Ultra low emission of microporous precision -- membrane covering of dedusting filter material process
The finishing process of needle punched nonwoven filter material for bag filter mainly includes singeing, calendering, dipping, heat setting, film covering, etc.
Filtration of membrane covered filter material is carried out on the membrane surface. Unlike deep filtration of ordinary filter material, it belongs to surface filtration. Under normal working conditions, the filtration efficiency of membrane covered filter material can reach 99.99%, which can control the emission accuracy below 5mg/Nm3.
The membrane materials used for membrane covered filter media are mostly polytetrafluoroethylene (PTFE) microporous membrane, which is divided into high-temperature membrane and normal temperature membrane. PTFE microporous membrane is attached to the filter material by high temperature and pressure. For thermoplastic fiber filter media, the cohesive force produced by the remelting of the molten material on the surface after uniform singeing plays a positive role in the film covering fastness; For thermosetting fiber filter material, PTFE microporous membrane can be firmly bonded after special surface treatment.