Coating strip material with protective/decorative layers while avoiding use of solvents

Abstract

A process and apparatus for coating a surface of an elongated strip article, e.g. aluminum sheet, with a layer of solid polymer material. The process involves heating the polymer to produce a melt having a viscosity of at least 1000 centipoise when measured according to ASTM D4440 at 1 radian per second, extruding the melt onto a moving surface of the strip article through an elongated slot in a coating head having an extended surface adjacent to the slot arranged at an angle to the moving surface to form a coating gap converging in the direction of movement, thereby forming a coating on the strip article, and pushing the coating head towards the surface of the strip article as the melt is extruded as the coating onto the surface from the slot to reduce the coating thickness to a desired range by pressing the extended surface of the coating head onto the coating as the coating is formed. The apparatus includes coating heat, provided with a heater to maintain the viscosity of the melt, and load application device for the coating head, as well as means for melting the polymer and supplying the melt under pressure and at the desired temperature to the coating head. The process and apparatus allows strip articles to be coated with thin (1-100 microns) coatings of polymer materials without employing liquids as solvents or the like that cause atmospheric pollution problems.

Dependencies are inferred from the claim text.