Swiss Aluminium Ltd.

Wilhelm Franschitz

Marcus Textor

Martin Werner

A process for manufacturing a partially permeable membrane is such that a 20-200 .mu.m thick aluminum foil in the non-recrystallized condition is etched in an electrolyte at a current density in the range 2-20 kA/m.sup.2 and the surface given an after-treatment to prevent hydration reactions. The membrane is particularly suitable for ultrafiltration, gas separation or pervaporation and to that end can also be employed in combination with a polymer membrane.

Process for manufacturing a partially permeable membrane

A process for manufacturing a microfilter is such that a foil having an aluminum content of at least 99.95% and thickness 20-250 .mu.m is given a recrystallizing anneal, is etched in an electrolyte in stages at constant current density in the range 0.01 to 2 kA/m.sup.2, and the surface given a stabilizing after treatment to prevent hydration reactions.

Growing community of inventors

Neuhausen, Switzerland

Wilhelm Franschitz