Removable core for pre-stretched tube

PURPOSE: To provide a core for PST which can be linearly extruded and is hard to be crashed by assembling, in zigzag, protruding sections provided at a regular interval on the opposite sides of rectangular movable sheets, into a cylindrical body, and by providing thin straight lines on its surface. CONSTITUTION: Plural protruding sections are provided at an almost regular interval on each of two sides opposing in the direction of axis of a rectangular movable sheet 11. This protruding sections are alternately assembled in zigzag to form a cylindrical body having a coupling section 12 with protruding sections protruded to the outer surface or outward. Further, a thin line or a perforated cut line extending from one point in one protruding section to the intermediate part of the root of another two protruding sections is linearly provided in the direction of the circumference on the surface of the cylindrical body. And a ribbon 23 for drawing extending along the thin line from the protruding section of the one end is provided. After arranging a core 1 thus obtained to a wire connecting section, the cylindrical body is removed in the shape of a belt which turns by 180 deg. at the protruding section, tearing the body along the thin line by starting a linear draw of the ribbon 23.