SMC(Sheet moulding compound) is a fiber reinforced thermoset material,in the form of a malleable sheet material, that is used to make glass reinforced plastic (GRP) products. It is formed into products by compression moulding.
Compression moulds is usually designed with hydraulic cylinders with folw diverters for the ejection side.Matched mould are mounted in a hydraulic press machine,a measured charge of moulding compound is placed in the open mould,for example,SMC was cut into desired shape,peeling off the protective film on bothside,overlapped according to a certain requirements,then placed in the mould on proper position.we need to know,Placing the compound into the mould is fairly easy,but orienting the various layers of material correctly requires training and experience.The heated mould halves are closed in the press under very high pressure ranging from 800 psi to over 2000psi,depending on material type,thickness,size and shape of par.The mould remains closed for a set peried of time based upon the given material,cycles time range from less than a minute to about nine minutes.This allows the resin material to melt and flow within the mould,thus completely filling the void between the two mould halves before solidifying,then remove the product from the compression mould.
SMC used worldwide and represent a major part of the world's thermoset composites.
In the automotive and truck industries, SMC parts are used notably in exterior and interior body panels,painted (class A parts) and unpainted, semistructural and structural parts . Basically, class A means that the surface finish has to exhibit an aspect of flatness,smoothness, and light reflection similar to that of stamped steels.A nonexhaustive list of automotive parts gives, for instance, bumpers, fenders, trunk divider, hood and door assemblies, deck lids, body panels, fenders, roof panels, spoilers, step assists, back panels, wheelhouses, firewalls,grilles, tailboards, cargo lids, stowage tubs, headlamp housings, and supports. More recently, high temperature underhood parts have been developed.
