compression mold[kəm′presh·ən ‚mōld]
(also, metal die pressure cast mold), a device for producing three-dimensional castings or articles from metals, plastics, rubber, molding compounds with paraffin or stearin bases, and ceramic and other materials. In compression molding, pressure is exerted on these materials by die-casting machines or presses.
Compression molds are used in die casting of metals and injection molding of polymers, in casting by the lost-wax method, and in pressure molding of polymeric materials. They may be manual, semiautomatic, or automatic and portable, semi-portable, or stationary, with horizontally or vertically split molds. A compression mold may contain one or several mold cavities, which have inner surfaces that are the reverse of the outer surface of the castings. The interior cavities of hollow articles are shaped by dies and cores. The components of compression molds are made from carbon or alloy steel, nonferrous metal alloys, gypsum, or other materials.
A predetermined temperature balance, which depends on the material and purpose of the casting, is maintained in the mold. The mold temperature may be maintained using steam or water supplied by openings in the mold housing, by special heating rings with semiconducting layers, by electrical heating elements, or by other devices.
The use of die-casting machines and presses with compression molds to produce castings and articles is a characteristic feature in lot and mass production. Compression molding is used, for example, in the automotive, radio engineering, and electrical engineering industries. It is also used to produce sanitary-engineering equipment.
REFERENCESLeikin, N. N. Konstruirovanie press-form dlia izdelii iz plasticheskikh mass, 2nd ed. Moscow-Leningrad, 1966.
Demin, E. N. Spravochnik po press-formam. Moscow, 1967.
M. B. BEKKER