| Investigations were made to develop a new type of edge mask to give an adequate answer to the strip edge over-coating problem in electroplating process. Because of its inherent nature of the strip edge on which the electric field or current flux tends to be concentrated, many problems were caused, such as edge over-coating, powdering, burning and zinc tree. The conventional therapy for these problems adopted so far is, for example, like bringing either the current density or the coating weight lower. But with such a declining Control, the productivity was doomed to be lowered nor any appropriate answer was suggested for edge over-coating problem. Thus, a new type of edge mask and its optimal conditions are suggested in this paper. It was concluded that the edge mask should be positioned in between -1 to +1 ㎜ from the strip edge and kept from contacting with the strip surface. A new type edge mask satisfying fore-mentioned conditions and being compatible with the shape of electroplating cell was sketched as well. |
|
