| 摘要 |
PURPOSE:To obtain a hollow vessel substantially free from shrinkage with the passage of time within a shortened forming cycle, by making a lining layer of material having a low thermal conductivity, and cooling a hollow vessel, which is blow-formed inside a steadily heated metal die, into a solid state from its interior with low-temperature gas. CONSTITUTION:A preform 4 is set inside a metal die 2 having a surface on which a lining layer 1 is formed from low-thermal conductivity material. High- pressure air is introduced into the metal die, and an elongating rod 9 is protruded downwards to blow-elongate the preform 4. The resultant hollow vessel 10 is held 1-30sec under a condition in close contact with the lining layer 1 and heated. Thereafter, low-temperature air is let flow through the interior of the hollow vessel 10 to cool the hollow vessel 10. |
