| 摘要 |
PURPOSE:To form a large number of scorelines on burrs attached to a main body simultaneously at its molding in order to facilitate deburring by a method wherein a split mold, along the edge of the cavity of which a pinch-off ridge is protruded and in the direction intersecting with said edge of the cavity of which a large number of scoring ridges are also protruded, is employed. CONSTITUTION:The desired cavity 4 is formed at the split surface 3 side of the body 2 of each of a pair of molds 1 and at the same time the pinch-off ridge 5 is protruded along the edge of said cavity 4 at the split surface 3 and furthermore a large number of the scoring ridges 6... intersecting said pinch-off ridge 5 at proper angles are protruded over the whole split surface 3 at proper interval in the split molds 1. A cylindrical parison P, which is made of thermoplastic resin and kept at fused state, is hung down by being extruded between both the split molds 1 and then closed by being pinched with both the split molds 1 in order to be blow-molded by being blown with compressed air. In addition, the height of the scoring ridges 6... is rendered to be same as or a little lower than that of the pinch-off ridge 5. |
