US2799895A

US2799895A - Spinning apparatus

Info

Publication number: US2799895A
Application number: US320219A
Authority: US
Inventors: Elssner Richard
Original assignee: American Enka Corp
Current assignee: Akzona Inc
Priority date: 1951-11-17
Filing date: 1952-11-13
Publication date: 1957-07-23
Anticipated expiration: 1974-07-23
Also published as: CH308529A; BE515565A; FR1066569A

Description

y 1957 R. ELSSNER 2,799,895

SPINNING APPARATUS Filed Nov. 15, 1952 INVENTOR.

BY 5M W1 M 2,799,895 Patented July 23, 1957 Free SPINNING APPARATUS Richard Elssner, Randerath, near Aachen, Germany, assignor, by mesne assignments, to American Enka Corporation, Enka, N. C., a corporation of Deinware Application November 13, 1952, Serial No. 320,219 Claims priority, application Germany N overnher 17, 1951 3 Claims. (Cl. 18-8) The present invention relates to a process and apparatus for spinning viscose, and more particularly to a process and apparatus which achieves the spinning of viscose in such manner that there is no formation of tensioned areas on the viscose filament, which tensioned areas generally cause weakening and breaking of the filament.

in order to obtain high strength and stretching of capillary filaments of viscose in the spinning of viscose solutions in highly concentrated sulfuric acid baths it is necessary that the capillary threads be drawn from the nozzle while avoiding as much as possible any tension forming on the thread. This has been accomplished in the past by very slowly drawing the individual capillary filament from the nozzle from which it is ejected and in exactly the desired direction without deviating to any extent. It is necessary according to this process to very carefully watch the flowing rate of the bath. Inasmuch as the filament bundle has a high specific weight when removed from the bath, there is a tendency of the individual capillary filaments comprising the main filament to break at the moment when the filament bundle is drawn from the spinning bath.

An acid coating enveloping the individual capillary filament is drawn along with the filament bundle. This acid coating more or less unevenly flows back along the capillary filaments onto the surface of the spinning bath, and as it is caused to whirl, washes the individual capillary filaments from the filament bundle. These washed apart filaments do not break immediately; they frequently break later however, because of the untimely stretching and difference in condition between these portions and the main body of the filament bundle.

It is therefore an object of the present invention to provide a process and apparatus which allows for the spinning of viscose filaments without any unevenly tensioned zones being formed in the filaments which might subsequently cause the filaments to break.

It is another object of the present invention to provide a process of spinning viscose from highly acid spinning baths so that the acid is homogeneously removed from the viscose filament and does not cause the formation of tensioned zones in the filament.

It is another object of the present invention to pro vide an apparatus which can directly spin viscose filaments from spinning baths in a manner such that the final filament is practically tension-free and has no Weakened zones which may break in later stretching.

With the above objects in view the process of the present invention mainly comprises withdrawing a filament of viscose from a viscose spinning bath containing sulfuric acid onto a moving transporting band, preferably of some flexible material such as rubber, so as to draw the filament from said bath while simultaneously allowing excess sulfuric acid on the filament to run off and drain down on the transporting band, thereby avoiding the formation of any tensioned portions on the filameut due to weighting of the same by excess acid adhering thereto; and recovering a tension-free viscose filament.

The filament is preferably drawn off onto the transporting band moving, with the transporting band at an acute angle to the horizontal liquid level of the spinning bath. This acute angle, which is designated as a on the accompanying drawing, allows for the excess sulfuric acid adhering to the filament to easily drain back into the bath not only along the filament itself but also along the transporting band. The transporting band provides a drain along which the excess liquid acid flows so that the same is homogeneously removed from the filament.

The apparatus of the present invention comprises a container adapted to hold a viscose spinning bath, which for example, may contain a high percentage of sulfuric acid, a spinneret located in said container and adapted to eject from the spinning bath a substantially continuous filament of viscose, and a movable transporting band, preferably of some flexible material such as rubber, adapted to receive a filament of viscose upon ejection by said spinneret from the spinning bath and transport the same while allowing excess liquid on the filament to run off onto said band so as to avoid any tensioned areas forming on said filament and possible resultant breaking of said filament upon stretching due to the weight of excess liquid adhering to the filament.

The transporting band which may be located above the container or even directly over the same, preferably forms an acute angle with the horizontal level of liquid in the spinning bath. The lower end of the transporting band is preferably located very close to the container so that the viscose filament travels only a very short distance before contacting the transporting band.

The novel features which are considered as charac teristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

The figure diagrammatically illustrates the apparatus claimed in the present invention.

Referring more particularly to the drawing, the freshly spun filament 1 ejected from the spinneret is taken up on the continuous belt 2, shortly after leaving the level of the bath, indicated by the dash-line. The continuous belt 2 is located on the pulleys 3 and 4. The pulley 4 is so located with reference to pulley 3 that an acute angle is formed between the belt 2 and the horizontal liquid level in the container.

It is to be noted that the arrangement according to the present invention provides for a degree change in direction of the filament 1 as it leaves the spinning bath and is taken up by the belt 2.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus differing from the types described above.

While the invention has been illustrated and described as embodied in apparatus and process for the spinning of viscose, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

The process shall be further illustrated in the following paragraphs by way of example, reference being made to the accompanying drawing:

The viscose was prepared in the conventional manner from a refined cellulose, the alkali cellulose being subjected to a short ageing process only. The viscose had a cellulose content of 6.5 percent and a NaOH content of 8.0 percent. At the time of spinning the viscosity (measured by the ball fall test) amounted to 156 seconds. The precipitating bath contained from 900 to 980 grams of H2804- per liter, the temperature being of 20 The spinneret used had 1400 holes with a diameter of 60 microns each. 67 grams of viscose per minute were forced through the spinneret by means of a conventional viscose ptunp. The band 2 moved along with a speed of 125 metres per minute.-

The spinneret had been located at a level of 12 mm. below the surface of the precipitating bath. The distance for the filaments from the spinneret to the egress of the freshly formed thread from the precipitating bath was of 285 mm. The diameter of the roller 3 amounted to 20 mm. and its axis was at a level of 30 mm. above the surface of the precipitating bath. The angle of deflection for the thread at the roller 3 was of 80. The axis o'f the roller 4 was spaced by 160 mm. from the axis of the roller 3. The angle a between the surface of the precipitating bath and the extension of the track band 2 wasof 40. i a

What is claimed as new and desired to be secured by Letters Patent is: 1. A spinning arrangement comprising, in combination, spinneret means for emitting a continuous filament from a spinningbath; conveyor means for receiving a filament from said spinneret means and for conveying the filament along a given path while liquid drains from the filament, said conveyor means extending in an upward direction for conveying the filament upwardly and having 'a bottom end spaced from said spinneret means, in the direction of filament travel from said spinneret means to said conveyor means, and located at a slightly higher elevation than said spinneret means so that the filament moves in a substantially horizontal direction to said conveyor means .from a spinning bath having a level higher than said ,spinneret means and lower than said bottom end of said "conveyor means, said conveyor meansbeing substantially normal to the direction of filament travel and having a top end located nearer to a vertical plane passing through said spinneret means than said bottom end of said conveyor means so that the filament movesnearer to said plane as it is conveyed upwardly by said conveyor means.

2. A spinning arrangement comprising, in combination, spinneret means for emitting a continuous filament from a spinning bath; conveyor means for receiving a filament from said spinneret means and for conveying the filament along a given path while liquid drains from the filament, said conveyor means extending in an upward direction for conveying the filament upwardly and having a bottom end spaced from said spinneret means, in thedirection of filament travel from said spinneret means to said conveyor means, and located at a slightly higher elevation than said spinneret means so that the filament moves in a substantially horizontal direction to said conveyor means from a spinning bath having a level higher than said spinneret means and lower than said bottom end a of said conveyor means, said conveyor means having a top end located nearer to a vertical plane passing through said spinneret means and being substantially normal to the direction of filament travel than said bottom end of said conveyor means so that the filament moves nearer I to said plane as it is conveyed upwardly by said conveyor means; and a roller located between said plane and said conveyor means for guiding the filament which leaves said conveyor means.

3. A spinning arrangement comprising, in combination, a pair of pulleys one of which is located at a higher elevation than the other and nearer to a given vertical plane; an endless band extending about said pulleys to be moved when said pulleys turn; spinneret means located in said given plane at a-slightly lower elevation than said other pulley for directing a filament from a spinning bath to said band at a part thereof engaging said other pulley, so that the filament moves from a spinning bath whose level is lower than said other pulley and higher than said spinneret means along a substantially horizontal path to engage and be moved upwardly by said band.

References Cited in the file of this patent UNITED STATES PATENTS Germany Oct. 15, 1936