GB404062A - Improvements in or relating to the production of artificial filaments - Google Patents

Abstract

<PICT:0404062/IV/1> <PICT:0404062/IV/2> <PICT:0404062/IV/3> <PICT:0404062/IV/4> In apparatus for making filaments from solutions of cellulose or cellulose esters there is provided, in combination with a spinning nozzle and pump and in the line of flow between the pump and the nozzle, a device consisting of a hollow cover, a flexible diaphragm beneath the cover forming a chamber between the cover and the diaphragm, and a non-fluid cushioning medium in the said chamber supporting the diaphragm. The device may be positioned in such manner that the diaphragm cuts off communication in the delivery conduit between the pump and the nozzle when the pump is not being operated. The cushioning medium may be a spring, preferably of the coiled conical type, or it may be a mass of rubber, preferably spongy rubber. The chamber formed between the cover and the diaphragm may be in communication with the atmosphere through a vent hole, or it may be entirely closed. In the latter case, the air enclosed within the chamber exerts a cushioning effect additional to that of the spring or mass of rubber. As shown in Figs. 1 and 2, the casing 10 for a filtering device 12 has at one end a reduced neck 14 with a central bore therethrough, and an enlarged head 16 screwed into the other end. The head 16 has a central passage 18 communicating with a passage 20 in the filter 12. Spinning solution from a pump passes through the passage 30 to the bottom of a screw threaded well in which is secured a flexible diaphragm 22, preferably of rubber, and a hollow cover 24, and then passes to the passage 18, filter 12, and the spinning jets. Fig. 2 shows the position of the diaphragm when subjected to the pressure of the spinning solution which is opposed by a spring 32 of the coiled conical type. As shown in Fig. 4 a truncated-conical rubber block 40 is employed as the cushioning medium, the upper surface having a depression which receives a corresponding projection of the cover 24 while the lower surface rests on the diaphragm. As shown in Fig. 6, the whole of the space between the cover and the diaphragm is filled with sponge rubber 50. The apparatus absorbs pulsations in the viscous stream due to the action of the pump and leads to the production of threads of more uniform denier.