The outside of the window is exposed to UV radiation, temperature changes, moisture and hailstorms. The wood must therefore be protected by a suitable coating. The glazing beads usually receive the same surface treatment as the window sash.
For small to medium scale production, windows are usually spray-painted by hand in a spray booth. For larger quantities, automated solutions are economical: spraying robots, dip coating plants or flowcoating systems are possible. With a large number of different window combinations, maximum flexibility is also required for coating. When applying the coating, air pollution control is generally important to ensure high surface quality and to protect the health of workers and the environment. A drying time must be observed after lacquering. This is drastically reduced when UV-curing coatings are used.
Spray booth
In a spray booth, the air is guided in such a way that overspray is collected in a filter, which is located in a suction wall. The supply air usually comes from the ceiling. Separate painting rooms are often equipped with an underfloor extraction system and the corresponding supply air units and heat exchangers.
Spraying robots
The spraying robot automatically applies lacquer with a spray gun. This reliably ensures that on the one hand a sufficient layer thickness is achieved and on the other hand that no dripping noses are formed due to an excessive amount of lacquer.
Dip coating plant
The sash or frame is once completely immersed in a lacquer bath and pulled out again. After the excess lacquer has dripped back into the bath, the part is conveyed further and the drying phase begins.
Flow coating system
In a flowcoating system or flooding tunnel, the window sash or frame is suspended from a conveyor and guided through a spray paint jet that wets the component abundantly from all sides. Excess lacquer drips off and is recovered. The drying phase then begins.
Vacuum coating system
A vacuum coating system applies a primer to all sides of profiled parts in one operation. The application quantity can be perfectly adjusted and safely maintained. Excess lacquer is completely recovered; no lacquer is lost. The vacuum coating unit must be used between profile sanding and gluing.
