GB145612A - Improvements in the process for manufacturing flexible paper tubes - Google Patents

Abstract

145,612. Keller, E. Aug. 25, 1917, [Convention date]. Void [Published under Sect. 91 of the Act]. Bending, cupping, creasing, scoring, and the like. - In a process for manufacturing flexible paper tubes, a plain paper tube is first provided with comparatively shallow helical grooves, then compressed in an axial direction when moist, and allowed to dry. Fig. 1 shows one method of producing the shallow grooves on the tubes. The paper tube 5 having been slightly moistened is slipped over the threaded spindle 1 and secured thereto at one end by the locking device 4, so that the tube 5 and the spindle 1 may rotate together. The threaded nut 3, which although capable of moving along the spindle is secured against rotation, is slid over the tube 5 and the spindle 1 rotated. The threads of the nut 3 force the walls of the tube 5 into the threads of the screw spindle 2 thus producing the desired grooves. In a modified arrangement shown in Fig. 2, the nut 3 and the threaded spindle 2 remain stationary, while the paper tube 5 is rotated around the spindle and drawn between the nut and spindle to produce the grooves. In both constructions the depth of the nut thread, and in the second construction the spindle thread also, is gradually increased from the inlet towards the outlet end, to secure a gradual shaping of the paper tube. An oscillating movement may be imparted to the nut 3 to prevent the scraping of the paper and to facilitate working.