Ultra-filtration is designed to remove oils from water. This will allow for more consistent cleaning and improved quality. The down side is that the more a cleaning agent is structured like an oil, the more likely that those components are to be selectively depleted.
The larger the molecule the more likely it is to be removed; Surfactants being the materials most likely to be removed. Non-ionics first, then anionics, and finally amphoteric materials will be removed with ultra-filtration.
In the specific case of cellulose fiber filtration and Metal Medic 7375, ultra-filtration will remove the de-foaming surfactant with time. The best control for this system will be to move to a free alkalinity test kit to maintain optimum levels. It may be necessary from time to time to add small quantities of the de-foaming surfactant; such as: Metal Medic 7830. Metal Medic 7375 has been used with ultra-filtration.
The best product for multi-metal cleaner rust preventive for use with ultra-filtration is Metal Medic 7657 HT. Metal Medic 7657 HT was built with cellulose ultra-filtration in mind and has been field tested with ultra-filtration units and found to out perform other cleaners offered for this purpose.
A discussion of objectives is in order. If the parts coming to a parts washer are loaded with oils that emulsify, ultra-filtration on a cleaner stage may be in order.
In most cases oils will split and can be skimmed out or in other cases the soil is significant but light. In either of these examples the ultra-filter will do more good on the rinses to reduce BOD and COD to the waste treatment system or POTW. In any case ultra-filtration for after traditional waste treatment to polish the water makes one of the better applications for this type of technology.