| 摘要 |
802,292. Making containers and closures therefor. BASSAN, M. R. May 1, 1956 [May 12, 1955 ; July 13, 1955], No. 13408/56. Class 87(2). [Also in Group XVII] A process for the manufacture of containers having walls made of thin flexible sheets of thermo-weldable plastic material comprises injection moulding, at at least one of the extremities of the body, a reinforcing rib of the same plastic material onto those edges that are to be joined, the material being injected at a temperature sufficient to produce fusion of the plastic material constituting the thin walls. In Fig. 2, the mould comprises a dished outer part 33 having a gate 34, and a piston-shaped inner part 35 having an annular rubber gasket 36 for co-operating with a rim 37 on the part 33. In operation, a tube 38 of thermoplastic sheet material is stretched over the rubber gasket 36 and a thermoplastic end sheet 39 is placed on the inner part 35. The outer part 33 is then placed in position and a plastified thermoplastic material is injected through the gate 34 to form ribs uniting the tube 38 to the sheet 39. Strengthening ribs may at the same time be moulded onto the sheet 39. The container may be closed by flattening it at its upper end as in Fig. 4 and inserting the flattened end into an injection moulding machine for applying thereto a reinforcing strip 6 complete with handle 11, screwed spout 7 and screw cap 9. Fig. 6 is a cross-section through a mould for this purpose. It comprises two parts 20, 20a having cavities for making the parts 6, 7, 9 and 11, the spout-cavity 22 containing a core for forming the passage of the spout 7. The flattened top edges of the container walls 27 are inserted from below into the cavity 21, the base of the cavity 21 being sealed by a rubber gasket 29. An injection gate 25 is made in the mould part 21. Polyvinyl chloride and polythene are suitable plastics. Several different containers (see Group XVII) are described. The stiffening ribs may be reinforced by metal wires, fiber threads or other material of high tensile strength. |
