These plastic casings are usually a composite material made up of a thermoplastic matrix such as acrylonitrile-butadiene-styrene ( ABS ) in which calcium carbonate chalk , talc , glass fibers or carbon fibers have been added for added strength , bulk , or electrostatic dispersion .
These plastic casings are usually a composite material . It is a thermoplastic matrix such as acrylonitrile-butadiene-styrene ( ABS ) in which calcium carbonate chalk , talc , glass fibers or carbon fibers have been added for added strength , bulk , or electro-static dispersion .