Compression composite molding

CCM compression composite molding CGATS Committee for Graphic Arts Technolo-... 

Composite molding n. The process of molding two or more materials in the same cavity in the same shot, but a combination of transfer and compression molding. For example, in making a ring gear, a loose nylon-fiber-filled material is loaded into an open mold around the tooth circle, the mold is closed, and then molten nylon is injected by transfer molding. 

Pillai, K. M., Tucker, C. L. and Phelan, F. R., Numerical simulation of injection/ compression liquid composite molding. Part 2 Preform compression . Composites Part A Applied Science and Manufacturing, 32(2), 207-220, 2001. 

Fillers enhance most of the properties of phenoplasts and aminoplasts, but the resulting effects depend on the nature of the fillers and on their content in the composites. For example, the effect of wood flour content on the resistance to compression of molded objects goes through a maximum at about 25% by volume, as shown on Fig. 4.1. 

Eoamable compositions in which the pressure within the cells is increased relative to that of the surroundings have generally been called expandable formulations. Both chemical and physical processes are used to stabilize plastic foams from expandable formulations. There is no single name for the group of cellular plastics produced by the decompression processes. The various operations used to make cellular plastics by this principle are extmsion, injection mol ding, and compression molding. Either physical or chemical methods may be used to stabilize products of the decompression process. 

Pewter. Modem pewter may have a composition of 90—95 wt % tin, 1—8 wt % antimony, and 0.5—3 wt % copper. Lead should be avoided by contemporary craftsman because it causes the metal surface to blacken with age. Pewter metal can be compressed, bent, spun, and formed into any shape, as weh as being easily cast. A wide variety of consumer articles ate available from domestic and foreign manufacturers. Reproductions of pewter objects from colonial times, some cast from the original molds, ate popular. The annual U.S. production of pewter exceeds 1100 t. 

Kohli et al. [27], for instance, showed that the tensile modulus of a highly drawn PC-TLCP composite could be modeled effectively by the simple additivity rule of mixtures, while the compression molded composite samples with a spherical TLCP morphology had moduli according to the inverse rule. In both cases, the tensile modulus of the TLCP (Ei,c) itself was assumed to be a constant value determined from a tensile test of the pure TLCP samples. But whether or not the dispersed TLCP fibers and deformed droplets have the same modulus as the bulk TLCP samples remains a question. 

This low pressure process, also known as elastic reservoir molding, consists of making basically a sandwich of plastic-impregnated open-celled flexible polyurethane foam between the face layers of fibrous reinforcements. When this plastic composite is placed in a mold and squeezed, the foam is compressed, forcing the plastic outward and into the reinforcement. The elastic foam exerts sufficient pressure to force the plastic-impregnated reinforcement into contact with the heated mold surface. Other plastics are used. 

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