| 摘要 |
PURPOSE:To obtain an extrusion foaming mold for obtaining a rectangular (platy) foam. CONSTITUTION:In an extrusion foaming mold used for an apparatus wherein a volatile foaming agent and thermoplastic resin, after mixing by melting with an extruder, is extruded into a low pressure area through a mold to make a rectangular foam, the mold 40 is composed of a tubular rectifying area part 40A having a smooth inner peripheral surface, and a squeezing in area part 40B continued to the rectifying part. The squeezing in area part 40B has a shape wherein a sectional area decreases gradually toward a rectangular outlet side. Further, a ratio of a sectional area X at an inlet of the mold to an sectional area Y at an outlet of the mold (squeezing in ratio) [(X-Y)/X] is 90-99.9%. A platy foam which is free from occurring of a void can be molded thereby. |
