US1413193A - Process of expanding the cross sections of spun-silk yarn - Google Patents

Description

profitably treated be made permanent.

UNITE- sT rs PATET. osric.

sai or-i1 SAKANE, on KAMIKYo-KU, JAPAN;

rnoonss or nxrannme rnn cnoss snor'rons or SPUN-SILK YARN.

1,11s,1es.

No Drawing.

To all whom it may concern Be it known that I, SEIIoHI SAKANE, a subject of the Emperor of Japan, residing at No. 370 Motoshinnyodo-cho, Kamikyo-ku, Kyoto, Japan, have invented new and useful Improvements in a Process of Expanding the Cross Sections of Spun-Silk which the following is a specification.

This invention relates to a process of expanding the cross section of a spun-silk yarn by counter twisting the said yarn and steaming it. It has for its object to make elastic and soft woolly yarn of spun-silk.

The expression spun-silk is used here in a broad sense; it is used to mean not only ordinary silk that is spun but those of mandarin silks, Japanese oak silks, Chinese oak silks and the like. Silk yarn containing cotton or woollen portions may also be by this new process.

To describe further, to treat twisted single yarn, it is at first heated in dry or wet state for twenty or thirty minutes, so that the curling ofsilk fibres in the said yarn may Where the yarn has been already heated 'in a previous treatment, such for instance as bleaching, scouring or dyeing so that the curling of the silk. fibres has become permanent, the preparatory treatment above described may be dispensed with.

The yarn thus treated after being dried, is then counter twisted, by any suitable twisting machine in order to untwist about a half or one third of the total number of twists of the yarn. After untwisting, the silk fibres of the yarn become separated one from the other, thereby expanding the cross section of the yarn.

Next the yarn is reeled on a swift and made into a hank by any suitable means such, for instance, as by winding it loosely on a pair of parallel bars. The hank is then steamed so as to prevent the yarn from retwisting but is left free to shrink. In about five minutes of steaming, the silk fibres are permanently set in their separated condition and, consequently, the cross section of the treated yarn gets larger and the yarn becomes elastic, soft and woolly. It looks like woollen yarn but is more lustrous.

Doubled yarn may be treated in the same way. When it is steamed and counter twisted, the single yarns of which the twine is Yarn, of

Specification of Letters Patent. Patgntgd Ap 18, 1922.

Application filed December a, 1920. Serial No. 429,153.

made and the silk fibres in the single yarns respectively separate themselves from one other, thereby expanding the cross section of the doubled yarn. The single yarns and theirfibres are permanently set in separated condition in a succeeding steam-treatment.

Instead of the preparatory steaming and untwistlng in the process of above mentioned, another method may be used for doubled yarn. Single yarns, of which doubled yarn 1s to be made, are first twisted in a required number of filatures, and then they are twined by a doubling machine so as to produce a number of twists corresponding to about half the number of the filatures. For ex ample, when two single yarns of. spun-silk ber of twists or filatures of-the single yarns 1s 472 per meter in the metric system, while the corresponding number of twists is 425 per meter. In the present method, the 'num ber of twists is reduced to about from 200 to 300 per meter, so that the tendency of the single yarns to further twist is the same as yarn of 120 ply are to be doubled, the numwhen a twisted yarn is untwisted-by the counter twisting about half of the total number of twists of the twistedyarn, and subjecting the yarn to steam-treatment while keeping said yarn free to shrink but preventing it from twisting back.

3. The process of expanding the cross section of twisted yarn which consists in tw1st-.

ing single yarns, doubling said yarns so'as to produce a number of twists corresponding to approximately half the total number of twists or filatures of the single yarns, and subjecting the yarn to steam-treatment, while keeping the yarn free to shrink but preventing it from twisting.

sEnoHI SAKANE.