| 摘要 |
940,803. Moulding skinless articles of sponge polyurethane. ROTH FRERES S.A. Oct. 30, 1961 [Nov. 9, 1960], No. 38718/61. Heading B5A. Skinless sponge polyurethane articles are moulded from a mixture of an isocyanate resin and activators, in a mould lined with a film which will adhere to the mould surface and to the skin which forms upon the article during polymerization. The moulding mixture is introduced into the lined mould and the mould heated to partially polymerize the mixture. The partially polymerized article is then removed from the mould during which process the skin formed on the article adheres to the lining film, and is retained within the mould with said lining. Polymerization is then completed outside of the mould. The mould lining film and its adherent skin are easily removed for speedy re-use of the mould. Such a film may be obtained by brushing or spraying a fluent substance, e.g. a solution of rubber latex or a pulp suspension on to the mould surfaces and allowing it to dry. The film may be preformed and applied to the mould surfaces by a vacuum technique.
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