Patent ID: 6410094
Filing Date: 2002-06-25
Classification: B05C,G03C,G11B

Abstract:
An extrusion coating method comprising the steps of:providing an extrusion coating head extending in a width direction perpendicular to a conveying direction of a continuously conveying flexible support and including an upstream side block and a downstream side block aligned in the conveying direction, in which the upstream side block and the downstream side block respectively have edge surfaces on which the flexible support is pressed and the upstream and downstream side blocks define therebetween a slit through which a coating composition is extruding and applied onto the flexible support; providing a pair of tension rollers for pressing the flexible support toward the upstream side block and the downstream side block such as to generate a pressure p2 on a doctor edge surface based on the pressing of the flexible support; and adjusting, independently and at discrete locations along the width direction, a length (t) of a perpendicular line which is drawn from an upstream end (A) of the edge surface of the downstream side block to a tangential line (L) of the edge surface of the downstream side block which is drawn from a downstream end of the edge surface of the upstream side block, so that when the length (t) is adjusted the sum P of a pressure loss p1 during passage of the coating composition through the slit and the pressure p2 becomes uniform in the width direction of the support, to partially adjust a coating thickness to obtain a uniform thickness distribution while applying the coating composition on the flexible support in the width direction.