| 摘要 |
PURPOSE:To provide a mold for the extrusion molding of a synthetic resin tubular body constituted so that a core is supported within a land by bridges and characterized by that the local reduction of wall thickness is well prevented by sufficiently uniformizing the resin flow made non-uniform due to the passage through the bridge parts without bringing about the increase of the length of the land and the increase of operation load. CONSTITUTION:In a mold wherein a core 2 is supported within a land 1 by a plurality of bridges 3, cavities 4 are provided to the surface of a passage with respect to the bridges at the regions on the downstream side of the bridges 3. |
