The surface of the fi lter plate contacting with the medium and its holes are made of PFA. The heated PFA particles areevenly coated and formed on the outer surface of the billet by the Teflon molding process. The product is formed at onetime without joints, and the corrosion resistance is fu lly gua ranteed by the inherent characteristics of PFA material. Atthe same time, sufficient billet th ickness is adopted to ensure its service stiffness and service life. After molding, theouter surface of the product is flat and smooth, and it is not easy to stick medium, which ensures the seal ing reliabilityand easy cleaning after assembly in the equipment. The thickness of the li ning layer is tested by the national standardhigh-voltage spark test to ensu 「e its safety and durability.