| 摘要 |
1374787 Electro-chemical roughening, anodizing moving strip KALLE AG 29 Dec 1971 [30 Dec 1970] 60415/71 Heading C7B A metal (e.g. Al or Al alloy) foil strip, for manufacturing lithographic planographic printing plates, is continuously pretreated by mechanical e.g. sand-blasting or brushing, chemical or electrochemical roughening in acid, alkaline or neutral solution, e.g. an HCl electrolyte containing Hg ions, and/or anodic oxidation to produce thereon an (hydrated) oxide layer, e.g. using as electrolyte a solution of nitric, sulphuric, chromic, oxalic, acetic, malonic or lactic acid with A.C. or D.C., wherein, to avoid or remove sludge deposits on the metal surfaces during and/or after the pretreatment stages, ultrasonics of a frequency of at least 10 Kc/s act on the surfaces whilst the strip and a liquid are moved relative to one another at a speed of 0.5 - 50m/sec. Preferably the strip 1 moves uniformly via rollers 2a, b through a slit-like channel 8, formed by driven insulated drum 3 and alternate electrodes 9 and ultrasonic vibrators 10, and through which appropriate electrolyte 5 is forced from storage vessel 12 via filter 7 by pump 6 to flow back via overflows 11 and conduits 17. The strip may be treated electrolytically and with ultrasonics on the same or opposite surfaces. The electrodes themselves may be constructed as ultrasonic vibrators. Individual electrodes and vibrators may be wholly or partly screened. An electrolyte for roughening Al is specified containing 1% HNO 3 and 0.25% Al (NO 3 ) 3 . |
