US2393595A

US2393595A - Manufacture of threads, filaments, and the like from viscose

Info

Publication number: US2393595A
Application number: US428435A
Authority: US
Inventors: Dawson Daniel Sutherland
Original assignee: Courtaulds PLC
Current assignee: Akzo Nobel UK PLC
Priority date: 1941-02-06
Filing date: 1942-01-27
Publication date: 1946-01-29
Anticipated expiration: 1963-01-29
Also published as: GB546979A

Description

u s I v M O R F E K I L E H T D N A S T N E M A L I F S D A E R H T F O m U C A F U N A M Jan. 29, 1946.

D. s. DAWSON Filed Jan. 27, 1942 fig. 2. HERLAND DAWSON SUT 6y is 2292? meys Patented Jan. 29, 1946 MANUFACTURE OF THREADS,

THE LIKE FROM VISCOSE Daniel Sutherland Dawson, Tettenhall, Wolverhampton, England, nssignor to Courtaulds Limlted, London, England, a British company Application January 27, 1942, Serial No. 428,435 In Great Britain February 6, 19:41

2 Claims. 18--8) The common method or producting threads, filaments and the like from viscose consists in extruding the viscose through holes into a bath containing sulphuric acid and sodium sulphate filaments are thereby injured and possibly broken.

It has therefore been customary to maintain a certain amount of humidity in the atmosphere with which the thread comes into contact, and since the higher the percentage of sodium sulphate in the spinning bath the greater will be the tendency for it to crystallise out on the thread, it has been desirable to employ a spinning room atmosphere "in which the humidity is greater when greater concentrations of sodium sulphate are employed in the spinning bath. Under some conditions of working, the humidity required to avoid crystallisation of sodium sulphate on the thread is so high that the atmosphere becomes oppressive to the workmen.

It has already been proposed-in the Huttinger Patent 2,042,529 for the purpose of removing salt deposits from the spinning box or the walls of the small chamber containing the spinning box, to project a spray of a salt-dissolving liquid, such as water, against the outer surface of the spinning box or against the inner wall of the small chamber within which the spinning box is situated. Obviously such treatment can have no efiect on the thread before it reaches the spinning box. I hav now found that considerable advantages are obtained when producing irom viscose threads, filaments and the like,

which will hereinafter be referred to as threads, by extruding the said viscose into a bath containing sulphuric acid'and sodium sulphate, with or without other ingredients, if the thread be enclosed during its passage from the bath to the collecting device and one Or more sprays of water, either in the liquid or gaseous state, he intro duced inside the enclosure of the thread. One convenient method of enclosing the thread is by enclosing the spinning machine;

The humidity 01' the air introduced into the workshop is then preferably maintained at a relatively low figure. By means, or the sprays, water is introduced in the form or vapour or very finely divided droplets and this greatly reduces the tendency of the sodium sulphate to crystallise, or even prevents it from crystallising, on the threads or on to the other parts of the machine, thus avoiding damage to the threads, to the spinning machine or to the workmens hands. It is also unnecessary to introduce into the workshop air with such a high degree of humidity as is injurious o unpleasant to the workmen.

The process oi. this invention is of particular use when the viscose is being spun into a bath containing say 16 per cent or more of sodium sulphate. The spray of water or aqueous vapour can be employed at the ordinary or at a raised temperature, and the process can even be carried out by blowing steam into the enclosure of the threads or machine. The enclosing of the machine can be effected in any suitable manner; for instance, the known method of effecting an enclosure by means of glass windows is convenient.

The drawing accompanying this specification will assist in illustrating the nature of this invention, but the invention is not restricted to the method and apparatus shown in the drawing.

In the drawing-Figure 1 represents a crosssectlon through a spinning machine, showing sufiicient parts to enable the invention to be understood, while Figure 2 is a sketch showing part of the machine. In one or both of these drawings A represents the pump which delivers the viscose through the candle filter B to the nozzle C. The thread D, which is formed as the viscose leaves the nozzle, passes through a guide E, shown only in Figure l, to the first godet F, thence to the second godet G and through the funnel H into the centrifugal box J. The front of the machine is closed during normal working by means of windows K, which are hinged at L. The spray of water or watervapour is introduced through a series of spraying nozzles, of which one, marked M, is shown in each figure. Air is drawn from the machine through the chamber N surrounding the spinning box, and also if desired through holes P in the back of the machine in the neighbourhood of the second godet G.

In the following claims, the term "Water is used in a sufilciently general sense to apply whether it be in a liquid or gaseous state.

What I claim is: 1. In the production of artificial threads by projecting viscose through a periorated nozzle into an aqueous spinning bath containing sulphuric acid and at least one metallic salt. the method which comprises passing the thread from the spinning bath while damp and in an unwashed condition through a relatively long path from the spinning bath to the collecting device and within an enclosed air space, and simultaneously spraying finely divided water into said enclosed air space to create a moist atmosphere extending along the path of the thread as it passes through said enclosed air space, whereby the tendency of the metallic salt of the spinning bath to crystallize on the unwashed thread is reduced 2. In a machine for the production of artificial threads by projecting viscose through a periorated nozzle into an aqueous spinning bath containing sulphuric acid and at least one metallic salt, the combination of a closed container including a thread forming section, a spinning bath within said thread forming section, a spinning nozzle in said bath, a thread collecting device,.means tor-guiding the formed thread while still damp and in an unwashed condition throu h the thread forming section and to the thread collecting device, and means for spraying finely divided water into the thread forming section to create a moist atmosphere therein to reduce the tendency for the metallic salt of the spinning bath to crystallize on the thread as said thread is guided through section.

DANIEL SUTHERLAND DAWSON.

the thread forming