| 摘要 |
1,195,578. Making tubes. TETRA PAK A.G. 27 Sept., 1967 [28 Sept., 1966], No. 43898/67. Heading F2P. The overlapping edges 2c, 2e of a web 2 of plastics coated paper which has been formed into a cylinder are joined by heating one or both edges, prior to passing them between presser rollers 8, by a stream of hot air issuing laterally from a pipe 14 via lateral openings (not shown) in the pipe, the stream of air being contained within a chamber or chambers (only one chamber for heating one edge of the pipe being shown), the or each chamber consisting of a frame supporting a lining formed by a strip of non- adhering material such as polytetrafluoroethylene-glass fibre fabric, the strip being wrapped around the pipe 14 and around tubular supports 10, 11 of the frame to provide a vertical slit-shaped opening to receive the edge of the web. The frame consists of the tubular supports 10, 11, which are of thin stainless steel to avoid extracting an appreciable amount of heat from the web, a tubular part 9 and welded crossmembers 12, 13 to which the outer ends of the strip are secured. |
