| 摘要 |
1305859 Seaming non-metallic sheet material COSDEN OIL & CHEMICAL CO 19 April 1971 [24 March 1970] 23667/71 Headings B5K and B5N Two flat plastics surfaces 24, 26 are superposed with particles 28 of a thermoplastic polymer positioned therebetween and are welded together by the application of sonic vibrations thereto at a point near the joint to be formed . The thermoplastic polymer must be heat-sealable to the surfaces. The sonic vibrations are of a sufficiently high frequency and are applied for a sufficient time to melt the particles 28. In examples, (i) high impact polystyrene particles are moulded into a disc and a bar which are sonically welded in face-to-face contact with polystyrene particles sandwiched therebetween; (ii) high impact polystyrene particles comprising polystyrene graft copolymerized with six per cent by weight of high cis transpolybutadiene rubber are moulded into a disc which is sonically welded to a cellulose butyrate sheet with polystyrene particles sandwiched therebetween; (iii) two polyethylene sheets are sonically welded with polyethylene particles sandwiched therebetween, and (d) acrylonitrile butadiene styrene polymer sheets are sonically welded using particles of the same polymer sandwiched therebetween. |
