There are two main reasons for the difference of hard chrome bonding strength of glass mould:
1. Cast iron structure is not dense, porous, easy to seepage into the solution and not easy to clean;
The carbon content of cast iron is relatively high, the erosion is a bit excessive, and the surface can produce floating carbon, resulting in a poor binding force.
Cast iron chrome plated should strictly according to the following: first, grind the plated surface, do not have any rust, oil removal by hand, and carefully again electricity to remove oil, clean thoroughly with hot water, with a dilute sulfuric acid or hydrochloric acid activation, short time thoroughly clean with clear water, quickly into the trough, use first impulse current (2 ~ 3 times that of the normal current) plating 2 ~ 3 minutes, turn into normal current plating, till the end. In addition, it should be noted that there is no gap between the installation and insulation, or the solution in the crevice will slowly leak through the plating process, which will not only cause the coating to be combined, but also contaminate the plating solution.