GB861447A - Process and machine for manufacturing a sealed cell assembly - Google Patents

Abstract

861,447. Laminated or moulded plastic sheet materials. POLIBENTO S.r.L. April 18, 1957 [April 24, 1956; Nov. 14, 1956; Dec. 18, 1956; April 4, 1957]; No. 12726/57. Class 140. [Also in Groups V and XVII] Thermoplastic materials, e.g. polyvinyl chloride or polythene are continuously formed by extrusion into parallel longitudinal tubes having their outer surfaces integrally connected, and are then heat-sealed along lateral lines to form cells into which is introduced compressed gas, liquids, pastes, powders or individual articles at the open end of the cells; which are sealed by heat and pressure effected by cooperating blades operating intermittently to divide the tubes into sequences of individuallysealed cells containing the material fed in. The plastic material is heated in a cylinder 2, Fig. 1, and is forced by a feeding screw through a slotted die 10, Fig. 4, having circular recesses at intervals, each with a central core 11 fixed by bridge arms 12. The cores are connected together by a feed-pipe 13 communicating with injection pipes 15, terminating in flexible airtight funnel nozzles 16. The extrusion sheet 4 consisting of a laterally connected tube assembly is filled with compressed gas, liquid, &c. through the injection tubes 15, and the filled tubes are then sealed between welding- blades 140 which apply heat and pressure to weld the filled tubes at predetermined intervals. The blades 140, Fig. 2, are reciprocated by levers 142 actuated by cams 143, and are provided at the pressure face with a silicone rubber pad in which is fixed an electricallyheated welding wire held by a sheet of P.T.F.E. During welding the tubular assembly is momentarily held stationary and the extrusion is allowed to deform in the region before the welding blades, and immediately after welding the assembly is drawn forward at slightly increased speed to correct the deformity. In a modification, a plurality of spaced welding- blades are provided, each with respective lever and cam units. The dies used to form the tubular sheet may be circular as shown or oval, triangular, or square section; and a bank of such dies may be used to form two or more interconnected layers of tubes. When solid articles are inserted, e.g. nuts and bolts, the feed-pipe 13 is dispensed with and the injection pipes 15 are extended upwards through the cores 11 to a suitable feed apparatus which supplies the articles at timed intervals to leave free welding spaces in the tube being filled. The filled assembly'may be severed into individual cells by cutting members to provide a series of the packed materials. Before severing the packed tubular assembly may be provided with a covering layer of textile or fibrous material. The products may be used as capsules for. packing materials as described, or as protective coverings, upholstery stuffing or buoyant garments, when filled with air or other gas, the pressure of which may be varied.