US1917512A - Yarn with even shrinkage - Google Patents

Description

z a new is. n conronirrron GLADTZSTQFE Ema ilo Brewing. Application died July 9,

My new invention has to do with a novel; method for preventing the uneven shrinkage oi? artificial filaments.

' More particularly, my invention has to do with the prevention or uneven shrinkage occasioned b drying cakes of artificial filements pro need by the pot spinning or centrifugal process.

In the pot spinning or centrifugal method for producing artificial filaments, a cellulosic solution is made up and extruded by pressure through line orifices into a setting medium from whence it is carried over guiding means to a rapidly revolving receptacle which collects and twists the groups of filaments which are led thereinto. This receptacle or. pot throws the'filaments against itssides and thus builds up a cake of filaments which, when a suficient number of filaments has been bunched, is removed thereirom. These cakes are then washed, dried, and otherwise treated. As a result of these treat ments the filaments are no longer tightl caked but are comparatively loosely woun The cakes may be dried either by skeining the cakes or drying the yarn directly in cake form. The drying in the cake form may be done by drying from the inside or from the outside but drying in one direction only, or

the yarn is dried from both sides towards the middle of the cake. If the yarn is dried from the outside towards the center the outer lying filaments tend to shrink before the inner filaments and thus an uneven shrinkage of the yarn in the cake results. Similarly, if the yarn is dried from the inside toward the outside an uneven shrinkage results. I have discovered a method whereby this uneven shrinkin may be overcome.

Accor ing to my new method the cakes are taken from the centrifugal pot, washed, or otherwise treated, and then dried, for example, ir'om the outer to the inner side. The cake is then wet again and dried. now from the inner to the outer side. This double drying has the unusual result that the filaments first shrink from the outside to the inside thus partially shrinking the middle filaments, and then shrink from the inside to the outside thereby completing the shrinking or the middle filaments and equalizing the shrinking of both the outer and inner sides. This two step drying, wetting, and drying process results in a cake of filaments area acacia.

the inner to the outer layer of filaments.

Then the outer cover is removed; the cake is wet with water; and the water and air tight coverplaced about the inner surface of the cake. The drying is then repeated this time from the outer to the inner layer of filaments.

1 As an alternative method, I have found it feasible to dry, for example, from the inner to the outer side,- reverse the loose cake of filaments, that is, turn the now loose cake inside out, and dry again in the same direc-. tion.

It should he understood that when the outer layer is covered as set out above, the top and bottom surfaces of the cake may be similarly protected by fiaps extending rrom this cover.

Having now fully set forth my new invention as required by the patent statutes, what I desire to claim is: I

l. A process for producing even shrinkage of filaments produced by the pot spinning process, which comprises drying the cake.

the inside of the cake with an air and water tight wrapper, then drying the cake from the outside.

8. In a process for handling spun cakes of artificial filaments, the steps of wrapping the outside of a wet cake produced by the centrifu al process with a covering, drying the cake y applying the drying medium to the uncovered portion of the cake, removing the covering, rewetting the cake, wrapping the inside portion of the cake with a covering, and drying by applying the drying medium to the uncovered ortion of the cake.

In testimony w erect I ans myisi ature.

Brennan ELSS na, u