Method of continuously producing heat shrinkable amorphous polystyrene foam layer

A method of continuously producing a heat shrinkable thermoplastic film and an amorphous polystyrene foam to form a heat shrinkable two-layer sheet that is easily storable without substantial shrinkage at ambient temperature and a sheet that will heat shrink rapidly at substantially lower temperatures to form a label or a cup, the method comprising the steps of:

• A. coextruding a thermoplastic film and an amorphous polystyrene foam layer to form a two-layer sheet having a continuously formed length as it is conducted away from the coextruder, the length being greater than the width of the sheet;
• B. bringing the two-layer sheet to its orientation temperature after the foam layer is formed;
• C. stretching the two-layer sheet at its orientation temperature in a longitudinal direction to reduce its thickness and provide a dimensionally stable, storable, oriented thermoplastic film/amorphous polystyrene foam sheet;
• D. printing on the oriented sheet to decorate the same to thereby provide an oriented, decorated, storable sheet;
• and
• E. heat shrinking the storable, oriented sheet to form a final attractive, decorated structure.