SURFACE TREATMENT WITH OR WITHOUT ROBOT
Main advantages of using robots for protective coating:
- Quality improvement by accurately controlling the dry film thickness
- Improvement of working environment
- Better cost effectiveness; An industrial paint robot is not as expensive as many people think
- Consistent surface quality
- Savings in energy
- Savings in paint consumption
- Less masking needed
- Less exposure to paint dust and solvents
- Optimization of production time
For repetitive paint spraying jobs, robots may be superior compared to human operators in terms of the uniformity for what concerns the paint work that is produced. When chosing a robot to do the paint work one or more of the following improvements will be obtained:
- High positioning precision of the steel surface in relationship to the paint gun
- High repeatability and transport of parts on line tracking conveyors
- No deviation due to fatigue or other human related spray patterns
- Highly accurate inspection and measurement using in-situ DFT measurements etc.
These process improvements not only improve the visual appearance of a paint job, but in terms of spray painting, better overlaps is achieved due to the tighter control of the gun angle and controlled distance from the spray tip to the surface to be coated.
This not only improves the layer thickness consistency, but it also gives a major saving in material use and therefore a great saving in cost. Similar improvements can be achieved for other surface operations such as zinc spray metallizing and of course for sand blasting as well.
Improvement of the Working Environment
In order to get the best long term performance from the work force it is important to make the working environment as conducive as possible to obtain high quality and a high output. Automation should be used to reduce fatigue and to minimize the risk of injury, and with the current trend of increased health and safety legislation it is predicted that companies within surface coating should consider automated procedures:
- Shot blasting in order to eliminate the heavy work of controlling stiff blast hoses and the noisy and dusty work environment
- Metallizing is not only a repetitive job, but also expose the operator for UV light and zinc dust.
- Spray painting not requires fatiguing hand actions to apply the spray fan accurately on the surface, but may also expose the painter to dangerous VOC levels and if not correctly protected.
There are thus many possibilities to improve both the quality of the surface treatment, but also to improve the working conditions to which the operators are exposed.
Many jobs within the coating industry take place in an environment which is really bad and unhealthy to the human body. Many organic solvents from paint spraying are to be avoided for the human body, and sand blasting booths are quite noisy and can cause hearing damage and they are generally very dusty.
Robots can easily handle these environments if they are protected in a paint suit, or for shot blasting the robot needs a protective neoprene suit.
Our surface coating robots are able to to operate continuously on a line 24/7 in order to get the best productivity output from them, but if they are running on lines staffed by human operators who require breaks it is not possible for the robots to run 24/7. Often it is the human operators in the process (DFT measurements etc.) who limits the output of robot cells in surface coating. There is of course the natural savings as a robot should not have salary and does not have the same needs for work breaks etc, but in the cost saving equation the benefit of the robot can be mentioned as:
- The life time of a standard industrial robot is at least 10 years when correctly maintained and protected.
- The robot requires less air ventilation and no heating of substituted air during the cold months of the year.
- The robot will perform a consistent coating job that will save paint and other consumables.
It is our experience that those previously employed people in coating operations are typically trained as process technicians who can perform program changes and optimization of the robotic coating processes.
The scribing process can be performed using off-line programming when the spray fan widths is proven. This reduces some of the programming work, but there is no 100% substitution for on-site programming.