Method of making expandable polystyrene packaging materials

摘要

An extrudable mass of thermoplastic polystyrene and blowing agent is provided with an olefin, e.g. polyethylene, or polypropylene in an amount of from 1% to 5% by weight of the mass. The resulting pellets that are processed from the extrudate are characterized in being dust free and in having a smooth shiny skin without cracks, a sponginess greater than a conventionally made polystyrene pellet and a bulk density of less than 0.2 pounds per cubic foot.