| 摘要 |
<p>PURPOSE:To obtain a heat-shrinkable tubing which requires no regulation of a supply air pressure and is not limited in the length of a material tube, by confining compressed air in the tube fed between delivery rollers 11 and draw-off rollers 14. CONSTITUTION:Delivery rollers 11 are kept open when a manufacturing process is started. Thereby a compressed air pressure is applied between the end of a material tube and take-up rollers 14. The material tube softened when passing through a heater 12 runs expanding through a cooling die 13, whereat an expanded part 10 of outside diameter is formed. When a detecting means detects the formation of this part, the feed rollers 11 stop their operation, and thereby compressed air is confined in a heating section. Therefore, the tube running continuously is expanded with a constant air pressure to form the expanded part 10, and thus no regulation of the air pressure is required even when the length of the material tube between the end and an expanding point 9 is lessened.</p> |
