| 摘要 |
A process for producing foamed articles comprises mixing a blowing agent with molten thermoplastic resin and extruding the resultant solution from a superatmospheric pressure zone into an atmospheric pressure zone, the rate of extruding being at least as high as the rate at which the resin fractures when extruded without dissolved blowing agent. Suitable resins are polyethylene, polypropylene, polybutene, polystyrene, ethylene copolymers, styrene copolymers, polyhexamethylene adipamide, polycaprolactam, polymethylmethacrylate, methylmethacrylate copolymers, polyoxymethylene, polyvinyl chloride, polyvinylidene chloride, polychlorotrifluoroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene, polycarbonate resins and cellulose resins. |
