FLAT PERMEABLE MEMBRANE AND METHOD FOR MANUFACTURE THEREOF

摘要

A flat permeable membrane of polyolefin 10 to 500 mu m in thickness, which membrane has compact layers of intimately bound fine particles of polyolefin formed one each in the opposite surface regions of the membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 mu m formed between the compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of the membrane to establish communication between the opposite surfaces of the membrane and a method for the manufacture of the permeable membrane.