| 摘要 |
PURPOSE:To manufacture a synthetic resin tube generating almost no heat shrinkage when the same is used at a high temperature, at low cost by heat treating the synthetic resin tube after extruding and cooling in the no-tension state on-line. CONSTITUTION:A synthetic tube T extruded out of a die of an extruder 1 is cooled in a cooling water tank 2, and then transferred by a transfer caterpillar 3, placed on a conveyor 5, passed through inside a heat treatment device 4 and heat treated. In that case, the speeds of the caterpillar 3 and a driving roller 6 are controlled so that tension is not applied substantially to the synthetic resin tube T on the conveyor 5. The synthetic resin tube T thus heat treated is moved from the driving roller 6 and taken up on a take-up unit 8 through a tension controller 7. As the synthetic resin to be used, especially fluorine resin is preferred. Thus the residual tension in the tube is released almost completely. |
