| 摘要 |
1,161,014. Method of making paper tubes. TETRA PAK A.G. 27 Sept., 1967 [28 Sept., 1966], No. 43897/67. Heading F2P. In a method of producing an unkinked tube from a web 2 of material, e.g. paper having on one, or both, sides a synthetic plastics coating, in which method the web is passed over a guide roller 3 and slidably through a forming ring 5, after having run over the guide roller and before entering the forming ring, the web is passed through a gap defined between two deflecting rods 4a, 4b disposed substantially perpendicularly to the axis of the tube to be formed. The synthetic plastics coating is preferably polyethylene which welds when subjected to heat. Side guide members, e.g. smooth cylindrical pins 6a, 6b, are preferably provided to urge the curled edge portions 2b, 2b off the roller 3. The pins 6a, 6b could be replaced by lightly spring- loaded rollers. The deflecting elements 4a, 4b which are inclined slightly downwards, could be replaced by completely straight rods which may be placed parallel to each other. The web 2 is continuously drawn from a rotatable supply roll 1 and the guide roller is preferably resiliently supported by springs 7 so that, when one or more sealing jaws, not shown, are clamped across the formed tube after it leaves the ring 5 in order to form transverse seams for making packages, undesirable fluctuations of speed, caused by the sealing jaws, are avoided. The rods 4a, 4b are preferably adjustably spaced. |
