| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce manufacturing costs, and raise the heat insulation property by being formed with a synthetic resin hollow main body and heat insulation layers consisting of a corrugated board material closely disposed through inmold on the outer wall of the main body. SOLUTION: The extrusion blow molding apparatus 2 is in that heat insulation materials 5 as heat insulation layers consisting of a corrugated board material being formed in appropriate configurations are set in appropriate numbers in advance by being pulled mechanically or by a vacuum device furnished within molds 3, 4 within two-split type molds 3, 4 having the same cavity configured as a hollow heat insulation body. Setting positions of the heat insulation materials 5 are places where dew condensation is made readily on the outer wall of a main body of the hollow heat insulation body by cooling air passing through in the hollow heat insulation body after molding, namely, appropriate places equivalent to corner parts. Inasmuch as the heat insulation layer consists of a corrugated board material, cost is reduced.</p> |
