A microbead/nanofiber composite air filter material with gradient structure and preparation method thereof

Abstract

The invention relates to a microbead / nano-fiber composite air filtration material with a gradient structure and a preparation method thereof. The preparation method consists of: introducing microbeads into a nano-fiber layer, adjusting the mass ratio of a spinning solution for spinning the microbeads to a spinning solution for spinning the nano-fiber to control gradual increase of the microbead content along the filter material thickness direction from the bottom up, thus obtaining a microbead / nano-fiber layer with a gradient structure, and compounding a nonwoven substrate, the microbead / nano-fiber layer and a nonwoven covering layer by hot rolling process so as to obtain a sandwich structure composite air filtration material. According to the invention, the preparation process is simple, refitting of an electrospinning machine is not needed, the application range is wide, and the prepared composite filtration material has the advantages of high filtration efficiency, small resistance pressure drop, large dust holding capacity and long service life.

Description

technical field [0001] The invention relates to a microbead / nanofiber composite air filter material with a gradient structure and a preparation method thereof, belonging to the technical field of electrospinning nanofiber air filter material preparation. Background technique [0002] With the rapid development of my country's industrialization and the sharp increase in car ownership, the problem of air pollution has become increasingly serious, especially in recent years, severe weather such as smog and sandstorms that have frequently occurred in most parts of my country has caused serious damage to people's health and quality of life. Therefore, the demand for air filter materials is increasing, and the requirements for its filtration performance are also increasing. Electrospun nanofibers have the characteristics of small fiber diameter, large specific surface area, small pore size, and high porosity. They are very suitable for the production of high-performance air filter ...

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Problems solved by technology

The different ways of adding particles involved in the existing literature are (1) adding nanoparticles to the spinning solution to obtain a composite spinning solution and then performing electrospinning, such as a ball-thread combined composite fiber air filter material and its Preparation method (CN103706182A), the disadvantage of the above scheme is that the particles in the spinning solution are prone to agglomeration, which affects the smooth progress of the spinning process and the uniformity of the nanofibers, thereby affecting the actual filtration performance of the nanofiber membrane; (2 ) to prepare a mixed suspension of nanofibers and particles and then coat it on the substrate, such as a high-adsorption nanofiber composite filter material and its preparation method (CN104014196A), an organic-inorganic composite nanofiber membrane filter material and its preparation method (CN104689724A), the disadvantage of the above scheme is that it is difficult to effectively control the fiber packing density and pore structure, so it is difficult to significantly reduce the resistance pressure drop of the material, and the process is relatively complicated; (3) the nanofiber layer and the beaded fiber layer are alternately spun For example, a high-efficiency and low-resistance nanofiber air filter material for masks and its preparation method (CN104645715A), the disadvantage of the above scheme is that there is no optimized design for the arrangement structure of the nanofiber layer and the beaded fiber layer, only two layers Repeated stacking between them, the nanofiber layer and the beaded fiber layer need to be spun separately in sequence, which takes a long time and reduces production efficiency, and this method needs to be modified to the conventional electrospinning machine, so the scope of application is limited

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