| 摘要 |
1316589 Moulding tubes POLYTUBE Inc 25 Aug 1970 [28 Aug 1969] 40864/70 Heading B5A [Also in Divisions B8 and F2] A flexible cylinder for use as the body of a collapsible, tubular container, e.g. for toothpaste, is made from a laminate of metal foil sandwiched between plastics layers, the laminate being convolutely wound through approximately 720 degrees (Fig. 6), placed in a cylindrical mould, urged outwardly against the mould surface by an inflatable mandrel, and heated by conduction through the mould so that the plastics layers fuse together (Fig. 4). The foil 110 may be of aluminium and the plastics material 106 polyethylene. The convolute winding is effected in a chamber 138, Fig. 12, having a tangential entry 150, by a driven rubber roll 154. The cylindrical preform is then pushed from chamber 138 into one of a number of cylindrical moulds 142b, Figs. 16, 17 and 23, mounted on an indexable table, Figs. 18, 20-22 (not shown). After indexing the table one step a rod 174 carrying a balloon mandrel 172 is inserted and inflation to the Fig. 17 position effected. The wall thickness of balloon 172 increases towards its ends so that inflation begins midway along the balloon's length. This ensures elimination of air from between adjacent turns of the cylindrical preform. Semicylindrical heating blocks 212 are now clamped around the mould 142b. After fusion of the plastics layers, the table is indexed to move the mould 142b through three cooling stations, at each of which cooling shells, similar in form to heating shells 212, are clamped around the mould. The balloon 172 is deflated and immediately reflated between the second and third cooling stations and is finally deflated after the third cooling station to break any bond between the formed cylinder and the mould. To remove the cylinder from the mould, a pick-up tube, Figs. 27-34 (not shown), similar in form to the inflatable mandrel, is inserted into the cylinder, inflated, withdrawn (together with the cylinder) from the mould, deflated and passed longitudinally through a slot in a plate to strip the cylinder from the pick-up tube. |
