| 摘要 |
PURPOSE: To form a heat shrinkable pipe wrap by orienting a polyolefinic film in a longitudinal direction, irradiating one surface of the resulting film from an electron beam of a dose for bringing about a differential crosslinking, and then forming an adhesive layer. CONSTITUTION: Second and third rolls rotate at about the same speed and a first roll rotates at a slower speed, a top roll is heated to a temperature above a melting point of a polyolefinic material, a middle roll is heated to an elevated temperature below its melting point, and a bottom roll is chilled relative thereto. A blank of the polyolefinic material is stacked in a nip between the first and second rolls of the three roll calenders, and the film is fed from the calenders under tensile condition, and partially oriented in a longitudinal direction so that all molecular orientation given during calendering is substantially maintained. Then, one surface of the resulting film is irradiated from a low energy electron beam at a current to a film surface speed ratio for bringing about crosslinking, and then coated with rubber adhesive to form a tape. |
