US2045326A - Manufacture of artificial filaments and similar materials - Google Patents

Description

June23,1 936. EHKINSELLA 2,045,326

MANUFACTURE OF'ARTIFICIAL FILAMENTS AND SIMILAR MATERIALS Filed Feb. 27, 1955 ""FlQlw WS AHormusg Patented June 23, 1936 ATENT oFFicE MANUFACTURE OF ARTIFICIAL FILAMENTS AND SIMILAR MATERIALS Application February 2'7, 1933, Serial No. 658,781 In Great Britain March 12, 1932 3 Claims.

This invention relates to the manufacture of artificial materials and in particular to the manufacture of artificial filaments and similar products by the extrusion of a spinning solution into 5 a setting medium. In such operations, and especially in the production of artificial filaments or the like by the dry or evaporative method, in which case the spinning solution usually consists of cellulose acetate dissolved involatile solvents such as acetone, it is important to control the temperature at which the solution is extruded through the spinning jets into the setting medium. 7

It is however a matter of considerable difficulty l-o to apply a heat exchanger for the purpose of controlling the temperature of the solution because of several considerations. In the first place, a spinning machine usually consists of a large number of units, allof which are required to produce the same kind and quality of product and therefore are required to work under precisely similar conditions. Consequently any heat exchange for the control of the temperature of the spinning solution in any of these units should be the same as that taking place in all the other units of the machine. This consideration necessitates the provision of a common supply of attemperating medium for all the units so that conditions between unit and unit may be maintained constant. At the same time it is of particular importance that the heat interchange be effected as close as possible to the point of extrusion so as to avoid the spinning solution being affected by extraneous influences after having been brought 35 to the required temperature. A suitable point for controlling the solution temperature is at the filter for the spinning solution, which, in the case of dry-spinning apparatus, is most usually in the spinning cell immediately before the jet. A heat exchange device applied at this point has the advantage that access to the spinning jet can remain unrestricted, so that the periodical changing of the spinning jet for cleaning purposes or for replacement by a jet having holes of different sizes or with a'difierent number of holes can readily be effected.

It is, however, necessary to clean the filters fairly frequently, and this necessitates the removal of the whole or part of the filter body. The object of the present invention is to provide an attemperating device which does not interfere with cleaning of the filter orwith the accessibility of the jet vicinity.

The device according to the invention comprises a member adapted to be secured about the filter body preceding the jet, and to be supplied with a heating medium, or, if desired, a cooling medium, while being capable of removal from the filter body without the necessity for breaking its connection with-the supply of heating. or cooling 5 medium. Thus, for example, the device may comprise a cylindrical jacket adapted to be slipped over a cylindrical filter body to make close contact therewith, pipe connections being provided on the jacket for connection to the, supply and 10 discharge means for fluids such as steam or water. The jacket may be made a sliding fit on the iilter body so that it can be held in place, for example by friction, or, if desired, additional means such as a binding screw or clamping plate may be pro- 15 vided so that the jacket may be held securely in position.

If the connecting means for the steam or water are made in the form of flexible tubes, the jacket may be slipped from the filter body and left on one side for removal of the whole or part of the filter for cleaning purposes, the supply of steam or Water thus not being interfered with. In this way removal or replacement of the jacket may be effected in a very short space of time, thus facilitating attention to the filter while not interfering with the flow of the attemperating medium.

' It is usual for the diameter of the filter body to exceed that of the jet fitting, and the jacket may thus be slipped over the jet fitting. Instead of a jacket a coiled pipe may be employed, this pipe being conveniently formed as a helix adapted to surround the filter body closely.

A similar arrangement may be employed but using electrical heating means adaptedto surround the filter body closely, and again flexible connections may be provided, allowing the device to be removed and replaced without disconnection.

In order to secure the maximum effect from the attemperating medium the device, whether supplied with a fluid medium or whether heated by electricity, may be surrounded by lagging which conveniently forms an integral part of the device so as to be removed and replaced there- 45 with. 1

Where a fiuid attemperating medium is employed, the supply is conveniently efiected by large capacity conduits serving a series of spinning jets, or if desired the whole of the jets of 50 the spinning machine, two such conduits being provided, one for delivery of fluid and the other for carrying away fluid which has passed through the jackets. The fiuid is preferably carried through these conduits at a high rate so as to avoid as far as possible substantial temperature changes along the length of the conduit in order to ensure equality of temperature conditions between all the spinning jets. The device according to the invention need not be secured to a filter body. Thus, the spinning solution may be caused to pass through a pipe, preferably of large crosssection, before reaching the jet, and the device may be attached to this pipe so as to heat the solution and yet be capable of ready removal when required.

As has been stated above, the attemperating device according to the invention is particularly applicable to. the spinning of artificial filaments and the like from cellulose acetate by the dry or evaporative method. It may also be employed in the production of filaments or the like from other cellulose derivatives, for example other cellulose esters such as cellulose formate, propionate, and butyrate, or cellulose ethers such as ethyl and benzyl cellulose.

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

Figure 1 is a side elevation in section of a spinning cell provided with apparatus according to the invention;

Figure 2 is a large scale part sectional plan view of the apparatus shown in Figure 1 taken along the line 22; and

Figure 3 is a front elevation of a metier comprising a plurality of spinning cells of the type shown in Figures 1 and 2.

- In Figure 1 a spinning cell 4 is provided with a filter candle 5 carrying a spinning jet 6. The filter candle 5 is enclosed by a jacketed vessel I which is supported by spring clips 8 bearing upon the upper flange of the candle. Hot water from a conduit 9 passes through a valve I0 and a flexible tube II to the jacket I, a pipe I2 being provided within the jacket to deliver the hot water at the top of the jacket. The hot water flows around the jacket and leaves by a pipe I4 and valve I5 conducting it to a conduit I6. A pocket is provided in the filter candle 5 to receive the tube of a thermometer II, a suitable slot being provided in the vessel I for this purpose. By this means the temperature of the interior of the filter candle may be observed.

As shown in Figure 2, the hot water entering by the pipe I2 is constrained to flow completely round the jacket, to the outlet pipe I3 by a baffle I8 which prevents the direct passage of the water from the pipe l2 to the pipe I3. The vessel I is surrounded by lagging 2|, which is secured to the vessel, and removable therewith from the filter candle 5.

As shown in Figure 3, a plurality of spinning cells 4 are served by the supply pipe 9 and the exhaust pipe IS, the supply pipe drawing hot water from a supply header I9 while the exhaust pipe I6 delivers to a return header 20. In this manner the rate of flow through each of the vessels I is maintained equal. The temperature of the fluid supplied to the different vessels I is maintained substantially equal by providing for a rapid rate of flow of hot water through the systom, the conduits 9, I 6 being of large bore, so that the temperature drop along their length is small.

It will be seen that when it is necessary for the filter candle 5 to receive attention, the vessel I may be slipped off the candle, and passed over the jet 6, which is of slightly smaller diameter than the candle, without breaking the connection made by the pipes II and I4. Subsequently the vessel I can equally easily be returned to position.

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

1. In apparatus for the manufacture of artificial filaments and similar materials by dry spinning processes, means for attemperating the spinning solution comprising in combination a filter body through which the spinning solution passes immediately prior to extrusion, and a hollow member adapted to surround at least in part the filter body, means for removably securing said member about the filter body, a pipe for supplying an attemperating fluid to the hollow member, and a pipe for removing said fluid after circulation through the member, said pipes being flexible to permit of removal of the member from about the filter body without interrupting the cir- 30 culation of the attemperating fluid.

2. For use in a dry spinning process wherein the spinning solution passes through a filter body immediately prior to extrusion, a hollow body adapted to surround at least in part the filter body, means for removably securing said member about the filter body, a pipe for supplying an attemperating fluid to the hollow member, and a pipe for removing said fluid after circulation through the member, said pipes being flexible to permit of removal of the member from about the filter body without interrupting the circulation of the attemperating fluid.

3. In apparatus for the manufacture of artificial filaments and similar materials by dry spinning processes, a plurality of spinning jets, means, including a filter body, for supplying spinning solution to each jet, and means for attemperating the spinning solution immediately prior to extrusion, said attemperating means comprising, in combinationwith each jet, a hollow member adapted to fit round at least part of the filter body and to be readily removable therefrom, a common conduit for supplying an attemperating fluid to the hollow members, a further common conduit for returning said fluid from said hollow members,andflexiblesupply and return pipes connecting said hollow members in parallel with said supply and return conduits so as to provide for the circulation of attemperating fluid through said hollow members while allowing of the ready removal of any member from the corresponding filter body without interrupting the circulation of the attemperating fluid.

EDWARD KINSELLA.

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