Forming tool for preparing multi-layer tube, has connection portions closely situated to central axis of rotation than contact portions that are enrolled in rectangular mold, and chamfering cone to carry out chamfer and edging at tube

摘要

The tool (1) has a forming portion (6) introduced in a mouthpiece of a tube and driven in rotation with respect to the tube around a central axis (A). The forming portion has three round contact portions entered in contact with an interior tube wall, and four intermediate straight connection portions are provided between the contact portions. The connection portions are closely situated to the central axis of rotation than the contact portions. The contact portions are enrolled in a rectangular mold, and a chamfering cone (11) carries out an inlet chamfer and edging at the tube.