| 摘要 |
PURPOSE:To prepare a long insulating tube by extruding rubber or plastics on a core bar, inserting it into a pipe and heating it there, blowing high pressure air into the pipe for expansion and cooling the blown tube. CONSTITUTION:Uncross-linked rubber of plastics 12a is extruded on a core bar 18 and heated, compressed, cross-linked and cooled, in a cross-linked tube. The sharp point 260 of a pipe 26 is inserted between one end of the rubber or plastics 12a and the core bar 18, sealed 28, 30, 34, 36, the whole body is inserted into a metallic pipe 22 provided with both heating and cooling functions and supported so that it can come to the central axis. It is heated by the pipe 22, high pressure air 38 is blown into the plastics 12a through the pipe 26 and the tube is expanded until it comes in contact with the inside of the pipe 22 and the outer diameter is equalized. Then, the tube is cooled by the pipe 22 and separated from the core bar 18 to obtain a thermally shrinkable tube. |
