| 摘要 |
The present invention relates to a method for injection stretch blow molding of blow molded products. More specifically, according to the method: a stretching rod stretches a preform, and the stretching rod and an ascending mold adhere in the outside so as to exactly keep the preform′s balance, thereby being able to increase precision of the blow molded products; a preform gate can move to a bottom part so the preform gate is formed bigger, and the thickness of the blow molded products can be thicker as a body unit of the preform moves to the bottom in the case of blowing, thereby enhancing elasticity, tensile strength, and durability of the blow molded products and preventing cracks in the same. The present invention comprises the following steps of: molding a preform, which has a gate unit formed in the middle of a lower end as big as possible within a limit on the preform size, to have a length the same as the length of a bottom mold; inserting the stretching rod in the interior of the preform by putting the preform into the bottom mold so as to adhere to the bottom of the interior of the preform; stretching for stretching the preform using the stretching rod; inserting the gate unit in the interior of the mold while pressurizing the gate unit from the inside and the outside by adhering the ascending mold of the bottom mold to the gate unit of the stretched preform; molding the products by blowing the preform, in which a discipline unit is formed by being inserted, through the stretching rod; and forming the blow molded products by separating the bottom mold after the previous step. |
