PREPARATION OF FIBER-REINFORCED EXTRUSION-MOLDED PIPE

摘要

PURPOSE:To attempt to prepare an extrusion-molded pipe having excellent strength by rotating a molding core and a screw in the same direction in the first extruder and extruding a tube-like molded matrix without rotation in the second extruder. CONSTITUTION:A molding matrix 8 mixed with a reinforcing fiber 7 is filled in a molding cylinder 2 of the first extruder 1 and is extruded between the inner periphery of an outlet of the molding cylinder 2 and the outer periphery of a molding core 6 by rotating a screw 3 to mold a cylindrical molding matrix 9. The cylindrical molding matrix 9 is then inserted in a molding cylinder 11 of the second extruder 10 and at the same time outserted to a molding core 13. The molding matrix 9 is pushed toward an outlet of the molding cylinder 11 by molding a piston 12 by means of an oil pressure cylinder 14 and a molding core is simultaneously accompanied with it in the same direction. The diameter of the molding matrix 9 is gradually made smaller and extruded between the inner periphery of an outlet of the molding cylinder 11 and the outer periphery of the molding core 13 to mold a molded pipe 16 with a required thickness. The strength of the molded pipe 16 is improved as the reinforcing fiber does not line in the biased direction.