Drink cans are generally made of steel and aluminium. Can manufacturers apply a coating to both the inside and outside of their cans, not just to make cans look striking and make them more sustainable, but also to prevent drinkers from being left with a metallic taste in their mouths.

Strict requirements for drink cans

Soft drink manufacturers set very strict requirements for the quality of the coating used for their cans. For example, the protective coating must not have any irregularities, because otherwise it will peel off. This is, however, exactly what happened at one company that makes coatings for industries such as the food and beverage industry, prompting them to call on the know-how and expertise of BÈTA industrie’s specialists two years ago.

Too many coating imperfections

One of the can manufacturer’s customers noticed that there were too many defects in the cans’ interior coating. Millions of cans had to be destroyed. Together with BÈTA industrie co-owner Sjoerd Scholte, the coating company ultimately managed to find the root cause of problem. Initially, the coating company thought that the surface imperfections were caused by using the wrong cups under the filter cartridges. ‘After a visit to the plant, we soon realised that that was not the problem,’ Scholte explains.

Filter housings under the microscope

Sjoerd Scholte carefully examined all filter housings holding the filter cartridges. And what did he find? The bottom plates of the filter housings were bent. This led to the liquid used to make the coating passing alongside the cartridge filter rather than through it, causing the coating defects on the inside of the drink cans. The solution? All filter housings, which are 1.5 metres tall and 50 centimetres wide, were modified one by one by welding a new bottom plate to each one. The end result? A perfectly smooth and tight coating that fully meets both the can manufacturer’s and the customer’s specifications.

Switching filter cartridges

Since the coating company was highly impressed with the results, they asked Scholte to also take a look at the other filter cartridges that they were using in their filtration processes. Following BÈTA industrie’s advice, they switched from the nominal filter cartridges they were using to ‘absolute’ filter cartridges that are better suited for liquids tested based on a beta ratio of 5000. Most filter cartridge manufacturers use this internationally recognised testing method to rate the efficiency of a filter cartridge. A ratio of 5000 means that only one in five thousand particles of the tested size is allowed to pass through the filter during this kind of test.

Filtration processes analysed

‘What we have done over the past two years is analyse all the filtration processes and check what filters they used,’ says Scholte. ‘And I still go to the plant once or twice a month to optimise their filtration processes. Partly due to the varying quality of the raw materials used to make the coating, it is key to carefully assess now and again whether they are still using the right filters.’ If you are interested in finding out what our filtration solutions can do for your processes, contact us! Our specialists will be happy to assist you. Simply give us a call on +31 79 341 55 18 or click the button below! Contact us