| 摘要 |
<p>Processes and apparatus and filaments produced thereby wherein endless, molecularly oriented, multifile filaments of thermoplastic polymers are produced by extrusion of foil or web which is longitudinally ribbed to provide longitudinally extending breaking or tearing lines or zones with filament-forming ribbons or strips of polygonal cross section therebetween; cooling said foil upon exit from extrusion nozzle or immediately thereafter by air jet, cooling rollers or drums, or immersion in liquid coolant; drawing the extruded foil by at least several times its original length, e.g. 5-20 times its original length, to orient polymer molecules monoaxially in said ribbons or strips and to tear said foil into filaments or strands, said drawing preferably occurring in part prior to cooling followed by later stretching at preselected elevated temperature provided by a heating zone between stretching roller assemblies; deflecting the foil and/or strands several times to facilitate tearing or breaking, and producing special visual effects or properties in resultant filaments such as improved handle provided by ragged tear edges, extrusion of foil in two or more layers or zones of different polymers, different colored polymer and/or one or more layers of foamed polymer, surface embossing of foil, and incorporation of metal foil particles or other laminallae in polymer foil.</p> |
