PROCESS FOR PRODUCING THERMOPLASTIC RESIN SHEET WITH CONTROLLED WARPAGE

摘要

A process for producing a thermoplastic resin sheet with controlled warpage, characterized in that in the extrusion forming of a thermoplastic resin sheet, mechanically controlled warpage is applied to the sheet at the position where the temperature of extruded sheet is close to the glass transition temperature (Tg) of the thermoplastic resin constituting the sheet. In this process, preferably, mechanically controlled warpage is applied to the sheet by causing the sheet to pass through a gap of a vertical pair of warp controlling rolls at the above position and selecting the morphology of the warp controlling rolls and/or arranging the warp controlling rolls above or below the height for realizing a flat sheet. By this process, the thermoplastic resin sheet with controlled warpage can be efficiently produced in an easy manner.