US1867609A - Yarn treatment - Google Patents

Description

- No Drawing.

Patented a1, 19, 1932 UNITED STATES PATENT OFFICE JACK L. BITTER AND RICHARD ELSSNER, OI JOHNSON CITY, TETINESSEE, ASSIGNORS TO AMERICAN GLAN'ZSTOFF CORPORATION, OI. NEW YORK, .N'. Y.,-A CORPORATION OF DELAWARE after passing through the coagulating medi um, is wound in the wet form upon a spool which might be any of the well known forms,

such as perforated, laminated, or corrugated. The threads of this yarn are then washed, and, for example in the viscose process, desulphurized, as well as bleached, etc. After the wet treatment, the yarn is usually dried by a drier or a drying process which circulates hot air through and over the surfaces of the same while it is still on the spools. By following the usual processes the yarn is ordinarily allowed to dry both from the outer and inner surface towards the middle thereof. By this process the outer and inner portlon of the thread body are first dried and have a tendency to shrink and then the center portion is dried. Inasmuch as the innermost layers rest upon a solid bobbin or spool, and the outermost layers .are resting upon the middle layers, which are drying last, the outer and inner portions do not have sufficient chance to shrink in the same way the middle layer does. This causes an uneven shrinkage, or contraction of the filaments comprising the yarn body and is very undesirable.

Our present invention has to do with a new method of drying and treating the filaments so that a high and uneven shrinkage or contraction is totally eliminated.

One method whereby our new process may be accomplished follows:

The yarn is extruded as usual and wound upon any ordinary type of bobbin or spool. Then a cloth or other suitable air and liquid tight covering of suflicient thickness is wrapped about the spool so that all the moisture contained in the yarn must be dried out from the inside. The spool is then placed in Application filed Jul 2,1931. Serial in. 548,474.

for the inner filaments, are indicated.

the drier and allowed to dry as usual. wrapping causes the inner and middle layers of the yarn .to become dried first thereby giving the outer layers room within which to shrink. After thus drying the yarn body upon the spool, the spool or bobbin is then placed upon a rewinding machine, as, for example, a twisting machine, a winding machine, etc'., and the yarn wound upon another bobbin or spool, so that the resulting yarn body is loose and room is allowed for shrinking. By this rewinding the position of the yarn body is changed about and the layers which were on the outside before are now upon the inner side. The spool is then rewet,

wrapped again'witha sufficient amount of cloth or a water and air tight covering of siutable material so that moisture can only This be taken out from the inside and again placed in the dryer. This drying allows the inner layers or the middle layers to dry first, as in the first case thereby giving theouter layer,

which was before the inner layer, suflicient room within whichto shrink to the same degree that was obtained in the other two layers. The performance of the second drying gives a yarn body the parts of which are all evenly dried and therefore evenly shrunk.

Graphs have been made, depicting the evenness (or unevenness) of drying of artificial filaments when different processes are used. Results show that in the old direct spool process, described in paragraph four of the present specification, the drying produces a very uneven shrinkage of the yarn or filaments being treated. A shrinking of approximately 3.4% on the inside of the spool, of approximately 2.5% on the outside, and varying percentages of shrinking, varying irregularly,

owever, when the outer surfaces of the spooled filaments are covered, usually with a flexible, water-tight covering, as indicated above, a more even shrinkage curve results. The shrinkage when the applicants present process is used more nearly approaches that of skein drying. Because drying the filaments in skein form involves many extra steps and is comparativelyexpensive, it may be easily seen that the present process covers a great step forward in the art. I 4

Although we have hereinbefore described specifically one method whereby the yarn- 5 might be driedin one direction only, rewet,

.drying' the same rewound, and dried in the other direction-because of the changed space of the yarn, it must be understood that we do not desire to limit ourselves to this specific modification but the invention includes within its purview whatever changes that come within the terms or 1spirit of the appended claims.

I aving now fully set forth our invention as required by the patent statutes, what we desire to claim is:

1. In a method for drying artificial filaments wound upon a perforated bobbin, the step of removing the moisture from the yarn body in one direction only the outer surface of the filaments with an impermeable covering, and then applying a dry- 111% medium to the inner side only of the b0 bin so that the yarn body dries from the inner side only.

2. In a process for drying artificial yarn which has been collected on a foraminous holder, the step of covering the outer surface of the yarn bod with an impermeable covering, and applylng the drying medium to the inner side of the holder so that the yarn body dries only from the inner side.

3. A. process as set forth in claim 1, wherein the yarn is rewound onto another bobbin, rewet, and then redried from the inside only.

4. The process as set forth in claim 2,

wherein the yarn is then rewound upon another similar holder, so that a loose w1nding.

results and the filaments are then rewet and redrie 5. In a process of the class described, the steps of wrapping wet artificial yarn wound upon a perforated spool with an impermeable covering, and then applying a drying" medium to the inner surface of the spool, thus drying the yarn'from the inner side of the spool only.

6. In a process for drying artificial yarn, filaments, etc., upon a forammated spool, the steps ofcoverin the outer surface of the filaments etc., wit an impermeable covering,

from the inside only by introducing a drying medium to the inner side of the spool, rewinding onto another spool or bobbin, rewetting the filaments, and then redrying, with the use of an impermeable cover, from the inside of the spool onl In testimony whereof we :xour signatures.

DR. JACK L. BITTER. DR. RICHARD ELSSNER.

by first covering,