Preparation of binder-free composite filters material and their efficient removal of slag powder

The manufacture of high strength, high precision filtration materials for solid-liquid separation are still a challenging problem. As we all known, woven filter cloth is widely used in solid-liquid separation. However, their application in industry has faced great challenges due to their large pores, low precision and susceptibility to filter penetration. In this paper, fabric-based three-layer gradient composite filtration materials were prepared using a simple method. Hot pressing composite method was used to investigate the effect of hot press temperature and time on the filtration structure of composites. The adhesive layer and the fine filtration layer were made of polypropylene/polyethylene melt-blown bicomponent nonwovens (PP/PEMBN), which improved the filtration precision. The effects of hot press temperature and time on the peel strength, permeation flux and filtration precision of the composite filter material were systematically evaluated. It was shown that the composite filter material had excellent pure water flux (18,447.86 L/(m 2 h)) and separation efficiency (slag powder: 99.99 %), and the filtrate turbidity reached 7.9 NTU under the conditions of hot press temperature of 120 degrees C and 80 s. In addition, the prepared composite filter material had good regeneration performance and excellent mechanical strength. The potential filtration mechanism of the composite filter material was also studied. This work provides a new direction for the large-scale production of high-strength fine filter cloth.