Abstract: An aluminum alloy suitable as a base for printing plates consists essentially of aluminum containing iron (Fe) and manganese (Mn), the Fe content being 1.2 to 2.1% by weight, the Mn content being 0.1 to 0.9% by weight and the sum of the Fe and Mn contents being 1.3 to 2.2% by weight. A printing plate can be produced with such a base, the base being mechanically, chemically and/or electrochemically roughened and if required, anodically oxidized and hydrophilized. The printing plate includes at least one radiation-sensitive reproduction layer applied on the base.

Abstract: Disclosed is a sheet, foil or strip material comprising aluminum or an alloy thereof, which is first mechanically and then electrochemically roughened on one or both surfaces to produce the following parameters:(a) from about 60 to 90% of the surface comprise a basic structure, in which the arithmetic mean of the distribution of diameters D.sub.a1 of the pits is in the range from about 1 to 5 microns,(b) from about 10 to 40% of the surface comprise a superimposed structure formed of elevations having an average base F from about 100 to 1,500 microns.sup.2, in which the arithmetic mean of the distribution of diameters D.sub.a2 of the pits is in the range from about 0.1 to 1.0 micron,(c) the center line average roughnesses R.sub.a of the entire surface are at least 0.6 micron, and(d) the contact area t.sub.pmi of the entire surface is not more than about 20% at a stylus working depth of 0.125 micron and not more than about 70% at a stylus working depth of 0.4 micron.

Abstract: In the process for continuously anodically oxidizing one surface of strips of aluminum or an aluminum alloy, a direct current is caused to act on the strips, by at least one anode and at least one cathode, which are arranged in an aqueous electrolyte. The anode(s) and cathode(s) electrochemically act, from opposite sides and simultaneously, on the strip which moves past them and which is, in particular, substantially horizontally conveyed past the substantially horizontally arranged electrodes.A device for carrying out a process of this kind comprises (a) at least one treating bath (2) which is filled with an aqueous electrolyte (3), (b) at least one anode (5) each, which is arranged in the electrolyte, below the strip (1) to be treated, and (c) at least one cathode (4) each, which is arranged in the electrolyte, above the strip (1) to be treated.

Abstract: The thickness of a thermoplastic kneading mass having a temperature of at least 40.degree.C in the feeding region of a roller gap, is measured by scanning in the said feeding region the zone of bare roll to kneading mass and kneading mass to rolling sheet with an infrared radiation receiver of high geometrical resolution defined by a diameter of the measuring field of from 0.5 to 3 mm with a measuring distance of from 0.2 to 3 m, recording the curve of thermal radiation and determining the thickness of kneading mass from the distance of the two points of discontinuity in the recorded curve of thermal radiation with consideration of the ratio of the scanning speed to the speed of registration.