| 摘要 |
PURPOSE:To make cutting work for splitting a synthetic resin foamed tube unnecessary and facilitate the splitting work by a method wherein a splitting member for dividing the flow of molten foamable synthetic resin and joining it again, is arranged near the outlet port of an extrusion mold. CONSTITUTION:An extrusion mold 1 is constituted of an outer mold 11 and an inner mold 12 while an annular resin passage 2 is formed between the outer mold 11 and the inner mold 12. In this case, a splitting member or a needle screw 3 is screwed from the front surface of the outer mold 11 to project it into the resin passage 2 and contact the tip end of the screw with the inner mold 12. Then, molten foamable resin 4 is sent to the site of the needle screw 3 through the resin passage 2. In this case, the molten foamable resin 4 is divided into two parts at the site of the needle screw 3 and is joined again after passing through the site. Thereafter, the molten foamable resin 4 is discharged into atmosphere to foam and cool it, and a synthetic resin foamed body tube 5 is molded. According to this method, cutting work for splitting is made unnecessary and the splitting work is facilitated. |
