| 摘要 |
PURPOSE:To obtain a plastic duct having a flange of high strength, by inserting an apex part of a mandrel in a through-hole of a reinforcing member, placing the reinforcing member in a parison, pressing the inner wall of the parison on the side of the reinforcing member, pressing the parison on the inner wall of a mold by feeding air and molding a specific shape. CONSTITUTION:An apex part 50a of a mandrel 50 is inserted in a through-hole 25 of a reinforcing member injection-molded in advance by using a resin such as polypropylene and so on, and the reinforcing member 26 is thereby held on a flange part 50b of the mandrel 50. The reinforcing member 26 supported on the mandrel 50 is placed in a parison 51 whose cross-section is a ring-shape and made of a resin such as polypropylene and so on. Mold 52 and 53 are pressed on the outer circumference of the parison 51 to press the inner wall 51a of the parison 51 on the side of the reinforcing member 26, and at the same time, air is fed in the parison 51 to form the parison 51 to a specific shape. The molded item is taken out of the molds 52 and 53 and the mandrel 50 and a plastic duct whose flange part is reinforced is thereby easily prepared. |
