| 摘要 |
PURPOSE:To improve adhesive strength of a pinch-off part, by performing blow molding within inactive-gaseous atmosphere. CONSTITUTION:As inactive gas may be good if it does not oxidize the surface of resin, carbon dioxide (CO2), helium (He) and argon (Ar) other than N2 gas are used. Blow molding resin such as high-density polyethylene or polyamide is in a molten state at the time of either injection or extrusion of a parison and oxidization progresses already from the time of the extrusion or injection of the parison so long as atmosphere is within aerial atmosphere. Although it is necessary to perform the title method within inactive-gaseous atmosphere from the time of the extrusion or injection of the parison, an improvement is sufficient adhesive strength is observed even if inactive gas is blown into at the time of only blowing. A container W is molded by a method wherein simultaneously with extrusion of the parison P at a resin temperature of 210 deg.<= N2 gas is blown off through a blow pin B by making use of a single-layer blow molding machine and the N2 gas is blown off by inserting the parison P between molds M. |
