| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a screw type extrusion molding apparatus for production of cylindrical members which eliminates the possibility of crushing of moldings during extruding a cylindrical molding after cutting in the rear part of the mold or during cutting even in cases where the mold has a core and thereby enables stable molding of cylindrical moldings with consistent outside and inside dimensions. <P>SOLUTION: The extrusion molding apparatus has a mold section 8 consisting of a mouthpiece 81 and a core 82 inserted to the outlet 8a of the mouthpiece 81, and the core 82 has a passage 84 for gas which extends from the opening of the tip on the side of the outlet 8a through a supporting member 83 of the core 82 to the outside of the extrusion molding apparatus 1. Even when the cross-section of a cylindrical molding is crushed on cutting in the rear part of the mold section 8, therefore, aeration of a gas into the cylindrical molding is never blocked. The resultant retention of the internal pressure of the cylindrical molding eliminates the possibility of the whole crushing of the cylindrical molding, leading to an improved efficiency of manufacturing cylindrical moldings. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
