| 摘要 |
<p>An extrusion molding die (50) is provided which produces a tube that contains a portion in which the cross-sectional area ratio of an inner layer and outer layer in axial cross-section continuously varies, wherein said cross-sectional area ratio can be changed in a short time. The extrusion molding die (50) moves a second inner layer mandrel (54) in the axial direction and changes the flow passage volume of an inner layer resin flow passage (62a) in accordance with changes in supply quantity of an inner layer forming resin.</p> |
