| 摘要 |
<p>1439353 Moulding reclaimed plastics PLASTIC RECYCLING Ltd 6 May 1974 [10 May 1973 (2)] 22277/73 Heading B5A [Also in Division C3] Plastics products containing at least 50% of reclaimed thermoplastics are made by mixing particles of relatively flexible thermoplastic with fibres and/or flakes of relatively stiff, plastics, the latter being at least 10% by weight of the mixture, forming a mat of the mixture on a support, heating the mat to soften at least the relatively flexible plastics and consolidate the mat, and cooling the surface of the mat in contact with the support without substantial cooling of the remainder to facilitate removal from the support. Preferably 85-100% of the material is reclaimed plastics and at least 15% is the relatively stiff platics, the fibres or flakes of which have a maximum dimension of 0À1 to 0À3 inch and a thickness of up to 0À03 inch. The stiff plastics may be phenolic, melamine or polyester resin; polystrene; P.V.C.; H.D. polyethylene; A.B.S.; nylon or acrylic resin. The flexible plastics may be pellets, flakes or fibres of L.D. polythene, polypropylene or plasticized P.V.C. A mixture of polystyrene flakes and granules of L.D. polyethylene are dispensed from a hopper on to an endless P.T.F.E. conveyer 10 in the form of mats 18 by means of a splined roller 16. The mats are heated in an oven 22 to soften the polythene and a doctor blade 20 levels the mats as they enter. Water-cooled rollers 24 consolidate the mats 18 and air nozzles 26 cool the conveyer 10 to cool the underside of the mats. A knife 28 lifts the mats and they are immediately transferred to a press 32 for moulding into pallets, tote boxes, or building boards. The press dies need not be heated since sufficient heat is retained in the mats.</p> |
