METHOD AND APPARATUS FOR MANUFACTURING OR RIBBED CURRUGATED TUBE

摘要

PURPOSE:To obtain the ribbed corrugated tube readily and at low cost, by maintaining the tubular forming material provided with the thick wall part at the place where the rib is to be shaped at the heat-softened state and moving it inserted between the split molds. CONSTITUTION:The tubular object 22 provided with the thick wall part 22A at the place where the rib it to be formed is extruded from the extruder 11 of which the die 6 is attached to the extruder body 1. It is maintained at the heat- softened state and the predetermined wave form 23A and rib 23B are formed in the split molds 12 which move to the extrusion direction, then the molded article 23 is parted by splitting the split molds. The forming by the split molds may be either expansion forming or vacuum forming.