Plastic tube manufacturing method for e.g. flow-type heater, involves inserting connecting piece including connecting geometry deviated from cross sectional geometry of plastic tube to end of plastic tube

摘要

The method involves manufacturing a plastic tube using extrusion. An end of the plastic tube is inserted into an injection molding tool. A connecting piece including a connecting geometry deviated from a cross sectional geometry of the plastic tube is inserted to the end of the plastic tube. An insert corresponding to the connecting piece is inserted into the injection molding tool before the insertion of the connecting piece. Polyethylene is cross-linked by irradiation cross linking after the insertion of the connecting piece. An independent claim is also included for a water heater.