US1692717A - Method of treating spun yarns in the course of their manufacture - Google Patents

Description

Patented Nov. 20, 1928.

UNITED STATES- PATENT OFFICE.

JAMES J'. BOYLE, OI! NEW YORK MILLS, NEW YORK.

METHOD OF TREATING SPUN YARNS IN THE COURSE OF THEIR MANUFACTURE.

No Drawing.

The present invention relates broadly to new and useful improvements in the method of treating spun yarns in the course of their manufacture.

The invention hasparticular relation to the treatment of yarns which have been spun from relatively short lengths of rayon or other similar artificial fibers or filaments.

When a yarnis spun, as, for instance, on

regular cotton spinning machinery, from relatively short lengths of rayon, a substantial loss is to be noted in the luster of the yarn as compared with the luster which existed in the rayon filaments or fibers before they were spun.

The principal object of the present invention is to provide a method whereby the original luster of the rayon fibers or filaments may be substantially restored in the finished spun yarn.

In spinning the relatively short rayon fibers or filaments on cotton machinery, it is necessary, of course, as in cotton yarn manufacture, to impart a substantial twist to the yarn in order that the fibers composing it may be properly interlaced and the yarn thereby given the required strength. It is frequent practice, for instance, to put in a finished No. 20 cotton yarn a twist of seventeen turns to the inch.

It has been found that the rayon filaments or fibers thus twisted or spun together produce a yarn possessing substantially less luster or sheen than that found in a mass of the same short-length rayon fibers before they were spun and twisted together. This result is apparently due to the following dissimilar conditions: The sheen or luster to be noted in rayon in its original state results in large 40 measure from the fact that the fibers are relatively straight and are arranged in groups wherein each individual fiber is parallel to the other fibers ofthe group. An unbroken.

reflecting surface of relatively large area thus exists and thesheen or luster apparent is consequently of substantial degree. But when the rayon fibers-are twisted together by the spinning process, this parallelism is substantially reduced and the fibers intertwined and crossedso that the surface of the yarn is broken up and, consequently, at no point does a smooth reflecting surface exist in anything like the degree found in the original state of the rayon fibers and filaments.

Application filed August 27, 1926. Serial No. 132,032.

I have discovered, however, that this original parallelism and the relatively unbroken reflecting surface produced thereby can be substantially restored if after the yarn has been passed completely through the spinning operation, it is then subjected to a reverse twisting process. Hence, the method of the present invention consists in spinning the yarn and twisting it in the spinning machinery and subsequently gving it a reverse twist under slight tension. Apparently, this reverse twisting under slight tension causes the individual fibers to approach their original parallelism sufficiently to largely restore the sheen or luster.

The extent to which the reverse twisting is done is, of course, dependent upon the size of the yarn being produced, the tensile strength required of the particular yarn for the particular use to which it is to be put, and a number of other practical commercial considerations.

In general, it may be said that the reverse twisting should not reduce the original number of twists per inch bymore than thirtythree and one-third per cent, although this is not an absolute limit. 7

It is found that while the reverse twisting alone will substantially improve the luster of the yarn, even greater improvements can generally be effected if the yarn is moistened and the reverse'twisting done while the yarn is in the moistened condition.

It should be mentioned that the yarn when thus subjected to reverse twisting is not in its wet state as strong as .it was before the reverse twisting was done, but that in a dry condition it is stronger than formerly.

My experiments and trials to date indicate that the reverse twisting process is desirable and commercially usable only where it is desired-to have a soft, lustrous yarn and where it is not required that the yarn be possessed of great tensile strength.

What I claim is: y Y

1. The method of treating spun rayon yarns which consists in subjecting the yarn in the presence of moisture to a reverse twisting after the yarn has been completely spun to thereby improve the luster.

2. The method of treating spun rayon yarn which consists in iving the yarn a relatively high twist and su sequently giving the yarn a reverse twist-to reduce in the finished prodnot the number of twists per'inch originally existing, whereby the luster of the yarn is improved.

3. The method of treating spun rayon yarns which consists in moistening the yarn 6 and then subjecting it to a reverse twisting after the yarn has been completely spun.

4. The method of treating spun rayon yarn which consists in giving the yarn a relatively high twist and subsequently moistening it and then giving it a reverse twist to reduce in the finished product the number of twists per inch originally existing, whereby the luster of the yarn is improved.

In testimony whereof I afiix my signature.

JAMES J. BOYLE.