| 摘要 |
1413356 Fibrids of thermoplastic materials BADISCHE ANILIN- & SODA-FABRIK AG 23 Feb 1973 [25 Feb 1972] 8938/73 Heading B5B Fibrids (i.e. short fibres) of a thermoplastics material are made by introducing a high-speed propulsive jet and a slower-moving stream of a liquid co-currently into a mixing tube arranged coaxially with the jet, whereby a shear gradient is set up in the mixing tube between the highspeed jet and the slower-moving liquid stream, and feeding the molten thermoplastics material through a die into the region of the shear gradient, whereby the thermoplastics material is broken up into fibres by the action of shear stresses within the region of the shear-gradient. Specified thermoplastics materials include polyethylene, polypropylene and their waxes and extended waxes, polyamides, polyesters, polyvinyl chloride and polystyrene. In Fig. 1, the apparatus is enclosed in container 4. Melt is supplied via 6 to outlet orifice 2; the spinning medium, suitably water, is supplied via 5 to the outlet orifice 1 of the propulsive jet; 3 is the impulse exchange chamber or mixing tube. If the relatively slow-moving stream of liquid entrained from the container is replaced by liquid coming from a pump, the container may be dispensed with, as in Fig. 2, where 7 is the feed-line for the slow-moving medium (water) spinning being effected in tube 3 which acts as impulse exchange chamber. |
