| 摘要 |
541,566. Tubular films. HEAVEN, H. S. May 31, 1940, No. 9586. [Class 2 (ii)] A seamless, flexible tubular body is made from a cellulosic solution, such as viscose, by extrusion from an annular die into a coagulating bath, and the space in the tubular body close to the die is separated from the space remote from the die. The pressure in the former space only slightly exceeds that acting on the exterior while the pressure in the latter space is maintained substantially higher than the exterior pressure. The annular die 25 is supplied with material through the conduit 26, and this material is extruded into the coagulating bath 28. It passes in tubular form, slightly downwards, beneath a glass rod 29 which holds it depressed, after which it emerges from the bath and may be sprayed with treating and washing media. The gaseous pressure in the remote part 39 can be varied by raising or lowering the depression rod 29. The back end of the extrusion die can be left open for the coagulating liquid to enter the near part 40 of the tube or, as shown, the end of the die can be closed by a rubber bung 31 with conduits passing through. The conduit 32 supplies coagulating liquid to the interior of the tube and this liquid is withdrawn through the conduit 33 while the pressure of this liquid is indicated by the level in the conduit 35. The gas pressure in the part 39 of the tube is maintained by the supply of gas through the conduit 34 and the flexible tube 40. Specifications 408,774 and 540,747 are referred to. |
