different denier yarn may be ob properties. The kinky, rippled or pebbly nature tained by maintaining all conditions the same, of the yarn gives an increased loft to fabric made with the exception of the pump delivery which therefrom. The Component members of the yarn may be increased for one of the yarns. The which are spun at different tension, possess dif denier may be further increased by slowing down 5 ferent dyeing characteristics and, therefore, may the take-up of the yarn. The denier differential provide a novelty dyeing effect in the fabric. may be further effected by using spinnerets hav The fabrics are full, voluminous, and possess a ing large orifices. less slippery hand. The kinky, rippled yarn of In the examples, processes have been described this invention possesses the further advantage in which the yarns when reeled to skeins were Over the prior art yarns in that the ripples are acid-free and in some cases purified. It is to be permanent and will not be pulled out on stretch understood that satisfactory results, and in some ing. cases more satisfactory results may be obtained Since it is obvious that many changes and by a process in which acid gel yarns' are reeled modifications can be made in the detailed proc to skeins and dried in the relaxed state. 2 s esses above described without departing from The spinning tension to which the yarn is sub- - the nature and spirit of the invention, it is to jected may be controlled by the length of bath be understood that the invention is not to be lim travel. It may be further effected by the use of ited except as set forth in the appended claims. a series of rollers in the bath around which the I claim: yarn must travel. Additional tension may be 1. In the method of making a rippled Compos applied by providing said rollers with vanes. 30 ite yarn by wet spinning, at different spinning This invention has been described in terms tensions, a plurality of yarns of different deniers of a yarn containing two components, but it is Composed of artificial cellulosic flaments, the obvious that three, or in some cases four or more improvements comprising applying to the yarn Component yarns may be twisted together to of least denier a spinning tension at least two produce the composite yarn. times the spinning tension of the yarn of largest The present invention is described with par denier, doubling said yarns, and drying the dou ticular reference to the production of regenerated bled yarns while they are still in the gel state Cellulose from viscose solutions. The invention by supporting them in a loose condition free from is, however, generally applicable to the produc 40 tension. tion of yarn from any aqueous cellulosic solution 2. In a method of making a rippled composite which is coagulable in an acid coagulating bath. yarn by wet spinning, at different spinning ten Production of cellulosic yarns from aqueous solu sions, a plurality of yarns of different filament tions with the coagulation of the aqueous solu deniers composed of artificial cellulosic fila tions in an acid or neutral bath will be referred ments, the improvements comprising applying to to herein as a "wet spinning' process. . the yarn of least flament denier, a spinning ten In the process described in the examples, the sion at least two times the spinning tension of yarn was reeled to skeins and allowed to dry the yarn of largest flament denier, doubling said while relaxed. The process is not to be limited, yarns, and drying the doubled yarns while they however, to drying the yarn in skein form as are still in the gel state by supporting them in a satisfactory results will be obtained by any proc loose condition free from tension. ess in which the yarn is dried while relaxed. ARCBBAD STUART BUNTR.