Filter screens for pharmacy and chemical industries Wewin screen gasket company's filter discs are plain or twill woven by quality stainless steel wires, black iron wires or copper wires, and are cut into different diameters according to customers' request. And our discs can also be welded into multilayer filter discs in round, square, or rectangular shapes. The discs are mainly used in pharmacy and chemical industries to filter gas, liquid and oil. They have the advantages of acid-resisting, alkali-resisting and corrosion-resisting. Five filter discs with different mesh counts and the two smallest have metallic margins, three don't have margin. Filter discs with high mesh number can better stop the foreign particles into liquid or gas.