Surfactant – Free, Aqueous, Acrylic Dispersions for Plastic Coatings

By Dirk Mestach, Eric Manning

Plastics are used in virtually all sectors of industry, from the manufacture of mobile phones to automotive engineering. Most plastics are now coated for protection against weathering, attack by solvents and scratching, as well as for decorative reasons.

Coating systems commonly used in this industry fall into three categories: three-coat, two-coat, and single-coat systems. The three-coat system is the most common-a primer, a base coat, and a clearcoat.

After each layer the paint is allowed to dry for a short period (flash-off for 5-15 min at 60 ° C). Once the complete system is applied, the coating is force-dried at tempera­tures of 60 to 80 ° for 15-30 min. Typical dry film thickness for the three­ coat system ranges from 25-75 µ for the primer, 25-50 µ for the basecoat, and 25-125 µ for the clearcoat.

A two-coat system is only a base coat applied straight to the substrate, then a clear coat. Typical dry film thickness for the two-coat system is 50 µ for the basecoat, and 50-125 µ for the clearcoat.