US2031647A - Manufacture of spun yarns - Google Patents

Description

Feb. 25, 1936. F. c. HALE MANUFACTURE OF SPUN YARNS Filed June 8, 1933 til Patented at. 25', 1936 I MANUFACTURE OF SPUN YARNS 2 Frank Corbyn Hale, Spondon, near Derbmi'ingland, asaignor to Celanese Corporation of America, a corporation of Delaware Application June a, 1933, Serial No. 674,829

a In Great Britain July 4. 1932 l a 5Claims. This invention relates to the manufacture or 'yarn's having a basis of continuous filaments, but

having the appearance of spun yarn, that is yarn made from'staple fibre.

' In the manufactureoi spun yarn from artificial fibres, the usual practice is to cut continuous artificial filaments or waste filaments into comparatively short lengths, for example 01 1 to 2 inches or more, and then subject the staple fibres produced to a series oi operations appropriate to the length of the fibre,,such operations being similar to thoseaccorded to natural fibres such as cotton or wool, including opening, carding, drawing and spinning. These operations represent considerable expense in the production of such yarns, since they involve a relatively slow transformation of the initial fibrous materialto a finished yarn.

The object of the present invention is to produce yarn having an appearance similar to that of yarn made from spun fibre while avoiding the necessity for forming continuous filaments into short lengths and spirming the fibres thus produced. The particular purpose of the invention is to enable a fairly close measure of control to be obtained over the length'ot the fibre, so as to obtain a spun yarn as uniform as possible in structure. and consequently 01' a. fairly high degree of strength;

.Accordingto the invention, the filaments to be v converted into fibre vary in denier at intervals along their length, so that breakage occurs at the thinner and weaker parts when the filaments are subjected to a breaking load. Thus the breakage is eflected at substantially predetermined *points, the actual length of the fibres corresponding closely-to the intervals between the thin pore tions of the filaments. Preferably the variation in denier occurs at regular and uniform intervals so as to enable the fibres to be of substantially equallength.

In addition to thecontroL-given over fibre length by localizing the points of rupture of the filaments toweak parts of the filaments, undue extension or the filaments under the breakage load may be avoided except close to the points of breakage, so that the elasticity of the material as a whole is not lost. The degree to which the whole filament is extended by the breaking operation will, however, depend on the denier ratio between the thin parts and the rest of the filaments. Thus, for example, a ratio of 1.1:1 may give sufiicient denier variation for breakage to A I be confined to the thin portions, but it may be advisable to have a somewhat .higher ratio, say

1.5:1, toensure that the permanent elongation 2:1 or upwards, may be employed, but in general it is advisable to keep to as low a ratio as possible in order to avoid difliculties arising from the individual fibres varying in thickness.

It is, of course, necessary thatv a fibrous yarn should have its fibres distributed substantially evenly in its structure so as to impart strength and evenness to the yarn when spun. Consequently, the fibrous mass produced by breaking the filaments of varying denier should have the ends of its fibres in overlapping relationship so that they can be properly spun. This may be effected by arranging that the filaments simultaneously broken have their weak places occurring at'spaced intervals, as between filament and filament. It is, however, more convenient to form a multi filament yarn of varying denier by extending all the filaments equally and simultaneously, so that all the thin places appear side by side in the yarn. (Reference may be had to U. 8. Patent No. 1,898,085 and U. S. applications 8. Nos. 574,851 filed 13th November, 1931 and 573,422 filed 6th November, 1931, for methods of giving yarns a varying denier, either continuously with the production 01' the yarnsfor subsequently thereto.) Though the pointsoi breakage of the filaments oi such yarns would probably not coincide precisely, yetthey would be-sufiiciently close to prevent the fibres having any substantial overlap. These yarns can, however, be utilized by taking a plurality or such yarns from separate supplies and combining them together before, during, or after breakage. If, say 4', 8, 10 or 12 such yarns are so combined, the fibres produced-1mm them are generally evenly distributed throughout the com-,

- varying denier is so efi'ected that the continuity oi" the mass is not broken except for the conver sion oi. the filaments intov fibres, so that there is produced a sliver-elikebundle which can be transformed into an even yarn. Breakage is conveniently carried out by passing the filaments through two pairs of rollers in series, the rollers of each-pair being pressed together so as to grip the filamentsfirmly and the second pair being driven at a speed suificiently greater than that of the first pair to break the filaments at their thin portions. A form of apparatus using such ing and methods of carrying out the invention will now be described with the aid of the drawing.

Four nds a, b, c, d of yarn containing continuous filaments, the denier of which varies so as to form thin portions at regular intervals along their length, are unwound from cheeses 2, 3, 4 and 5 and are led through the nips of two pairs of rollers 6,! and 8, 9 to the fiyer I9 and bobbin ll of a fiyer twisting and winding device.

The rollers 6, I and 8, 9 are pressed together I by a bridge piece H which rides at its extremities in necks l3, l3 formed in the top or press rollers 1, 9. A bolt M which may be loaded by a spring (not shown) passes through the bridge piece l2 and is provided with a wing nut i 5 by which the pressure on the bridge may be adjusted.

The ratch or distance between the nips of the two pairs of rollers approximates, or is slightly in excess of the distance between the thin portions of the yarn (indicated as e on the end 0) The bottom'rollers 6, 8 are the driven rollers i'n each pair and are fluted, while the press rollers I, 9 are covered with rubber, leather, or like resilient material, indicated at l6, so that the filaments, while being securely gripped, are not inlured or broken when passing through the nips of the rollers.

In operation the rollers 8, 8 are driven at a speed sufficiently greater than that of the rollers 6, I to break the filaments between the rollers, the

breakage occurring at or about the thin portions of the filaments so that the thicker portions are not subjected to undue stress.

In order that the continuity of the ends as a whole is maintained the threads are unwound from the cheeses 2-5 'and delivered to the first 45 the-individual yarns are broken completely across their width, the points of breakage are so distributed that the total mass of filaments is never severed completely across the width.

It will be understood that the fineness of the filaments prevents true illustration of their number, and while each thread a,-d is shown bobbin 1 I.

as containing only a few filaments there are many more in practice. Actually the filaments are much closer together than can be shown and form a sliver-like mass of material extending between the nips of the rollers so that on breakage, the loose ends are carried forward to the nip of the rollers 8, 9 by the mass of the other filaments. If desired, however, the yarns may be supported on breaking by means such as a travelling endless band or'by one ormore sup porting rollers or carriers. u

The breaking action of the two pairs of rollers thus converts the continuous yarns into a fibrous sliver f of maintained continuity and which is -'twisted into a coherent roving and wound on the A comb guide I! situated between the cheeses 2-5 and the rollers 5, 1 guides the yarns and maintains them in' evenly spaced relation prior to-their entering the nip of the rollers. The guide ll also serves to spread out the filaments of each yarn'into a fiat band, and reciprocates along the length of the roller 1 in order to prevent undue wear at any one point or series of vthe requisite twist.

I 2,031,647 rollers is illustrated inthe accompanying drawpoints on the surfaces of the two pairsof rollers.

The variation in denier. in the filaments occurs at intervals corresponding to'the type of spun yarn to be produced, such as 1 "-2 to produce a yarn having characteristicssimilar to those of cotton yarn, or '2 /z"12" or more to produce a yarn having worsted yarn characteristics. The ratch of the rollers is adjusted in accordance with such spacingof the denier variations. 1

If desired the. silver from the rollers 8, 9, may be passed-through a further set of draw rollers before being twisted so as to reduce its size and may even be brought to final size, in which case the twisting may be of sufficient degree to finish the yarn in the one continuous operation of breaking, drafting and twisting.

Alternatively, the roving wound on the bobbin Il may be subjected to one-or more drawing operations similar to those used on yarns of natural fibres, and two or more rovings may be combined in order to increase the evenness of the final yarn.

Doubled yarn may be produced by twisting together two or more yarns which have been reduced to the desired degree of fineness and given The operation according to the invention may be applied to the breaking of all kinds of continuous or substantially continuous filaments of varying denier into staple fibre. For example, the filaments may consist of cellulose acetate or other organic derivatives of cellulose, such as other cellulose esters, e. g. cellulose formate, propionate and butyrate, and cellulose ethers such as ethyl and benzyl cellulose. Thus yarns oi cellulose acetate may be given a varying denier continuously with their production by the dryer evaporative method by any of the means described in U. S. Patent No. 1,898,085 and U. S. applications S. Nos.

574,851 filed 13th November, 1931 and 573,422

portance of maintaining the even arrangement of I the fibres in the sliver-like mass produced by.

breaking the filaments, it is desirable that any such media should be applied to the filaments before breaking. Such media may be of an insoluble type, e. g. kieselguhr, talc, pumice, carborundum, and emery, and may be applied dry or as pastes or suspensions at any suitable stage prior to breaking, e. g. continuously with the production oi. artificial filaments. Soluble materials in crystalline or powder form may also be applied dry. Soluble media may also be used, conveniently being applied as solutions of high concentration, as described in vU. S. application S. No.

585,381 filed 7th January, 1932, so that drying can be economically effected to leave the desired amount of roughening media on the fibres.

Where the materials are subject to electrification, as for example in the case of cellulose acetate or other organic derivatives of cellulose, hygroscopic materials may be appled to the materials. 'For example,- hygroscopic bodies may be applied as described in U. S. application 8. No.

ably being dried before breaking.

What I claim and desire to secure by Letters Patent is:--

1. Process for the production of yarn of fibrous character, which comprises continuously subjecting to a. breaking load a pluralityof continuous filaments-having thin portions at intervals along their length, said thin portions occurring at spaced intervals and being staggered as between filament and filament so that by the breakage of the filaments occurring at the thin portions the filaments are converted into fibresoverlapping each other, and collecting the fibres thus produced as a continuous end.

2. Process for the production of yarn of fibrous character, which comprises continuously subjecting to a breaking load a plurality of yarns of continuous filaments, the filaments in each yarn having thin portions at intervals along their length and the thin portions of the several yarns occurring at spaced intervals and being staggered as between yarn and yarn, so that by the breakage of the filaments occurring at the thin portions, each yarn is converted into fibres overlapping the fibres produced from the other yarns, and collecting the fibres thus produced as a continuous end.

3. Process according to claim 1 wherein the thin portions 01' the filaments occur at uniform intervals so that the filaments break into fibres of substantially equal length.

4. Process for the production of yarn of fibrous character, comprising continuously subjecting to a breaking load a plurality of continuous filaments of cellulose acetate having thin portions at intervals along their length, said thin portions occuring at spaced intervals and being staggered as between filament and filament so that by the breakage of the filaments occurring at the thin portions-the filaments are converted into fibres overlapping each other, and collecting the fibres thus produced as a continuous end.

5. Process for the production of yarn of fibrous character, comprising continuously subjecting to a breaking load a plurality of yarns of continuous filaments of cellulose acetate, the filaments in each yarn having thin portions at intervals along their length and the thin portions of the several yarns occurring at spaced intervals and being staggered as between yarn and yarn, so that by the breakage of the filaments occurring at the thin portions, each yarn is converted into fibres overlapping the fibres produced from the other yarns, and collecting the fibres thus produced as a continuous end.

- FRANK CORBYN HALE.

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