PREPARATION OF THERMOPLASTIC RESIN SHEET WITH EMBOSSED PATTERN HAVING LARGE UNEVENNESS

摘要

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 0.2-2.5mm. and this sheet is adjusted to a range from temp. 20 deg.C higher than a Vicat softening point to temp. 50 deg.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 2-10 times the thickness of the sheet. The Vicat softening point is measured according to ASTM D-1525.