| 摘要 |
PURPOSE:To obtain the titled core material reinforced up to required strength by molding a hollow board body by blowing a parison of synthetic resin with air while forming reinforcing boards by one section of the parison. CONSTITUTION:A parison 37 under a melted condition is inserted to the center of divided molds 31 (31a, 31b), the blow molds 31 are closed, the parison 37 is pinched off, sliding plates 34, 35 are pushed into the molds, both side walls of the parison 37 are held partially and pressure-welded and a welded section 39 is made up. The sliding plates 34, 35 are backed, and the parison 37 is blown with air. Thus, the parison 37 expands to the whole cavity while indentations formed on the surface of the parison are removed, the welded section 39 is extended in a laminar shape and reinforcing plates 24, 25 are built up to the welded section. Consequently, the titled core material, which consists of a hollow board body surrounded by a front board 21, a rear surface board 22 and side walls 23 and in which the reinforcing plates 24, 25 are integrally formed between the front board 21 and the rear surface board 22, is obtained. |
