| 摘要 |
1,131,127. Composite artificial film. DOW CHEMICAL CO. 22 July, 1966 [22 July, 1965], No. 33127/66. Heading B5B. A composite thin multilayer film is made by forming coaxial streams of heat-plastified synthetic resins and passing them through a sheeting-die with an elongated slot-like orifice. The inner stream(s) may be of rectangular or circular cross-section, and the outer stream may be of circular cross-section. The first stream may emerge through rectangular orifice 55 at the end of passage 53 a portion of which is surrounded by passage 37 which supplies the second stream. The coaxial streams then emerge through rectangular orifice 34 at the end of passage 35 which is surrounded by inlet end 15 of passage 13, the three coaxial streams emerging through circular orifice 14, and pass through die 67 via passage 69, cavity 68, and slot 70. Resins exemplified are (a) polyethylene, (b) polypropylene, (c) vinylidene chloride/vinyl chloride copolymer, (d) polystyrene, (e) ethyl acrylate/ethylene copolymer. Composite films are exemplified having (a) encapsulating (b), (c) and (d); and a triple film having (c) in (e) in (a). |
