SMC (Sheet Moulding Compound) and <B><I>BMC (Bulk Moulding Compound)</I></B> are fibre reinforced composite materials which primarily consist of inorganic ingredients. The organic plastics content is less than 30 per cent by weight: unsaturated polyester resin, a thermosetting resin, which cures by means of a <B><I>cross-linking</I></B> reaction. Fibre glass reinforcement guarantee superior mechanical properties. Additional additives like low-profile components, fillers, release agents, catalyst, process additives etc. are used to enhance the performance or processing of the material.
<>Glass fibres in SMC are chopped into length of 25 or 50 mm. BMC usually contains fibres of 6 or 12 mm length. The amount can vary from 20 to 60 per cent by weight.</P>
<>As with any material system, be it metallic or plastic, SMC can be formulated to meet specific performance requirements of each material. Such as high tensile strength, high dimensional stability, high heat resistance, excellent electrical performance, class “A” surface, low density, chemical stability, corrosion resistance etc. </P>
SMC/BMC offer many design advantages in part consolidation. Different wall thicknesses, sharp angles, ribs and bosses are feasible. The design flexibility offered by SMC is a good starting point for the consolidation of parts and functions, leading to high performance solutions, at reduced costs.</P> |