Fiber Morphology Regulation Of Electrospinning And Its Effect On Filtration Properties Of Filter Media

Once particulates in the air enters the human body,it will cause respiratory diseases,and once it enters the equipment,it will cause component erosion,fouling,and corrosion,etc.,which will seriously affect the industrial production and daily life.Therefore,removing particulates in the air and controlling the air quality are the basic requirements to ensure the normal progress of production and life.Electrospinning nanofibers are commonly used raw materials for the preparation of high efficiency air filter media,but the composite filter media prepared from them normally have high pressure drop.The fibers and beads in the bead-on-string fiber composite filter media prepared by electrospinning technology are randomly distributed to form a rich three-dimensional network structure,which provides an effective method for preparing high efficiency and low pressure drop air filter media.It is of great significance to explore the influence of different forms of electrospinning fibers on the filtration performance of electrospinning composite filter media for the preparation of high efficiency and low pressure drop air filter media.Aiming at the filtration efficiency test of single-size particulate,a monodisperse filtration efficiency test system was built.By adjusting the electrospinning process parameters,the morphology of electrospinning fiber was controlled,and electrospinning composite filter media with different fiber structures and diameter ranges are prepared.The influence of fiber morphology on the filtration performance of air filter media was explored.The specific research content and main conclusions of this article are as follows:1.The monodisperse filtration efficiency test system was designed according to ISO21083-1:2018.The test system characterizes the monodisperse filtration efficiency of the filter media by counting method,the measurable particle size range is 80?500 nm,and the effective test area is 100 cm2.The experimental results are reliable,which solves the problem that the existing equipment in the laboratory cannot test the filtration efficiency of the single particle size of the filter media.2.Using polystyrene to explore the impact of four process parameters on the fiber morphology during the electrospinning process,including solution concentration,voltage,solution flow rate and receiving distance.It is verified that low concentration is beneficial to the formation of bead-on-string fibers,which provides a basis for the preparation of electrospinning bead-on-string fiber composite filter media.3.Two electrospinning bead-on-string fiber composite filter media with the average fiber diameter of 250 nm and 500 nm were prepared and characterized.The results showed that under the conditions of close pressure drop,the structure of the bead-on-string fiber composite filter media was fluffier,and the influence of the pore size were small.In addition,nanofiber composite filter media with two fiber diameters were prepared,and the pressure drop of the composite filter media was close to that of the bead-on-string fiber composite filter media.The results showed that the nanofiber composite filter media owned a compact structure and the pore size was reduced to half of the substrate.4.The filtration efficiency of the prepared electrospinning composite filter media was characterized.The experimental results showed that when the pressure drop of the composite filter media was close,the easiest penetrating particle size of the bead-on-string fiber composite filter media with average fiber diameter of 250 nm before static removal was 100 nm,and the corresponding filtration efficiency and quality factor were respectively 58.9%and 0.017 Pa^-1,the fiber charge strength is 28.57?C/m².The comprehensive filtration performance is the best.5.The pressure drop of the electrospinning composite filter media during the dust holding process showed that it took the longest time for the bead-on-string fiber composite filter media with an average fiber diameter of 250 nm to be loaded with ISO12103-1 A1 ultrafine test dust to reach the termination pressure drop.The longest time was 7520 s,which was 1522 s longer than that of the nanofiber composite filter media with same fiber diameter range.Therefore,the addition of bead-on-string fibers is beneficial to extend the time for the composite filter media to reach its lifespan.