PROCESS FOR SEALING ANODISED ALUMINIUM

摘要

Processes for sealing anodised aluminium carried out in a bath having a pH of at least 7 and in the presence of a smut,inhibiting additive have been discovered to give rapid, efficient sealing without the formation of bloom. Examples of smut-inhibiting additives are phosphonates, benzene hexacarboxylic acid, and the reaction products of an aldehyde or dimethylol urea with sulphonated aromatic compounds. The reduction in time required for sealing reduces energy consumption in the anodising operation.