GB990351A - Method and apparatus for producing pressure-moulded articles from chip board or like material - Google Patents

Abstract

990,351. Compression mouldings. FORMWOOD Ltd. July 31, 1963, No. 30390/63. Heading B5A. Compression mouldings of organic or inorganic fibrous materials, e.g. wood chips, and a thermosetting binder are made in a two-stage process, the first stage comprising compression without the application of heat to form an evenly compressed blank 10, Fig. 2, slightly larger and of the same general shape as the final article 9, Fig. 1, and the second stage comprising compression in a heated mould in which one or more corners and edges of the blank are more highly compressed than the main body of the article. The mould for the second stage of the process is shown in the open and closed positions in Fig. 2 and Fig. 1 respectively, the compression being effected by first bringing the mould sections 1, 2, 3, 4 in pressure contact with blank in the position shown in Fig. 2 and finally moving the sections 2 and 4 relative to sections 1 and 3 respectively to the position shown in Fig. 1 to produce an article with corners 13, 14, 15, 16, 21 more highly compressed than the rest of the article. The strength of the corners may be increased by adding additional resin to these parts. The resistance of the article to particular external influences may be increased by the use of particular resin binders, e.g. phenolic resins, to increase weather resistance and by the addition in the preparation of the fibrous material of various substances, e.g. naphthalene chloride to protect against insects and silicones to make the -material waterrepellent. The article may be given a thin covering of synthetic plastic or other suitable material, e.g. paper or wood veneer, by removing the article 9 before the binder is completely set and applying the covering to the core 9 or to the pressure surfaces of the mould before completing the pressing.