US2182540A - Apparatus for making artificial silk - Google Patents

Description

Dec. 5, 1939. J. L. HUTCHINGS I APPARATUS FOR MAKING ARTIFICIAL SILK Filed May 11. 1938 2 Sheets-Sheet 1 Dec. 5, 1939. J. L. HUTCHINGS APPARATUS FOR MAKING ARTIFICIAL SILK '2 Sheets-Sheet 2 Filed May 11, 1958 Patented Dec. 5, 1939 STATES OFFICE APPARATUS FOR SMAKING AR'HFI Application May 11, 1938, Serial No. 207,359

2 Claims.

This invention relates to apparatus for and methods of manufacturing artificial thread, for instance rayon or artificial silk, and particularly to methods of and apparatus for treating tubu- 6 lar packages or cakes formed of artificial thread in what is known as a spinning pot.

In the manufacture of rayon a viscose solution is pumped through spinnerettes, congealing as it passes through a coagulating bath, then 10 passing over a godet or godets and is conducted into the entrance end of a spinning pot funnel, the opposite end of this funnel having an opening disposed on the axis of the spinning pot or bucket, which pot or bucket is rotated at high velocity. The thread passing through the spinning pot funnel is thrown outwardly after leaving the funnel against the inside Wall of the rapidly rotating spinning pot, owing to the action of centrifugal forces, the thread being given at the same time the desired twist. The funnel through which the thread is passed has an oscillating motion in a vertical path and this motion is controlled so as to cause the thread to be disposed uniformly over the inside surface of the spinning bucket. Gradually a tubular package or winding of thread is thus built up within the bucket, this package being generally designated in the art a spun yarn cake. 1

After the cake has been has been completed it is removed from the spinning bucket and is ready for further treatment. The completed cake, ready for such further treatment, has a wall thickness of approximately three-fourths of an inch and has the general appearance of the frustrum of a hollow cone. Before the spun yarn cake is subjected to any further treatment, such as washing, bleaching, dissulphuring. etc. for the removal of various salts and acids which it may contain, it is generally wrapped with a fabric member or an elastic fabric stocking to protect it from abrasion in further handling. The cake as thus wrapped is then placed in an apparatus for performing the operations of washing, bleaching, dissulphuring and soaping. After having been washed it is sometimes subjected to a hydroextracting operation to remove excess liquid, prior to being subjected to the final drying operation. In the drying operation the thread tends to shrink and unless pro- 50 vision is made to relieve the tension in the thread prior to placing the cake in the drier, a serious difliculty is met with in that the yarn from the inside of the spun cake does not color as uniformly as that upon the outside of the cake. This inequality in covering during the dyeing operation is attributed to the fact that the yarn at the inside of a spun cake is free to shrink, without being unduly tensioned, whereas the outside strands are placed under considerable tension in the process of drying, these 5 strands being supported by the strands directly beneath them while drying and hence being prevented from contracting. It is believed that the excessive tension to which the outermost strands of the cake are subjected causes the 10 formation of hard spots in these strands or filaments which in turn results in non-uniform dyeing.

Various means for and methods of dealing with this difflculty have heretofore been designed it or suggested. It has been suggested for instance that by deforming the cake by the application of mechanical means applied radially thereto, so as to form a number of spaced indentations extending inwardly, the outer strands or convolugo tions of thread will be provided with a sumcient amount of slack to prevent excessive tensioning due to shrinkage upon drying. The purpose of the present invention is to provide an improved method of and apparatus for treat- 5 ing cakes or packages of artificial thread in such manner as to provide the necessary slack in the outer convolutions but without deforming the cake in a substantial manner as heretofore, the cake retaining substantially its smooth, frus- 3e toconical inner and outer surfaces. The apparatus and method comprising the present invention likewise are useful in the formation of a spun yarn cake in which the threads are crinkled or serpentine in form, which configura- 35 tion of thread is highly desired for certain purposes. Every convolution or strand of a cake of thread subjected to theoperation of the apparatus is crinkled uniformly throughout its length and enough slack produced in every increment of length to enable the thread to shrink when dried without being tensioned.

A further advantage of the invention resides in the fact that hydroextraction is or may be accomplishedat the same time that the thread is crinkled and provided with slack. If it be preferred, however, to employ the centrifugal method of hydroextraction, the method used in placing the slack in the strand of the yarn cake automatically reduces the cake in diameter so that it may be readily placed in the smaller diameter hydroextracting bucket and the operation of hydroextraction carried on in the centrifugal manner.

The apparatus employed in the practice of the improved method is of the simplest character. It comprises essentially a tubular mandrel having a diameter slightly less in length than the inner diameter of the tubular cake which is to be contracted, together with fluid pressure actuated means for acting on and contracting the cake so that it closely engages the mandrel. This means may be caused to function either by creating a greater than atmospheric pressure against one side, or a sub-atmospheric pressure against the other side thereof. In the first case means is provided for supplying a pressure chamber with a fluid under pressure and when such fluid is introduced it deflects a flexible inner wall of the chamber radially inward toward the mandrel so that this flexible wall contacts with and bears against all areas of the outer surface of the yarn cake interposed between the mandrel and chamber. The pressure may be increased at thewill of the operator to any desired extent and a pressure is employed which is sufficiently great to cause the diametric contraction of the cake, the inner diameter of the cake being shortened until the inner surface thereof lies snugly against the surface of the mandrel. During this operation all thread convolutions of the cake are contracted circumferentially and all individual convolutions are crinkled or rendered serpentine in configuration, for the purpose specified. In the second case a vacuum pump may be employed to create a sub-atmospheric pressure within the mandrel, which causes said means to move in its cake compressing direction.

Two embodiments of the apparatus are illustrated in the accompanying drawings by way of example but it will be appreciated that further variation in design and construction of the component elements of this apparatus may be freely made without departure from the invention.

In the drawings:

Figure 1 is a section through the axis of the mandrel used with one form of the apparatus and also through the axis of the encircling pressure chamber, these two members being coaxial, showing a cake positioned to be acted upon intermediate the mandrel and pressure chamber;

Figure 2 is a similar view showing the movable wall of the pressure chamber, and the work or spun yarn cake, in the positions which they occupy at the conclusion of the compressing operation;

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a perspective view of a spun yarn cake, portion of the fabric wrapping being broken away to disclose the outer convolutions or windings of thread;

Figure 5 shows in elevation portions of cer tain surface convolutions of a thr d or yarn cake before the cake is subjected o the compression operation;

Figure 6 is a similar view showing these convolutions after the cake has been compressed in the specified manner;

Figure 7 is a section similar to that of Figure 1, taken axially through an apparatus of the suction type; and

Figure 8 is a section on line 8-8 of Figure 7.

The apparatus comprises essentially a suitably supported base which is indicated at 10 in the drawings and which may conveniently be in the form of a disc having a central hub l0 provided with an aperture for the reception of sliding rod II. The pressure chamber may conveniently be annular as shown and in the form of the chamber illustrated comprises an outer cylindrical wall l2 having horizontal flanges l2 and I: extending inwardly, so that the wall I 2 may be said to be channel-shaped in vertical cross-section, and a flexible inner wall 13 which is in the nature of a diaphragm, being preferably formed of gum rubber. The flexible wall 13 is tubular and its upper end extends outwardly over the annular flange I2 being retained between that flange and a clamping ring II, this ring being secured to flange I 2 by means of screws such as indicated at IS. The lower margin of the flexible wall l3 likewise extends outwardly and is retained between the upper surface of the base I 0 and the annular lower flange I! of the pressure chamber wall l2, flange l2 being secured to base ID by screw bolt Hi.

Secured to the upper end-of the vertically slid able rod- II, at a point above the base "I, is a disc 20, the periphery of this disc being grooved on its underside to receive an annular shoulder I0 integral with and projecting upwardly from the base. Shoulder I0 likewise comprises means for definitely locating the pressure chamber I2 coaxially with the base 10, when the parts are being assembled. The mandrel is indicated at 2| and is seen to comprise a tubular member dis-- posed coaxially with the base and with the pressure chamber, this mandrel having a peripheral flange at its upper end, portion of which lies in the plane with the flange l2 of the pressure chamber, and portion of which overhangs the pressure chamber so that, by means of rods 22, which pass through aligned apertures in the outer margin of the base Ill and the outer margin of this mandrel flange, and wing nuts 23, the mandrel may be rigidly but detachably secured to the base.

It will be perceived that the outer surface of the tubular portion of the mandrel tapers downwardly and that the inner surface of the flexible wall is of the pressure chamber is correspondin ly tapered. In the space intermediate the mandrel 2| and the flexible wall l3 may be positioned the spun yarn cake, generally indicated at C, this cake having its annular lower edge surface resting upon the plate or disc 20 and its upper annular end surface lying quite close to, even actually in contact with, the undersurface of the mandrel flange which is disposed directly above it. It will be perceived that the cake C is in the form of a hollow frustrum of a cone and that its inner and outer frustoconical surface have the same angularity as those of the mandrel and inner wall of the pressure chamber. A conduit or pipe for introducing fluid into the pressure chamber is indicated at 25 and a fluid escape conduit at 26, conduit 25 being provided with a control valve 2? and conduit 26 with a control lalve 28.

The mandrel has formed therein a plurality of radially extending apertures 30 to permit liquid expressed from. the cake C to pass into the interior of the mandrel and the disc 20 is provided with one or more apertures 3| to permit such exand 3, with a cake C intermediate the mandrel and the flexible wall IS, the valves 21 and 28 may be opened and water or other fluid allowed to flow into the pressure chamber. After the chamber has been filled valve 28 is closed to prevent further escape of liquid but valve 21 allowed to remain open to admit further quantities of liquid under the desired pressure. This pressure acts upon the movable wall iii of the pressure chamber and deflects this wall'inwardly into contact with the outer surface of the tubular cake 0. Continued application of the pressure in sufflcient amount causes the wall ill to exert suflicient pressure upon the outer surface of the cake to" radially and circumferentially contract this cake,

the pressure being maintained until the innerwall of the cake is in full contact with the outer surface of the mandrel 2|. Such moisture as is expelled from the cake during the application of this pressure will flow through apertures 30 in the mandrel and escape in the manner previously described.

After the cake has been fully compressed the valve 21 may be closed and valve 28 opened, thus permitting the fluid within the pressure chamber to escape to a certain extent and the flexible wall I3 to resume the position in which it is shown in Figure 1. The wing nuts 23 may then be loosened and the mandrel 2| lifted and placed to one side. Thereafter the rod 2| and disc 20 may be lifted, elevating the cake C into such position that it may readily be grasped by the operator. A fresh cake may be placed on the disc 20, the mandrel replaced, and the operation repeated.

Prior to this diametrical and circumferential compression of the cake C its threads have the appearance of those shown in Figure 5, whereas after the compression operation has been carried out, these threads will have somewhat the appearance of those shown in Figure 6, being longitudinally compressed and crinkled" or rendered serpentine, the advantages of which thread formation have been heretofore described.

The embodiment of the apparatus shown in Figures '7 and 8 includes the major features of the apparatus illustrated in Figures 1 to 3 inclusive, but here the movement of the cake compressing member or rubber diaphragm Ill is brought about by reducing the pressure within the mandrel 4| instead of increasing the pressure on the outside of the diaphragm as before. It will be perceived that the hollow tubular portion of the mandrel is closed by the web 4| and that the diaphragm supporting member 42 is provided with openings 42' so that the outer surface of the diaphragm is always subjected to atmospheric pressure. The mandrel wall is perforated as before and the disc 43 is likewise perforated, as at 43'. An aperture 44' in base 44 is in communication with a conduit 55 having a branch 56 leading to a water separator and vacuum pump and a branch 51 leading to the atmosphere, these branches being controlled by valves 56' and 51' respectively. By closing valve ,51' and opening valve 56' a sub- I atmospheric pressure may be established within the mandrel and within the diaphragm 40 so that the cake is compressed on the mandrel by inward movement of the diaphragm 40 under the external pressureof'the atmosphere. A pressure gauge is indicated at 60 and a packing around rod 6| is indicated at 62, this packing preventing drawn without exerting an unduly high mechanical pressure upon its outer strands or convolutions, which is undesirable, and the degree of moisture extraction may be such as to make unnecessary further water extracting operations, such as an extraction by the centrifugal method, thus simplifying the process as a whole and lowering the cost. The extracted water or other liquid is of course withdrawn from the cake through the apertures in the mandrel and passes downwardly through pipe 56 to a water and gas separating device.

If desired the cake to be treated may be subjected to internal suction and positive external pressure simultaneously by applying a greater than atmospheric fluid pressure to the outside of the diaphragm and establishing a sub-atmospheric pressure within the diaphragm and mandrel. The fluid used in creating a pressure upon the outside of the diaphragm may be either a liquid, such as water, or a gas, such as air. Obviously the details of design of the various elements of the apparatus may be considerably modified without departure from the invention.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for use in the manufacture of artificial thread including a tubular mandrel, and a pressure chamber encircling the mandrel, the inner wall of the pressure chamber being spaced from the mandrel surface to permit introduction of a tubular thread cake between said wall and the mandrel, said wall comprising a flexible diaphragm adapted to engage all surfaces of the cake when deflected inwardly by increase in pressure in said chamber.

2. The combination set forth in claim 1 in which the inner wall of said chamber comprises a tubular member of rubber.

JOSEPH LYALL HU'I'CHJNGS.

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