Lacquering offers an unlimited choice of colors with excellent color conformity. Powder coating is by far the dominant lacquering method used today. Powder coating is done using a polyester powder with a layer thickness of about 60 microns, while wet lacquering gives a layer of about 25 microns. There are generally no limitations as regards the choice of colors. The RAL and NCS-S palettes offer a wide range of colors.
The profiles are subjected to nine pre-treatment steps prior to lacquering:
1. Alkaline cleaning
In order to obtain the right quality of the lacquered surface, it is important that the pre-treatment, lacquer application and curing are performed correctly. Since maximum adhesion and durability are desired, the pre-treatment is of critical importance. It usually consists of degreasing and passivation of the surface, followed by a chrome-free chemical treatment. The pre-treatment is finished by rinsing the profiles in deionized water. This pre-treatment process provides by far the optimal corrosion resistance and adhesion when lacquering products to be used for outdoor applications.
The pre-treated profiles are covered with polyester powder. The polyester powder adheres to the profiles as a result of electrostatic or friction charging, after which the powder coating is cured in an oven at 180 °C. Powder coats are applied and cured without using solvents. The ventilation air from the powder application process is cleaned in efficient purification plants. The powder that misses the profiles is collected in a recycling system and returned to the spray gun.
Color range for lacquering
Sapa works with all lacquer types that are requested. Apart from the traditional powder lacquer, this includes structural, metallic and clear lacquers. Polyester powder is used for powder coating and alkyd lacquer is usually used for wet lacquering. With lacquering there are practically no limitations as regards the choice of colors. We can offer all the colors that are included in the NCS-S and RAL palettes.