Forming plastic panels
AssigneeIPCO Ventures Limited
InventorsPeter Aylmore, Simon Wiper
Life of this patent
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Abstract
A method of moulding articles from powdered material, comprising the steps of laying down at least two layers of powdered material of different granular fineness which include a heat mouldable material, in an open-topped mould, applying a top closure to the mould, and then heating the mould and the closure to melt and fuse the powdered material. In this way an article such as a building panel can be made to include recycled material, with three layers, including two outer skins of relatively fine-grained material, and an inner core including coarse-grained material such as ground-up waste.
Claims24
A method of moulding articles from powdered material, comprising the steps of
- (a) laying down a first layer of material of a first granular fineness, in an open-topped lower mould;
- (b) laying down a second layer of material of a second granular fineness, on top of the said first layer;
- one of said layers including a foaming or blowing agent, and the other of said layers including heat mouldable material;
- (c) applying a top closure to the mould;
- and
- (d) heating the mould to melt and fuse the heat mouldable material while the foaming agent is activated to expand, and thereby form the article in the mould.
A method of moulding articles from powdered material in a mould comprising upper and lower halves, the method comprising the steps of:
- (a) laying down a first layer of relatively fine-grained heat mouldable material in a lower mould to form a lower layer;
- (b) laying down a second layer relatively coarse-grained material including a foaming or blowing agent to form a central core layer;
- (c) laying down a further layer of relatively fine-grained heat mouldable material to form an upper layer;
- (d) causing relative movement between the upper and lower mould halves so that the upper mould contacts the upper surface of the upper layer so as to enclose the layers of material in the mould;
- and
- (e) applying heat to the mould so as to fuse the outer layers of material to form a skin, while the central layer is foamed so that it expands and fuses with the two outer skin layers, and the outer surfaces of the upper and lower layers are thereby moulded into close contact with the inner surfaces of the mould halves.
Dependencies are inferred from the claim text.