| 摘要 |
1,169,287. Making pipes. J. W. ROBERTS Ltd. 8 July, 1968 [9 Aug., 1967], No. 36533/67. Heading F2P. A pipe or channel is made from a continuous strip of fibre-reinforced thermoplastics material by passing it through a forming die which first heats it and then cools it to set it rigid. As shown for the manufacture of a pipe 12 from a strip 1 of P.V.C. reinforced with asbestos fibre, the strip is heated to 120‹ C. on plate 2, its edges are coated with adhesive and it is curved in a heated preforming die 5. It then passes to the tube-forming die 8 consisting of a steamheated conical lead part 9 followed by a watercooled coreless tube-forming part 10. The die is made in the two halves which may part slightly to accommodate excessive tube material. The channel-forming die (Fig. 2, not shown) is similar. |
