US2846840A - Superpolyamidic threads and manufacture thereof - Google Patents

Description

J. BILLION Aug. 12, 1958 SUPERPOLYAMIDIC THREADS AND MANUFACTURE THEREOF Filed May 18, 1953 Inventor; occ u s B lion LAM- vs.

United States Patent'O SUPERPOLYAMIDEC THREADS AND MANUFACTURE THEREOF Jacques Billion, Lyon, France, assignor to Societe Billion & Cie., Lyon, France Application May 18, 1953, Serial No. 355,712

Claims priority, application France May'20, 1952 8 Claims. (Cl. 57-157) The present invention relates to methods for producing yarns formed from individually kinked-resilient component superpolyamidic filaments.

More particularly, the present invention pertains to a modification of and improvement in the methods and "products described and claimed in U. S. Patent'No.

2,564,245, issued August 14, 1951.

Patent No. 2,564,245 describes generally a method for producing an improved yarn having a superpolyamidic base, which method comprises the steps of highly twisting a yarn consisting of a plurality of superpolyamidic strands or filaments, permitting free shrinkage of the resulting highly twisted thread, setting the deformation resulting from the shrinkage, and then back twisting thethread to a low twist or. substantially no twist, followed, if desired, by a relaxation of the filaments by a heat treatment.

According to one embodiment of the invention. de-

scribed in U. S. Patent 2,564,245, two or more threads, each obtained by subjecting a superpolyamidic yarn me high twist, free shrinkage, setting and untwisting .to .a

low twist or no twist, may be combined into a yarn bya low twist. Specifically, the patentdescribes a method ,of making a yarn of great flufliness and excellent thermal 'insulatingproperties which consists in. twisting a. super- .polyamidic yarn to approximately 3500..turns permeter left twist, twisting a second, superpolyamidicyarnidentical with the first yarn to approximately 3500 turns ;per meter right twist, permitting both-the resulting.,high ly twisted threads to shrink freely, setting the deformations resulting in. both threads from the shrinkage, .untwisting .both threads individually to approximately 125 ,turns per meter left twist and assembling said -two-threadsto .form a yarn by twisting them together.at approximately 125 turns per meter right twist.

While yarns made by the methods described and claimed in U. S. Patent 2,564 ,245 provide. optimumprop- .erties for the manufacture of a wide variety, particularly of knitted products, there are nevertheless instances where eertainadditional propertiesare desired. More specifically, yarns made according to U. S. Patent, 2,564,245 with a'low final assembling twist of up to ,about l25 turns per meter are excellently adapted to'beknitted into sweaters of a soft, warm and elastic texture,.but sheer fabrics such as womens stockings cannot .besatisfactorily made from such yarn, nor is it possible to pro duce fabrics having the high snagandburrresistance and a great resistanceto frictionalabrasion whichis required in certain cases.

It is the principal object of the ,present invention to produce composite or multi-ply yarns which combine:

-(a) the desirable characteristics generally inherent in superpolyamidic yarns such as high tensile strength,high stability under dry and humid conditions and indifference to the action of ordinary-organic solvents with (b) the peculiar advantageous properties obtainable according to U. S.Patent'2,564,245 such as smooth and velvety touch, .dull texture with little metallic sheen, high elasticity-and excellent thermal insulating properties, and=which fur- 2,846,840 Patented Aug. '12, 1958 thermore (c) are suitable for the manufacture of fabrics and some of the resiliency seem to'be lost when two threads of no twist or low twist are combined by twisting to a final twist of more than about1250to300, turns per meter.

According to vthe present invention the essential advantageous properties of the yarns obtainable according to U. S. Patent 2,564,245 are retained and additional desirableproperties are added by amethodwhi'ch comprises subjecting superpolyamidic component yarns each consisting of a plurality of filaments individually to a high twisting operation to produce a twist of the order of about 1500 to about 4000 turns per meter, permitting the resulting highly twisted yarns to shrink freely, setting the deformation resulting from the shrinkage of the yarns, back twisting the individualyarns until each .of themhas reached a final twist in one and thesame predetermined .direction-and of an intermediate magnitude corresponding to about 400 to about 800 turns, per meter. and finally combining a number of yarns having an identical intermediate twist in said predetermined direction .by twisting .or plyingthem together in a direction opposite to said predetermined direction to proivde a twist-of assembly having a magnitude equal .to that, of; the previous intermediate twist of the individual component yarns. As a result of this plying operation thev individual filaments ot: the: untwisted component yarns are-held assembled in the finished composite multi-ply yarn .by .the plying twist of intermediate magnitude, while within each-component yarn the filaments are restored to zero twist. The numerous .kinks, waves or undulations .in each filament are fully; preserved, but the position of anyparticular crimped or kinked individual filament within eachcomponent yarn of the plied yarn is so controlled :with respect to every other filament within the same component yarn andalso within the composite multi-ply yarn that the multi-ply yarn has a smaller volume and a much greater resistance to snagging, burring or frictional abrasion,-all new properties which up to the present it has not been possible ;to obtain with yarns of this type by any known method.

The yarns, according to the present invention therefore lend themselves readily to the manufacture of 'new textile products which cannot be made from yarns produced by the methods described in U. S. Patent2,564,245.

If, for instance, a number of highly twisted, shrunken and set yarns are back twisted to a twist in one and-the same-predetermined direction of 500 turns per meter and two ormore of such yarns are assembled by twisting them together to 500 turns per meter in the direction-opposite to said-predetermined direction, composite yarns are obtained which are suitable forthe knitting ofsheer womenshosiery having a high snag resistance. If,,on the other hand, a number of highly twisted yarns, after shrinking and setting of the deformation resulting from the shrinkage, are back twisted untilv they have-a twist in one and the same predetermined direction of 700 turns per meter and then two or more of such yarns, are combined 'by twisting or plying them together to 700,,turns per meter in the direction opposite to said predetermined direction, yarns-are obtained which canbe woven into tightandelastic fabrics such as gabardines of excellent thermal insulating properties and high resistance to frictional abrasion suitable, for instance, for the manufacture of ski suits.

According to a preferred embodiment of the present invention a first superpolyamidic yarn consisting of a plurality of filaments is highly twisted in a first direction and a second superpolyamidic yarn similar to said first yarn is highly twisted in a second direction opposite to said first direction, said first and second yarns being given substantially the same amount of twist. Both the resulting highly twisted yarns are then permitted to shrink freely and the shrunken yarns are subjected to a fixing treatment for setting the deformations in the individual filaments of the yarns resulting from the shrinkage. Then the first yarn is partially untwisted to an intermediate value of twist in said first direction and the second yarn is completely untwisted and retwisted to said same intermediate value of twist in said first direction. Finally, the two yarns having the same intermediate twist in the first direction are assembled to form a multi-ply yarn by twisting or plying them together in said second direction to the same value of intermediate twist whereby the crimped filaments in each of the yarns which were originally twisted to a high twist in opposite directions have substantantially no twist within each yarn, said filaments being held together by the plying twist or twist of assembly in said second direction.

The fixing or setting of the crimped deformations in the individual filaments of each highly twisted yarn resulting from the shrinkage of the yarn may be effected in known manner by heat treatment or by sizing or the like. According to a preferred embodiment of the invention, the shrinkage and setting are combined in a single operation by subjecting the highly twisted yarns while wound on collapsible supports to a high humidity at an elevated temperature.

One embodiment of the invention is hereinafter described in detail solely by way of illustration with reference to the accompanying drawing, in which:

Fig. 1 shows a yarn of polyhexarnethylcne adipamide highly twisted to 2500 turns per meter to the left and wound on a tubular support which is radially collapsible under a predetermined pressure.

Fig. 2 is a similar illustration of a yarn twisted to 2500 turns per meter to the right.

Figures 3 and 4 show, on a reduced scale, a collapsible support filled with the yarn twisted to the right and a collapsible support filled with the yarn twisted to the left, disposed in a treatment chamber before and after, respectively, having been subjected to the shrinking and setting treatment.

Figure 5 shows, on an enlarged scale, two yarns twisted at 700 turns per meter to the left, and

Figure 6 shows the same two yarns combined by a twist of 700 turns per meter to the right to form a yarn according to the present invention.

The starting material is a yarn of polyhexamethylene adipamide, 45 deniers, consisting of 13 strands or filaments combined by a twist of turns per meter to the left and delivered by the spinning plant wound on a wooden support (not shown). This yarn is unwound from the support and highly twisted to 2500 turns per meter to the left, and the resulting highly twisted yarn is wound on a support 3 (Fig. 1) formed of plastic material and collapsible to a reduced diameter under a predetermined pressure.

A second yarn, which is identical with the first yarn, is highly twisted to 2500 turns per meter to the right, and the resulting highly twisted yarn is similarly wound on a collapsible support 5 (Fig. 2) identical with that used for the yarn 2 twisted to the left.

The two highly twisted yarns 2 and 4 on their respective collapsible supports 3 and d are next placed in a treatment chamber 6 (Fig. 3) where they are subjected to a high humidity treatment at 95% relative humidity and at a temperature of C. for 45 minutes. By this single treatment, the yarns are caused to shrink, thus crushing their collapsible supports, and the component strands or filaments of each yarn are deformed so that they have innumerable kinks, waves or undulations which become fixed or set by the action of the high temperature. After drying in free air, the yarn which was previously twisted to 2500 turns per meter to the left is partially untwisted to a residual intermediate twist of 700 turns per meter to the left and the yarn which was previously twisted to 2500 turns per meter to the right is completely untwisted and retwisted to an intermediate twist of 700 turns per meter to the left.

After this operation, the two yarns 2a and 4:: (Fig. 5) Which were originally twisted, one to 2500 turns per meter to the left and the other to 2500 turns per meter to the right, respectively, and which are now both twisted to 00 turns per meter to the left, are assembled or plied together by a twisting of 700 turns to the right to form a yarn according to the present invention.

in the yarn thus obtained, the two component yarns 2a and 4a of 45 deniers each are combined and held together by a plying twist of 700 turns per meter to the right, whereas within each of the individual yarns, the 13 component crimped or undulatory filaments are not held together by any other than the plying twist.

Thus, in the final yarn, in each of the two component yarns, the individual filaments which are apparently parallel, do not turn with respect to one another (see Fig. 6). This parallelism is only apparent, however, because as soon as the tension is relieved, each of the 13 individual filaments is given free play and forms kinks or undulations which cause each filament to separate itself from the remaining 12 strands. On the other hand, the freedom of movement of each individual filament is restricted, because seven times over each centimeter of its length each filament of each component yarn is pressed against the group of 13 filaments of the other yarn with which it is plied.

The multi-ply yarns obtainable according to the present invention may be used to provide a warp thread which can be combined on a loom with a woof thread of wool. The fabric thus obtained displays all the advantages of strength, resistance to organic decomposition, and chemical inertness which are characteristic of yarns having a superpolyamidic base. Such a yarn further provides the advantages of softness, elasticity, high thermal insulation, and the flattering appearance which are attributable to yarns produced according to the method of Patent 2,564,245.

Finally, due to the use of a plying twist or twist of assembly of 700 turns per meter given to the yarn made up of the two component untwisted yarns, the individual kinked or crimped filaments of the yarns are held together seven times in each centimeter of the length of the plied yarn and therefore do not present free loops or ends which are liable to be damaged by friction.

Thus, a fabric comprising yarns made according to this invention combines the advantages resulting from the use of the superpolyamidic threads with all the desirable characteristics of a fine wool worsted fabric.

What I claim is:

1. A method of producing a yarn having a superpolyarnidic base which comprises subjecting superpolyamidic yarns each consisting of a plurality of filaments individually to a high twisting of the order of about 1500 to about 4000 turns per meter, permitting the resulting highly twisted yarns to shrink freely, setting the deformation resulting from the shrinkage of the yarns, back twisting the individual yarns until each individual yarn has reached a final twist in one and the same predetermined direction of an intermediate magnitude corresponding to about 400 to about 800 turns per meter, and finally combining a number of yarns having an identical intermediate twist in said predetermined direction by twisting them together in a direction opposite to said predetermined direction to a twist of assembly having a magnitude equal to that of the intermediate twist of the individual yarns, whereby, the individual yarns have no twist remaining and are held together by said twist of the assembly.

2. A method of producing a composite yarn having a superpolyamidic base which comprises the steps of highly twisting a first superpolyamidic component yarn consisting of a plurality of filaments in a first direction to about 1500 to 4000 turns per meter, highly twisting a second superpolyamidic component yarn similar to said first yarn in a second direction opposite to said first direction, said first and second yarns being given substantially the same amount of twist, then permitting each of said highly twisted yarns to shrink freely, subjecting the shrunken yarns to a treatment for setting the deform'ations resulting from the shrinkage, then untwisting the first yarn to an intermediate value of twist in said first direction of between about 400 to about 800 turns per meter, completely untwisting the said second yarn and retwisting it to said same intermediate value of twist in said first direction, and finally assembling the two component yarns to form said composite yarn by twisting them together in said second direction to said intermediate value of twist, whereby the filaments in each of the component yarns originally twisted to a high twist in opposite directions have substantially no twist within each component yarn of said composite yarn, said filaments being held together by the twist of assembly in said second direction, whereby the individual filaments of the component yarns are without torsion,

. the filaments being assembled by the relatively high twist of assembly of the component yarns, thereby securing high resilience relative to the bulk of the composite yarn and obtaining resistance to snag and burr.

3. The method according to claim 2 wherein the two component yarns, before shrinking, are highly twisted to about 2500 turns per meter in opposite directions.

4. The method according to claim 2, wherein the two component yarns are back twisted to an intermediate value of twist of 500 to 800 turns per meter in the same direction and the two component yarns are combined by a twist of assembly having a value of 500 to 800 turns per meter in the opposite direction.

5. A method of producing a yarn having a superpolyamidic base which comprises subjecting superpolyamidic yarns each consisting of a plurality of filaments individually to a high twisting of the order of about 1500 to about 4000 turns per meter, setting the said high twisted yarn, back twisting the individual yarn until each individual yarn has reached a final twist in one and the same predetermined direction of an intermediate magnitude corresponding to more than 300 to about 800 turns per meter, and finally combining a number of yarns having substantially the same intermediate twist in said predetermined direction by twisting them together in a direction opposite to said predetermined direction to a twist of assembly having a magnitude substantially equal to that of the intermediate twist of the individual yarns.

6. A method of producing a yarn having a superpolyamidic base which comprises the steps of highly twisting a first superpolyamidic yarn consisting of a plurality of filaments in a first direction to about 1500 to 4000 turns per meter, highly twisting a second superpolyamidic yarn similar to said first yarn in a second direction opposite to said first direction, said first and second yarns being given substantially the same amount of twist, then untwisting the first yarn to an intermediate value of twist in said first direction between about 400 to about 800 turns per meter, completely untwisting the said second yarn and retwisting it to substantially the said same intermediate value of twist in said first direction, and finally assembling the two yarns to form a yarn by twisting them to gether in said second direction to substantially the said intermediate value of twist, whereby the filaments in each of the yarns originally twisted to a high twist in opposite directions have substantially no twist within each yarn, said filaments being held together by the twist of assemhly in said second direction.

7. The method of producing an elastic and abrasion resistant multi-ply yarn consisting of filaments having a superpolyamidic base which comprises the steps of: separately twisting a plurality of component yarns, each component yarn consisting of a plurality of individual filaments, said twisting step bringing said filaments to a high twist in the range of from about 1500 to 4000 turns per meter; treating said highly twisted yarns to form permanently crirnped deformations in said individual filaments; subsequently bringing said component yarns to equal intermediate twists in the same direction, said intermediate twists being in the range from about 400 to about 800 turns per meter; and plying said yarns of intermediate twist together with a twist of assembly equal and opposite to said intermediate twists, whereby the individual crirnped filaments of each component yarn are substantially parallel to each other within the component yarn and are held assembled in said multi-ply yarn by said plying twist.

8. The method of producing an elastic and abrasion resistant two-ply yarn consisting of filaments having a superpolyamidic base which comprises the steps of separately twisting two component yarns in opposite directions, each component yarn consisting of the same number of similar individual component filaments, said twisting step bringing said filaments to a high twist in the range from 1500 to 4000 turns per meter, treating both of said highly twisted yarns to form permanent crirnped deformations in said individual filaments, untwisting one of said fixed yarns to an intermediate twist in the range of from about 400 to about 800 turns per meter, completely untwisting the other one of said yarns and retwisting it in the same direction as said one yarn to an intermediate twist which is equal to the intermediate twist of said one yarn, and plying said two yarns of intermediate twist together with a twist of assembly which is equal and opposite to said intermediate twist, whereby the crirnped individual filaments of each component yarn are substantially parallel to each other within the component yarn and are held together in said two-ply yarn by said plying twist.

References Cited in the file of this patent UNITED STATES PATENTS 2,564,245 Billion Aug. 14, 1951 2,585,518 Valentin Feb. 12, 1952 2,597,577 Drisch et a1. May 20, 1952

Claims (1)

1. A METHOD OF PRODUCING A YARN HAVING A SUPERPOLYAMIDIC BASE WHICH COMPRISES SUBJECTING SUPERPOLYAMIDIC YARNS EACH CONSISTING OF A PLURALITY OF FILAMENTS INDIVIDUALLY TO A HIGH TWISTING OF THE ORDER OF ABOUT 1500 TO ABOUT 4000 TURNS PER METER, PERMITTING THE RESULTING HIGHLY TWISTED YARNS TO SHRINK FREELY, SETTING THE DEFORMATION RESULTING FROM THE SHRINKAGE OF THE YARNS BACK TWISTING THE INDIVIDUAL YARNS UNTIL EACH INDIVIDUAL YARN HAS REACHED A FINAL TWIST IN ONE AND THE SAME PREDETERMINED DIRECTION OF AN INTERMEDIATE MAGNITUDE CORRESPONDING TO ABOUT 400 TO ABOUT 800 TURNS PER METER, AND FINALLY COMBINING A NUMBER OF YARNS HAVING AN IDENTICAL INTERMEDIATE TWIST IN SAID PREDETERMINED DIRECTION BY TWISTING THEM TOGETHER IN A DIRECTION OPPOSITE TO SAID PREDETERMINED DIRECTION TO A TWIST OF ASSEMBLY HAVING A MAGNITUDE EQUAL TO THAT OF THE INTERMEDIATE TWIST OF THE INDIVIDUAL YARNS, WHEREBY, THE INDIVIDUAL YARNS HAVE NO TWIST REMAINING AND ARE HELD TOGETHER BY SAID TWIST OF THE ASSEMBLY.

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