High filtration efficiency fluffy material: nano-fiber constructing gradient structure on recycled curved PET micro-fibers web

Abstract

High efficiency filtration materials focus on electreted melt-blown polypropylene nonwoven and nano-scale fibers membrane in industry. However, the charge decay and the balance of efficiency and resistance are still facing challenges on research and practical applications. In this research, combined with traditional electrospinning and carding process, a simple and new fluffy gradient filtration material was designed by constructing nano-scale poly(lactic acid) (nano-PLA) fiber membranes on recycled three-dimensional curved poly(ethylene terephthalate) (R-PET) micro-fibers webs. Influences of basis weights of nano-PLA membranes and curved types of R-PET fibers on the filtration performance and the dust-holding capacity of R-PET/nano-PLA mats were investigated. Besides, the filtration mechanism of R-PET/nano-PLA mats was systemically studied. Results show that R-PET with zigzag curve (R/Z-PET) possesses the highest filtration efficiency of 99.992% comparing with 99.517% of linear R-PET, the pressure drop fall to 201.11 Pa, and a quality factor level up from 0.024 to 0.047 Pa −1. The pressure raising rate of the R/Z-PET/nano-PLA mat is the slowest. R/Z-PET fibers with a folding angle of 90° benefit to decrease the friction between fiber and particles when the location angle of zigzag fiber is 45° along the airflow direction, which decrease the pressure drop at high filtration efficiency. Surface residual charges contribute some effect on the overall filtration performance of the R-PET/nano-PLA mat. A new way of simple curved micro-PET fiber combining with nano-scale fibers provides an industrial available path to mass production of high efficiency filtration material serving for air pollution control without electret process.

Material Properties Influencing the Charge Decay of Electret Filters and their Impact on Filtration Performance

“…The electret filter as opposed to the mechanical filter display enhanced ability of capturing airborne particles due to the benefit of coulombic attraction and induced polarization. Thus, electret filters tend to give higher quality factor (QF), which is the relative efficiency to a unit pressure drop [6,22,23]. The limitation of electret filter comes from the charge decay, which occurs through environmental aging that causes electric conduction or charge carrier mobility [8,[16][17][18].…”

Recent Studies on Recycled PET Fibers: Production and Applications: a Review

“…To improve the properties of products or to obtain new properties in recycled PET fibers, additives must be used or blended with another polymer (Chinchillas-Chinchillas et al 2020;Deng et al 2019;Sarioğlu et al 2020;Thomas and Moosvi 2020b). Therefore, in the future, it may be possible to get better properties from products made from recycled PET fibers with new and better auxiliary compounds or to increase the amount of use of recycled PET fiber without lowering the quality, which is in line with economic and environmental goals.…”

“…Air filtration (Deng et al 2019) 2 -Nano-PLA membrane helped with the filtration yield of mats. 3 -Fluffy zigzag-curved R-PET fibers provide a greater chance for particles to move within the filtration material.…”

Customization of hierarchical air filter media by tailoring the structural parameters of needle punched nonwoven

“…In a study, Deng et al. [12] designed a gradient structured filter by using recycled PET microfibres. They noticed that the electret filter consisting of gradient structure is more capable to produce a higher quality factor (QF) which is the relative efficiency to a unit pressure drop.…”

“…Huang et al [11] developed a hierarchical filter media by electrospun nanofibers treated by solvent vapour annealing and found excellent efficacy for a range of PM2.5 to PM10. In a study, Deng et al [12] designed a gradient structured filter by using recycled PET microfibres. They noticed that the electret filter consisting of gradient structure is more capable to produce a higher quality factor (QF) which is the relative efficiency to a unit pressure drop.…”