| 摘要 |
PURPOSE:To restrict contraction in a bottle made of PET to a very small value, by a method wherein a primary molded form or a piece is molded by melting the PET material and molding through injection molding while this piece is reheated and molded through biaxial orientation blow molding under a condition that the moisture content of the PET material has arrived at a specified value. CONSTITUTION:Polyethylene terephthalate resin, molten under a condition that the moisture content thereof is 0.007% or less, is injected and molded to make a piece as a primary molded form, and said piece is reheated and molded to obtain a container through biaxial orientation blow molding when the moisture content of the polyethylene terephthalate resin has arrived at the range of 0.10-0.3%. The deterioration of the transparency, barrier property and mechanical strength of the piece, which is due to the whitening phenomena at a connecting part between the piece and a gate, can be obviated. |
