| 摘要 |
865,323. Anodizing aluminium. ALUMINIUM-WALZWERKE SINGEN G.m.b.H. Nov. 20, 1958 [Nov. 23, 1957], No. 37403/58. Class 41. In a forming bath in which aluminium foil is subjected to anodic oxidation, the foil is screened from the action of the forming current by means of a shielding tube until it is immersed in the bath to a depth more than one centimetre, whereupon it is subjected to the full intensity of the forming current, and vapour bubbles adhering to the surface of the foil are removed by vigorous motion of the electrolyte relative to the foil. The tube may be immersed up to a depth of one metre below the surface of the bath, the preferred distance being 5 to 20 centimetres. The electrolyte may be 10% aqueous boric acid and the cathodes may be of stainless steel. As shown, the foil 1 passes into the bath 5 through tube 3 of plastic material fitted with an air-tight rubber seal 8 at each end. Air is introduced at 12 and escapes at 4, which protects the foil from the action of heated vapour rising from the bath. The foil may be passed through the bath at at least one, and preferably more than ten, metres per minute. |
