| 摘要 |
1311795 Producing moulding surfaces IMPERIAL CHEMICAL INDUSTRIES Ltd 19 April 1971 [4 March 1970] 10431/70 Heading B3A A process for the production of moulding surfaces comprises forming a metal shell 1 around a model 2 of an article to be moulded wherein an insert, 9, provided as part of the metal shell, said insert being adapted to receive and receiving at least one other insert within the mould cavity. Insert 9 has a recess 10 which takes an insert 11 during formation of the shell but is then removed so that recess 10 will form a rib in an article produced in the mould. The insert is preferably an aluminium alloy and is threaded so that it will key with the metal shell. Insert 9 is held in position on the model surface by a pin which engages with the insert and the model. The metal shell can be produced by metal spraying (flame or compressed air) or by electro-deposition of metal. Further, the metal shell can be provided with pipes for cooling the resulting mould. One or more layers of reinforcing material, e.g. cement, plaster of Paris or an epoxy resin may be applied to the shell which may also be impregnated with a curable resin. The impregnated shell may be plated with one or more thin layers of metal on the face against which the moulding is to be formed viz. copper, nickel or chromium. With flame spraying the metal is preferably zinc or aluminium whereas if compressed air spraying is used low melting alloys such as bismuth/tin alloys are preferred. |
