US1867618A - Drying process - Google Patents

Description

Patented July 19, 1932 UNITED STATES PATENT OFFICE RICHARD ELSSNER, OF JOHNSON CITY, TENNESSEILASSIGNOR TO AMERICAN GLANZ- STOFF CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE DRYING PROCESS No Drawing.

My present invention has to do with a new method for drying yarn on spools.

.' One object of this invention is to provide a spooled yarn with a technically even shrinkage.

Other objects will become pparent'from a study of the following speci cation.

In the manufacture of artificial silk by the viscose process, the solution is extruded through fine openings in a spinneretintoafixing or coagulating bath. Here the filaments are hardened to a certain degree, and then wound upon some type of holder, vfor example, a foraminated spool or bobbin. The yarn thus formed must be wet-treated in order to free it from chemicals, and dried. It has been found that this drying tends, ordinarily,

to cause an uneven shrinkage of the formed filaments. It is to overcome this uneveness that I have devised my new process.

As one method of applying my new process, the following may be considered. The filaments are formed and collected on normal spools, which may or may not be perforated. After the customary wet-treatmcnt the spools containing the yarn are dried very slowly, for example, at a temperature of from 20 to 0., and an air humidity of from 60 to 80%. No wrappings are employed on the filaments during this drying process.

The dried yarn is then twisted, from the spool in a loose body, upon another spool.

This yarn is then rewet (by spraying or dipping, for example) and again dried very slowly as noted above.

As an example of my process, spool 200 mm. long holding viscose yarn of 150 denier, 32

filaments (about 370 grams of yarn per spool) v is dried for a period of approximately 60 hours at a' temperature of from 20 to 30 C., and a relative humidity of about 50 to 70% until the moisture content is about 10 to 18%.

. After twisting and rewettin in the manner outlined above, this type of s ow drying is repeated. I No wrapping of any type 15 employed.

Although the description of my invention has been written with respect to the viscose filament-forming process above, it is to be understood that I do not desire to limit my Application filed September 11, 1931. Serial No. 562,427.

invention thereby. This process may also be used where other processes requiring wetproximately 80% twisting into a loose body onto another holder, rewettingthe yarn, and redrying the same slowly.

2. In a process of the class described, the steps of spinning a viscose solution directly onto spools, wet-treating the yarn thus spun, drying slowly at a temperature of from 20 to 30 0., and at a humidity of 80% or over, rewinding in a loose bod onto another spool,

and then rewetting an redrying the yarn slowly.-

3. In a process for producing artificial yarn with a technically even shrinkage, the steps of wet treating the filaments, drying them slowly at approximately room temperature and in an atmosphere possessing a humidity of or over, rewinding the yarn body so that the filaments formerly on the outside are on the inside, rewetting the yarn, and redrying it.

4. A process as set forth in claim 3, where in the second drying is also at approximately room temperature and in an atmosphere of relatively high humidity.

In testimony whereof I alfix my signature. DR. RICHARD ELSSNER.