A study on reproducibility of cellulose acetate membranes

The variation in flux and rejection of replicate cellulose acetate membranes is measured within a membrane sheet as well as between membranes. Although the casting conditions were carefully controlled and various influences were studied. the source of variation in replicates was not identified. It is shown that the cause of variation is not due to hand or machine casting technique, casting solution composition, heat treatment, dust, overall film thickness or pressure history.