Abstract: The invention relates to the manufacturing of porous polymer membranes by (a) providing pellets comprising a polymer matrix and particles in the ratio 90:10 to 10:90, (b) converting said pellets into a non-porous film by a solvent-free process; (c) removing said particles from said film with an aqueous composition to thereby obtain said membrane. The invention further relates to pellets useful in such manufacturing process as well as porous polymer membranes obtainable or obtained by such manufacturing process as well as textile materials and articles containing such membranes; to the use of such pellets, membranes, and articles.