Processing method using the core material and the core material for bending of plastic pipe

摘要

PURPOSE: To provide a bending method in which a plastic tube to be bent can easily be pressurized by molds, the plastic tube can be prevented from being made flat, and a core material can easily be extracted from the plastic tube. ;CONSTITUTION: A core material 1a is composed of a laminate of a plurality of sheets 1A-1M having an approximately circular cross section. The sheet 1G provided in nearly the center of the layers is divided into two parts in the longitudinal direction thereof. After the core material 1a is inserted into a plastic tube, the plastic tube is bent under heat while the sheets 1A-1M of the core material 1a are slid to each other. After the bent plastic tube is cooled, the core material 1a is extracted. When the core material 1a is extracted, firstly the half sheets 1G are extracted from the each end thereof and, thereafter, the remaining sheets 1A 1F and 1H-1M are extracted.;COPYRIGHT: (C)1993,JPO&Japio