ALUMINIUM SHEET WITH ROUGH SURFACE

摘要

Aluminium sheet suitable for use as a lithographic plate support has a surface that is uniformly rough by virtue of: a rippled topography having an aspect ratio of at least 1.3 on a scale of 5 - 200 mu m; and a superimposed pitted structure on a scale of 1 - 20 mu m. A method of making the aluminium sheet involves pack rolling two aluminium ribbons to generate facing surfaces having the transverse rippled structure; followed by a small amount of a conventional roughening or graining treatment to develop the pitted structure.