Fourthly, the filtration mechanism of the membrane fiber layer
Membrane filter material is a layer of expanded polytetrafluoroethylene microporous film (ePTFE film) compounded by hot pressing or adhesive bonding
High-end dust filter material made on the surface of conventional fiber layer filter material. The ePTFE membrane has a three-dimensional network structure, irregular pore shape, curved channel, pore diameter of only 0.2~3.0μm, porosity up to 80~90%, is the most reasonable fiber microporous structure to date. In terms of the filtration mechanism, in addition to the common effects of inertia, interception, diffusion, static electricity, etc., the mesh effect plays a leading role. Using this microporous film instead of the primary dust layer, even in the early stages of filtration, fine dust particles are difficult to penetrate into the fiber layer, achieving a veritable surface filtration. Its filtration efficiency can reach 99.99%, which is an order of magnitude higher than that of non-film conventional filter materials. The ePTFE membrane is non-sticky, has low surface tension, and has excellent cleaning performance.
Post-processing measures such as calendering, singeing, and coating on the surface of the conventional fiber layer filter material, as well as the development of high-density surface layer gradient structure fiber layer filter material, are designed to improve the micropore structure of the fiber layer filter surface and minimize dust It is deposited in the fiber layer to realize the conversion from bulk filtration to surface filtration, but its effect is still not as good as that of membrane filter material.