Abstract: A polystyrene foamed sheet suitable for thermoforming and containers such as cups or trays formed therefrom, the foamed sheet comprising a polystyrene resin as the base resin which contains a specific quantity of each a rubber component and a filler, having specific bulk density, thickness, stretch ratio and residual gas quantity, and said sheet being preferably laminated with a film.

Abstract: This invention relates to a process for producing economically shaped article of polystyrene foam with a small wall thickness and sufficient strength by a continuous simple operation including a short forming cycle in which the sheet of polystyrene foam having a bulk density of 0.15 to 0.7 g/cm.sup.3, a thickness of 0.3 to 1.0 mm, 5 to 20 cell membranes widthwise of the sheet and a draw ratio of up to 1.25 and containing 0.03 to 0.3 mole/kg of the residual gas of the blowing agent is formed by an extruder and utilized to produce the shaped article.