Lacquers for Vacuum Metalizing Process
Thermal-cured lacquers are used for base coating in vacuum metalizing. The performance of the metallization greatly depends on the base coat lacquer. The Knowledge of the functions, limitations and proper usage of lacquers is essential to the metalize who wishes to use these lacquers.
Other basecoats are available, such as UV-cured and water-based coatings. Although some of these are becoming more popular because of solvent emission control regulations, solvent-based lacquer coatings are still the most widely used.
Thermal-cured lacquers
The basecoat is a lacquer that is applied to the surface of a part before metallization can be done. Basecoats serve two primary functions for the vacuum metallizer:
- Basecoats level out minor imperfections on the substrate, allowing for a smooth and mirror-like surface.
- Basecoats also promote the adhesion of the metalizing onto the substrate.
Key Elements of Lacquer Coating
All lacquer-type coatings are composed of three main ingredients:
Resin
Resin is also known as the solids of a coating. In a coating, the resin is a polymer that remains after drying. It depends on several factors, including the type of plastic the substrate is made of, which polymer is used in the coating
The percentage of solids in the liquid coating will affect the method of application and the cost per liter of the coating. Usually, the higher the percentage of solids in a coating, the more expensive it is.