PURPOSE: To stably prepare an embossed pattern having large unevenness without generating strain, by heating a molten sheet formed by a calender to temp. in the vicinity of a Vicat softening point before passing the same between emboss rolls.
CONSTITUTION: A thermoplastic resin such as polypropylene, polyethylene or polyvinyl chloride is formed into a film under melting by a calender or an extruder and the formed film is cooled by two cooling rolls having a smooth surface to obtain a sheet with a thickness of 0.2W2.5mm and this sheet is adjusted to a range from temp. 20°C higher than a Vicat softening point to temp. 50°C lower than said softening point. This heated sheet is subsequently supplied between two rolls respectively engraved in a recessed and protruded state to obtain the objective sheet having unevenness 2W10 times the thickness of the sheet. The Vicat softening point is measured according to ASTM D-1525.
FURUTA SHIGEO
IKEBUKURO MASATO
DOI YOSHIO
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