Goals like sustainability and saving valuable resources are increasingly becoming competitive factors across practically all industries. When it comes to cleaning a variety of industrial processing liquids, the cleaning centrifuges from Rösler offer a substantial potential for reaching these goals. Along with significant savings in the use of chemicals, they help reduce the consumption of water by up to 90 %. With these benefits the Dutch company Ulamo, specialized in powder coatings, could not only make a contribution towards environmental protection but was also able to reduce the annual costs for pre-treatment by thousands of Euros.
Over the past 60 years Ulamo has grown to become a provider of complete coating solutions and today is a leading supplier for the manufacturers of radiators. The company, located in Ulft, Netherlands, offers powder coatings to customers all over Europe for various products made from aluminum and different steel grades. Ulamo also produces decorative radiator panels, which the company sells to its customers under the trade name „Sentimo“.
Problems with the pre-treatment liquids
Before they can be powder-coated, the components must generally be de-greased and undergo a “wet” chemical cleaning process in the form of a spraying operation. The cleaning liquid, contaminated with dust and grease, is collected in a special tank. To maintain the cleaning characteristics of the liquid and re-use it, certain chemicals have to be added. The downside of this approach is that the degree of contamination is rapidly increasing. To partially offset the progressive contamination, the amount of added chemicals has to be continually raised. In addition, the dirt contained in the liquid migrates into the spray nozzles and, subsequently, is passed onto the components. This created numerous problems:
Plugged up nozzles prevent the cleaning liquid from reaching all surface areas of the components, resulting in a highly erratic pre-treatment.
Therefore, frequent controls of the nozzles and their exchange are becoming indispensable. This causes frequent interruptions of production and high labor costs.
Moreover, the liquids must be regularly replaced and cleaned, which is also costly and disturbs the production flow. In addition, the discharge of the tanks and refilling them is an environmental hazard.
Simon Wagenaar, manager of the technical services department for coating at Ulamo Coating BV explains: „The contamination of the cleaning liquids was costing us thousands of Euros for personnel, lost sales and scrap parts.”
Cleaning centrifuge eliminates the problems
It is not surprising that Ulamo was looking for a solution to this problem and finally found one at the Dutch subsidiary of Rösler. The solution consists of a cleaning centrifuge: A charging pump transfers the liquid from the tank into the rotary basket of the centrifuge. The high centrifugal force of the rotary basket causes the tiny dirt fines to be deposited on the basket wall in the form of sludge. The liquid, now free of the contaminants, is transferred back into the cleaning process. Simon Wagenaar continues: „Any investment in new equipment should amortize itself relatively quickly. Therefore, it is always good to learn that an investment really pays for itself. Rösler allowed us to test the centrifuge free of charge for a month. So, we only had to commit to a purchase after we had learned that our requirements can be met. For my department, where we are coating aluminum components, we installed a semi-automatic centrifuge.”
A second centrifuge for coating of steel components
Later on, for the coating of steel components, primarily radiator components, the company purchased a second cleaning centrifuge. Norbert Becking, production manager for coating at Ulamo Metaal B.V., adds: „Once we saw how well the centrifuge technology works, we purchased a fully automatic centrifuge for my department. We had previously tested a unit from another supplier. But this was too big and complex.”
Semi-and fully automatic centrifuges
The semi-automatic centrifuge is used for the pre-treatment of aluminum components and is handling very contaminated liquids. The insertable basket containing the sludge separated from the liquid is manually exchanged and emptied once per day. This work is done without having to interrupt production. The fully automatic centrifuge for pre-treating steel components is connected to two tanks containing pre-treatment liquid. The centrifuge cleans the liquid from one tank at a time. Switching from one to the other tank is handled by a special valve. The fully automatic centrifuge removes the sludge from the drum wall automatically and dumps it into a large, mobile container that must only be emptied once a month. Norbert Becking explains: „Rösler helped us in organizing the switch from one tank to the other. The compact machine is easy to operate. Twice a year it is thoroughly checked by Rösler and, therefore, demands very little attention by our technical department.”
Zero scrap parts, higher productivity and less environmental pollution
Both centrifuges have been in operation for over a year. And both investments have been a win for Ulamo. The spray nozzles are not plugged up anymore and must, therefore, not be checked and replaced so frequently. The pre-treatment liquids must only be replaced once a year instead of three times before. Because of the substantially more stable quality of the liquids fewer chemicals must be added. And finally, the employees became free to perform other, more productive tasks. Overall Ulamo is highly satisfied with the centrifuges. Simon Wagenaar concludes: „In a few years we want to replace the tanks in our production line. On this occasion we will replace the semi-automatic centrifuge with a fully automatic unit. Moreover, we plan to expand our production capacity with an additional line. For this project we will again use the products and service from Rösler.”