Compression Mold

compression mold

[kəm′presh·ən ‚mōld]
A mold for plastics which is open when the material is introduced and which shapes the material by heat and by the pressure of closing.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Compression Mold


(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.


Leikin, N. N. Konstruirovanie press-form dlia izdelii iz plasticheskikh mass, 2nd ed. Moscow-Leningrad, 1966.
Demin, E. N. Spravochnik po press-formam. Moscow, 1967.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
A process for stabilizing a product from a pledget, comprising the steps of: providing a pledget into a compression mold; compressing said pledget in said compression mold to form a compressed pledget; unloading said compressed pledget from said compression mold and loading said compressed pledget into a stabilization mold by a transfer member, whereby said transfer member advances to a loading position; retracting said transfer member to a stabilizing position; stabilizing said compressed pledget in said stabilization mold to form a stabilized product, wherein said transfer member remains in said stabilizing position during at least a portion of the step of stabilizing said compressed pledget; and unloading said stabilized product from said stabilization mold.
Mold filling of the injection/compression molding process is comprised of two stages: first, injection mold filling of polymeric melt into a mold cavity with a slightly open mold, and subsequently compression mold filling into the rest of the cavity while closing a movable mold.
The machine can be used to injection compression mold a double pad with numerous bodywork plugs using valve gate cold runner technology.
It uses a pair of extruders--one to melt the resin and another to combine the melt with precut glass and then extrude a "log" which can be robotically transferred to an injection cylinder or compression mold. CPI took a Pushtrusion license last year.
Azdel, Inc., a joint venture of GE Plastics and PPG Industries, is exploring it to compression mold Class A car parts from SuperLite glass-mat thermoplastic (GMT) composite sheet.
Offers 2-D CAD; 3-D CAD/CAM; large CNC machining; small and large high-speed CNC machining, grinding, polishing; small and large EDM; large CNC EDM, sawing, gun drilling, CMM inspection; and injection and compression mold tryout.
The sheets are heated for i to 2 min in a microwave oven and then are cut into charges automatically and robotically transferred to a compression mold.
PTT makes it possible to compression mold cellulose without thermally degrading it because FITs melt temperature at 437 F is so much lower than PET's (490 F).
SACMI builds CCM systems in which a plastic profile is continuously extruded and cut off into blanks that are automatically deposited into individual compression molds that move continuously on a conveyor.
In addition, compression molds are often made of aluminum because they are geared towards prototyping or low volume runs.