Novel filter material by glass fiber foam laying for nonwoven fabrics

The needle punched nonwoven fabrics are widely used as the flue gas filter materials while continuous efforts have been made to improve the filtration efficiency in order to meet the low emission requirement. In this study, filter materials with high filtration efficiency were developed via glass fiber foam laying and PTFE (polytetrafluoroethylene) emulsion coating process. Influences of surfactant type, fiber diameter and fiber content on the foam-ability and foam stability of glass fibers were analyzed. The resulting filter materials, obtained here for the first time with glass fiber foam laden and PTFE emulsion coated needle punched nonwoven fabrics, were characterized for morphology, pore size, air permeability, wear resistance and filtration properties. The results were compared against structures obtained from needle punched nonwoven fabrics before and PTFE emulsion coating. Remarkably, compared to untreated and PTFE emulsion coated needle punched nonwoven fabrics, the glass fiber foam laden and PTFE emulsion coated fabrics displayed higher filtration efficiency and lower outlet particle concentration. Overall, glass fiber foam laying is found to be effective to improve the filtration performance of needle punched nonwoven fabrics and is promising to be commercialized after optimizing the foam composition and PTFE emulsion coating process.