In the powder coating process, proper preparation of the metal surface is crucial. One of the most important stages in this process is washing the metal components in water baths with the appropriate chemicals. The effectiveness of this stage significantly influences the quality of the final coating and the durability of the process. What if the chemistry used facilitates oil separation and extends the life of the chemistry?
The problem of foreign oils in the washing process
The washing of metal surfaces inevitably results in the ingress of foreign oils, which come from a variety of sources such as lubricants, machining coolants or anti-corrosive agents. These oils usually tend to emulsify in the water bath, making their removal more difficult and the cleaning process less effective.
Specificities of the phosphatising process
In particular, in the case of the phosphating process for metal surfaces, there is a intensive oil emulsification in a chemical bath. Phosphates, which form the basis of this process, facilitate emulsion stabilisation, which makes oil separation by traditional mechanical methods significantly more difficult. As a result oil remains suspended in the bath, reducing the efficiency of the entire process. This results in the need for more frequent medium changes, higher operating costs and increased chemical waste generation. In addition, a stable oil emulsion in a phosphate bath negatively influences the quality of the phosphate coatings obtainedwhich can directly translate into reduced durability and adhesion of the powder coating. And a clean bath also means clean nozzles in the washing chambers. Check out -> Case study elimination of hydrogen sulphide odour and optimisation of the chemical cleaning process.
Solutions from Kairos Poland - how chemistry can make the oil separation process easier
Modern chemical technology Kairos allow the effective separation of foreign oils from the bath surface. This enables regular and efficient removal of contaminants using, for example, simple belt de-oilers or overflow baffles , with numerous technical and economic advantages:
- Extended life of the chemical bath: The separation of foreign oil allows the bath to maintain its optimum operating parameters over a longer period of time, minimising the need for frequent oil changes.
- Reduction in production downtime: The cleanliness of the baths and the stability of the process reduces the need for frequent stops associated with changing the medium, which has a direct impact on production efficiency.
- Lower disposal and environmental costs: Less frequent replacement of the chemical bath means a significant reduction in disposal costs and reduces the environmental impact.
- Higher metal surface quality: The elimination of foreign oil from the bath improves cleaning efficiency and allows for perfectly clean surfaces, resulting in better powder paint adhesion and coating durability.
If the oil separates on the surface, what methods are available to remove it?
Oil separation techniques include a variety of solutions to suit production needs. The easiest method to implement is the use of a simple belt separator, which collects oil floating on the surface of the bath and removes it mechanically. This method is relatively inexpensive, simple to operate and effective for lower oil contamination.
More advanced methods include gravity separators and flotation systems, which allow oil separation even at higher contaminant levels and intense emulsification. Gravity separators take advantage of the difference in density of the substances, enabling efficient separation of oil and water. Their effectiveness can be simply enhanced by adding, for example, an additional mesh with a smaller mesh.
Still other methods of oil separation are disc separators and floating hose or suction separators. Disc separators, due to their centrifugal force, remove fine particles and oil emulsions, allowing the bath to be used longer and maintaining a high quality of surface preparation. Floating hose separation is a method of removing oil from the surface of liquids, most commonly used in degreasing or washing baths. The floating hose is terminated with a special suction that floats on the surface of the bath, where the oil accumulates, and automatically sucks in only the oil layer without taking the liquid from underneath it.
Summary
Effective separation of foreign oil from water baths is an investment that brings tangible benefits - not only by improving the quality of the process, but also through real savings resulting from reduced waste generation and improved plant continuity. By ensuring that the oil is removed from the bath on a regular basis, we also ensure the quality and reliability of the entire powder coating process. A clean bath is pure profit!
Kairos Poland provides a chemistry whose benefits are difficult to fit into a single article. Effective cleaning in 25°C, washing in one step, oil separation on the surface is another. With the above attributes, we reduce unnecessary paint shop costs (energy, sludge disposal, additional chemicals) and guarantee staff safety. If you are looking for modern, efficient i economically justified surface preparation methods for powder coating, contact usto see how surface preparation can be, more efficient, cheaper in many dimensions and friendlier for your business.
