US2477744A - Textile operation - Google Patents

Description

Aug. 2, 1949. F. B. HILL ET AL TEXTILE OPERATION F iled Feb. 7, 1945 Fla. 2

Inventor; EB-HILL E T. HITCHIN 4V)! Attorneys Patented Aug. 2, 1949 TEXTILE OPEEA'IIQN Frank Brentnall Hill and Edgar Tom Hitchin, Spondon, near. Derby, England, assignors, by mesne assignments, to Celanese Corporation of America, a corporation of Delaware Appiication February '7, 1945, Serial No. 576,548 In Great Britain February 1, 1944 Section 1, Pubiic Law 690, August 8, 1946 Patent expires February 1, 1964 3 Claims.

This invention relates to textile operations and particularly to the taking up or collecting of running yarn, and is especially concerned with the taking up and collection of yarn-as it is delivered from a stretching operation and with the further treatment of such yarn.

The stretching of yarns in the presence of a softening agent such as moist steam is an operation which may beapplied to yarns of certain materials, particularly continuous filament artificial yarns, for the purpose of improving their tensile strength and other characteristics. The operation is particularly applicable to continuous filament artificial yarns of cellulose acetate or other organic ester of cellulose and, when applied to these yarns, may be followed by a saponifying operation whereby the stretched yarns are converted into regenerated cellulose yarns, retalning in their new form the high degree of tensile strength imparted to them by the stretching op eration. The stretching operation is one that can conveniently be carried out on a number of yarns simultaneously, the yarns being run together through a stretching chamber in which the moist steam or other softening agent is introduced and in which the-yarns are stretched. By running the yarns close and parallel to one another a chamber of relatively small cross-section can be used for the stretching of a large number of yarns. The taking up of the yarns as they are delivered from the operation, however, presents considerable difficulties since it is desirable to collect the yarns individually, for which purpose accommodation has to be found for a large number of collecting devices inthe immediate neighbourhood of the exit end of the relatively narrow stretching chamber. It is also desirable that the collecting device employed should be capable of quick threading so as to facilitate the starting up of the stretching operation, of being individually stopped and started independently of one another and of collecting the stretched yarn in the form of packages of substantial size.

The present invention is concerned with means whereby it is possible to use for the collection of yarn as it isdelivered from a stretching operation, a. collecting device of the type known as Topham box, in which the yarn is fed to the interior of a short cylindrical box rapidly rotating about-its axis: and isflung outwards by centrifugal force to the inside wall. of'thebox where it accumulates in the form of a hollow cylindrical cake of twisted yarn. The yarn is delivered to the interior of the boxthrough a funnel down which pa ses a stream of liquid to carry the yarn into the box, the funnel being traversed up and down along the axis of the box' so as to distribute the yarn uniformly over the interior of the cylindrical surface of the box. The-Wall of the box isperforated to allow the stream of liquid entering through the funnel to escape under centrifugal force.

According to the invention, the yarn-is drawn from the delivery rollers of the stretching machine and forwarded to the collecting'device by intermediate drawing and forwarding means. The tension exercised on the yarn by the draw ing and forwarding means must be sufficient to detach the yarn, which may be damp, from the delivery rollers. It-is desirable, however, to avoid imparting undue tension since theyarn, having recently emerged from the stretching operation is temporarily susceptible tovariatirms in its characteristics if too much tension is employed at this stage. To avoid these difiiculties, the yarn coming from the stretching operation may" be forwarded to the collecting device by means of a pair of intermeshing swifts i. e-. relatively large drum-like members whose surfaces are made up of a relatively small number of bars or ridges, the bars or ridges of one such member entering slightly into the spaces between thebars or ridges of theother. The swifts are driven with a pcripheraLspeed slightly greater than that of the rollers, so as to engage the damp yarn gently, but with suilicient firmness to prevent it lapping round the rollers, andforward it to the funnel oi the collecting device; The yarn coming from the intermeshing swifts is taken up by the liquid current passing through the funnel and is delivered to the rotating box as fast as it is receivedfrom the stretching operation.

By means of the present invention yarn cakes of substantial size may be produced. Thus cylin' drical'boxes measuring internally as much as 8 inches in height and 8- inches in diameter may be employed, rotating at a speed of 7000 R. P. and collecting a cake of yarn of 2 lbs; in weight. In order to give stability to largecakes of yarn thus formed, and alsoto facilitate the-uniform penetration of treating liquor during subsequent saponification of other liquid treatment, it is preferable to traverse the funnel up and down the axis of the collecting device at a rapid rate. For example, with a pot of the dimensions mentioned above the funnel may be traversed up and down once for every six to eight turns of yarn delivered to, the pot so giving an angle of wind on the outside of the package of the order of 4 /2-6" to the horizontal. Since the yarn coming from a stretching operation in which moist steam is employed is in a moist condition a smaller flow of liquid into the funnel is sufficient to carry the yarn in than if the yarn were completely dry. Thus while the flow of 30 cos. per minute may be sufficient for feeding moist yarn at a rate of 100 metres per minute, completely dry cellulose acetate yarn might require 10 times this amount or more.

The saponification of cellulose ester yarns in cake form while they are still contained in the pot is preferably effected during an operation subsequent to winding, the box being rotated at a speed lower than winding speed sufficient to cause the saponifying liquor to flow under centrifugal force through the yarn, but insuificient to compress the yarn against the outside of the box so as to impede such flow. The liquor may be introduced by means of a spray nozzle i. e. a tube closed at the end but Perforated over part of its length corresponding to the axial length of the cake. It is possible to saponify the yarn during the actual Winding operation by employing saponifying liquid to carry the yarn through the funnel into the box. This operation, however, has a tendency to produce irregular saponification on account of the fact that outer turns of yarns are subjected to treatment for a much longer period than the inner turns, while at the same time the treatment must be carried on for some time after winding is completed in order to complete the saponification of the inner turns. Saponification during winding may, however, be resorted to at the latter end of the winding operation, as an auxiliary to a subsequent s-aponification in which the box is rotated at a speed lower than winding speed. In this way the tendency of the outer turns of yarn to be over-treated when saponified during winding may be caused to counteract a tendency to undertreat them in a separate operation, due to .a slight weakening of the saponifying liquor on its way from the inside to the outside turns of yarn in the box.

In order to avoid a possible danger of the cake of yarn collapsing during saponification or other liquid treatment carried out on the yarn while it is in the box, some form of support for the yarn may be provided. For example the cake ma be held in place in the box by means of lease bands or cords passed through holes in the walls of the box, and threaded in and out of the yarn on the cake. Several of such bands e. g. siX, may be employed around the periphery of the box. Alternatively where the yarn is subsequently to be unwound with the aid of an expanding swift, the swift employed may be provided with a perforated hub or barrel (from which the arms of the swift extend) and the swift may be placed in position inside the cake of yarn prior to the liquid treatment. The perforation of the barrel of the swift enables the treating liquor to be fed inside the barrel, from which it emerges through the perforations in the form of a spray under the action of centrifugal force. After treatment the cake may be removed from the box on the swift .4 and unwound in the manner described above.

The expedient described above of inserting in the box means for supporting the cake of yarn wound therein, may be adopted for liquid treatments other than saponification, for example, a shrinking operation.

The accompanying drawings illustrate diagrammatically apparatus according to the invention and suitable for use in taking up and collecting cellulose acetate yarn as it comes from an operation in which it is stretched while in a softened condition and also for use in the subsequent saponification of the yarn.

In the drawings Fig. 1 shows the apparatus used for taking up and collecting the yarn Fig. 2 shows in detail the funnel forming part of the apparatus shown in Fig. 1

Fig. 3 shows the apparatus used in saponifying the yarn after winding.

Referring more particularly to Fig. 1 of the drawings, the apparatus shown comprises the end of a stretching tube I, stretching output rollers 3 and 4 mounted on shafts 5 and 6 and, beneath these rollers, a pair of swifts l consisting of a plurality of bars 8 mounted at their ends in cheeks 9 so shaped as to permit intermeshing of the swifts, the bars of one swift entering slight- 1y into the space between the bars of the other. Situated between the meshing point of the swifts l is the traversing funnel H the lower end of which is within the collecting box [2 carried on collar [3 attached to the shaft M of a spindle unit [5. The box I2 is provided with perforations I6. The traversing funnel II is carried on a support H which is traversed up and down the aXis of the collecting box 12 by cam l8 mounted on a shaft is. Water feed pipe 20 provided with a control valve 2| debits into a funnel ll. Referring more particularly to Fig. 2 the funnel II is shown as having conical walls 22 which slope steeply towards the tubular portion 23 thereof, namely at a semi-vertical angle of less than 35. The lower edge 24 of the tubular part 23 of the funnel is turned outwards smoothly so that said lower edge is rounded.

Referring to Fig. 3 the apparatus for use in the saponification of the yarn consists of the collecting box l2 carried upon the collar l3 secured to the shaft [4 of the spindle unit I5 as shown in Fig. 1. In addition, however, the collecting box is provided with an external catchpot 25 provided in the base with an outlet pipe 26 while the traversing funnel H and water feed 20 is replaced by a caustic soda feed pipe 2'! provided with a control valve 28 and having perforations 29 in the extremity within the yarn cake 3!] contained in the collecting box [2.

In operation the yarn 2 softened and stretched in the stretching tube l is drawn therefrom by the output rollers 3 and 4. The stretched yarn is drawn from the surface of roller l by tension exerted by the swifts l and positively fed forward to the traversing funnel it into which a stream of Water is passed from the water feed 20. The yarn and water pass through the traversing funnel and enter the collecting box 12 which is rotated at a speed of 7,000 R. P. M. by the spindle unit [5 while the traversing funnel is traversed up and down the axis of the box IE once for every six to eight turns of yarn delivered to the pot.

The rapid rotation of the collecting box causes the yarn with the water supplied with it to be flung by centrifugal force to the inside wall of the box where it accumulates in the form of a hollow cake of twisted yarn, the water passing out of the box through the perforations I6. By reason of the particular shape of the funnel H as shown very clearly in Fig. 2 no difficulty is encountered either in the initial threading of the funnel itself or during the building up of the cake of yarn, for example as a result of breaking of the yarn insid the box.

When a complete cake of yarn has been built up the supply of water from feed pipe is cut off and no more yarn fed to the collecting box. Thereafter lease bands 31 are threaded in and out of the yarn forming the cake and through the holes IS in the box l2, so as to secure the cake to the box. The yarn is then saponified using the apparatus shown in Fig. 3. For saponification with this apparatus the collecting box with the cake of yarn it contains is rotated at a speed of 500 R. P. M. by the spindle unit 15 while a 0.6% solution of caustic soda containing 10% of sodium acetate and maintained at a temperature of 60 C. is passed through pipe 27 into the interior of the collecting box 12. The solution emerges from the pipe 21 through the holes 29 in the form of a spray which settles on the interior of the cake of yarn 30 and passes through the cake by centrifugal force. From the outside layer of the cake the solution passes through the holes I6 in the collecting box into the catchpot 25, and is returned to a sump (not shown) by the pipe 26. After caustic soda has been passed for a sumcient length of time to effect the required saponification, water may be passed through the cake of yarn employing the same apparatus in order to wash the cake free from saponifying agent and soluble products of the saponification, and thereafter the cake may be removed for drying.

Having described our invention, what we desire to secure by Letters Patent is:

1. Method of taking up and collecting yarn as it comes from an operation in which it is stretched while in a softened condition, which comprises drawing th yarn from a point at which it is free from stretching tension and forwarding it by applying sliding friction in the direction of travel of the yarn to a point at which it is wound into the form of a cake, successive layers of said yarn being laid one inside the other by centrifugal force applied to the yarn.

2. Method of taking up and collecting yarn as it comes from an operation in which it is stretched while in a softened condition, which comprises drawing the yarn from a point at which it is free from stretching tension and forwarding it by applying sliding friction in the direction of travel of the yarn to a point at which it is wound into the form of a cake, successive layers of said yarn being laid one inside the other by centrifugal force applied to the yarn and the yarn feed being traversed up and down the axis of the cake so that each layer consists of three to four turns of yarn.

3. In the manufacture of artificial yarn of high strength taking up and collecting cellulose acetate yarn as it comes from an operation in which it is stretched while in a softened condition by drawing the yarn from a point at which it is free from stretching tension and forwarding it by applying sliding friction in the direction of travel of the yarn to a point at which it is wound into the form of a cake, successive layers of said yarn being laid one inside the other by centrifugal force applied to the yarn and the yarn feed being traversed up and down the axis of the cake so that each layer consists of three to four turns of yarn, and. subjecting the yarn in cake form to saponification by supplying a saponifying liquor to the interior of the cake during at least part of the Winding operation while the cake is rotated.

FRANK BRENTNALL HILL. EDGAR TOM HITCHIN.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,402,538 Rittenhouse Jan. 3, 1922 1,663,555 Jessen Mar. 27, 1928 1,677,940 Wagner July 24, 1928 1,739,458 I-Iazeley et a1. Dec. 10, 1929 1,779,313 Hegan et a1. Oct. 21, 1930 1,990,617 Sanders et al. Feb. 12, 1935 2,053,767 Dreyfus Sept. 8, 1936 2,073,839 Harrison et a1 Mar. 16, 1937 2,074,022 Oppenlaender Mar. 16, 1937 2,089,159 Dannenberg et a1. Aug. 3, 1937 2,223,914 Karns Dec. 3, 1940 2,227,355 Lawson Dec. 31, 1940 FOREIGN PATENTS Number Country Date 335,049 Great Britain Sept. 18, 1930

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