US2045377A - Manufacture of artificial materials - Google Patents

Description

June 23, 1936. I w. l. TAYLOR MANUFACTURE OF ARTIF Filed Oct. 26, 1952 ICIAL MATERIALS WILL/FM l- T Yl. 0R I YI/ENTOR Patented June 23, 1936 UNITED STATES MANUFACTURE OF ARTIFICIAL MATERIALS William Ivan Taylor, Spondon, near Derby, England, assignor to Celanese Corporation of America, a corporation of Delaware Application Octoberv 26, 1932, Serial No. 639,612 In Great Britain November 13, 1931 8 Claims. (o1. 18-8) This invention relates to the production of artificial filaments or the like especially by the dry or evaporative method, for example, the dry spinning of filaments of cellulose acetate or other derivatives of cellulose such as other cellulose esters, e. g. cellulose formate, propionate and butyrate, and cellulose ethers, e. g. methyl, ethyl and butyl cellulose. The invention consists in particular in an improved or modified apparatus for carrying out the process described in U. S. Patent No. 1,934,618.

According to the prior specification evaporative medium is introduced into the evaporative atmosphere of a dry spinning cell in the immediate vicinity of the spinning jet for the purpose of controlling the quality of the filaments extruded from the jet, various forms of apparatus for effecting this introduction being described in the specification.

The object of the present invention isto provide a simple apparatus by means of which the precise position with respect to the jet to which the evaporative atmosphere is injected into the cell, as well as the precise amount and nature of such injected atmosphere can be regulated in accordance with the particular requirements of any spinning operation and especially in accordance with the denier and rate of extrusion of the filaments.

According to one feature of the invention, a'conduit is arranged in the cell extending over a length covering, measured parallel to the direction of extrusion, the extremes of the positions in the vicinity of the spinning jet at which the evaporative atmosphere, usually air, is to be injected and a series of apertures is provided in the conduit through any of which the air to be injected near the spinning jet can be permitted to escape into the cell. Means are provided for closing such apertures as are not required for any particular denier or rate of extrusion, the closure means conveniently comprising apertured registers or caps adapted to be fitted over the apertures. The apertures'are conveniently in the form of slots which direct the air over the whole width of the space occupied by the bundle of filaments issuing from the jet. The slots may be formed in a cylindrical, rectangular, or other conduit of about the same width as the slots so as to'distribute air evenly over the length of each slot. Where caps are used to close such slot or slots as are not required, the caps may conveniently be carried by chains or the like which enable them to be sus-' pended in an accessible position.

Controlof the flow of the air through the conduit, which may either be effected by the suction usually employed to withdraw air from the spinhing cell or by pressure means adapted to force air through the conduit may be effected by valve or other means in the air connection to the conduit.

A simple form of control device which has the advantage of enabling any desired number of such injector devices to be supplied with the same quantity of air, as is required in dry-spinning apparatus in which a large number of cells are used to produce the same quality of filaments, consists in a screwed plug terminating the air supply pipe for the device, the plug being bored with an opening of predetermined size. supply of air to the pipe, the plug is conveniently located in a small chamber to which the air is supplied, the chamber being provided with a cover adapted to be moved to provide access to the plug. The plug may be formed as a nut or provided with a milled edge so that it can be readily removed for replacement by a plug having a different sized aperture. A needle-valve or other type of control device may, however, be used.

According to a further important feature of the invention, the conduit by means of which air is injected into the cell is made of such material and is of such configuration within the cell as to bring the air passing through the conduit to, or nearly to the temperature of the air in the cell before it is injected. For this purpose the conduit may be arranged to have a fairly long path within the cell and in addition may be of such form as to offer a large area for the exchange of heat in comparison with its cross section. Thus the conduit may have a flattened cross section, or it may be corrugated so as to present ridges to the air outside it or it may have to be finned or gilled to present additional surface. Or, again, the conduit may be annular in form so as'to present internal as well as external heating surfaces. Further means may be provided for heating the additional air, e; g. a heating jacket surrounding a coil in the air supply pipe outside the cell.

One or more of the devices according to the invention may be provided in each spinning cell, e. g. Where the spinning cell contains two spinning jets, two of the devices may be provided and arranged so that their apertures direct the air towards the jets. In order to provide ready access to the jets, the two devices may be placed in two corners of the cell adjacent to the door through which the jets may be reached. In this way the devices themselves are easilyaccessible for control of their apertures and yet do'not'prevent the jets For the from being attended to. If desired the control of the apertures may, however, be arranged to be effected from outside the cell. The apertured plugs by which the amount of air passing to each device is regulated are preferably arranged outside the cell.

The device according to the invention may be employed in connection with any suitable form of dry spinning apparatus and in connection with any desired means for supplying air to or circulating air through the spinning cell. For example, a device or devices may be employed in connection with cells in which a draw-off device is provided at or near the level of the jets to exhaust air from the cell or to produce a current of air through the cell. The airintroduced by the device or devices need not, however, be exhausted wholly at such point, but may be exhausted from some other point or points or partly from one point and partly from another, and may be used alike in apparatus for upward or downward spinning and having a counter flow of evaporative medium or a flow in the same direction as the filaments.

The invention will now be described in greater detail with reference to the accompanying drawing, but it is to be understood that this description is given by way of example only and is in no respect limitative.

Figure 1 is a side elevation in section of a spinning cell provided with air injection means according to the invention.

Figure 2 is an inverted sectional plan view of Figure 1.

Figure 3 is a rear View of the top of the spinning cell shown in Figure 1.

Figures 4 and 5 show two alternative methods of controlling the rate of air injection, and Figures 6 and 7 show two methods alternative to that shown in Figure 1 of combining the main air flow through the spinning cell with the air injection of the present invention.

Referring to Figures 1 to 3, a spinning cell I0 is provided with a pipe I l for the supply of spinning solution, the pipe ll leading the spinning solution through a filter candle l2 to a spinning jet l3. The filaments l4 extruded from the jet [3 pass down the length of the cell I0, round a guide rod I5, and out of the cell through an aperture l6. After leaving the cell, the filaments 14 pass over a wick I! by means of which a lubricant or other conditioning agent is applied to them, over a feed roller I8, and thence to the guide I9 of a cap spinning device 20 by means of which they are twisted, and wound on to a bobbin 20. A current of air enters the cell It] through an inlet pipe 23, passes up the cell and leaves through a draw-off pipe 24 conveying it to a header 25, the rate of flow through the draw-off pipe 24 being adjusted by means of a valve 26 and flow gauge means 27. A conduit 30 is arranged within the cell at about the level of the jet I3, the conduit being provided with apertures 3i, 32 by means of which air may be injected into the cell in the neighbourhood of the jet l3. The conduit 30 is provided from a pressure header 33 through branch pipes 34 and a control device 35 described'in greater detail hereafter.

The apertures 3|, 32, provide means for injecting air at any desired level, and, as will be seen, the two apertures 3| are shown to be closed by means of caps, while the third aperture 32, is open, the slot 37 through which the air passes being visible. A gauge 38 is provided in the header 33 in order to indicate the pressure of the shown in Figure 1 enables both jets l3 and both conduits 30 to be reached, the positions of the conduits not interfering with the accessibility of the jets.

As may be seen in Figure 2, the conduit 36 is of flattened cross section, in order to present a large surface to the warm air in the cell IE3. In this manner the temperature of the air injected is raised approximately to that of the cell. In addition, the conduit 30 may be made of a material of high heat conductivity, e. g. copper, the walls being as thin as is compatible with sulficiency of strength, in order further to assist the transfer of heat.

In Figure 4 the control device shown at 35 in Figures 1 to 3 is illustrated in detail. The pipe 34 leads the compressed air from the header 33 into a passage 40 opening into a chamber 45 which is closed by means of a cap 46 and a pack ing ring 41. The air passes from the chamber 45 to a passage 49 leading to the conduit 38 shown in Figures 1 to 3, but the rate of flow of the air from the chamber 45 is controlled by means of a screwed plug 50 having a precisely drilled orifice 5|. In order to vary the rate of flow of the air from the chamber 45, the cap 46 is removed and the plug 50 is replaced by a plug having a bore 5| of different size. In this manner the rate of flow of air into the cell in the neighbourhood of the jet can be readily and simply controlled.

An alternative control device is shown in Figure 5, wherein the passage of the air from the chamber 45 to the passage 49 is controlled by means of a needle valve 53 working against a seating 54. The needle valve 53 is operated by means of a rod 55 passing through a cover 56 closing the chamber 45, a suitable gland 51 being provided to keep the cover air-tight. The rod 55 screws into the cover 56 at 59 and is controlled by means of a knurled head 60.

In Figure 6, an air injection device according to the invention is illustrated in conjunction with means for passing a co-current of evaporative atmosphere through the spinning cell. The main current of air enters the cell through an inlet pipe 6| controlled by means of a valve 62, and leaves near the bottom of the cell by a draw-oil pipe 63 controlled by means of a valve 64 and pressure gauge 65, the evaporative medium leaving in this manner passing into a header 6B. conduit 30, nozzles 3|, 32 and associatedparts are of the type described with reference to Figures 1 to 3. In this figure, the heating eifect of the fiat conduit 40 is supplemented by a preheating device, consisting of a coil 61 in the air supply branch pipe 34, the coil 61 being enclosed in a jacket 68 through which passes a heating fluid by the connections 69, so that the air is heated before reaching the conduit 30.

In Figure 7 air enters by the bottom of the cell as described with reference to Figure 1, and the main current of air leaves the cell by means of a draw-off device 10 provided with control means similar to those described with reference to the draw-off device 24 of Figure 1. Opposite the The nozzles 3|, 32 mounted on the conduit 30 an additional draw-01f device 12 is provided, also controlled by means such as those described in connection with the draw-off device 24, the combination of the air injecting means 30, 3|, 32 and the draw-off device 12 inducing a current of air to cross the cell below the face of the jet 13.

What I claim and desire to secure by Letters Patent is:-

1. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passing a current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of which air may be injected as desired.

2. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passinga current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of slots through any of which air may be injected as desired in the form of a wide, flat stream to cover the whole width occupied by the bundle of filaments issuing from the jet.

3. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passing a current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of which air may be injected as desired, the said conduit being of such length, cross-section and material as to facilitate the transfer of heat from the spinning cell to the air passing through the conduit.

4. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passing a current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising a control for the additional evaporative medium in the form of a plug, bored with an opening of predetermined size, and readily exchangeable with plugs having openings of different size, and a conduit for the air passing through said plug, arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of which air may be injected as desired.

5. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passing a current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising two conduits disposed in. adjacent corners of the cell arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and each provided with a series of apertures through any of which air may be injected as desired.

6. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed therein, means for passing a current of evaporative medium through the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising means for heating the additional evaporative medium, a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of which air may be injected as desired.

'7. Apparatus for the production of artificial silk, comprising a spinning cell, a spinning jet disposed at one end thereof, means for introducing a current of evaporative medium at the end of the cell remote from the spinning jet, means for withdrawing said current at the end of the cell in which the spinning jet is disposed,

and means for introducing additional evaporative medium in the neighborhood of the spinning jet,

said means comprising a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of' which air may be injected as desired.

8. Apparatus for the production of artificial silk, comprising a spinning cell,- a spinning jet disposed at one end thereof, means for introducing a current of evaporative medium at said end of the cell, means for withdrawing said current at the opposite end of the cell, and means for introducing additional evaporative medium in the neighborhood of the spinning jet, said means comprising a conduit arranged within the cell extending over a length covering the extremes of the positions at which the additional evaporative atmosphere is to be injected and provided with a series of apertures through any of which air may be injected as desired.

WILLIAM IVAN TAYLOR.

Images