| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sheet having excellent quality in good productivity by melting a thermoplastic resin, extruding the melt into a molten sheet, and solidifying the molten sheet by cooling its surface by insertion into between a charging roll composed of a metallic part and a non-metallic part and a cooling medium. SOLUTION: A thermoplastic resin such as a polyester resin is molten and extruded into a molten sheet. The molten sheet is cooled and solidified by insertion into between a charging roll with a surface composed of a metallic part and a non-metallic part (an areal coverage of 20-80%) and having an applied voltage of 100 V to 10 kV and a cooling medium such as a casting drum. If required, the sheet is heated to the glass transition temperature or higher and subjected to stretching and heat-treatment. The surface of the charging roll is composed of a metallic part such as carbon steel, stainless steel or those chrome-plated thereon and a non-metallic part such as a silicone resin and has a surface roughness of 1S or below. The drum acting as the cooling medium has a hard-chromium-plated surface and has a surface roughness of 0.5S or below.
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