| 摘要 |
892,942. Seaming non-metallic sheet material. DUBOIS, J. R. N. June 18, 1959 [Nov. 13, 1958], No. 20959/59. Drawings to Specification. Class 42 (1). [Also in Group XI] A process for welding thermoplastic materials comprises bringing together the edges of parts to be welded, covering the abutting edges with a metal conductor and with an adhesive strip which adheres to the conductor and to the thermoplastic material on each side of the conductor, passing a current through the conductor to heat the thermoplastic material to a plastic state so as to weld the parts together, stopping the current to allow the weld to cool and removing the strip and conductor. Pressure may be applied during welding and a metal conductor and adhesive strip may be applied to both sides of the joint. The conductor may be adhered to the strip before application to the parts to be welded and it may be a film of electric current conducting alloy. It may be in the form of a number of parallel conductors or in sinusoidal longitudinal shape. Various embodiments include butt, lap and mitre joints and means for closing a filled bag. |
