| 摘要 |
788,536. Oil-coated thermoplastic sheet or tube. RADO, L. May 5, 1954 [May 28, 1953], No. 14900/53. Drawings to Specification. Class 140. [Also in Group XVII] A liquid or paste-filled container of plasticised thermoplastic material, e.g. p.v.c., has its inner walls coated with a thin layer of an oily substance, e.g. liquid paraffin, to isolate the plasticiser from the liquid or paste. If the container has double walls, an additional layer of oily substance may be introduced between the walls. The coating may be applied to the sheet material from which the container is formed or, in the case of containers formed by filling and subdividing a length of extruded tubing, the latter may be coated internally before filling by introducing a small quantity of the oily substance at one end and passing the tubing through compression rollers so that the substance is caused to flow through the tubing to the other end. Alternatively, the tubing may be inclined upwardly and the substance introduced at the lower end which is then connected to means for filling the tubing with liquid or paste under gravity or other pressure, the filling material pushing the substance before it as it fills the tubing. The oil may be heated to a temperature below the softening point of the thermoplastic material to facilitate its application. Specification 599,174, [Group XVII], is referred to in the Provisional Specification. |
