| 摘要 |
Aluminium foil for use as capacitor electrodes is etched electrolytically while an inert gas is bubbled through the etching bath over both surfaces of the foil. Typically a strip of aluminium foil is fed continuously through the bath and while moving in a vertical direction is subjected to upwardly rising streams of gas bubbles in co- or counter-current flow. Typically the etching bath is an aqueous solution containing per litre 10 to 20 gms NaHSO4, at least 200 gms NaCl and at least 2.5 gms of aluminium e.g. added as AlCl3, the pH being between 0.5 and 2.8, the temperature being from 85 to 100 DEG C., and an anodic current density of 5 to 10 amps/sq. in being employed. |
