| 摘要 |
PURPOSE: To form a sheath and a foamable core material finished completely of a platen by mixing foaming agent reacted with a plastic material later, and cooling a mold to match a delay time by various cooling operation relative to a desired sectional structure. CONSTITUTION: A line feed wheel-stop wheel set 8 is provided at each of both ends of a platen 7, moldings 9 are similarly provided at both ends, and bearing recesses 10 are concentrically provided with the platen. A range of the platen 7 useful as a pole pressure state is foamed by slightly cooling the molding therein, and a severe sheath is provided in an outside area 7a. The set 8 and both ends faces of the platen 7 constituted as bearings 9, 10 are provided with a completely precise material state by strongly cooling the molding in the manufacturing step, and sufficiently wear resistant for functions given for them. |
