Preparation of low resistance fluffy ultrafine filter media by centrifugal electrospinning

Abstract

Fluffy poly(vinyl alcohol) fiber filter material was prepared by the centrifugal electrospinning process combined with the opening process, which is used in the field of air filtration. We used a conductive ring to connect the positive high voltage with the centrifugal spinning rotation cup in order to improve the electrostatic loading stability of the centrifugal electrospinning process and make the electric field more concentrated. It can reduce the high voltage attenuation and reduce the voltage deviation from 1.47–1.86 kV to 0.02–0.04 KV. The effects of the loading voltage (0–20 kV) and rotational speed (4000–8000 rpm) of the positive high voltage loading mode on the fiber diameter were investigated. The results show that the voltage loading was beneficial to the formation of fibers with good morphology, especially under the condition of low rotational speed. Moreover, the improvement effect of voltage was more obvious, which can curb the problems caused by insufficient solvent volatilization, such as too thick fiber diameter, fiber dissolution bonding, spot bonding, and so on. In addition, the increase in rotational speed was also beneficial to the refinement of the fiber. We loosened the filter material processed by the centrifugal electrospinning process and explored the effect of the opening process on fibers of different morphologies in order to further promote the application of the centrifugal electrospinning filter material and improve the fluffy degree of the filter material. The results showed that the fiber with good spinning and fewer shift defects has a better opening effect and fluffy degree. Finally, the filtration efficiency of the fiber mat prepared with different process parameters before and after the opening was tested using a filter material tester. The results show that the fiber with few shift defects can effectively reduce the resistance without greatly reducing the filtration efficiency. In fact, the results play a guiding role in the preparation of medium-effect fluffy filter media.