Combining high-speed laser perforation and cold roll forming for the production of biomedical microfiltration membranes

A novel high speed two-step technique capable of performing large matrices of very small pores with micron dimensions in large sheets of thin stainless steel foils has been developed. This process combination is initiated by high-speed “on-the-fly” laser perforation. A 100 W fiber laser is capable of a very high drilling rate making it an attractive option for the creation of large drilling matrices and pore widths <20 μm. The second step consists in cold-roll forming of the previously laser microperforated foil. This mechanically induced plastic deformation leads to a pore size reduction in one dimension perpendicular to the rolling direction. The minimum pore width determines the filtration parameters and the 5 μm pore width achieved here is well suited for the removal of spherical particles.