| 摘要 |
PURPOSE:To manufacture a thermally shrinkable tube having a prescribed shrinkable property at all times by a method wherein a corrective pipe is covered with plastic material, shrunk thermally in a continuous measurement and cooled quickly when it reaches a prescribed value. CONSTITUTION:A corrective pipe 2 is covered on the surface with a plastic extension tube 14, rotated and heated by a heater 9. With the rise of temperature the tube 14 shrinks and attaches to the surface of the corrective pipe 2 and the lengthwise strain of the tube begins to disappear gradually. This change is measured by differential transformers 11, 12, transmitted to a controller 13 and an electromagnetic valve V1 is closed by a signal S1 to quench the heater. The controller 13 sends a signal S to scatter cooling water from a cooler 10 onto the tube and supplies cooling water into a corrective pipe 2 for forced cooling. Therefore, the tube 14 is hardened as dimensions specified in the lengthwise direction are changing. The hardened tube is removed to manufacture a thermally shrinkable tube as a product. |
