Differential Electrospinning Multi-stage Structural Filter Material Design And High Efficiency Air Filtration Application

As a kind of ultra-fine fiber green preparation process without solvent,melt electrospinning technology prepares nanofibers with small fiber diameter,large specific surface area,high porosity,and has broad application prospects in air filtration.In order to alleviate the contradiction between filtration resistance and filtration efficiency in fiber air filter research,this paper gives full play to the advantages of melt differential electrospinning technology.Firstly,by preparing high-efficiency air filter membrane,it integrates nanofiber continuous uniformity and low flow resistance.Advantages,enhance the filtration efficiency of the mechanical fiber of the reinforcing fiber;secondly,prepare the electret air filter membrane,increase the charging ability of the fiber by adding inorganic nanoparticles,thereby enhancing the electrostatic adsorption effect,greatly reducing the resistance while improving the filtration efficiency,and exploring A multi-stage pore structure having a low resistance property to further improve the air filtration performance of the nanofiber membrane.This paper focused on the following four aspects,the main contents are as follows:(1)A melt differential electrospun nanofiber high efficiency air filter membrane was prepared.The PLA/ATBC air filter membrane is prepared by melt differential electrospinning technology.The flexibility of PLA is improved by adding plasticizer ATBC,which is beneficial to solve the problem that the pure PLA has high brittleness and poor toughness and is difficult to resist the resistance of airflow.Problems with air filtration applications.When the ATBC mass fraction is 10%,the air filter has the highest porosity,the average fiber diameter is 0.42 ?m,and the filtration efficiency is up to 99.95%,which is the filtration grade H13 of the high-efficiency filter in the European standard EN779.(2)The structural form of the air filter membrane with lower filtration resistance was obtained under the same level of filtration efficiency.A multi-stage structured air filter material with different fiber packing densities was prepared by melt electrospinning using polylactic acid PLA with 10%by mass of plasticizer ATBC as raw material.The results show that the multi-stage air filter with different pore size distribution has low resistance characteristics.The fiber membrane with different pore diameters inside the fiber filter with increasing pore diameter forms a inverted pyramid shape,which reduces the filter resistance of the filter material.(3)A melt differential electrospinning method combined with electret technology was proposed to prepare a polypropylene composite electret filter membrane,which solved the contradiction between the filtration efficiency and the filtration resistance of the air filter membrane,and the morphology of the electret filter membrane.Characterization of characteristics,charge capacity,and filtration performance.The results show that the fiber has an open-type loose structure due to the mutual repulsiveness of the same kind of fibers,and the fiber morphology appears slightly uplifted,which effectively reduces the filtration resistance.The addition of tourmaline effectively improves the charging ability of the melt electrospun air filter membrane,and the electrostatic effect is remarkable.Under the premise of ensuring air filtration efficiency,the air filtration resistance is greatly reduced.(4)The anti-smog screen and air purification humidification machine was designed,and the melt differential electrospinning fiber membrane was used as the filtration membrane of the two filtering devices,thereby accelerating the conversion rate of the melt differential electrospinning technology into practical application.In summary,this paper adopted the ultrafine fiber green preparation process without solvent,namely the melt differential electrospinning technology,to prepare the melt differential electrospinning nanofiber high efficiency air filter membrane,which achieved the filtration of the high efficiency filter membrane in the European standard EN779.Grade H13;This research explored the multi-stage structure of air filter with different fiber packing density.The fiber filter with increasing pore diameter has low resistance characteristics.A method combining melt differential electrospinning and electret technology was proposed to prepare a melt differential air composite electret filter.This study alleviated the contradiction between filtration resistance and filtration efficiency in fiber air filter design,and provided an important way to achieve green,high efficiency and low resistance air filter design goals.