CROSS-FLOW MICROFILTRATION FOR EXTENDING THE SERVICE LIFE OF AQUEOUS ALKALI DEGREASING SOLUTIONS

Aqueous cleaners are being substituted for chlorofluorocarbon solvents in both the metal and electronics industries. Alkaline cleaners are often used at elevated temperatures and at high alkalinity, but require replacement when the levels of oil and other contaminants become too high. Microfiltration, using a ceramic membrane, has proven to be a successful method of extending the service life of alkaline cleaners, by maintaining a low contaminant level of the bath. This article presents a case history and other applications data gained over the past four years.