High density composite plastic material - includes mineral-filled polyamide or polyester resin and is useful in forming balls for use in firing range

摘要

A plastic composite material which is machineable and can be cold-formed comprises: a polyamide or polyester with mineral particles as a filler; metallic particles; and an anti-shock additive. The content of mineral and metallic particles is such taht the density of the material is at least 3.5. The material contains at least 50% of mineral particles and brass or bronze balls. The anti-shock component is a paraloid material such as butadiene-styrene methacrylate. Compsns. are claimed as follows: Polyester resin-filled with 60-65% of mineral particles 17-25%; Paraloid 1-18%; and brass or bronze balls 55-85%. USE/ADVANTAGE - The material is mostly used in the manufacture of balls for use in practice firing ranges; it can also be used to form moulded articles such as lamp bases, vases, cups, etc.. The high density of the balls formed and their resistance to thermal and mechanical stresses enable their use in automic weapons. The presence of the anti-shock component enables successful cold-working and maching operation without fracture of the material.