| 摘要 |
<p>PURPOSE:To manufacture a large diameter pipe for underground installation with a sufficient pressureproof property and a light weight by winding a belt member made of a hard polyvinyl chloride belt body with a U-shape section, which consists of a middle part and both ribs, and a soft synthetic resin material weld to the outer surfaces of the sides of the ribs, in a spiral form, and fusing and connecting the ribs each other. CONSTITUTION:A belt body 1 made of a hard polyvinyl chloride (hard PVC) is formed of a plain belt-form middle part 1a and projecting ribs 1b and 1b, making the section form into U-shape. At the outer sides of the both ribs 1b and 1b, a soft polyvinyl chloride (to be called soft PVC thereafter) materials 2 and 2 with an excellent fusion property with the hard PVC are weld integrally to form a belt member A. The belt member A is wound in a spiral form by making the recess of the U-shape of the hard belt body 1 face outer side, the soft PVC materials 2 and 2 welded to the ribs 1b and 1b are welded to each other, and then the ribs 1b and 1b are welded and connected each other to form a pipe P. Consequently, the pipe can be formed easily only by winding a single belt member.</p> |
