| 摘要 |
Synthetic fibres for making paper pulp are made by extruding as a continuous monofilament a mixture of two normally solid, mutually incompatible synthetic thermoplastic resins, cold-drawing to induce molecular orientation of the fibrils of the monofilament and chopping into pieces, e.g. 0.3-5.0 cms. long. The cold drawing may increase the length 3.5 to 20 times. In example, 55 parts of polystyrene and 45 of polyethylene from a conical blender are fed to a 3 cm. bore extruder and extruded through a 0.3 cm. die at 1.5-3 metres per minute, passed through ethylene glycol at 132-141 DEG C., and stretched 500%. Other examples mention polystyrene with styrene-acrylonitrile, vinyl chloride-vinyl acetate-maleic anhydride copolymer with polyethylene, and polyethylene with vinylidene chloride-vinyl chloride or with polyvinyl acetate. |
