A DIRECT EXTRUSION PROCESS FOR PREPARING A COATED SUBSTRATE

摘要

A direct extrusion process for preparing a coated substrate from a viscous coating composition which comprises:(a) feeding the component material or material of a coating composition into an extruder,(b) advancing the material or materials forward in the extruder barrel to obtain a molten homogeneous composition, and(c) passing the homogenous composition through an elongated extrusion die directly onto a substrate as it moves on a coating roll post the orifice of said die to form a coated substrate, whereinsaid orifice is positioned over said coating roll in such manner that the distance between the substrate and the die orifice is no greater than about 50 mils,said substrate is drawn to the die orifice from the direction such that the angle formed between a line representing the direction of approach of the substrate and a line representing the direction of extrusion is less than 90 degree , andsaid coated substrate is drawn away from the die orifice in a direction such that the angle formed between the direction of extrusion and a line representing the initial departing direction of the coated substrate immediately on formation is no greater than 90 degree.