| 摘要 |
PURPOSE:To provide the said laminated tube which is round, stable in quality and excellent in durability by a method wherein a reinforcing net and external layer resin are wound in a unitary body around a thermoplastic resin tube in which compressed air is charged. CONSTITUTION:A plurality of threads 2a are knitted with a knitting machine at a specified angle around a thermoplastic resin tube 1 having a length of 100-200m in which compressd air is charged to obtain an intermediate 3 covered with a reinforcing net 2 having a uniform net work. Then, this product 3 is introduced into a die 5 and nozzles 6 of an extrusion molding machine and the external layer thermoplastic resin 4 fused at a high temperature is joined and sticked to the external circumference 8 of the product 3. At the same time the tube 1 is softened by large heat of the resin 4, swollen into the space of the net 2 by means of expansion of the air in the tube 1, and the tube 1, the net 2 and the resin 4 are bonded closely and cooled through the internal part of a cooling device 13. |
