US3380242A - Yarn and method of making same - Google Patents

Description

P 1968 A. RICHMOND ETAL 3,380,242

YARN AND METHOD OF MAKING SAME Filed Feb. 11, 1958 2 Sheets-Sheet l '23 /20 v I /5 k 25 mmg-wfors A/frec/ Rwhmopd ROber/A/berf K/ng A /ex0nder Henderson Gem/e P 30, 1963 A. mcumouo ETAL 3,380,242

YARN AND METHOD OF MAKING SAME Filed Feb. 11, 1958 2 Sheets-Sheet 2 /nven/0r$ A/fred Man/770m Robe/f A /0 en K/ng A /ex0nde/ Henderson Gen/7e By Dav/s, Hox/, fbi/hful/ 8 Hapgood Afforneys Uited States Patent O 3,386,242 YARN AND METl-ifil) OF MAKING SAME Alfred Richmond, Robert Albert King, and Alexander Henderson Gentle, Spondon, near Derby, England, assignors, by mesne assignments, to American Erika Corporation, Erika, N.C., a corporation of Delaware Filed Feb. 11, $58, Ser. No. 714,601 Claims priority, application Great Britain, Mar. 1, 1957, 6,876/5'7 3 Claims. {57-146) This invention relates to the production of voluminous yarn and more particularly to a method in which a yarn, especially a continuous filament yarn, is subjected to the action of a turbulent stream of fluid, the resulting yarn, and fabrics made therefrom, having a characteristic appearance and handle similar to those of a staple fibre yarn. The term yarn is used as including untwisted bundles of filaments as well as products containing twist.

According to the present invention, in subjecting a yarn to the action of a turbulent stream of fluid for the purpose stated, a hot gaseous fluid is used with the object of increasing the degree of permanence of the loops and sinuosities imparted to the individual filaments of the yarn by the action of the turbulent stream. It has been found that, although it is still desirable that the resulting yarn should have some degree of twist to lock the loops and convolutions of the filaments, it is possible to use a lower degree of twist for this purpose. Moreover, it has been found possible to produce yarns in which the sinuosities of the individual filaments exposed on the yarn surface are more numerous and more evenly distributed through the length and body of the yarn but are of less exaggerated form,'being rather arch-like, or of the nature of deep waves, than of complete ringlike loops. it appears possible that the softening effect of the hot gaseous medium enables the sinuosities of the filaments to be retained through the critical period between their formation and their being locked into the yarn by such twist as is employed for this purpose, thus retaining in the final yarn a degree of voluminosity, which with the use of a cold fluid stream is momentarily imparted to the yarn but is for the most part lost before it can be locked into the yarn.

While, in general, any hot gaseous medium may be employed for the purposes of the invention, it is clearly undesirable to use gases liable to produce a chemical reaction on the yarn or upon the apparatus employed. Indeed, for this purpose, it is better to avoid the use even of hot air, the oxygen content of which might tend to discolor the yarn, though there appears to be no reason why a hot inert gas, particularly nitrogen, should not be employed. However, the preferred gaseous medium is steam, particularly moist steam, since the presence of moisture in most cases reduces the temperature to which the gaseous medium needs to be heated to produce the desired effect. Accordingly, the invention is described hereafter with particular reference to moist steam.

The invention is applicable generally to yarns of continuous filaments of materials susceptible to the influence of heat, with or without moisture, for imparting to them some degree of permanence of the form in which they are so treated, and this includes most textile materials. The invention is particularly applicable, however, to thermoplastic materials, such as acetone-soluble or other cellulose acetate or other organic derivatives of cellulose, copolymers of vinyl chloride and vinyl acetate, and acrylonitrile polymers and copolymers of acrylonitrile with moderate proportions of other vinyl compounds. The invention is most especially applicable, however, to yarn of filaments of materials which are capable of heatsettrng, such as cellulose acetate of acetyl value at least 59 percent calculated as acetic acid (hereinafter referred to as cellulose triacetate), copolymers containing a substantial proportion of vinylidene chloride, polyaminocaproic acid, polyhexamethylene adipamide and polyethylene terephthalate, which substances appear, at high temperatures short of their melting points, to be subject to an increase in crystallinity, whereby the form in which they are treated is stabilised and rendered more nearly permanent. Yarns of cellulose triacetate filaments may be such as have been made by wet-spinning, dry-spinning or melt-spinning processes.

The yarn is subjected for the purposes of the present invention to the action of a turbulent stream by passing it through a suitable form of jet to which the hot gaseous medium is supplied. The yarn is thus passed through a turbulent zone of the hot gaseous fluid. A form of jet particularly suitable for the purpose is that described in US. application Serial No. 540,596, W. Pool, filed October 14, 1955, now Patent No. 2,982,082, in which an inlet tube for the entry of the yarn into the jet extends through a chamber within the jet and is provided with a tip facing and entering the mouth of a venturi through which the yarn and the hot gaseous stream leave the jet, the venturi and the outer surfaces of the tip being so shaped that a fluid stream blown under pressure into the chamber will create a vortex beyond the tip of the inlet. Such a jet can be used, if desired, in conjunction with the baffle plate described in US. Application Serial No. 356,349, filed May 21, 1953, now Patent N0. 2,942,402, or the jet described in that application, with a battle, may be used. Or again, the jet described is copending US, application of A. Richmond, W. Pool and A. H. Gentle, Serial No. 714,602- filed February 11, 1958, now Patent No. 3,010,270, may be employed.

The moist steam may be supplied to the jet employed at a wide variety of pressures, ranging from about 15 lb. gauge pressure up to lb. or more (according to the speed of travel of the yarn and the intensity of treatment desired) corresponding to a steam temperature of -170 C. or more. Where dry steam, or other dry hot gas is employed higher temperatures will generally be necessary, e.g. up to 250 or more but short, of course, of the melting point of the filaments. With such gases the supply pressure can be adjusted to a value, preferably the minimum value, which will give the desired degree of voluminosity to the emergent yarn. With moist steam, however, the pressure may be dictated by the temperature requirements and may be greater than is necessary to give the desired degree of voluminosity, which will then be determined by the relative speeds of input and drawoff of the yarn into and from the jet.

The input and draw-off arrangements, by which the degree of voluminosity may be controlled, may comprise two sets of yarn driving rollers, namely feed rollers and draw-off rollers of different speeds and/ or diameters providing the required amount of overfeed. Alternatively, a single roller may be used with tWo portions of differing diameter, the yarn passing from the portion of larger diameter to the jet inlet and back from the jet outlet to the portion of smaller diameter. The feed rollers may take the yarn over-end from a stationary package, or from one which is rapidly rotated, or from a package mounted on a double twist spindle, to impart twist to the yarn additional to that (if any) already in the yarn. From the draw-oil rollers the yarn may be led to a suitable takeup device, preferably driven at a constant peripheral speed equal to or slightly lower than that of the draw-off rollers. Alternatively, where it is desired to impart locking-twist, or further locking-twist to the yarn the yarn may be supplied from the draw-off rollers to a twisting spindle where such twist is imparted to the yarn as it is collected.

If desired, two or more yarns may be treated by passing them together through the jet. Depending on. the conditions employed and also on the twist and/ or other characteristics of the yarns, the latter may be separated after treatment and wound separately. Alternatively, the product may be such that, owing to entanglement of the filaments of one yarn with those of another, separation is not possible.

By way of example, an apparatus for the production of voluminous yarn, and the method of using it in accordance with the present invention will be described in more detail with reference to the drawings in which:

FIG. 1 is a cross section of a jet suitable for treatment of a filamentary bundle in accordance with the invention.

FIG. 2 shows diagrarnatically a general arrangement of jet and associated filament feed and take-up devices.

FIGURE 3 is a schematic drawing greatly enlarged of a yarn according to the invention.

The apparatus comprises a jet unit of the general type described in the above application Ser. No. 540,596, now

Patent No. 2,982,082. The jet unit as shown in FIG. 1

and indicated at in FIG. 2, comprises a T-piece 11, the double limb 12 of which communicates at each end with the atmosphere, while the third limb 13 is connected to a steam header 14 for the supply of steam to the unit. Within the double limb 12 is slipped a cylindrical member 15 which is circumferentially grooved about one-quarter and three-quarters way along its length for the reception of rings 16 of suitable packing material adapted to make a tight joint against the wall of the double limb. Into one end of the cylindrical member is slipped a tubular yarn inlet member 17, the tip 18 of which is of double-conical form, having conical angles of 47 near the tip and 33 a short distance behind the tip. The inlet has an entry bore 19 of A3", which tapers to X at the tip. At the other end of the cylindrical member 15 is inserted a venturi tube 20 having an inlet cone 21 of 40 angle, a throat diameter 22 of and an outlet cone 23 of 10 angle, the tip 18 of the inlet jet entering into the inlet cone 21 of the venturi. Both the inlet jet 17 and the venturi tube 20 are externally flanged to engage against the ends of the cylindrical member 15 and are held in place by two collars 24, 25 internally flanged to engage over the external flanges of the inlet jet 17 and venturi 20 respectively, and internally screw-threaded to screw over the cylindrical member 15. The inner edges of the collars 24, 25 engage the packing rings 16 and compress them against the wall of the double limb 12 of the T-piece 11, so holding the whole assembly in place. Mid-way along its length the cylindrical member 15 is bored with diametrically opposite holes 26 for the admission of steam entering from the steam main 14 through the third limb 13 of the T-piece 11. A gauze collar 27 may be provided surrounding the middle portion of the cylindrical member 15.

Yarn 29 is fed into the inlet of the jet 10 from a stationary or rotatable package 30 by means of a pair of feed rollers 31, 32 disposed parallel to and beneath the steam main 14, and is taken up as it leaves the venturi outlet of the jet by a second pair of rollers 33, 34 delivering the treated yarn 29a via a guide rod 35 to a drumdriven cheese winder in which a driving drum 36 drives the cheese of yarn 37, the yarn being guided by the traverse guide 38. The feed rollers 31, 32 are driven at a somewhat higher speed than the delivery rollers 33, 34 so as to give the required overfeed, and steam at the appropriate pressure is supplied to the steam main 14 and thence to the jet 10 through which the yarn passes. The steam serves a series of jet units supplied by feed and delivery rollers each driven by a common shaft.

From FIGURE 3 it will be seen that in yarn according to the invention the individual filaments, while physically separate and unbonded, are entangled with one another. Each has a curvilinear, sinuous, three-dimensional crimp which is randomly distributed along its length. The crimp may be fixed by the crystalline structure developed by heat setting, as noted above, and is substantially free from ringlike loops.

The invention is illustrated by the following examples. In Examples I to III treatment is effected using the apparatus described above with reference to the drawings.

EXAMPLE I A dry spun yarn of cellulose triaceta-te (acetyl value 61 percent measured as acetic acid) consisting of 50 continuous filaments of a total denier of 200, and having 5 turns per inch Z twist is drawn over-end from a supply package rotating at 8,000 revolutions per minute to increase the twist. The feed rollers are driven at a speed of 55 yd. per minute and supply the yarn to the inlet of the jet. Steam is supplied to the jet at a gauge pressure of 30 lb. per sq. in. C.) and the yarn is drawn out by the draw-oil? rollers at 50 yd. per minute and wound into a cheese. The resulting yarn has a denier of 240 and a twist of 10 turns per inch Z, and is of a bulky character, exhibiting a few ringlike loops on its surface at intervals along its length but a much greater number of archlike loops.

EXAMPLE II A continuous filament melt spun yarn of cellulose triacetate of a nominal total denier of 700, is made by doubling to 2.5 turns per inch S twist two yarns each consisting of 30 continuous filaments of a total denier of 350 and a singles twist of 3.5 turns per inch Z. The doubled yarn is drawn over-end from a stationary supply bobbin at 40 yd. per minute and fed into the jet, which is supplied with steam at 60 lb. per sq. in. (153 C.). The resulting yarn had a total denier of about 900 and is very bulky in character exhibiting a large number of archlike loops and practically no ringlike loops.

EXAMPLE III A heavy yarn of continuous filaments of polyaminocaproic acid, consisting of filaments twisted together to 2 /2 turns per inch and having a total denier of 6,800 is drawn over-end from a supply package at 44 yards per minute and fed to the jet which is supplied with steam at 90 lb. per sq. in. C.), the resulting yarn being taken-up at 33 yd. per minute and having a total denier of about 8,800. The resulting yarn is very bulky and woollike in character and is suitable for use as the pile yarn in the manufacture of a tufted carpet.

EXAMPLE IV In this example the apparatus used is similar to that used according to Examples I to III except that the jet is replaced by that shown in FIG. 1 of the drawings of copending application Ser. No. 714,602 filed Feb. 11, 1958, of A. Richmond, W. Pool and A. H. Gentle, now Patent No. 3,010,270. Further the yarn feed and yarn collecting arrangements are duplicated so that two yarns can be fed through the jet.

A yarn is prepared by doubling together, with 3.5 turns per inch Z twist, three ends of acetone-soluble cellulose acetate yarn each of 750 denier and 50 filaments and I turn per inch S twist. Two such yarns are fed together at an input speed of 40 metres per minute to the jet which is supplied with saturated steam at 80 lbs. per sq. in. The two yarns are withdrawn at 30 metres per minute, separated, and wound on to separate cones. Each bulked and concd yarn has a final denier of about 2,600.

EXAMPLE V Three ends of 0.5 turns per inch Z twist 600 denier 40 filament of melt-spun cellulose acetate of acetyl value about 61 percent calculated as acetic acid are doubled together with 3.5 turns per inch S twist; three of the doubled yarns are then twisted together with 3 turns per inch Z twist to form a yarn of about 5,500 total denier. This heavy yarn is then run through the apparatus shown in FIG. 2 of the drawings of co-pending U.S. application Ser. No. 714,602, filed Feb. 11, 1958, now Patent No. 3,010,270, using the jet shown in FIG. 1 and the collecting arrangement shown in FIG. 3. The jet is supplied with saturated steam at 80 lbs. per sq. in. pressure, the yarn input speed is 40 metres per minute and the yarn output speed 27.5 metres per minute. The resulting yarn is very suitable for forming the pile of a carpet.

What we claim is:

1. The process of imparting a persistent crimp to synthetic linear polymeric filaments and yarns which comprises feeding the same to a plasticizing stream of a compressible fluid having a temperature of at least about 300 F. in which the individual filaments, while in a plastic state and under substantially zero tension, are separated from each other and crimped individually While whipping about in the turbulent plasticizing stream, the crimp having a random, three-dimensional, curvilinear, extensible configuration, and setting the crimp thereby imparted to the said filaments.

2. A process for making a multi-filament yarn the individual filaments of which have a highly persistent crimp with a sinuous, curvilinear, three-dimensional, extensible configuration randomly disposed along the length of the filaments, said process comprising subjecting, under sub- 25 stantially zero tension, a yarn of continuous thermoplastic filaments capable of heat setting, to a turbulent stream of a compressible fluid having a temperature sufficient to set said filaments, and thereby setting said filaments in a sinuous, curvilinear, three-dimensional, extensible, random crimp imposed upon them by said turbulent stream.

3. A continuous filament yarn comprising a plurality of entangled bu-t physically separate filaments, each of said filaments being individually permanently fixed by a crystalline molecular structure in a persistent, random, three-dimensional, sinuous, curvilinear, extensible crimp and being substantially free from ring-like loops.

References Cited UNITED STATES PATENTS 2,435,891 2/ 1948 Lodge 28-72 XR 2,783,609 3/1959 Bree 57-157 XR 2,807,862 10/1957 Griset 28-72 2,852,906 9/1958 Breen 57-34 2,869,967 1/1959 Breen 57-140 2,379,824 7/1945 Mummery 57-34 2,584,043 1/1952 Oberly 57-34 2,815,559 12/ 1957 Robinson.

2,962,794 12/ 1960 Field 28-72 XR 3,009,309 11/1961 Breen et a1 57-139 MERVIN STEIN, Primary Examiner.

RUSSELL C. MADER, Examiner.

I. B. MAIER, Assistant Examiner.

Claims (2)

1. THE PROCESS OF IMPARTING A PERSISTENT CRIMP TO SYNTHETIC LINEAR POLYMERIC FILAMENTS AND YARNS WHICH COMPRISES FEEDING THE SAME TO A PLASTICIZING STREAM OF A COMPRESSIBLE FLUID HAVING A TEMPERATURE OF AT LEAST ABOUT 300*F. IN WHICH THE INDIVIDUAL FILAMENTS, WHILE IN A PLASTIC STATE AND UNDER SUBSTANTIALLY ZERO TENSION, ARE SEPARATED FROM EACH OTHER AND CRIMPED INDIVIDUALLY WHILE WHIPPING ABOUT IN THE TURBULENT PLASTICIZING STREAM, THE CRIMP HAVING A RANDOM, THREE-DIMENSIONAL, CURVILINEAR, EXTENSIBLE CONFIGURATION, AND SETTING THE CRIMP THEREBY IMPARTED TO THE SAID FILAMENTS.

3. A CONTINUOUIS FILAMENT YARN COMPRISING A PLURALITY OF ENTANGLED BUT PHYSICALLY SEPARATE FILAMENTS, EACH OF SAID FILAMENTS BEING INDIVIDUALLY PERMANENTLY FIXED BY A CRYSTALLINE MOLECULAR STRUCTURE IN A PERSISTENT, RANDOM, THREE-DIMENSIONAL, SINUOUS, CURVILINEAR, EXTENSIBLE CRIMP AND BEING SUBSTANTIALLY FREE FROM RING-LIKE LOOPS.

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