MOLD FOR MUTUALLY WELDING END PARTS OF THERMOPLASTIC RESIN STRIPS

PURPOSE:To reduce the generation of the flush of a molded product by providing a protruding surface whose width is slightly smaller than that of a female mold to a male mold and setting the depth of the groove larger than the thickness of a thermoplastic resin strip and constituting the male mold of a material having the coefficient of linear expansion larger than that of the material of the female mold. CONSTITUTION:In such a state that a male mold 1 and a female mold 2 are heated, the gaps between the side walls constituting the groove 20 of the female mold 2 and the side walls of the protruding surface 10 of the male mold 1 become smaller than those at the time of room temp. and the protruding amount of a thermoplastic resin is reduced. In the mold K consisting of the male mold 1 and the female mold 2, the female mold 2 is constituted of an iron material and the width of the upper surface of the groove 20 is set to 300mm and the common difference.upper limit thereof is set to +0 and the common difference.lower limit thereof is set to -0. The male mold 1 is made of an aluminum material and the width of the under surface of the protruding surface 10 is set to 30.0mm and the common difference.upper limit thereof is set to +0 and the common difference.lower limit thereof is set to -0 to set the depth of the groove 20 of the female mold 2 to about 2-3 times the thickness of a belt 3.