XMC™ and HMC™ are two families of fiber glass reinforced molding sheets that can be processed into structural shapes through the use of heated matched metal dies and hydraulic presses. The need to remove weight from power driven vehicles has increased in direct proportion to the world-wide energy shortage, and in light of this XMC™ and HMC™ were designed to compete with high density, high strength metals commonly used in structural parts for the transportation industry.
XMC™ and HMC™ are distinguished from other molding compounds by their very high percentage of fiber glass (up to 80% by weight) which is incorporated into thickenable, thermosetting resin systems. XMC™ utilizes filament winding techniques and programmed winding angles to incorporate continuous strands of fiber glass. Upon completion of the filament winding process, the XMC™ is removed from the mandrel as a to continue before molding. HMC™ utilizes chopped fiber glass strands and is produced by the same processing methods as are used in the manufacture of SMC.
TM = Trademarks of PPG Industries, Inc.
The development of XMC™ and HMC™ as unique, high strength molding materials offers the automotive manufacturers a much needed capability to remove weight from the American automobile. XMC™ is expected to be used in such applications as door beams, transmission supports, and structural back-ups for bumpers while potential applications for HMC™ are radiator supports, hood inners, catwalks, and wheels. In addition to 50-60% weight reductions the consumer will also receive the superior corrosion resistance of these high strength compounds. Their ability to be shaped into high performance parts of complex configuration and non-uniform thickness gives the engineer new latitude in structural design. directionally reinforced sheet of uncured composite and its maturation process is allowed