2. Return of static baths to treatment baths

This is an interesting technique, as it enables significant material savings. However, it must be applied with care, as not only are the useful constituents "brought up", but also impurities that risk concentrating in the bath and disrupting its operation.

There are two ways of ascending:

• eco rinse technique (figure 2 ). The eco rinse is a bath that is not supplied with water and is not drained. The parts are immersed in the eco bath, then in the treatment bath, and again in the eco bath. The concentration remains constant at half that of the treatment bath;

• simple return to the bath. This operation, which is usually automated, is performed when the treatment bath evaporates and the evaporated volume...