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Guo D, Zhu Z. Influence of a Meltblown Die with a Laval Airstream Channel on the Manufacturing Process of a Polymer Fiber Based on an Orthogonal Test and Simulation Analysis. ACS OMEGA 2023; 8:48742-48755. [PMID: 38162728 PMCID: PMC10753729 DOI: 10.1021/acsomega.3c05643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/23/2023] [Accepted: 11/23/2023] [Indexed: 01/03/2024]
Abstract
A Laval nozzle is a device that accelerates a low-speed airstream to form a high-speed airstream. In this work, we use a Laval nozzle in the airstream channel design of a meltblown die to improve the tensile properties of the fiber in the airstream field of the meltblown die. The features of the airstream field of the meltblown die are analyzed by numerical simulation. For a given parametrization, six factors may be tuned to optimize the performance of the Laval airstream channel of the meltblown die. We thus use a five-level, six-factor orthogonal test method to optimize the airstream channel of the meltblown die to determine the various factors that influence the airstream field beneath the meltblown die. The results show that the optimized Laval meltblown die performs better than the traditional die and that the widths of the larynx and expansion segment most strongly affect the airstream velocity beneath the Laval meltblown die. Compared with a traditional die, the Laval die optimized by orthogonal testing increases the peak airstream velocity by 17.54%, average velocity by 96.81%, average temperature by 12.32%, and peak pressure by 14.61% and produces weaker turbulence intensity near the spinneret. These characteristics make the airstream beneath the die more stable and uniform and accelerate the attenuation of the fiber diameter, producing more polymer nanofibers. These results demonstrate a valuable approach to the design and optimization of meltblown dies and provide a technical reference for the production and application of the meltblown fiber production equipment.
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Affiliation(s)
- Dongjun Guo
- Engineering
Training Center, Nantong University, Nantong 226019, China
| | - Zhisong Zhu
- School
of Mechanical Engineering, Nantong University, Nantong 226019, China
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Bhangare RC, Tiwari M, Ajmal PY, Rathod TD, Sahu SK. Exudation of microplastics from commonly used face masks in COVID-19 pandemic. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:35258-35268. [PMID: 36527557 PMCID: PMC9758682 DOI: 10.1007/s11356-022-24702-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The COVID-19 pandemic forced use of face masks up to billions of masks per day globally. Though an important and necessary measure for control of the pandemic, use of masks also poses some inherent risks. One of those risks is inhalation of microplastics released from the mask materials. Since most of the mask materials are made from plastic/polymers, they always have the potential to expose the user to fragmented microplastics. To estimate the amount of inhalable microplastic exuded from masks, an experiment simulating real-life scenario of mask usage was performed. The study included collection of microplastics oozed out from the masks on to a filter paper followed by staining and fluorescence detection of the total number of microplastics using a microscope. Both used and new masks were studied. Based on the emission wavelength, the microplastics were found to be belonging to three different categories, namely blue, green and red emitting microplastics respectively. The number of microplastic particles emitted per mask over a period of usage of 8 h was about 5000 to 9000 for new masks and about 6500 to 15,000 for used masks respectively. The estimation of polymer type of plastic in the mask fabrics was also carried out using Raman and FTIR spectroscopy.
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Affiliation(s)
- Rahul C Bhangare
- Environmental Monitoring and Assessment Division, Health Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Mahesh Tiwari
- Environmental Monitoring and Assessment Division, Health Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Puthiyaveettilparambu Yousuf Ajmal
- Environmental Monitoring and Assessment Division, Health Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Tejas D Rathod
- Environmental Monitoring and Assessment Division, Health Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Sanjay K Sahu
- Environmental Monitoring and Assessment Division, Health Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, 400085, India.
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3
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Numerical Analysis of Fiber/Air-Coupling Field for Annular Jet. Polymers (Basel) 2022; 14:polym14214630. [DOI: 10.3390/polym14214630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
Melt-blowing technology is an important method for directly preparing micro-nanofiber materials by drawing polymer melts with high temperature and high velocity air flow. During the drawing process, the melt-blowing fiber not only undergoes a phase change, but also has an extremely complex coupling effect with the drawing airflow. Therefore, in the numerical calculation of the flow field, the existence of melt-blowing fibers is often ignored. In this paper, based on the volume of fluid method, a numerical study of the flexible fiber/air-coupling flow field of an annular melt-blowing die is carried out with the aid of computational fluid dynamics software. The results show that the pressure distribution in the different central symmetry planes of the ring die at the same time was basically the same. However, the velocity distribution may have been different; the velocity on the spinning line varied with time; the pressure changes on the spinning line were small; and velocity fluctuations around the spinning line could cause whiplash of the fibers.
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Jia J, Xie S, Zhang C. Airflow, Fiber Dynamic Whipping, and Final Fiber Diameter in Flush Sharp-Die Melt Blowing with Different Air-Slot Widths. ACS OMEGA 2021; 6:30012-30018. [PMID: 34778672 PMCID: PMC8582056 DOI: 10.1021/acsomega.1c04689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Melt streams were attenuated into microfibers by high-speed airflow during melt blowing. The present work explored the effect of air-slot width on the fiber diameter and diameter evenness in flush sharp-die melt blowing. The airflow in different die melt blowing was first numerically simulated by the CFD approach. Then, the fiber dynamic whipping was captured by high-speed photography. Finally, a spinning experiment was implemented and the fiber diameters were measured. The result reveals that the sharp die with a larger air-slot width produces fibers with a larger diameter, but the uniformity is obviously better. This study reveals that the air flow, fiber whipping, and final fiber diameter are closely related to each other. The quality control of melt-blown fiber can be carried out by controlling the fiber whipping motion.
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Affiliation(s)
- Jingjing Jia
- School
of Fashion and Design, Jiaxing Nanhu University, Jiaxing 314001, China
| | - Sheng Xie
- Key
Laboratory of Yarn Materials Forming and Composite Processing Technology
of Zhejiang Province, Jiaxing University, Jiaxing 314001, China
| | - Caidan Zhang
- Key
Laboratory of Yarn Materials Forming and Composite Processing Technology
of Zhejiang Province, Jiaxing University, Jiaxing 314001, China
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Ma J, Chen F, Xu H, Jiang H, Liu J, Li P, Chen CC, Pan K. Face masks as a source of nanoplastics and microplastics in the environment: Quantification, characterization, and potential for bioaccumulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117748. [PMID: 34265560 DOI: 10.1016/j.envpol.2021.117748] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/03/2021] [Accepted: 07/05/2021] [Indexed: 05/19/2023]
Abstract
Billions of disposable face masks are consumed daily due to the COVID-19 pandemic. The role of these masks as a source of nanoplastics (NPs) and microplastics (MPs) in the environment has not been studied in previous studies. We quantified and characterized face mask released particles and evaluated their potential for accumulation in humans and marine organisms. More than one billion of NPs and MPs were released from each surgical or N95 face mask. These irregularly-shaped particles sized from c. 5 nm to c. 600 μm. But most of them were nano scale sized <1 μm. The middle layers of the masks had released more particles than the outer and inner layers. That MPs were detected in the nasal mucus of mask wearers suggests they can be inhaled while wearing a mask. Mask released particles also adsorbed onto diatom surfaces and were ingested by marine organisms of different trophic levels. This data is useful for assessing the health and environmental risks of face masks.
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Affiliation(s)
- Jie Ma
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Fengyuan Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, SAR, China
| | - Huo Xu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, SAR, China
| | - Hao Jiang
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Jingli Liu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Ping Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Ciara Chun Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Ke Pan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
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Measurement and Comparison of Melt-Blowing Airflow Fields: Nozzle Modifications to Reduce Turbulence and Fibre Whipping. Polymers (Basel) 2021; 13:polym13050719. [PMID: 33652963 PMCID: PMC7956324 DOI: 10.3390/polym13050719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 02/23/2021] [Indexed: 11/17/2022] Open
Abstract
In the melt-blowing process, micro/nanofibrous nonwovens are attenuated and formed through aerodynamic force in a turbulent airflow field. In this work, two types of airflow-directors were added under a common melt-blowing slot-die nozzle to obtain modified airflow fields. The effect of airflow-directors on time-averaged characteristics, turbulence intensity, and temperature fluctuation intensity are achieved through the simultaneous measurement of fluctuating velocity and fluctuating temperature using a two-wire probe hot-wire anemometer. Moreover, the influence of airflow-directors on fibre oscillations are also investigated through high-speed photography. The distribution of turbulence intensity and temperature fluctuation intensity reveals the characteristics of fluctuating airflow fields formed by different melt-blowing slot-die nozzles. Through the analyses of airflow characteristics and fibre oscillations, we can find that the arrangement of airflow-directors has a great impact on both turbulence distribution and fibre oscillation.
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Ji C, Wang Y. Experimental investigation on the three-dimensional flow field from a meltblowing slot die. E-POLYMERS 2020. [DOI: 10.1515/epoly-2020-0058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractTo investigate the distribution characteristics of the three-dimensional flow field under the slot die, an online measurement of the airflow velocity was performed using a hot wire anemometer. The experimental results show that the air-slot end faces have a great influence on the airflow distribution in its vicinity. Compared with the air velocity in the center area, the velocity below the slot end face is much lower. The distribution characteristics of the three-dimensional flow field under the slot die would cause the fibers at different positions to bear inconsistent air force. The air velocity of the spinning centerline is higher than that around it, which is more conducive to fiber diameter attenuation. The violent fluctuation of the instantaneous velocity of the airflow could easily cause the meltblowing fiber to whip in the area close to the die.
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Affiliation(s)
- Changchun Ji
- New Energy Engineering, Shanxi Institute of Energy, 63 University Street, Jinzhong, 030600, P. R. China
| | - Yudong Wang
- College of Mechanical Engineering, Xinjiang University, 666 Shengli Road, Urumqi, Xinjiang, 830046, P. R. China
- College of Light Industry and Textile, Inner Mongolia University of Technology, Hohhot, 010051, China
- College of Textile, Donghua University, 2999 North Renmin Road, Shanghai, 201620, P. R. China
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