US 2010207 A
Description (OCR text may contain errors)
Aug. 1955- c. F. TOPHAM ET AL 07 MANUFACTURE AND PRODUCTION OF TUBULAR BODIES FROM SOLUTIONS OF CELLULOSE OR OF CELLULOSE COMPOUNDS Filed Jan. 20, 1954 *INVENTORS CHARLES FRED TOPHAM, EDWARD HAZELEfla/ni ERIC ANDREW 'MORTON by fixed" aHo/weys Patented Aug. 6, 1935 TUBULAR BODIES FROM SOLUTIONS OF CELLULOSE on F CELLULOSE C M- POUNDS Charles FredTopham, Earlsdon, Coventry, Ed-
wward Hazeley, Brookside, Coventry, and'Eric Andrew Morton, Coventry, England assignors to Courtaulds Limited, London, England, a
British Company Application January 20, 1934,Serial No. 707,594 l In Great Britain January 30, .1933 l 7 Claims. (o1. 18-15) viscose and cuprammonium cellulose.
It is well known that tubular bodies can be pro-' duced by projecting viscose through an annular slot into a suitable bath. This bath can be acid, in which case the viscose is converted directly into cellulose hydrate, or the bath may be alkaline or neutral, in which case a tube of cellulose xanthate is first formed and this is subsequently treated with acidto convert it into cellulose hydrate. It has hitherto been proposed to lead the tube, immediately after its production, through a tank containing hardening fluid, the tube being passed under and over guides or guide wheels or rollers so that the tube follows a zig-zag path. It has also been proposed to supply air under gentle pressure to inflate the tube until coagulation is complete.
-We have nowfound that advantages areobtained if the tube, after leaving the bath in which it is formed, is led in a more or less straight line in a slightly upwardly inclined direction, while it is subjected to a regulated inflation and any necessary treating liquid is allowed to fall on it during one part of its passage, and washing media, as for example water, allowed to'fall on'it duringa subsequentpart of its passage in' the slightly upwardly inclined direction. From the annular jet where the tube is formed to the point where the abovementioned washing is effected, .the tube travels more or less in a straight line and is not bent once or several timesthroughan angle of between 90 and 180, by passing over one or more rollers as hashitherto been described. We prefer'to make use of an annular jet submerged below the surface of the coagulating bath and provided with .a central hole through which the coagulating bath enters the inside of the tube at its formation. The tube travels along an inclined path in the bath, so that it soon emerges from the bath and is then ledonward, for instance along a trough above which, are situated spraying devices through which the treating fluid and the washing media are allowed to fall on the tube. If desired, the tube can be supported by a travelling band during its passage from the coagulatingbath to the trough, and even along other parts of its path. The tube is kept regularly inflated during the whole of the time until the washing is completed, and we prefer to effect this by means of a narrower rubber tube passingxthrough' the central orifice of the jet to a point beyond the level of the coagulating bath inside the tubeof cellulose or cellulose compound. The back end of the rubber tube is connected with a two-way valve, so that either compressed air or vacuum can be applied to the inside 'of the. cellulose tube. The front end of the rubber tubemay be provided with a flanged nipple which raises the end away from the surface of the cellulose tube, in order to prevent-the liquid which is draining down the said cellulose L-tube from entering the rubber tube, and as a rule we'prefer to work according to this method; it is, however, possible to arrange that the liquid drainingdown' the cellulose tube should betaken away by'means of the said rubber tube which is employed to regulate the pressure inside the cellulose'tube or by meansof another sim-' ilar tube. When commencing to form the tube by projecting the cellulosio solution through the of the cellulose tube to inflate it so that its diameter is about equal to that of the annular .jet. After the production of the tube has been inprogress for af-short time, particularly when viscose is employed as the cellulosic solution,
gases are evolved" inside the tube s'o that it becomes necessary to withdraw a certain amount of gas continually from the tube and this is done by applying reduced pressure to the back end of the rubber tube. 1 If desired, the pressure of the gas inside the cellulose tube can be-automatically controlled by means of a device which will. cause pressure 'or'vacuum to be applied throughthe rubber tube when the pressure be- ,comes too..1ow or too high respectively. We. can also, if desired, treat the z-infiated cellulose tube ,while it is still passing along the slightly upwardly inclined path, with other reagents, as for example sodium sulphide solution, bleaching solution and glycerine.
In, some cases advantages are obtained by carryingout the drying process in addition while the tube is passing along the said slightly upwardly inclined path and is subjected to the regulated inflation, but as a rule we prefer to carrymout the drying process separately because it is generallydesirableto subject the tube to a greater pressure when drying it, than is used during. its formation. .It is necessary to make the cellulose tube passfalong a slightly up wardly inclined path, because the liquid inside the tube then has greater facilities of draining back into the coagulating bath, or being taken away by a rubber control tube as hereinbefore described.
The accompanying drawing illustrates one ex.
ample of apparatus for carrying out the invention, which, however, is not limited to the example shewn. Figure 1 is a sectional elevation and Fig-1 ure 2 shews, also in sectional elevation, apart of' Figure l on a larger scale. Viscose is employed as the cellulosic solution, and this is projected into a coagulating vat containing a solution of an ammonium salt, where the tube is formed, the said tube being subsequently subjected to the action of a fixing liquid containing dilute sulphuric acid. Referring to the drawing, A represents the vat containing the coagulating liquor, the upper level of which is indicated by B. The annular jet C is fed with viscose through the pipe D, while E represents an attachment by which the jet can be raised or lowered. The viscose being supplied under pressure, and preferably fed by a pump to regulate its delivery, emerges through the ring orifice F of the jet C, and coagulates, giving rise to the tube K. The, said tube K is drawn in an upwardly inclined direction out of the coagulating liquor over the travelling band G along the trough H, where a spray of fixing liquid falls on tov it from the spraying device L. The trough H is provided with a perforated bottom, so that the fixing liquid falls through and collects in the tank M. The tube K, after leaving the trough H, passes along another trough N, where it is sprayed with water by meansv of the spraying device, the washing water collecting in a tank V 7 It may be necessary or desirable to employ morethan one trough and spraying device so as to effect sufiicient washing of the tube and it is also advantageous to carry out a part of the washing process with water at a high temperature or with steam. After the tube has been washed sufiiciently, it can be passed through a pairof nip rollers Q, R and then through one or more tanks S containing suitable liquor for after-treatment, as for example sodium sulphide solution, or bleaching solution, or diluted glycerine. We prefer, however, as stated above,
glycerine, while the tube is still passing more or less in a straight line in a slightly upwardly inclined direction, the said treating liquids being sprayed onto the tube from above while making use of troughs and spraying devices similar to those already illustrated at H, N and L, 1? respectively.
Figure 2 also shews the narrow rubber tube '1 which passes through the jet G into the interior of the tube K to a point beyond the level B'of the coagulating bath. 1"he inner end of the tube T is provided with a flanged nipple U, which raises that end of the tube away from the surface of the cellulose tube. The other end of the tube T is attached to a two-way valve (not shewn) by means of which either pressure or vacuum can be applied to the inside of the cellulose tube.
What we claim'is:-
1. Process for the production-of tubularbodies from cellulosic solutions comprising the steps of leading the tube after it has leftthe bath in which it is formed substantially in a straight line and in a slightly upwardly inclined direction, while it is subjected to the action of any necessary treating liquid and to the washing process necessary to remove the treating liquid and of subjecting the tube to a regulated inflation.
2. Process for the production of tubular bodies from cellulosic solutions comprising the steps of leading the tube after it has left the bath in which it is formed substantially in a straight line and in a slightly upwardly inclined direction, while it is subjected to the action of any necessary treating liquid and to the washing process necessary to remove the treating liquid and also to any additional wet treatment which is necessary or desirable before drying. and of subjecting the tube to a regulated inflation.
3. Process for the production of tubular bodies from cellulosic solutions comprising the steps of leading the tube after it has left the bath in which it is formed substantially in a straight line and in a. slightly upwardly inclined direction, while it is subjected to the action of any necessary treating liquid and to the washing process necessary to emove the r a in l qu d and of. subjectin the tube to a regulated inflation, bymeans of a pipe passing within th said tube and having its end above the level of the said bath.
4. Process for the production of tubular bodies from cellulosic solutions comprising the steps of leading the tube after it has left the bath in which it is formed substantially in a straight line and a slightly upwardly inclined direction, while it is subjected to the action of any necessary treating liquid and to the washing process neces-. sary to remove the treating liquid and also to any additional wet treatment which is necessary or desirable before drying and or subjecting the tube to a regulated inflation, by means of a pipe passing within the said tube and having its end above the level of the said bath. v
5. Apparatus for producing tubular bodies from cellulosic solutions comprising a bath with in which the tube is formed, an annular jet within the said bath means for supporting said jet at an acute an le to the surface of said bath, means for moving the tube substantially in a straight line in a slightly upwardly inclined direction, means for subjecting the tube to regulatable inflation and means for applying Wet treatment to the tube during said movement.
' 6:; Apparatus. for producing tubular bodies from inclined direction comprising a travelling belt and a pair of nip rollers, means for subjecting the tube to regulatable inflation comprising a pipe connected through a two-way tap to sources-of pressure and vacuum, and-means for applying wet for subjecting the tube to regulatable inflation and means for keeping the tube at the same pressure from the point at which it leaves the annular jet to a point at which the evolution of gas inside the tube has practically ceased.
CHARLESFRED TOP-HAM. EDWARD HAZELEY. JERIC ANDREW MORTON.