Patent ID: 10870086

Abstract:
Disclosed is a method and apparatus for manufacturing a continuous web of polymeric membrane and for continuous downstream processing of said web. The apparatus (10) comprises: a casting station (20) for casting the continuous web (M); a carrier (24) for carrying the web downstream; a membrane drier (30) downstream of the carrier, for drying the web; and a brushing station (40) downstream of the drier for brushing the web. Said drier is located immediately downstream of the carrier, and upstream of said brushing station. The apparatus (10) further includes an additional drying station (50) downstream of the brushing station (40). Brushing after drying retains more surfactant in the membrane which is useful for certain applications. In addition, initial drying eliminates virtually all solvents from the membrane, but leaves some non-solvent (e.g. water) within it, which in turn fixes the surfactant on the nitrocellulose fibers, which improves significantly the consistency and reproducibility of the membrane.