US1619768A - Manufacture of artificial silk - Google Patents

Description

March 1 1927. 1,619,768

F. W. SCHUBERT MANUFACTURE OF ARTIFICIAL SILK Filed June 21, 1926 W W/MQ' w). w m/ I Patented Mar. 1, 1927.

UNITED STATES PATENT OFFICE.-

'IRIEDRIGH WILHELM SCHUBERT, F APPERLEY BRIDGE, NEAR BRADFORD, ENG- LAND, ASSIGNOR TO BRYSILKA, LIMITED, OF APPERLEY BRIDGE, NEAR BRAD- FDRD, ENGLAND.

MANUFACTURE OF ARTIFICIAL SILK.

Application filed June 21, 1926, Serial No.

This invention relates to the manufacture of artificial silk from cuprammonia cellulose solutions and has particular reference to the production of artificial silk threads by the stretch spinning process wherein the spinning of the thread is effected by passing or conducting the viscous solutions or liquid through a single precipitating or coagulating liquor. The chief object of the present invention is to dispense withthe feeding of the liquor from above under pressure.

According to the present invention the precipitating or coagulating liquor through which the filaments pass or are conducted is supplied to the spinning vessel from below under atmospheric pressure in accordance with the drawing out of the .filaments and the speed of the collecting devices on or by which the filaments are stretched or spun during the winding, the liquor being circulated or replenished as a result of the surface friction of the thread through the liquor and in a direction opposite to the movement of the filaments. Thus in an embodiment of 25 the invention the precipitating liquor is supplied to .a tankopen to the atmosphere and into which the spinning vessel depends with its lower'open end submerged in the liquor. The upper end or head of the spinning vessel may be fitted with the usual spinneret top and have connected thereto a suction pipe controlled in any appropriate manner for exhausting the air.

Referring to the drawing where is diagrammatically illustrated a preferred manner of carrying out the invention, 1 indi cates a spinning vessel having a lower opened end which extends into a trough 2, and has its upper end closed and arranged to receive a spinneret nozzle 3, and a suction pipe 4, the latter being arranged to exhaust the air in the vessel so as to maintain a vacuum in the top thereof. The filaments or threads 7, as they leave the spinneret nozzle 3, pass down the vessel 1, around the guide roller 5, and onto a collecting or winding roller 6. The circulation of the precipitatin liquid within the spinning vessel 1 and t e trough 2, is effected by the surface friction of the filaments through the liquid, and the atmospheric pressure on the liquid in the trough, thus causing the liquid to circulate in a direction opposite to the move 117,533, and in Great Britain July 2, 1925.

ment of the filaments and as indicated by the arrows in the drawing.

In operation the filaments passing or being drawn through the liquor gradually become coagulated and a proportion or quantity of the liquor adjacent the filaments as :the latter descends has a tendency to follow the direction of the filaments, being replaced or counteracted by the upward flow from the tank, the liquor being thereby circulated or replenished as a result of the surface friction of the thread through the liquor. The movement of the liquor adjacent said filaments will be controlled according to the speed at which the filaments are drawn from the spinning vessel, said speed being controlled or governed by the various factors or conditions affects mg the viscosity of the solution, the percentage of cellulose, number of filaments, the percentage of ammonia and the strength and temperature of the caustic soda solution employed as the coagulating bath. The suction pipe at the upper end of the spinning vessel may have suitable control devices for regulating or varying the suction during the starting u of the machine until the air in the funne is displaced or removed. Other than the spinning nozzle openings and the suction inlet to the head of the spinning vessel the up er end of the latter will be entirely closes, thus the entire supply of p'reci itating or coagulating liquor 1s introduce only in a direction opposite to the movement of the filaments in contradistinction to known processes wherein the liquor acts in two directions or in a direction following that of the filaments or where the coagulating liquor'is fed to the top of and down the funnel. The. filaments during or after the stretch spinning process may be wound on to bobbins, reelsor other devices after passing through suitable washing fluids and either after or before twisting. The twisting of the filaments may thus be effected durm the stretch spinning stage and immediatrfiy prior to being wound on to the bobbins, reels or like devices.

1. A new and improved rocess of manufacturing artificial silk w ich consists in liquid, delivering the filament to a collecting device through an opened top trough into which the spinning vessel extends so that the coagulated liquid will be supplied to the spinning vessel through the bottom thereof by atmospheric pi'essure and in accordance with the drawing out of thefilament and the speed of the collecting device, the liquid be ing circulated due to the surface friction of the threads through the liquid in a direction opposite to the movement of the filaments.

2. A new and improved process of manufacturing artificial silk which consists in in-" troducing a cuprammonia cellulose Solution filament into a spinning vessel containing a precipitating liquid, delivering the filament to a revolving collecting device through an opened top trough into which the spinning vessel extends so that the precipitating liquidv will be supplied to and clrculated in the spinning vessel through the bottom thereof by atmospheric ressure and in accordance with the drawing out of the filament and the speed of rotation of the collecting device, the liquid being circulated due 'to the ,surface friction of the filaments through the liquid in a direction opposite to the movement of the filaments. FRIEDRICH WILHELM SCHUBERT.

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