A method for the production of open or closed packages made of foam material, preferably polystyrene foam

摘要

1315472 Making containers of foamed plastics material S E M SOLLERLID 19 April 1971 [11 Feb 1970] 21408/71 Headings B5D and B5K Containers of rigid foamed plastics material are made by simultaneously heating the edge surfaces to be joined over their whole extension until a molten layer of predetermined thickness is formed and then pressing the edges together. As shown in Fig. 2, the side walls of a container are made from a sheet 11 of foamed plastics material inserted between a former 10 and an angle member 13 and folded into the position shown in Fig. 2 by flaps 14, 15 operated by piston and cylinder units 16a, 16b. The edge surfaces of the sheet 11 are simultaneously melted by a heating means 19, the means 19 are retracted by means of a piston and cylinder unit 18, the flaps 14, 15 are further pivoted by piston and cylinder units 17a, 17b to bring the edge surfaces into contact, the assembly 10, 13, 16, 17 is rotated anticlockwise and a pressing means 20 is brought into contact with the edge surfaces whilst they set. The blank 11 is then removed from the former 10 and, as shown in Fig. 5, placed in a former 22, 23, above which a bottom plate 25 is held by suction on a plate 24. The edge surfaces of the plate 25 and blank 11 are simultaneously melted by heating means 28, the means 28 are removed, the plates 22 and 24 are moved towards each other, and a pressing and shaping device 30 is brought into contact with the edge surfaces whilst they set. A top plate may be attached to the container in a similar manner. In a modification, the surfaces of the heating means 28 may comprise alternating ridges and valleys which provide the edge surfaces of the sheets with a larger molten area for joining. The foamed plastics material may be foamed polystyrene or a laminate of foamed polystyrene and foamed polyethylene.