| 摘要 |
PURPOSE:To obtain a highly expandable material excellent in adhesion to a core material, thick and uniform in expansion by a method wherein expandable material is deflected and extruded from a slit die by a rotary head with the slit die having an obstacle near the outlet of the die and is wound closely round the rolling and travelling core material. CONSTITUTION:When the obstacle 10 to hinder the flow of the expanded material 3 is put near the outlet of the slit die 9, the expanded material 3 is extruded and bent to the side (lower side) of the obstacle 10 to make an expanded body 12. At this time, when the core material 1 is advanced at a suitable speed in the direction of an arrow to rotate the head part A of an extruder with the slit die 9, the expanded material 12' being extruded is put helically and closely around the core material 1, the expanded body layer 12 is made on the core material to obtain a long heat insulating pipe. |
