Verfahren zur Oberflächenbehandlung von Aluminium für Druckplatten

摘要

A method for treating the surface of an aluminum support for a printing plate, the hardness of abrasive used for the brush graining is lower than any conventional one, and the hardness in the new Mohs scale which has been not specified conventionally is set to be equal to or greater than 2 but less than 6. The minimum-side-to-maximum-side ratio of the grain should not be less than 0.4, and the sharpest angle of the grain to be used should be equal to or greater than 45 DEG . Aluminum hydroxide may be adopted as the abrasive having these characteristics. It is good when the average size of the grains is set to be equal to or greater than 5 mu m but less than 200 mu m. It is preferable that the density of the abrasive slurry is equal to or greater than 5 weight per cent but less than 90 weight per cent.