1. Choosing Dyes for Aluminum Oxidation Equipment
There are many types of organic dyes, and the choice depends on the intended use and product grade. Soluble reactive dyes are expensive but have excellent colorfastness, so they are often used to dye high-end aluminum products like pens, lighters, and hearing aids. Alcohol-soluble dyes are used for aluminum foil coloring, while oil-soluble dyes are used for aluminum foil printing. Before use, oil-soluble dyes are dissolved in nitrocellulose-based, ethylene-resin-based, or polyamide-resin-based varnishes, or in melamine and epoxy resins in baking paints. After printing, they form a resin film containing the dye on the cleaned aluminum foil surface. The types of dyes used for coloring aluminum products include acid dyes, acid complex dyes, acid mordant dyes, direct dyes, mild acid dyes, disperse dyes, soluble reactive dyes, reactive dyes, basic dyes, alcohol-soluble dyes, oil-soluble dyes, and more.
2. Anodized Aluminum Equipment Organic Dye Coloring Process and Control
Single-color dyeing: After anodizing aluminum products and rinsing them with clean water, immerse them in the dye bath at the specified temperature. The dyeing time depends on the color depth, and the bath volume can be controlled at a 10:1 ratio relative to the volume of the products.
Multi-color dyeing: If dyeing aluminum parts with two or more different colors, such as landscapes, flowers and birds, patterns, or text, printing techniques are usually used. Printing plates can be relief plates (zinc or paper) or silk screens, and methods may include direct printing, resist coating, or foam stamping. Generally, the process involves dyeing the first color, applying a protective coating to areas meant to retain that color, removing the remaining color, and then repeating the process for the second, third, and any additional colors.
