Abstract: An anode pipe includes a main pipe portion and a secondary pipe portion. The anode pipe has an inner circumferential surface that functions as an anode. The main pipe portion has a first connection end portion and a second connection end portion. The main pipe portion forms a flow channel for a treatment liquid that continues from the first connection end portion to the second connection end portion. The secondary pipe portion extends in a tubular fashion from the intermediate section of the main pipe portion. The interior of the secondary pipe portion communicates with the flow channel inside the main pipe portion. The cathode is disposed at a distance from the inner circumferential surface of the anode pipe. The cathode extends from a cathode attachment end portion toward the main pipe portion inside the secondary pipe portion.

Abstract: In order to regenerate permanganate solutions being utilized for the etching and roughening of plastics surfaces electrolytic methods are known. Though relatively small quantaties of by-products are produced with these methods as compared to chemical regeneration methods, large quantaties of manganese dioxide are produced when printed circuit boards are treated. In order to avoid formation of manganese dioxide during the regeneration method a novel cathode 2 has been found which is provided with a porous, electrically nonconducting layer 7 on the cathode body 3. The layer 7 preferably consists of a plastics material being resistant to acid and/or alkali.