JPS56136337A - Production of warming tube - Google Patents

Abstract

PURPOSE:To obtain a molded article of right circular cross-sectional shape without exerting any irrational forces on the inside and outside layers of the article by a method wherein a hollow tubular molded article with a tongue part is cured in a heating section and thereafter the tongue part is clamped and pulled. CONSTITUTION:A plurality of split molds 31 having a recessed surface on one side thereof are fitted to a pair of endless belts to constitute a cylindrical molding passages, in which a center core 32 is placed to constitute a molding section 3. An outside layer material 11 and an inside layer material 12 are introduced into the molding section 3, and a foamable and curable resin liquid is fed between the layer materials. The introduction is so conducted that the outside layer material 11 is contacted with the inside wall of the molding passage, while the inside layer material 12 is contacted with the surface of the core 32 and both end parts of the layer materials 11, 12 are projected outwards through a vertical slit 34 to constitute the tongue part 61. While the materials are passed through the molding section 3, the resin is foamed while filling up the passage, producing the worming tube. After curing the resin by introducing the tube into a heating section 4, the tongue part 61 of the molded article is pulled by a pulling device 5.