PURPOSE: To prevent current from leaking to dies and to control electrolytic deterioration of a polymer and to stabilize operability and to increase productivity and quality of a film by coating dies used for manufacture of the film and a sheet through extrusion of a molten polymer with ceramic.
CONSTITUTION: A pair of dies are made of carbon steel and have extrusion width 220mm. Both the flat surface of the upper part by 30mm from the discharge lower end on the internal surface of tips touching molten resin and the flat surface of the external surface 10mm of Tips are coated through exposure with γ-alumina at about 250μm thickness. Ruthenium carbonyl is added to a xylene solution containing 20wt.% perhydropolysilazane (average molecular weight is about 1200) at 300ppm. The xylene solution is applied to the coated surface. After the coated surface is air-dried and preliminarily dried at 80°C, it is burned at 300°C to perform sealing treatment. Then diamond grinding stone of No. 400-1200 is used and the coated surface is ground by a precision grinding machine.
SUGIMOTO MASANORI
MATSUMURA YUTAKA
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