| 摘要 |
PROBLEM TO BE SOLVED: To make the thickness and orientation of molecules uniform by infusing melted thermoplastic resin into space, before clamping, of a forming mold consisting of male and female blocks that have a cooling means, pressing and clamping it in a softening status and cooling and hardening it with a cooling means. SOLUTION: A forming mold 1 consisting of a male block 3 and a female block 3 which are respectively provided with cooling water channels 4. For instance, in the case of the production of a loudspeaker cone that has 130 to 160 mm diameter and 0.35 mm thickness, a thermoplastic resin material P such as polypropylene is heated and melted at 240 deg.C and is infused into space 1a between the facing blocks 2 and 3 which are not clamped from a pouring gate 3a. It is pressed and clamped by the blocks 2 and 3 with 500 to 600 kg/cm<2> , and also it is cooled and hardened cold water flowing through the channels 4. Since pressure in pressing and clamping is applied equally over an entire area of the blocks 2 and 3, the density of molecules is not biased and orientation property becomes uniform. |
