ASTM International Standard Classification System and Basis for Specification for Polystyrene and Rubber-Modified Polystyrene Molding and Extrusion Materials (PS) ASTM D4549-15(2021)

This specification, which covers polystyrene materials, both crystal and rubber modified suitable for molding and extrusion, is intended to be a means of calling out plastic materials used in the fabrication of end items or parts. Polystyrene materials are classified according to classes after being grouped as crystal, rubber modified, and others. The materials are further classified according to grades after being grouped as general-purpose, other medium impact, high impact, super-high-impact, and others. The materials shall conform to the prescribed injection molded properties and natural colors.