PREPARATION OF RAW MATERIAL PELLET FOR MOLDING OF BOX FOR ELECTROMAGNETIC SHIELDING

摘要

PURPOSE:To make it possible to prepare easily a pellet for injection molding contg. a metal fiber obtd. by means of a coil cutting method by a method wherein a bundle of the metal fibers prepd. by means of the coil cutting method have a mixed soln. of a polystyrene and a styrenic thermoplastic elastomer deposited on them and after the solvent is removed, the bundles are collected and are cut into a specified length. CONSTITUTION:A thin metal sheet 1 such as brass is wound on a mandrel 2 and a metal fiber 3 with a rectangular crosssection is prepd. by means of a cutting bite 4 etc. As this fiber 3 is short in length but is lightly entangled each other, it is possible that the fibers are collected together into a long bundle 5. This bundle 5 is impregnated with a 30% toluene soln. of a 50/50 mixture of a polystyrene and a styrenic thermoplastic elastomer and is squeezed through a die and is immediately dried by heating and is pelletized by means of a pelletizer. It is possible thereby to obtain a pellet with an extremely high metal content without bringing the fibers into separated pieces.