scholarly journals Influence of fiber diameter on filtration performance of polyester fibers

2019 ◽  
Vol 23 (4) ◽  
pp. 2291-2296 ◽  
Author(s):  
Xin Zhang ◽  
Yue-Sheng Fan ◽  
Guo-Ji Tian ◽  
Huan Wang ◽  
Hong-Li Zhang ◽  
...  

The filtration performance of four kinds of coarse polyester filters commonly used in the market was studied experimentally. The results showed that these filter materials had better filtration efficiency for particles larger than 5 ?m. There was a significant difference among the same grade filters on filtration efficiency and resistance. The maximum counting efficiency of all four Samples can be achieved when the filtration velocity was 1.1 m/s. Fiber diameter was one of the main influencing factors that affect the efficiency and resistance of polyester filters. The comprehensive effect was relatively good when the Sample fiber diameter was small.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Si Cheng ◽  
Alam S. M. Muhaiminul ◽  
Zhonghua Yue ◽  
Yan Wang ◽  
Yuanxiang Xiao ◽  
...  

AbstractBy applying the simultaneous corona-temperature treatment, the effect of electret temperature on the structure and filtration properties of melt-blown nonwovens was investigated. Fiber diameter, pore size, thickness, areal weight, porosity, crystallinity, filtration efficiency, and pressure drop were evaluated. The results demonstrated that some changes occurred in the structure of electret fabrics after treatment under different temperatures. In the range of 20°C~105°C, the filtration efficiency of melt-blown nonwovens has a relationship with the change in crystallinity, and the pressure drop increased because of the change in areal weight and porosity. This work may provide a reference for further improving filtration efficiency of melt-blown nonwovens.


Author(s):  
Xingcheng Liu ◽  
Henggen Shen ◽  
Xueli Nie

The main objective of this study was to determine the effect of filter pore size and fiber diameter on the performance of the baghouse filters for ultra-low emission. In this study, three kinds of conventional polyester filter (depth filtration media) and two kinds of polytetrafluoroethylene membrane-coated polyester filter (surface filtration media), having various filter pore sizes and fiber diameters, were tested to determine the performance of static and dynamic filtration. In order to determine the static filtration performance, the filtration resistance and the filtration efficiency of the clean filter media were measured by the arrestance method. The dynamic filtration performance experiments were conducted to determine the dynamic resistances, dust depositions, and dynamic filtration efficiencies of the dust-containing filter media under the condition of dust airflow filtration through a pulse-cleaning cycle. In the dynamic filtration performance experiments, the size of 50% test dust was less than 2.5 μm, and the mass mean aerodynamic diameter of the dust was 1.5 μm. The filtration velocity was 2 m∙min−1, and the dust concentration was 18.4 g∙m−3. The static filtration performance experiments showed that the filter pore size greatly affected the filtration resistance and the filtration efficiency of the fabric structure of the surface filtration media. In the depth filtration media, the filtration efficiency and the filtration resistance of the fabric structure were improved when the filter pore size and the fiber diameter were smaller in magnitude. For all the five filter media, smaller the pore size of the filter media, greater was the filtration precision (for fine particles, such as PM2.5) of the fabric structure. In the dynamic filtration performance experiments, the filter pore size and the fiber diameter of the depth filtration media affected the dynamic filtration resistance and the dynamic filtration efficiency of the depth filtration media by affecting the deposition rate of dust in the depth filtration media; however, the filter pore size of the surface filtration media affected the blocking rate of dust in the membrane micropores, thus influencing the dynamic filtration resistance and the dynamic filtration efficiency of the surface filtration media.


2017 ◽  
Vol 23 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Majid Aliabadi

Due to their high filtration efficiency and low basis weight nanofibrous filters are suitable for filtration applications. The objective of this study was to investigate the effect of electrospinning parameters including polymer solution concentration (10-15 wt.%), applied voltage (15-25 kV) and tip-collector distance (7.5-12.5 cm) on the filtration efficiency of polyamide (PA) nanofibers. The morphology of the PA nanofibers was characterized using scanning electron microscope (SEM) analysis. The SEM image results indicated that the average fiber diameter of PA nanofibers was 220 nm at PA solution concentration of 12.5 wt.%, applied voltage of 20 kV, tip-collector distance of 10 cm, flow rate of 0.5 mL h-1, temperature of 25 ?C and humidity of 40%. The obtained results showed that the highest quality factor and efficiency of 7.02?10-2 Pa-1 and 96% were optimal parameters for nanofibrous filters during 30 and 240 min of electrospinning time, respectively. The presented study showed that the morphology optimization of nanofibers is an effective method for improvement of filtration performance.


2021 ◽  
pp. 152808372110017
Author(s):  
Haiwen Mao ◽  
Zhijuan Pan

In order to solve the problem of dust accumulation at the joints of traditional filter materials and the reduction of filtration efficiency, weft knitting was selected to make the fabric cylindrical unwinding machine. The cylindrical filter material was formed by cylindrical needling machine in the later period. This type of novel seamless filter material was compared with the traditional one on the filtration performance and numerical simulation of filtration performance. The results show that when the warp and weft lining yarns in the seamless filter material were PTFE monofilaments containing tourmaline particles, the filtration efficiency was the optimal due to the presence of the surface static voltage. The filtration efficiency could greatly be improved by 7.24%. The relationship between the surface static voltage and distance was exponential. The filter material with electrostatic field on the surface increased the active filtration of electrostatic adsorption in addition to the passive filtration. This type of seamless filter material provided research and development ideas and theoretical guidance for the development and application of filter materials.


2011 ◽  
Vol 332-334 ◽  
pp. 379-382
Author(s):  
Cheng Yan Zhu ◽  
Wei Wei Ying ◽  
Hui Fang Zhang

The single-layered needle-punched nonwovens and multi-layered needle-punched composite fabrics were prepared in this paper, which were made by polyester fibers under proper parameters. The filtration performance of fabrics was evaluated through the analyses of filtration efficiency, filtration resistance, pore sizes, air permeability and porosity. The mechanical properties of fabrics were also studied. The results show that the filtration efficiency of multi-layered needle-punched composite fabrics increases by about 20% and the filtration resistance drops by about 200% when compared with those of single-layered needle-punched nonwovens. The tensile strength of multi-layered needle-punched composite fabrics goes up obviously. However, the difference between horizontal and vertical strength is visible and the stability is also poor. Compared to the composite fabrics with woven textiles, the composite fabrics with knitted textiles are better in filtration performance, but worse in mechanical properties.


Author(s):  
Kun Liu ◽  
Xueyan Yang ◽  
Moye Xin

Repetitive nonsuicidal self-injury (R-NSSI) is an extreme manifestation of nonsuicidal self-injury (NSSI) behavior that causes bodily harm and emotional and personality disorders. It is a growing concern, especially among adolescents; therefore, this study aims to provide empirical support for effective interventions on R-NSSI behavior among adolescents in China. We used data of about 1180 students from a survey conducted in seven middle schools in Xi’an, China, and applied multiple logistic regression to analyze NSSI and R-NSSI among male and female students, including their influencing factors. We found no significant difference between male and female students’ R-NSSI; however, regarding influencing factors, male students had more violent experiences and less social support than female students. Parental and familial factors played the most prominent role in social support. Social support was found to be a main-effect mechanism in the effect of violent experiences on R-NSSI among male students, whereas the mechanism had both a main effect and a certain buffer effect among female students. R-NSSI was found to be more prevalent among younger children, children with siblings, and those with romantic relationship experiences. We also found that healthy adolescent development involves the participation of families and schools. Health education should be conducted according to the students’ sex and characteristics.


2021 ◽  
pp. 004051752110505
Author(s):  
Hao Yu ◽  
Christopher Hurren ◽  
Xin Liu ◽  
Xungai Wang

Softness is one of the key elements of textile comfort and is one of the main considerations when consumers make purchasing decisions. In the wool industry, softness can reflect the quality and value of wool fibers. There is verifiable difference in subjective softness between Australian Soft Rolling Skin (SRS) wool and conventional Merino (CM) wool, yet the key factors responsible for this difference are not yet well understood. Fiber attributes, such as crimp (curvature), scale morphology, ortho-to-cortex (OtC) ratio and moisture regain, may have a significant influence on softness performance. This study has examined these key factors for both SRS and CM wool and systematically compared the difference in these factors. There was no significant difference in the crimp frequency between these two wools; however, the curvature of SRS wool was lower than that of CM wool within the same fiber diameter ranges (below 14.5 micron, 16.5–18.5 micron). This difference might be caused by the lower OtC ratio for SRS wool (approximately 0.60) than for CM wool (approximately 0.66). The crystallinity of the two wools was similar and not affected by the change in OtC ratio. SRS wool has higher moisture regain than CM wool by approximately 2.5%, which could reduce the stiffness of wool fibers. The surface morphology for SRS wool was also different from that of CM wool. The lower cuticle scale height for SRS wool resulted in its smoother surface than CM wool. This cuticle height difference was present even when they both had similar cuticle scale frequency.


2019 ◽  
Vol 11 (18) ◽  
pp. 5048 ◽  
Author(s):  
Tao Liu ◽  
Jixia Li ◽  
Juan Chen ◽  
Shaolei Yang

The urban ecological civilization construction relates to welfare of the people and the national future. It is an important field of the high-quality economic development to improve the urban ecological efficiency level. The purpose of this research is to provide a new perspective and method for the quantitative study of the urban sustainable development, and also to provide some decision-making references for the improvement of the urban ecological efficiency in Henan province. This paper uses the slacks-based measure-data envelopment analysis (SBM-DEA) model containing the undesirable output and the Malmquist index model to fully evaluate the urban ecological efficiency level in Henan province during the period of 2005–2016, via both the static and dynamic analysis. Based on this, the bootstrap regression model is applied in analyzing the influencing factors of the urban ecological efficiency. The research shows three findings. First, according to the static efficiency analysis, the urban ecological efficiency in Henan province is low as a whole and has a big promotion space. Moreover, there is a significant difference in the urban ecological efficiency level among the five regions because of the different geographical locations and social and economic development situations of the cities. Second, according to the dynamic efficiency analysis, in the last 12 years, the urban ecological efficiency in Henan province has shown an overall growth trend, and the technological progress has played a major role in promoting the urban ecological efficiency in Henan province. Third, according to the influencing factor analysis, the governmental financial support hinders the improvement of the urban ecological efficiency in Henan province, while the level of opening to the outside world, the urban population density, and the urban greening level promote it.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1307 ◽  
Author(s):  
Ting-Ting Li ◽  
Xixi Cen ◽  
Hai-Tao Ren ◽  
Fei Sun ◽  
Qi Lin ◽  
...  

A bark-like imitated polypr opylene (PP)/polycarbonate (PC) nanofibrous membrane was constructed by one-step meltblown technique for efficient particulate matter (PM) removal. The effects of PC content (0%, 1%, 3%, 5%, and 7%) on membrane thermal stability, microscopic characteristics, filtration performance, hydrophilicity, and water vapor transmission were investigated. The results demonstrated that using facile design of incompatibility and viscosity difference between PC and PP polymers decreases average fiber diameter, creating a bark-like groove appearance and increasing surface potential, making a new PP/PC membrane with high filtration performance. The resultant PP/PC membrane had finer average fiber diameter of 0.63 μm, which was nearly 89.41% lower than PP membranes (5.95 μm), and its quality factor (0.036 Pa−1) was nearly 2.12 times than that of PP membranes (0.017 Pa−1) with the die hole diameter of 0.5 mm. This fabrication technique of a special meltblown filter membrane saves the cost of die retrofitting and post-processing, which provides an innovative method for particulate efficient removal of high efficient filters.


2013 ◽  
Vol 311 ◽  
pp. 243-248
Author(s):  
Wei Cheng Chu ◽  
Chin Pan Huang ◽  
Tien Wei Shyr ◽  
Li Chou Chen ◽  
Shu Ping Chiu

For the wide application in the field of filtration and bio-medicine, the purpose of this study is to design a spinneret module of electro-spun which can produce composite nonwoven with sub-micrometer fiber continually. Applying the principle of melt-blown, a spinneret module with line-type and multi-holes which was assembled with small beads and filtering net, was designed. In order to construct a continual electro-spun production line, a traversal device was designed to control the traverse-motion of spinneret module for the even lapping and a stainless plate was adopted as collecting plate. In condition of 41KV working voltage, 0.3573 mL/min throughput and 42cm CSD (Capillary-Screen-Distance), a continual PEO nonwoven can be produced with average fiber diameter of 576nm and of CV% 13.4%. To a sampling area of 10cm×10cm and basis weight of 7.257 g/m2 electro-spun nonwoven, the CV% of gray level of its image is 2% and its filtration efficiency is up to 91.2% with pressure drop 13.8mm-H20 by TSI 8130 (32LPM, 5% NaCl).


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