Macro-preparation And Filtration Properties Of Solution Spray-spun Micro-nanofiber Membranes

Solution blowing is a new kind of nanofiber fabricating method that inspired from melt blowing and dry spinning technology.The method has the advantages of extensive applicability,easy operation and safety,large-scale production and so on.At present,the related researches are mainly focused on the fields of the nanofiber forming principles,the structures and properties of fibers and new nanofibers et al.However,the study about the industrial exploration and product development on the preparation of nanofibers were relatively few.In this work,a solution blowing pilot was designed and manufactured based on the previous research of solution blowing technology in our laboratory.Then,the equipment structure and some parameters of the pilot were validated and optimized by the spinning experiment to achieve continuous macro production of nanofibers.Single factor analysis experiment and BBD experimental design were used to investigate the influence of spinning process parameters and their interaction on fiber morphology and pore size when macroscopic PAN nanofibers were prepared by our Solution blowing pilot test machine,to establish the relations between PAN nanofibers Membrane average pore diameter,fiber diameter and spinning process parameters.Meanwhile,the air filtration performance of the PAN nanofiber membrane was studied and air filter material with a three-layer composite PAN nanofiber membrane was developed.The results show that the spinning parameters affected the fiber morphology.However,the fiber diameter was mainly affected by the spinning solution concentration,draft pressure and liquid feed rate.The induced voltage mainly affected the uniformity of fiber distribution.The average pore diameter of the fiber membrane was mainly affected by draft pressure and induced voltage.The PAN nanofibers can be controlled macroscopically by regulating spinning conditions.The produced composite PAN nanofibers had 99.923%filtration efficiency and 117 Pa pressure drop on 0.4 ?m DEHS particles after eliminating static electricity.In view of the urgent need of efficient high-temperature filter material in the current market,single factor analysis experiment applying solution blowing pilot test machine were adopted to study the influence of spinning process parameters on the pore diameter of PMIA nanofiber membrane and fiber diameter and on high temperature filtration performance of PMIA nanometer with different gram weights.The results show that the concentration of spinning solution which had a significant effect on the fiber diameter and the induced voltage affected the distribution and morphology of the fibers,both of which had a significant effect on the average pore size of fiber membrane.The macro-scale production of PMIA nanofiber membrane was realized and the scope of macro-scale production of nanofibers by pilot test machine was expanded.After static elimination,the filtration efficiency of PMIA fiber membrane was 72.9%and the pressure drop was 18.15 Pa when its weight was 2 g/m2.The filtration efficiency of PMIA fiber membrane could reach 99.787%and the pressure drop was 131.1 Pa When its weight reached 11g/m2.At the same time,the flexible PMIA nanofiber membrane maintained stable thermodynamic properties below 278.2 ?,which met the basic requirements of high temperature filtration materials.