In order to improve spray quality and coating efficiency as well as reduce operator health issue, robotic painting is widely used in coating industry. Due to the modern painting requirements, multi color painting is used more and more. In order to reduce wati time, automatic color change and cleaning system is necessary for guaranteed quality and efficiency. There’re multiple solutions of automatic color change system. Here we will generally introduce it’s principle about how it’s being processed and the availability for robot application.
The basic principle of automatic paint color change is magnetic control of paint valve and cleaning system. Paint, air and cleaning agent are central connected by multi-way connector, magnetic valve control will be programmed to automatic control of each valve open and close. When doing the color change job, paint valve will be closed and cleaning /air valve will be opened to clean up spray gun then switch to another color paint. Depends the actual operation requirements, we can add extra modules to program for multiple colors automatic switching.
12018 Double Color Change Device
This 12018 automatic color change device is our most popular model for two colors management. Technical data as following:
| Maximum paint pressure | 7bar |
| Maximum air pressure | 7bar |
| Maximum air consumption | 0.08m³/min |
| Maximum solvent consumption | 160cc/sec |
| Maximum rotation speed | 60rpm |
| Nozzole size | 75mm single nozzole, 60mm X 100mm double nozzles |
| Noise | ＜75db (A) |
| Dimensions | 480mm X 425mm X 845mm /1050mm X 425mm X 845mm |
- – improve painting quality and fine ratio, reduce wait time
- – reduce paint atomizer abrasion by maximum automatic operation
- – reduce cleaning agent and VOC emission
- – system is complete stainless steel 304 construction for easy cleaning
- – modular design for easy maintenance
- – pneumatic structure, safe and explosion proof
Two modes of cleaning program
Automatic color change device is available for two cleaning modes – long and short.
Under long cleaning working mode, program will start cleaning from tube /spray gun then switch to another paint valve. This is the regular way when there’s need of different colors paint operation. Tubes and spray gun will be compltely cleaned before changing to another color.
Under short cleaning working mode, program will only clean up spray gun with no color change. It happens when we spray the same paint but there’s some time waiting till the next spraying cycle. The purpose of this action is to maintain a cleaning atomizer without blockage or pollution. It’s a necessary action for some products with extremely high quality control like camera and optics components.
Problem & solution
We have collected potential problems and solutions when using automatic color change system. It’s quick fix and check just in case it happens.
1- color mixing
It’s mostly because of less time cleaning so the previous color pigment is not completely cleaned out. Especially when the paint is pearl color, it requires longer time cleaning. We should set longer time value with extra cleaning agent and compressed air blowing time.
2- shrink coating layer
It happens when cleaning agent is not completely blowed out by compressed air in paint tube and atomizer. So it’s suggested we program the robot not to spray on product for the first spraying. By this way, there will be no wastes remain in tube system. It’s required action in automotive industry. Even we do not make color change, the first spraying should not be on product directly if spray gun stayed some time without spryaing.
