Spray painting is logically a pretty easy job which seems to be hassle free for any people. As it’s basically to trigger spray gun to send out liquid paint by pumping. However, in real working condition we always have to hire a professional technician at fruitful costs for guaranteed output painting quality. Why is this and what makes this seem-to-simple task costly?
Paint spraying principle
The basic logic of paint spraying is to atomize liquid paint then apply to object surface smoothly. The necessary tools include a spray gun, pressurized pot or pneumatic pump for paint supply and a compressor. Spray gun is moving above object surface with specific angles and speed to complete the finishing process.
Spraying defective phenomenons
Common problematic phenomenons such as following:
Color difference – the most common issue for manual spraying. Because spray gun is completely handled by hand, the spraying angle and fluid rate and spraying frequency will vary every time. The direct result is unstable paint thickness on surface and give color difference phenomenon.
Dusts – it’s not referring to the environment cleanness but the spray gun. Spray nozzle will leave some solid particles during spraying, it will be blowed out when the next spraying triggered. If we shoot to the surface directly, it will form paint dusts.
More paint consumption – common issue for manual spraying. Since the process is completely handled by manual operator, any human factor will be a potential issue. The operator can not calculate spraying frequency every time, sometimes it will spray more or less and always have to spray more after eye observation. Paint consumption will increase a lot if its mass production.
How to improve?
Improvement or fix are based mentioned defective phenomenons such as above. Here we mainly explain on following points
Color difference – as it’s caused by paint thickness by varied spraying frequency, we need to make sure everywhere is sprayed the same with same fluid volume and spraying angle/distance. Manual operation is very hard to archieve this unless by very professional operator, but long time operation is not good at all for health consideration. Thus we suggest robotic automation on those high end mass production requirement. Only one time programming on spray gun, it can be non stop working and always maintain the same quality.
Dust issue – if we need to fix the solid paint dust issue, we normally spray outside product edge first then move to product face. That means we need to waste some paint by this operation. It can’t be avoided for manual spray gun as there’s only one trigger. But can be easily fixed on automatic gun where we can programmed to trigger air blowing first then paint spraying. By this way, the dust issue can be fixed perfectly without paint wastes. Automatic gun provides more air control and paint atomizing control by programming.
Paint wastes – since it’s by nonstable spraying frequency, the fix is to make the frequency with no change. The only way is by mechanical automation which is digital control for every operation. We can predefine the working properties and save different programs for various products with specific configuration.
How to reduce costs
Cost of paint spraying is composed by a variety of factors including labor costs, paint costs, machine costs and even the process flow management. If the operation cost is over our profit, there must be something to be fixed or improved. As we experienced in the past 10 years, we can improve at the following:
1- Hire more professional technician but reduce the total quantity. What we actually need is an experienced technician to provide necessary guidance to other operators, we don’t have to use many professional people at every station. Labor cost is a big part of actual investment, thus we need to optimize the structure properly.
2- Apply good maintenance to spraying device or use new machine if possible. Any mechanical device must be properly maintained in order to keep it’s efficiency. Especially for curing system, we need to maintain it’s cleanness well and make sure the heater is functional good. We don’t want to replace components every a few days and with extremely high electricity consumption. Especially the heater system, we should design a good ventilation and temperature control to make full use available hot air and reduce electricity usage.
3- Switch to automation if possible. Automatic machine might be a relative high cost at the beginning, but very cost saving choice for long run plan. It will save a lot side by side and make full use of energy. The production by automatic machine is continuous and always the same speed, there’s no more wait time for each stage thus no energy waste because of empty run.
