PRODUCTION OF THERMOFORMED ARTICLE FROM POLYESTER RESIN SHEET

摘要

PROBLEM TO BE SOLVED: To obtain a thermoformed article excellent in heat resistance and appearance such as a surface state or form from a polyester resin sheet. SOLUTION: A substantially unstretched polyester resin sheet is preheated to 60-95 deg.C and thermoformed within a thickness range satisfying the formula: 3<=t0 /t1 <=20 to form a thermoformed article and this article is brought into contact with a female mold set to a temp. of 130-270 deg.C and heat-treated within a thickness range satisfying the formula: 0.5<=t1 /t2 <=2. In the formulae t0 is the average thickness (mm) of the polyester resin sheet before thermoforming; t1 is the average thickness (mm) of the thermoformed article before heat treatment; and t2 is the average thickness (mm) of the thermoformed article after heat treatment.