| 摘要 |
PURPOSE:To form a synthetic resin tube with helical hollow projected lines of good accuracy by retaining a synthetic resin line material in a molding space, transferring the same successively on the molding rotating shaft together with the helical movement of an endless molding belt and fusion bonding inner peripheral ends of respective resin line materials in contact with each other on the molding rotating shaft. CONSTITUTION:When a synthetic resin hole line material 16 is fed from an extrusion molding machine 15 into a molding space 14 on a molding rotating shaft 3, a hollow reinforced section 16a of the synthetic resin hollow line material 16 is formed by belts 10 and 12. The same drives to expand by means of internal pressure and brought into contact with the belts 10 and 12 and shape retained, while both end surfaces of a flat section 16b pressed by an endless molding belt 10 are integrally fusion bonded successively to form a continuous flat tube wall. Thus, a synthetic resin tube constituted of a flat tube wall B having helical hollow projected lines A formed by a hollow reinforced section 16a and also having the inner surface of same diameter over the whole length by a flat section 16b is formed while being transferred continuously on the molding rotating shaft 3 heading for the winding end surfaces of the belt 10 and 12. |
