From Coil to Cathode
Modern manufacturing of cathode plates has evolved from treating individual plates to processing material in high-volume coil processing lines. This approach is more economical and ensures consistency .
Surface Treatment: A stainless steel strip (coil) is fed through a line where it undergoes mechanical and chemical treatments. This can include annealing, pickling (chemical etching), cold rolling, grinding, shot blasting, or brushing. Pattern rolling might be used to imprint a specific texture onto the surface.
Cutting and Fabrication: After the coil is treated to achieve the precise surface roughness, it is cut into individual blanks of the required dimensions. The hanger bar is then welded to the top edge.
Edge Masking: Plastic edge strips are applied to the sides, and the bottom edge is dipped in wax to prevent copper growth around the edges .
Quality Control: Measuring Adhesion
Producers must ensure the surface roughness is within the optimal window. A novel method to determine the ideal finish involves measuring the shearing force required to detach the deposited metal.
A test specimen is placed in an electrochemical cell to deposit copper onto its surface.
The specimen is then placed in a tensile testing machine.
The force required to shear the copper deposit from the steel substrate is measured. This quantifies the adhesion force, allowing manufacturers to correlate surface roughness (Ra value) and steel chemistry with actual stripping performance, ensuring the final product meets operational requirements .
