Ultrafiltration membrane is a microporous filtration membrane with consistent pore size specifications and a rated pore size range of 0.01 micrometers or less. By applying appropriate pressure on one side of the membrane, solute molecules smaller than the pore size can be screened out to separate particles with a molecular weight greater than 500 Daltons (atomic mass units) and a particle size greater than 10 nanometers. Ultrafiltration membrane is one of the earliest developed polymer separation membranes, and ultrafiltration devices were industrialized in the 1960s.