Verfahren zur Herstellung einer Oberflächenschutzfolie

Die Erfindung betrifft ein Verfahren zur Herstellung einer Oberflächenschutzfolie, die auf mindestens einer Seite eine hochglänzende fehlstellenfreie Oberfläche aufweist. Erfindungsgemäß wird ein mittels einer Schlitzdüse extrudierter Kunststoffschmelzefilm im Schmelzezustand einem Spalt zwischen einer Kühlwalze und einem umlaufenden metallischen Glättband zugeführt, durch Anlage an der Kühlwalze gekühlt und in einem Umschlingungsbereich, in dem das Glättband auf die Kühlwalze wirkt, mit einer durch die Bandspannung des Glättbandes erzeugten Druck flächig beaufschlagt - Fig. 1. The method for producing a surface-protective film, which has a high gloss surface on one side without defects, comprises feeding a plastic melt film (2), which is extruded by a slit nozzle (3), to a gap between a cooling roller (4) and a rotating metallic smoothing strip (5) in a melting state, cooling the plastic melt film by contacting to the cooling roller, and subjecting the plastic melt film with a pressure in a wrapping area, in which the smoothing strip acts on the cooling roller, where the pressure is generated by the strip tension of the smoothing strip. The method for producing a surface-protective film, which has a high gloss surface on one side without defects, comprises feeding a plastic melt film (2), which is extruded by a slit nozzle (3), to a gap between a cooling roller (4) and a rotating metallic smoothing strip (5) in a melting state, cooling the plastic melt film by contacting to the cooling roller, and subjecting the plastic melt film with a pressure in a wrapping area, in which the smoothing strip acts on the cooling roller, where the pressure is generated by the strip tension of the smoothing strip. A contact area of the cooling roller and/or the smoothing strip acting on the plastic melt film has a roughness of less than 1 mu m. The contact area of the cooling roller and/or the smoothing strip has a surface improved by a finish treatment or is provided with a coating improving the surface quality. Only the cooling roller or only the smoothing strip has a smooth contact surface acting on the plastic melt film for producing a high-gloss film surface. A counter surface acting on the plastic melt film is formed as rough surface to produce a matt film surface, which does not adhere on the smooth surface. The wrapping area, in which the smoothing strip acts on the cooling roller, is smaller than the cooling area, in which the plastic melt film lies on the cooling