Verfahren zur Herstellung von mit einem thermoplastischen Kunststoff ueberzogenen Formkoerpern aus Metall

摘要

A method of making articles, e.g. food containers, from metal or metal foil comprises coating the metal sheet with a thermoplastic synthetic resin, forming the coated sheet into the article, e.g. by deep drawing, and annealing the resin coating by heating it to its melting point, the minimum rate of heating being related to the time elapsed since the forming operation. The metal may be aluminium and the resin vinyl or polyolefin, e.g. polyethylene or polypropylene; the resin may be pigmented. Annealing of the coating should be effected not more than one hour following the forming operation; for an elapsed time of one hour a heating up time up to 10 seconds is required. If the coating is annealed immediately after forming, heating up may occupy up to 30 minutes. A minimum heating up time of one second or less is referred to. In an example, an aluminium strip is coated with low-pressure polyethylene using high-pressure polyethylene as an adhesive.