DYES - Zinc Plating Operations

Organic dyes are primarily used in metal finishing operations for identification or color coding purposes. Color is obtained through the absorption of the dye into the thin gelatinous chromate film. The chromate film acts like a sponge and will readily absorb dye immediately after it forms over freshly plated zinc or cadmium. Thicker chromate films will allow for more dye absorption and can produce darker more intense colors. High protection trivalent chromates and leached yellow chromates provide the best base for dye absorption. Not every dye works with every chromate, so sample testing is often required to achieve the desired color.

A variety of colors and intensities are possible depending on the dye concentration, the immersion time and the properties of the chromate film. The end color is often affected by the color already produced by chromate film (blue, yellow, black, olive drab).

The green ground screws that are found on electrical components are a common example of parts that have been dyed. These screws are typically zinc plated and chromated; then processed through a green dye to produce the “Ground Screw Green” color.

Dyes may reduce the salt spray protection of the chromate in which they are absorbed. Topcoats and post treatments are available to help improve protection.

METALLINE DYES – Most Commonly Used

Powders

Liquids

*NOTE: Yellow Toner or HI TEST™ YT can be added directly to our high protection trivalent chromates (TP-105 and HI TEST™ CC-3) to produce a yellow to bronze trivalent finish.