| 摘要 |
PURPOSE:To inexpensively obtain a profile having a foamed section and an unfoamed section in one cross section, by feeding a foamable material in the molten state, and extruding it while the gases generated by the foaming in a land section from where an unfoamed section will be extruded is being eliminated. CONSTITUTION:When a foamable material containing a foaming agent is fed to an inlet of an extrusion die 11 at the molten state, the material is caused to flow into lands 3a, 4a, 5a where the expansion of the gas generated by the foaming is suppressed on its way, and immediately after leaving die lips 3b, 4b, 5b, the material foams to form a base section 3, an attaching section 4 and a lower wall 5. On the other hand, as the unfoamed material flowed into a land 2a abruptly expands at a widened part 2d, and become turbulent, after the gases (N2, CO2, CO, etc.) generated by the decomposition of the foaming agent is breathed by discharging, it is passed through a die lip 2b to form a sheet-like, unfoaming suction section 2 without being foamed. |
