Filtration efficiency and loading characteristics of PM2.5 through commercial electret filter media

2018 ◽  
Vol 195 ◽  
pp. 101-109 ◽  
Author(s):  
Min Tang ◽  
Drew Thompson ◽  
De-Qiang Chang ◽  
Sheng-Chieh Chen ◽  
David Y.H. Pui
Keyword(s):  
Filtration Efficiency ◽  
Filter Media ◽  
Electret Filter

Degradation Processes in Corona-Charged Electret Filter-Media with Exposure to Ethyl Benzene

2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
J. Jasper Warren ◽  
Anushree Mohan ◽  
Juan Hinestroza ◽  
Roger Barker
Keyword(s):  
Direct Contact ◽  
Polypropylene Fiber ◽  
Filtration Efficiency ◽  
Benzene Vapor ◽  
Ethyl Benzene ◽  
Filter Media ◽  
Fiber Mats ◽  
Filtration Performance ◽  
Custom Made ◽  
Electret Filter

The degradation of filtration performance for corona-charged electret filter media exposed to ethyl benzene was assessed. Nonwoven corona-charged polypropylene fiber mats were exposed to ethyl-benzene using a custom made apparatus. Evaluated scenarios included ethyl-benzene vapor and liquid exposures. The filtration performance was evaluated using DOP as a test aerosol to measure filtration performance. It was observed that significant filtration degradation occurred only when liquid ethyl benzene came into direct contact with the filter media. No significant changes in the pressure drop or filtration efficiency was observed for any of the exposure scenarios in which the fibers were only exposed to ethyl benzene in the vapor phase.

Effect of Nanofiber Diameter on Filtration Efficiency

2012 ◽  
Vol 560-561 ◽  
pp. 737-741 ◽  
Author(s):  
Yan Ping Liu ◽  
Yi Bing Deng ◽  
Zheng Xiong Jiang
Keyword(s):  
Volume Ratio ◽  
Filtration Efficiency ◽  
Particle Capture ◽  
Filter Media ◽  
Nanofiber Diameter ◽  
Filtration Area

Electrospinning and its application in filtration area have been caught much attention because of the large surface-to-volume ratio of nanoweb , which affects the filtration efficiency by possibly giving more particle-capture sites. In this study, PAN is electrospun to produce ultra-fine nonwovens, and its characteristics as filter media are investigated.

scholarly journals Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

2021 ◽  
Author(s):  
M. Benboubker ◽  
B. Oumokhtar ◽  
F. Hmami ◽  
K. El Mabrouk ◽  
L.EL Alami ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Structural Changes ◽  
Fourier Transforms ◽  
Chemical Characterization ◽  
Small Variation ◽  
Filtration Efficiency ◽  
Respiratory Protection ◽  
Filter Media ◽  
Test Protocol ◽  
Efficiency Measures

AbstractDuring the Covid-19 pandemic, healthcare workers were extremely vulnerable to infection with the virus and needed continuous protection. One of the most effective and widely used means of protection was the FFP2 respirator. Unfortunately, this crisis created a shortage of these masks, prompting hospitals to explore opportunities to reuse them after decontamination.An approach for assessing the filtration efficiency of decontaminated FFP2 masks has been proposed and applied to evaluate the possibilities of their safe reuse. The decontamination processes adopted are those based on moist heat or hydrogen peroxide. The approach introduces efficiency measures that define the filtration and protection capacity of the masks, which characterize both chemical and structural changes, and encompasses many techniques including scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The test protocol was applied to mask samples that had endured different decontamination cycles and the results of their efficiency measures were compared to brand-new masks’ performances.The main result was that chemical and structural characterization of the decontaminated masks have shown no substantial change or deformation of their filter media structures. Indeed, the respiratory resistance test has shown that the results of both the FFP2 masks that have undergone a hydrogen peroxide disinfection cycle or a steam autoclave cycle remained constant with a small variation of 10 Pa from the EN149 standard. The chemical characterization, on the other hand, has shown that the filter media of the decontaminated masks remains unchanged, with no detectable chemical derivatives in its constituents.

Characterization and Efficiency Evaluation of Regenerated Filter Media

2012 ◽  
Vol 727-728 ◽  
pp. 1643-1647
Author(s):  
Priscila Martins de Barros ◽  
Eduardo Hiromitsu Tanabe ◽  
Mônica Lopes Aguiar
Keyword(s):  
Electron Microscope ◽  
Cellulose Fiber ◽  
Air Permeability ◽  
Filtration Efficiency ◽  
Efficiency Evaluation ◽  
Aerodynamic Diameter ◽  
Filter Media ◽  
Removal Efficiencies ◽  
Phosphate Concentrate ◽  
Scanning Electron

This study aimed to evaluate the characteristics of virgin and regenerated filter media and their relation with filtration efficiencies for particles with aerodynamic diameter up to 20 µm. The permeability of the filter media was determined and their fibers were observed in a scanning electron microscope. Filtration efficiency was obtained from the dust cake formed. The particulate matter used was phosphate concentrate and the filter media were cellulose fiber filters. The results showed that regenerated filter media presented higher air permeability due to the opening of the fibers observed in the microphotographs obtained; lower removal efficiencies were observed for particles smaller than 2.5 µm; and for particles larger than 2.5 µm, the efficiencies were nearly the same as those of the virgin filter, which was approximately 100%. It was verified that the regenerated filter media lost their initial characteristics, but continued to be efficient for particles larger than 2.5 µm.

Ageing of electret filter media due to deposition of submicron particles – Experimental and numerical investigations

2020 ◽  
Vol 251 ◽  
pp. 117299 ◽  
Author(s):  
Maximilian Kerner ◽  
Kilian Schmidt ◽  
Stefan Schumacher ◽  
Christof Asbach ◽  
Sergiy Antonyuk
Keyword(s):  
Submicron Particles ◽  
Filter Media ◽  
Numerical Investigations ◽  
Electret Filter

Surface Refining Treatment of Filter Media

2012 ◽  
Vol 441 ◽  
pp. 593-597
Author(s):  
Feng Wang ◽  
Yu Hai Guo ◽  
Hua Peng Zhang ◽  
Hong Yan Tang
Keyword(s):  
Double Layer ◽  
Porous Membrane ◽  
Filtration Efficiency ◽  
Uniform Thickness ◽  
Filter Media ◽  
Pore Sizes

In order to improve filtration efficiency and precision of the filter media, two methods of surface refining treatment were presented, which were the co-stretching PTFE micro-porous membrane and foam coating on nonwoven filter media. During the process of co-stretching, the pore diameters and thickness of the membrane were different on the surface. The double-layer PTFE base sheet was simultaneously stretched, which induced the reduction of pore sizes and uniform thickness of the filter media. After foam coating, the pore sizes of nonwoven filter media were reduced to under 10 μm because of the micro-pore membrane formed on the surface. Therefore, filtration efficiency and precision were remarkably increased.

scholarly journals Electrospun Nanofibre Filtration Media to Protect against Biological or Nonbiological Airborne Particles

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3257
Author(s):  
Fabrice N. H. Karabulut ◽  
Günther Höfler ◽  
Naveen Ashok Chand ◽  
Gareth W. Beckermann
Keyword(s):  
Pressure Drop ◽  
Filtration Efficiency ◽  
Weight Basis ◽  
Airborne Particles ◽  
Air Filtration ◽  
Filter Media ◽  
Ethylene Vinyl Alcohol ◽  
Electrospun Nanofibres ◽  
Level 1 ◽  
Level 2

Electrospun nanofibres can outperform their melt-blown counterparts in many applications, especially air filtration. The different filtration mechanisms of nanofibres are particularly important when it comes to the air filtration of viruses (such as COVID-19) and bacteria. In this work, we present an electrospun nanofibre filter media, FilterLayrTM by NanoLayr Ltd., containing poly(methyl methacrylate)/ethylene vinyl alcohol nanofibres. The outstanding uniformity of the nanofibres was indicated by the good correlation between pressure drop (ΔP) and areal weight with R2 values in the range of 0.82 to 0.98 across various test air velocities. By adjusting the nanofibre areal weight (basis weight), the nanofibre filter media was shown to meet the particle filtration efficiency and breathability requirements of the following internationally accepted facemask and respirator standards: N95 respirator facemask performance in accordance with NIOSH 42CFR84 (filtration efficiency of up to 98.10% at a pressure drop of 226 Pa and 290 Pa at 85 L·min−1 and 120 L·min−1, respectively), Level 2 surgical facemask performance in accordance with ASTM F2299 (filtration efficiency of up to 99.97% at 100 nm particle size and a pressure drop of 44 Pa at 8 L·min−1), and Level 2 filtration efficiency and Level 1 breathability for barrier face coverings in accordance with ASTM F3502 (filtration efficiency of up to 99.68% and a pressure drop of 133 Pa at 60 L·min−1), with Level 2 breathability being achievable at lower nanofibre areal weights.

Material Properties Analysis with Addition of Nanofibres for Air Intake Filtration in Internal Combustion Engines

2021 ◽  
Vol 18 (1) ◽  
pp. 8621-8636
Author(s):  
T. Dziubak
Keyword(s):  
Flow Resistance ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Filtration Efficiency ◽  
Combustion Engines ◽  
Test Results ◽  
Air Filtration ◽  
Filter Media ◽  
Air Filter ◽  
Filter Materials

The aim of this study is to provide an experimental properties evaluation of a standard filter material (cellulose) and materials with fiber layer addition with small diameters (nanofibers). Filter media, including cellulose, used in the internal combustion engine inlet air filtration are made of high diameter fibres, approx. 15 µm. Significantly higher separation and filtration efficiency performance are obtained for materials with lower fibre diameters (nanofibres), however, at the expense of a significantly higher pressure drop, affecting the engine performance. Filter media manufacturers mainly specify the structure parameters (pore size, air permeability and thickness), without giving any information on the dust filtration performance and rate. The literature includes test results for models of different filter media structures. Filtration process modelling using polydisperse dust with particles of different shape and density and irregular filter media structure is possible using advanced computer techniques, however, the process is complex and requires many simplifications. Test results can be applied directly in the automotive industry. The data can be obtained by experimental tests on filter medium specimens, complete filter elements or air filters which are costly and time-consuming tests, however, those test methods are the most reliable. Conditions and testing methodology for intake air filter materials used in internal combustion engines were developed. Filtration and flow resistance efficiency and accuracy were done depending on test dust mass stopped per unit area. Tested materials filtration efficiency was assessed by a filtration quality factor, which includes experimentally determined efficiency and accuracy as well as flow resistance values. Much higher efficiency and filtration accuracy of dust grains below 5 µm in filtration materials with nanofibers addition compared to standard filtration material (filter paper) were demonstrated. For the same flow resistance values, filter materials with nanofibers addition accumulate smaller dust mass than standard filter paper. Usage of materials with nanofibers addition used in motor vehicles intake air filtration ensures their high efficiency and accuracy. It minimises its components wear, but at the expense of faster flow resistance increase, which shortens filter life and increases filter replacement frequency. Results obtained during the experimental research partly fill the gap when it comes to the basic material properties used in internal combustion engines intake air filter partitions production.

Liquid-mediated particle capture by nonwoven filter media for automotive engine intake air filtration

2021 ◽  
pp. 152808372110610
Author(s):  
Shivendra Yadav ◽  
Dipayan Das
Keyword(s):  
Pressure Drop ◽  
Polypropylene Fiber ◽  
Nonwoven Fabric ◽  
Filtration Efficiency ◽  
Engine Oil ◽  
Air Filtration ◽  
Dust Deposition ◽  
Filter Media ◽  
Air Filter ◽  
Automotive Engine

This article reports on development, characterization, and performance of liquid-treated nonwoven air filter media for automotive engine intake application. A polypropylene fiber-based needle-punched nonwoven fabric was prepared for treatment with four viscous liquids (glycerol, SAE 20W/50 engine oil, PEG 400, and deionized water) by liquid spraying technique. The filtration performance was evaluated in terms of initial and final gravimetric filtration efficiencies, fractional filtration efficiency, evolution of pressure drop, and dust holding capacity. The liquid-treated filter media registered higher gravimetric as well as fractional filtration efficiency and higher dust holding capacity as compared to the untreated ones. The initial and final gravimetric filtration efficiencies were found to be directly related to liquid add-on via a power law relationship. The liquid-treated filter media also exhibited higher fractional filtration efficiency than their untreated counterparts for all sizes of tested particles. Interestingly, the increase of fractional efficiency was more for smaller particles as compared to larger ones. This was explained quantitatively through single fiber efficiency due to adhesion. The viscosity of liquid was found to be a very crucial parameter as the dust deposition morphology was contingent to the flow of liquid onto the filter media. The stickiest liquid yielded highest filtration efficiencies, displayed slowest rise of pressure drop, and exhibited highest dust holding capacity.

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