Abstract: A method for manufacturing a plastic object may include the steps of: (a) providing an injection moulding device with a mould that includes two mould parts which in a closed position define a mould cavity; (b) providing foaming means for causing foaming in the mould cavity of plastic injected into the mould cavity; (c) providing blocking means for temporarily rendering the foaming means effectively inactive; (d) energizing the blocking means; (e) choosing as plastic a mixture of two plastics, wherein the first plastic is a non-type A plastic and the second plastic is a type A plastic that constitutes a maximum of roughly 30 percent by mass of the mixture, wherein the type A plastic is a plastic with high melt strength compatible with the first plastic, for instance HMS PP which is high-melt-strength polypropylene; (f) causing a formed object to cool to a chosen temperature, opening the mould cavity and removing the cooled object.

Abstract: A method for manufacturing a plastic board comprising a sandwich-like structure comprises the steps of: (1) providing an injection moulding device with a mould which comprises at least two mould parts displaceable relative to each other by displacing means, which mould parts in a closed first extreme position bound a mould cavity connecting onto an injection unit and in an open second extreme position release a formed board for removal; (2) providing foaming means for causing foaming in the mould cavity of plastic injected into the mould cavity; (3) providing blocking means for temporarily rendering the foaming means inactive; (4) energizing the blocking means; (5) energizing the injection unit in the first extreme position of the mould; (6) ending the energizing of the blocking means; (7) ending the energizing of the injection unit; and (8) displacing the mould parts relative to each other.