Can the filter filter out the defoamer?
Foam formation is a common problem with lubricants, especially those with high system turbulence. Foam becomes a problem when it gets out of control or affects the operation of the machine. To solve the foam problem, defoamers are added to lubricants.
Unlike most additives, defoamers are usually larger in size and they are suspended in the oil. Since they are suspended rather than dissolved in the oil, another problem arises, which is the ability to be removed. On the one hand, they have a certain tendency to settle. If they are not fully stirred, the defoamer is likely not to be completely suspended. Especially if the oil is stored for a long time, the defoamer is likely to settle to the bottom of the container, which is one of the reasons why lubricants cannot be stored for a long time. On the other hand, defoamers can be filtered out by filters. Studies have shown that whether the lubricant foams or not is directly related to the degree to which the defoamer is filtered out. The degree to which the defoamer is filtered out depends on the average pore size of the filter and the filtration efficiency. Oil companies generally believe that filters with pore sizes less than 3 microns are very likely to filter out the defoamer. The stronger the filter’s decontamination ability, the higher the risk of filtering out the defoamer. There is no one-size-fits-all approach to ensure that filters do not damage defoamers, so filter selection requires a balance between achieving the target cleanliness level and minimizing damage to the additive.
