US3521324A

US3521324A - Wet-spinning system for fibers with multiple-hole spinnerets

Info

Publication number: US3521324A
Application number: US683654A
Authority: US
Inventors: Walter Hartmann
Original assignee: Filmfabrik Wolfen VEB
Current assignee: Filmfabrik Wolfen VEB
Priority date: 1967-03-02
Filing date: 1967-11-16
Publication date: 1970-07-21
Anticipated expiration: 1987-07-21
Also published as: GB1178445A; DE1660683A1; NL6709342A

Description

July 21, 1970 w; HAR I 'MANN' WET-SPINNING SYSTEM FOR FIBERS WITH MULTIPLE-HOLE SPINNERETS Filed Nov. 16, 1967 2 Sheets-Sheet l I III [llll FIGQ2 FIG. 1

INVENTOR WALTER HARTMANN July 21, 1970- w. HARTMANN WET-SPINNING SYSTEM FOR FIBERS WITH MULTIPLE-HOLE SPINNERETS Filed Nov. 16, 1967 FIG. 3

2 Sheets-Sheet 2 'INVENTOR .WALTER HARTMANN 3,521,324 WET-SPINNING SYSTEM FOR FIBERS WITH MULTIPLE-HOLE SPINNERETS Walter Hartmann, Wolfen, Germany, assignor to VEB Filinfabrik Wolfen, Wolfen, Germany Filed Nov. 16, 1967, Ser. No. 683,654 Int. Cl. mud 3/00 US. Cl. 18-8 5 Claims ABSTRACT OF THE DISCLOSURE A wet-spinning system for the spinning of fibers with multiple-hole spinnerets, comprising a delivery pump for the spinning solution, a filtering device vertically arranged on said pump, a casing for housing said filtering device, a jacket at least partly enclosing said cas a detachable rotatable and vertically slidable'tube for receiving a precipitating bath for said spinning solution, for fiber formation therefrom upon emergence of the spinning solution from the spinneret.

In the art of providing spinning systems for the wetspinning process it was felt to be advantageous to design a closed unit for every spinneret, because such an arrangement permits to utilize the spinning bath very effectively, to control the flow in such a manner that it will aid the fiber formation, and to remove the harmful gases formed during the spinning process in a more eflicient manner.

An arrangement is already known, in which a spinneret is placed in a spinning pot or bucket and a spinning tube is removably attached on the same. An elastic hose connects thespinning tube to an overflow, said hose effecting the detachable connection with the spinning bucket and aremoval of the spinning tube in such a manner that the spinneret is made accessible and can be exchanged. The spinning solution passes from a filtering device to the spinneret through a tube.

This arrangement has the disadvantage that upon detachment of the spinning tube from the spinning bucket the elastic connection undergoes increased Wear on the one hand by being subjected to bending and twisting stress, on the other hand due to chemical attack so that it becomes necessary to exchange this part quite frequently. Another factor is the difliculty of proper sealing between spinning tube and bucket, since for sealing the parts a certain turning is necessary upon locking them together and there is a limit due to the pliability of the elastic part. 7

A further drawback of the known devices, particularly with the use of large spinnerets, is the fact that the spinning solution is passed through a restricting tube to the spinnerets after filtration. At that time, air occulusions in the spinning solution may occur in the spinning chamber which occlusions are especially disadvantageous for the spinning process at the start.

It is the object of the present invention to provide a device which permits to avoid the above-mentioned shortcomings and which will function effectively and safely.

It is another object to provide a device which makes it possible to obtain fibers of fine titer even when using multiple hole spinnerets.

It is yet another object to provide a device which facilitates the spinning at the start of the operation and which makes exchange of parts in one unit possible Without interrupting the operation of other units.

Other objects and advantages will become apparent from the following detailed description and the drawings.

With the above objects in view, the invention is concerned with the combination of a filtering means, a spinneret and a precipitating bath tube to an easily and effectively operating device.

United States Patent 0 p CC Such a device is provided according to the invention by arranging a filtering device vertically upon a spinning pump on which it is secured. The filtering device has a casing which is provided partly or completely with a double wall, to which a superposed tube conveying the precipitating bath liquid is detachably connected; the tube is slidably arranged for vertical displacement in the direction of flow. A spinneret is mounted on the exit opening of the casing.

The double wall of the filter casing forming a jacket is arranged to surround the same completely when a rise in temperature of the spinning solution occurs shortly before the spinning process starts. If no additional heat ing of the spinning solution is necessary, the jacket will preferably be provided only in the upper third of the filtering device.

The tube for the precipitating bath is detachably connected with the jacket and is rotatably and slidably mounted by means of an overflow device. Thus this device serves for holding and guiding the bath tube, during the exchange of spinning nozzles, since at that time the connection with the jacket of the filtering device is interrupted. The filter, the bath tube and the overflow means are made of suitable plastic materials in order to make them lighter in weight and less liable to chemical attack. Thus the filtering device may be made of epoxy resin, the tube of the precipitating bath of polyvinyl chloride or epoxy resin, and the overflow means of polyvinyl chloride.

The device according to the invention has the advantage that no air occlusions can be present in the spinning chamber. The spinning becomes safer due to the immediate passage of the spinning solution from the filter space through the holes of the spinneret into the precipitating bath. Another advantage consists of the vertical slidability of the bath tube, whereby the nozzle becomes easily exchangeable, without the material of the bath tube being subjected to additional strain. Furthermore, the entire spinning device is easily exchangeable with few technical manipulations and without interruption of different spinning units of which the spinning system is built up during the spinning process becoming necessary.

The spinning device according to the invention will be more fully explained with reference to the accompanying drawings.

In the drawings,

FIG. 1 illustrates the overall arrangement of one embodiment of the spinning device, showing two of the spinning units side by side, the unit on the left-hand side in operation, and the unit on the right hand side during exchange of the spinneret;

FIG. 2 is a longitudinal section through the lower portion of the left-hand unit of FIG. 1 on a larger scale;

FIG. 3 is a longitudinal section through the upper portion of the unit shown in FIG. 1, left hand side likewise on a larger scale;

FIGS. 4 and 5 are horizontal sections on lines 4-4 and 55 of FIG. 3, respectively.

Referring first to FIGS. 1 and 2 of the drawing, I shows a base for mounting the spinning units; arranged at the bottom is a pump 1a for delivery of the spinning solution to a filtering'device generally designated by 10, and comprising the filtering means 2 and a casing therefor designated by 3; between the surface of the filtering means 2 and the casing 3, a space 19 is provided for passage of the spinning solution delivered from the pump to the inside of filter 2 and from there to the spinneret designated by 5 and attached on the exit opening of casing 3 by a screw connection 6. For the upper portion of casing 3a jacket 4 is provided to which a tube 7 is detachably connected, the latter serving for the admission of a precipitating bath liquid and hereinafter called the bath tube. Tube 7 is funnel-shaped in its bottom portion where the 3 precipitating bath is received; during operation, this portion is attached to the jacket 4 by way of screwing connection with the interposition of sealing means 7a. This funnel-shaped portion merges into a tubular upper portion 7b which extends upward for a considerable length, as illustrated in FIG. 3.

The means for admission of the precipitating bath liquid to the spinning unit comprises a conduit 8 issuing from a source of bath liquid (not shown); the conduit leads to a tube 18 directly connected with it and through there to a space 4a between walls of the jacket 4 and through openings 4b into the bath tube 7. In tube 18, a valve 9 is provided for regulating the flow of the bath liquid.

The device further comprises a stretching trough 11 ararnged above bath-tube '7 and capable of receiving the tubular upper portion 7b of said tube when it is to be detached from the wall of jacket 4 for spinneret exchange. The trough 11 has a cover plate 13 with a central opening through which the upper portion 7b of the bath tube is vertically slidable.

The last unit in the vertical arrangement is an overflow vessel 12 which is generally shaped in the form of a container but having a fairly large opening in the bottom through which a sleeve 30 is passed extending downwardly thorugh the central opening in plate 13 and upwardly into the interior of vessel 12; this member is a mounting means for tube 7b which is flanged at 38 and engages with the upper rim of sleeve 30 when in operating (bottom) position. Vessel 12 is further provided with a discharge tube 31 serving for draining the excess amount of bath liquid and for returning it by means of a return conduit 28 (FIG. 1) to a reservoir (not shown). This may be the source from which conduit 8 feeds bath liquid to bath tube 7 as described above.

Vessel 12 is provided with a lid 32 having a central hole 33 (FIG. 3). The vessel is mounted on plate 13 by means of

brackets

34 and 35, which are connectible by a screw connection 36 (FIG. 1) thereby providing connection of vessel 12 to trough 11.

Toward the bottom end of the tubular portion 7b of bath tube 7, projections 16 are provided which are capable of engagement with supporting brackets 17 on trough 11; this arrangement serves for holding the bath tube in raised position at the time of nozzle exchange.

In operation, the spinning solution is forced by means of pump 1a through filter 2 into the space 19 and from there through the holes of spinneret into the funnelshaped portion of bath tube 7, which acts as a spinning chamber. The precipitating bath liquid arrives over conduit 8 and valve 9 into the space between the walls of the jacket 4 and from there through openings 4a and 41) into the spinning chamber, where fibers 40 are formed; by a withdrawal means (not shown) the fibers 40 are taken up and carried through the exit opening of tube 7b to further processing. The excess bath liquid escapes through tube 31 to the return conduit 28 and from there to the reservoir mentioned before.

For the exchange of the spinneret unit 5, tube 7 is lifted until the projection 16 engages with the brackets 4 17 on trough 11. At the same time the flanged portion at the top of tube 7b slides beyond the top of member 30. The bath tube is held in lifted position by the engagement of

members

16 and 17 until the exchange of the spinneret has taken place. The other unit or units can in the meantime continue to operate without interruption.

For returning'the bath tube into operating position, the

members

16 and 17 are disengaged and the tube of the precipitation bath will be secured. The bath tube is lowel'ed into the position shown at the left hand side of FIG. 1 and ready for renewed operation.

What is claimed is:

1. Wet-spinning system for the spinning of fibers with a multiple-hole spinneret, comprising a delivery pump for a spinning solution, a filtering device vertically arranged on said pump, a casing for housing said filtering device, said spinneret having substantially the same horizontal cross-sectional area as that of said casing and being detachably mounted on the top edge of said casing, a jacket circumferentially enclosing said casing for providing a coaxial space therearound, means for feeding a precipitating fluid into said coaxial space, a vertical tube detachably mounted and hermetically sealed on top of said jacket for receiving said precipitating fluid from said coaxial space, for fiber formation upon emergence of the spinning solution from said spinneret; said tube being vertically movable from a first position in contact with said jacket to a second position detached therefrom.

2. The spinning system as claimed in claim 1, further comprising in vertical alignment with the tube a stretching trough and an overflow vessel thereabove, said tube slidably passing through the bottom of said through into said overflow vessel, and disconnectable holding means for holding said tube in said second position during spinneret exchange.

3. The spinning system according to claim 1 wherein said means for feeding the precipitating fluid comprise a conduit means communicating with said coaxial space and provided with a control valve.

4. The spinning device according to claim 2 wherein said overflow vessel is provided with a double-wall bottom portion, the outer wall of said bottom portion being pro vided with a discharge conduit.

5. The spinning device according to claim 2 wherein said holding means comprise a first holding part mounted on said tube and a second holding part mounted on said trough, said tube further being rotatably movable for mutually engaging said first and second holding parts in said second detached position of the tube.

References Cited UNITED STATES PATENTS 5/1961 Edwards et a1 188 8/1962 Soehngen 188