US2145004A - Manufacture of artificial silk - Google Patents

Description

Jan. 24,1939.

P. ESSELMAN N MANUFACTURE OF ARTIFICIAL SILK Filed J uly 25, 1954 i l lunl Patented Jan. 24, 1939 UNITED. STATES PATENT OFFICE many, assignor to I.

G. Farbenindustrie Aktiengesellschaft, Frankfort-on-the-Main, Germany Application July 25, 1934, Serial No. 736,946 In Germany July 28, 1933 4 Claims.

My present invention relates to the manufacture of artificial silk and more particularly to an improvement in the manufacture of artificial silk according to the bobbin spinning system.

One of its objects is an improvement in the manufacture of artificial silk according to the bobbin spinning system which is efficient and which avoids certain drawbacks involved with the bobbin spinning process as hitherto in use. Further objects will be seen from the detailed specification following hereafter. Reference is made to the accompanying drawing in which Figs. 1, 2 and 3 illustrate the process according to this invention.

Fig. 1 shows twisting in a centrifugal box according to this invention.

Fig. 2 shows a side view of an arrangement for spinning on a plate rotating about its axis and simultaneously performing a reciprocating movement, and

Fig. 3 shows a front view of the arrangement shown in Fig. 2.

Viscose artificial silks which have been finished by after-treatment on the spools with liquids sucked or forced through the silk; do not fulfil all the requirements of the textile industry, particularly the weaving industry; the desulfurization and drying on the spool produces unequal shrinkage in the inner and outer layers of the wound thread, and this is almost always a cause of lustrous shot-effects in the dyed fabric, whereby the finished goods are depreciated in value or even rendered unsaleable.

Various attempts have been made to overcome this drawback to the practice of finishing artificial silk on the spool, which otherwise has the advantage of shortening the process.

Thus, for example, the spools have been made with cores which are elastic, flexible or otherwise capable of reduction, and various modes of dyeing the threads on the spool have been tried.

None of these experiments, however, has yet been adopted for manufacture on a commercial scale.

By the present invention the quality of artificial silk made from viscose, spun or spools and, if desired, after-treated thereon, is so considerably improved that the silk can be used directly, even for weaving, without producing lustrous shot-effects in the finished fabric.

By the invention the viscose artificial silk washed on spools in the usual manner and, if desired, after-treated thereon, is unwound from the spool before drying and, preferably while simultaneously twisting it, is deposited in the formof a winding having no interior support.

Alternatively the silk on the spool can be deacidified, and only the interiorly unsupported winding produced in the twisting process aftertreated and dried.

In this process it is important that the silk should not be dried under tension on the spool, but in the form of the interiorly unsupportedwinding. By the expression cake having no interior support in the sense intended herein and in the appended claims is meant any winding or cake of stable form, not wound on a support, the threads owing to the manner of winding having suificient cohesion, so that they are not displaced in relation to one another or tan' gled to any considerable extent. Such cakes or windings are obtained, for example, by collecting the thread on a plate which has both a rotary and a reciprocating movement, or in a centrifugal box. As compared with the known process of working up spool-silk into skeins, the interiorly unsupported windings have, inter alia, the great advantage that only one textile operation and only one drying is necessary, and the layers of thread can yield as desired over the entire length. The new process is intended for operations in connection with spool spinning machines, and constitutes a new step towards shortening and cheapening the manufacture of viscose silk. The procedure may be varied in many ways. Preferably the de-acidified or completely after-treated thread is withdrawn from the spool from the top and is twisted in a centrifuge. The centrifugal box may consist of light sheet metal, for example sheet aluminium, and be mounted on an ordinary twisting machine. Instead of a centrifugal box there may be used a slowly rotating plate, which in addition to the rotation has a reciprocating movement. It is, however, also possible to rotate both the spool from which the silk is withdrawn and the receiving device, whereby the thread is doubly twisted.

When stationary spools are used it has been found to be advantageous in the twisting process to place the spools in liquid containing preparatory agents or soaping agents, so that in this manner the thread may be prepared as thoroughly as desired. The thread is then centrifuged in the collecting box and is thus quite uniformly permeated with the preparatory agents, which is of paramount importance for the subsequent operations.

The following examples illustrate the invention:

Example 1.--A silk spun on spinning spools, de-acidified, de-sulfurized and completely aftertreated, is directly subjected, without the usual drying operation, to the twisting process in which the thread is drawn off the spool from the top, passed over a galette and twisted into a light centrifugal box, or to be more precise, an internal-winding spindle. The draft, produced by the galette, amounts, for example, to 50 m., and the number of revolutions of the twisting spindle is 6000. It is preferable to use artificial silk spools spun as thick as possible in order to obtain spun threads of the maximum length. The completely twisted cake is then dried on rods or pins while avoiding tension, and can either be improved directly on cross-wound bobbins or cops, or be at once offered for sale.

If it is desired to provide highly prepared artificial silk, the spinning spool is placed in a vessel with the desired preparatory liquid, as shown in Fig. 1 of the accompanying drawing.

Example 2.Viscose artificial silk spun on spinning spools is only de-acidified and then, in wet state is drawn off from the top and twisted into a centrifugal box, in a manner similar to that described in Example 1. The cake is then desulfurized in known manner by mounting it in a permeable tube and forcing or sucking liquid through it, and is finally dried without tension.

Example 3.The completely after-treated, still wet spinning spool is placed on a twisting spindle and subjected. to a normal twisting process. The draft is produced by a galette and the thread is received on a reciprocating plate-mechanism (see drawing No. 2).

The invention will now be described with reference to the accompanying drawing.

Fig. 1 shows an arrangement for twisting artificial silk wound on bobbins which has been washed and eventually after-treated. From the non-rotating bobbin a the thread is unwound over-head by means of the galette c and twisted into the centrifugal box (1. The thread unwound from the bobbin is guided through the thread guide eyelet b. The centrifugal box is quickly rotated about its vertical shaft by means of the wheel is mounted on said shaft. At the centrifuged liquid flows away.

Fig. 2 shows a side view of a twisting device with which the thread is unwound from the bobbin a rotating at a high speed. The thread is drawn off by means of the galette c, the thread being wound twice around it, so that it dips into a bath 7!. of liquid under the galette. b and i are thread guide eyelets. The bobbin from which the thread is unwound, is by means of the wharve g quickly rotated by a driving belt. The twisted thread is collected on a plate which is driven in such a manner that the thread is deposited in the form of wellformed intericrly unsupported windings.

Fig. 3 shows a front view of part of a twisting machine with two spindles. The thread is unwound from the bobbin a which is quickly rotated. The galette 0 effects unwinding of the thread from the bobbin. The plate I on which the thread is collected is driven by a planetary gearing so that a winding with a stable form is produced.

What I claim is:

1. In the manufacture of viscose artificial silk according to the bobbin spinning system wherein a spun thread is wound on a bobbin, deacidified, desulfurized and washed, and thereafter is dried, the improvement which comprises drawing the thread, after washing and prior to the drying thereof, off of the bobbin by passing the same over a draft device, twisting the wet thread and collecting the same in the form of a cake having no interior support, and thereafter drying said cake while its interior is unsupported.

2. The improved process defined in claim 1, in which the twisted thread is collected in the form of a cake having no interior support by receiving the thread on a plate which in addition to rotating on its axis also performs a reciprocating movement.

3. The improved process defined in claim 1, in which the twisted thread is collected in the form of a cake having no interior support by receiving the thread in a centrifugal box.

4. The improved process defined in claim 1, in which the thread is drawn off of the bobbin through a bath of treating liquid.

PAUL ESSELMANN.

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