How to change the colors of powder paints correctly
Powder paint has a large number of different colors and textures for any case. In order to prevent mixing paints in production and free coating defects you need to know several important rules for changing the color of the powder.
The complexity of this process depends on the type of spray chamber and powder collection system.
Spraying can take place in one or more chambers.
Powder spraying chamber: cleaning
Changing the color of the powder, it is necessary to clean the walls of the chamber and check the filter: change or clean it.
First, clean the sprayer from all sides: inside and outside. Then remove the remaining powder from the walls of the chamber. If necessary, the filters and powder hoses are replaced.
In a production with 8-10 nozzles, all this requires 2 hours.
If the production is equipped with a multi-camera system, the colors are changing faster.
Having the certain space in the workshop, this system solves the problem of frequent color changes in powder paints. Two or more cameras are installed in production for that. While one is being used the other is being cleaned. The spraying chambers can be located side by side or one after the other on the same line.
If the chambers are installed in parallel then they are placed on opposite sides of the conveyor. If the cameras are located one after another then they can work simultaneously without moving.
The number of chambers is influenced by the colors used, the frequency of their changes and the volume of powder.
If there are two cameras in production then one of them is used for the main color, and the second for all the others.
It is better to have two copies of other equipment necessary for painting. Otherwise, you must also spend time cleaning it.
The material of the camera is also very important. It affects the speed and difficulty of cleaning. Polypropylene walls and the one made of transparent polymers receive a minimum amount of powder settles.
A polyethylene liner can be installed on the walls of the chamber. And for color changing you just need to replace it with a new one. But you still need to clean all the other elements of the camera.
Steel attracts powder on walls of the same material and paint settles more. They can be polished to make cleaning a little easier. Most often painted steel is used for the camera. Depending on paint steel can attract powder in different ways.
Cleaning the capture system
If you frequently change powder colors, it is better to choose equipment with a cyclonic collection system. They are easy to clean with compressed air, polymer or mineral fillers.
Cartridge filters must be replaced with new ones. It is better to use them when color changes do not occur very often or in case enough of the spray chambers are installed in the production.
Basic tips for changing colors
In order to quickly and efficiently clean the painting equipment from particles of the previous powder, follow several important rules:
- Start cleaning with the air supply and work your way through: hopper, pump, hose, sprayer, etc.
- After the feeding system, go to the inner walls of the chamber.
- The last step is cleaning the recuperation system.
- If you do not follow the stages, then cleaning may take more time. Moreover, it may not be of very high quality. And the remnants of the previous powder will become dirt in the coating during the next painting.
- In order to make all this easier and faster, there are special brushes and devices.
