| 摘要 |
PURPOSE:To dissolve a difference in strength according to a direction of orientation of a molecule and improve breaking resistance, by a method wherein molding is performed while turning a part of a material feed path or a part of a mold, in a matter molded into a fixed form by sending in a polymeric material through a material feed flow path. CONSTITUTION:In the case where boots for a uniform velocity joint are formed through blow molding, a screw 3 within a cylinder 2 is turned by a motor 1, a polymeric material K is extruded through the tip of the cylinder 2 by its rotation and fed to an inflow port of a crosshead 4. A die 5 forming the outside diameter of a parison 8 and a core 6 forming the inside diameter of the parison 8 are arranged on an output side of the crosshead 4 and the polymeric material K is fed between both the die 5 and core 6. Then during feeding of the polymeric material, the core 6 is turned by a rotary driving device 7, turning force is applied to a core side part of the polymeric material and a die side part of the polymeric material is orientated in a material supply direction. Then the produced parison 8 is put into the mold 9 and desired boots are manufactured. |
