Polifil ® RP-HIPS combines the good stiffness properties of polystyrene, with enhanced impact properties gained by the addition of impact modifiers, usually butadiene rubber. An amorphous resin, HIPS has low post-molding shrinkage, good melt strength, and a wide melt processing window, making the resin ideal for many sheet and thermoforming applications. Injection molding applications include cutlery, appliance parts, and furniture components. Sheet extrusion applications include thermoformed plates, cups, and trays.