ABSTRACT
The current spread of COVID-19 pandemics resulted in a surge of a need of respiratory protection devices, including medical facemasks and facepiece respirators. Large amounts of products based on nonwoven filtration material from non-renewable petroleum based plastics (polyethylene) has raised global concerns about excessive environmental impacts of these products. Unfortunately, the replacement of polypropylene nonwoven microfibre based single use masks by the multiple use products did not appear as an effective strategy due to a lower filtration performance, although potentially lower environmental impacts. Nanofibre based filtration devices introduce themselves as potentially more environmentally friendly ones due to a lower overall usage of raw polymer compared to microfibrous ones. We present the LCA modelling of environmental impacts of respiratory protective devices with nanofibrous filter materials and compare those against traditional micro fibrous materials (FFP1 and FFP2 respirator) and medical facemask. Generally, due to a lower mass of nanofibre, these products emerge as a better environmental option, providing similar protection level. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
The global COVID-19 pandemic has triggered a huge demand for the protective nonwovens. However, the main raw material of nonwovens comes from petroleum, and the massive consumption of petroleum-based polymers brings great pressure to ecosystem. Therefore, it is significant to develop biodegradable protective barrier products. In this work, a polylactic-based composite (a tri-layer nonwovens composed of spunbond, meltblown and spunbond, SMS) was prepared and applied for protective apparel. The surface morphology and chemical changes of the fibers were characterized and analyzed by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy (EDS). The liquid contact angle and permeability, breathability and moisture permeability, frictional charge and mechanical strength of the samples were evaluated and compared. The samples degradability was also recorded. The results demonstrate that the optimum formula for anti-fouling treatment on SMS is F-30. The treated fabric possesses superior liquid repellency and anti-permeability, with contact angles of water and alcohol at 128° and 115° respectively, while the alcohol repellent grade reaches level 7. The treated sample has less strength loss but exhibits favorable breathability, moisture permeability and anti-static properties, which can meet the requirements of protective apparels. After fluorine resin coating, the composite still provide excellent degradation performance, and the weight loss rate reaches more than 80% after 10 days water degradation. These results provide new insights for the application of PLA-based SMS in biodegradable protective apparel. © 2023 The Textile Institute.
ABSTRACT
The present pandemic has highlighted the necessity of infection protection gear as a crucial protective approach, particularly given the fact that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects individuals in poorly ventilated environments. Embedding antimicrobial function onto protection gear would have major implications in minimizing pathogen contamination and lowering healthcare associated illness. In this study, non woven polypropylene fabric (NWPP) which is widely used in personal hygiene products and hospital protective gears has been subjected to surface fictionalization with corona treatment. Surface polarity of the treated fabric was studied by use of dyne liquid which showed generation of surface polarization. Subsequently, the resultant surface polarized NWPP were spray coated with zinc oxide (ZnO) antiviral agent. The antiviral agents were rendered to adhere to NWPP by use of polyurethane solution coating on the fabric. The effect of antiviral coatings on NWPP fabric with the use of polyurethane solution as an adhesive were investigated in terms of antiviral activity and anti-bacterial activity against MS2 bacteriophage and Staphylococcus aureus and Klebsiella pneumonia bacteria respectively. Coating of surface polarized NWPP with polyurethene binder reduced the leaching of antiviral coating. More importantly, the fabrics exhibited promising antiviral and anti bacterial activity with 99.90 % reduction in microorganisms after 24 hours of exposure. © 2022 IEEE.
ABSTRACT
Despite the significant increase in research on mask filtration testing since the COVID-19 pandemic, there remains considerable ambiguity regarding which parameters affect particle filtration efficiency (PFE) and how differences in standard testing protocols can lead to divergent PFE values. We evaluated the PFE (and differential pressure) of several common face masks and community face mask materials including woven cotton, spunbond polypropylene, and meltblown polypropylene, testing in accordance with ASTM F2100/2299 standards for medical masks, using polystyrene latex (PSL) aerosol, as well as NIOSH standards for respirators, using NaCl aerosol. In both cases, PFE was measured with and without aerosol charge neutralization, which is used to bring the particle population to a known, equilibrium bipolar charge distribution. Aerosols of either composition that were not neutralized (untreated) led to significant increases in measured PFE, especially in the case of PSL. In contrast, effective neutralization led to lower PFE measurements that also showed little to no dependence on aerosol composition across most materials. To investigate further, the bipolar charge distributions of PSL and NaCl aerosols, both neutralized and untreated, were characterized using an aerodynamic aerosol classifier operated in tandem with a scanning mobility particle sizer (AAC-SMPS). This technique illustrated the differences in the distribution of particle charge states between PSL and NaCl aerosols of the same size, and between PSL particles of different sizes, revealing the presence of highly charged particles in many cases. Most importantly, the equilibrium charge distribution after neutralization is shown to be independent of particle composition or initial charge distribution, highlighting the crucial role of aerosol charge neutralizers in preventing overestimates of mask performance (due to electrostatic effects) and promoting consistency in standard testing procedures.
ABSTRACT
The global outbreak of COVID-19 results in the surge of disposable sanitary supplies, especially personal protective face masks. However, the charge dissipation of the electret meltblown nonwovens, which predominate in the commercial face mask filters, confines the durability and safety of commercial face masks. Furthermore, most of the face masks are made from nondegradable materials (such as PP) or part of their degradation products are toxic and contaminative to the environment. Herein, a type of face mask with biodegradable and highly effective PLA bi-layer complex fibrous membrane as filter core is reported. The prepared PLA complex membrane possesses a high-filtration efficiency of 99.1% for PM0.3 while providing a favorable pressure drop of 93.2 Pa. With the PLA complex membrane as the filter core, our face mask exhibits comparable or even higher wearability to commercial face masks, which further manifests our designed PLA complex membrane a promising filter media for face masks. © 2023, The Author(s), under exclusive licence to the Korean Fiber Society.
ABSTRACT
Atmospheric water harvesting (AWH) is a potentially promising small-scale approach to alleviate the water crisis in arid or semiarid regions. Inspired by the asymmetric structure of tillandsia leaves, a plant species native to semiarid regions, we report the development of a bioinspired composite (BiC) to draw moisture for AWH applications. With the advent of the post-COVID era, the nonwoven materials in used masks are discarded, landfilled, or incinerated along with the masks as medical waste, and the negative impact on the environment is inevitable. The nonwoven sheet has porosity, softness, and certain mechanical strength. We innovatively developed BiCs, immobilizing hygroscopic salt with a nonwoven mask for fast vapor liquefaction and using a polymer network to store water. The resulting BiC material manages to achieve a high-water adsorption capacity of 1.24 g g-1 under a low-moderate humidity environment and a high-water release ratio of ca. 90% without the use of photothermal materials, while maintaining high structural integrity in cyclic testing. © 2023 American Chemical Society.
ABSTRACT
The worldwide spread of COVID-19 has put a higher requirement for personal medical protective clothing, developing protective clothing with sustained antibacterial and antiviral performance is the priority for safe and sustaining application. For this purpose, we develop a novel cellulose based material with sustained antibacterial and antiviral properties. In the proposed method, the chitosan oligosaccharide (COS) was subjected to a guanylation reaction with dicyandiamide in the presence of Scandium (III) triflate; because of the relatively lower molecular weight and water solubility of the COS, GCOS (guanylated chitosan oligosaccharide) with high substitution degree (DS) could be successfully synthetized without acid application. In this instance, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the GCOS were only 1/8 and 1/4 of that of COS. The introduction of GCOS onto the fiber endowed the fiber with extremely high antibacterial and antiviral performance, showing 100% bacteriostatic rate against Staphylococcus aureus and Escherichia coli and 99.48% virus load reduction of bacteriophage MS2. More importantly, the GCOS modified cellulosic fibers (GCOS-CFs) exhibit excellent sustained antibacterial and antiviral properties; namely, 30 washing cycles had negligible effect on the bacteriostatic rate (100%) and inhibition rate of bacteriophage MS2 (99.0%). Moreover, the paper prepared from the GCOS-CFs still exhibited prominent antibacterial and antiviral activity; inferring that the sheeting forming, press, and drying process have almost no effect on the antibacterial and antiviral performances. The insensitive of antibacterial and antiviral activity to water washing (spunlace) and heat (drying) make the GCOS-CFs a potential material applicable in the spunlaced non-woven fabric production.
ABSTRACT
The current work focuses on designing a low-cost, reusable, and highly efficient facemask for protection from respiratory droplets that cause COVID-19, other infection-causing organisms, and dust allergies. Several masks available in the market are single-use that would choke the environment through plastic pollution or are expensive for the commoner to afford. In the present study, the facemask incorporates a waste-derived polyethylene terephthalate (PET) layer and a non-woven polypropylene (PP) layer sandwiched between two tightly woven cotton layers. Combining these layers provides comfort and breathability, besides high bacterial and particulate filtration efficiency. Moreover, the unique PET layer provides mechanical strength and a 3D shape that enables hindrance-free speaking and prevents spectacle fogging. Compared to commercial N95 masks, the developed mask can be reused up to 30 washes and recycled with zero waste discharge ensuing green technology. Moreover, the mask was produced at an affordable cost of Rs. 17 (0.22 USD), including labor charges, and sold at a 100% profit margin @ Rs.35 (0.45 USD) per unit. Further, the mask was certified by neutral testing agencies and provided to a population of more than 6 lakhs, thus significantly contributing to the mitigation of COVID-19.
Subject(s)
COVID-19 , Masks , Humans , Plastics , Textiles , Polyethylene Terephthalates , Preventive Health ServicesABSTRACT
Protective facemasks made of non-woven fabric are widely used during the Covid-19 pandemic. In the literature, it is reported that the surface properties of the facemasks are among the factors that could influence their filtration efficiency. Moreover, these properties could even have an effect on the step that precedes the filtration, which consists in the adhesion of the microorganism on the surface of these facemasks. In this study, we evaluate electron donor and acceptor character of the surface of five colored masks made of non-woven fabric using the contact angle method. The contact angle measurements showed that the five masks used in this work are classified as hydrophobic while the electron donor/acceptor character varies according to the color of the five facemasks. These results are discussed in terms of their potential impact on adhesion of microorganisms on the surface of the mask. © 2023
ABSTRACT
This study explored the degradation behavior of three types of disposable face masks in simulated seawater via the accelerated aging experiments. Microplastics (MPs) and dissolved organic carbon (DOC) were monitored in UV- and thermal-treated mask suspensions and their concentrations increased slowly in the early stage at 50 ℃ and 58 ℃. Owing to the high energy supply, the release rates of MPs and DOC at 76 ℃ were much faster than the above two temperatures. The time-temperature superposition principle (TTSP) was used to superpose the MPs/DOC release kinetics from other tested temperatures to the reference temperature and its applicability was verified by the similar activation energy. Then, a release kinetics model was established and fitted well with the superposed MP data (R2 ≥ 0.96). Since less than 0.1 % of carbon was leached, the superposed DOC data was roughly modelled by the exponential function (R2 ≥ 0.90). According to the TTSP and the established kinetics models, about 15 years were estimated to decompose half of a certain marine mask waste, together with leaching 0.21 ± 0.02 mg∙g-mask−1 of DOC. If mask consumption remains the same before 2025, they would contribute 40000–230000 tonnes of MPs and 13–97 tonnes of DOC to the ocean by 2040. © 2022
ABSTRACT
Since the outbreak of the Covid-19 pandemic, masks have been widely used as a personal protective equipment (PPE) to prevent respiratory infection. A major type of masks used is non-woven fabric mask (NFM), which is currently classified as domestic waste and mostly disposed to general rubbish bins then eventually sent to the already saturating landfills. Moreover, the contaminated NFM is not disinfected properly during the disposal, which increases the risks of viral transmission and pollutes the environment. To alleviate the existing pressure to the environment, the amount of used NFM being disposed to landfills should be reduced. This paper studied the feasibility of recycling the used NFM and developed a prototype of disposal machine as the primary recycling process. By inserting the used NFM into the disposal machine, the masks can be shredded, disinfected and packed for further recycling processes. © 2022 IEEE.
ABSTRACT
Community-wide mask wearing may contribute to the control of COVID-19 by reducing the amount of emission of infected saliva and respiratory droplets from individuals with subclinical or mild COVID-19. In this work, a brief review is presented on face masks and related things. First, the size of microorganisms in relation to PM2.5 and PM10 is given for an approximate estimate of the sizes of objects that needs to be filtered. In continuation, the principles of filtration of objects by the network of fibers (woven, non-woven, knitted, etc.) are given. Common fibers used for making face mask is presented along with various fabric structure and their manufacturing. Additionally, advancements like the treatment of fibers in terms of coated fabrics, nano-particle finishes, and green synthesized nano-particle coatings have been explained in view of their anti-bacterial and anti-viral properties. The classification of the face masks based on their fabric make-up has been given which has been extended to classification based on the barrier properties and various efficiencies of the face masks. The characterization of face masks like particle filtration efficiency, bacterial filtration efficiency, breathing resistance, flash resistance, and flame resistance are also included.
ABSTRACT
Non-woven disposable masks play a unique role in reducing the COVID-19 pandemic threat in transmission between people, but the huge amount of disposable non-woven masks generated every day are currently posing a serious challenge to our environment on a global-wide scale. In line with this emerging problem, a series of recycling processes were designed and conducted to evaluate the performance of material recovered from those waste masks for potential use in three-dimensional (3D) printing. A composite filament from recycled polypropylene (rPP) and an additive material, glass fiber (GF), was fabricated by melt-blending processing followed by single-screw extrusion. A variety of material properties, including the chemical/mechanical/microstructure property, thermal stability, printability, rheology performance, and geometrical accuracy toward GF/rPP composite filaments, were comprehensively analyzed. Our results demonstrated that two important mechanical properties, the compression strength and the tensile strength, to a 3D printed object by fused deposition modeling (FDM) from the GF/rPP composite were significantly higher than that of a FDM 3D printed object from GF/polypropylene composites. The specific warpage parameter (Wsp) and the surface roughness (Sa) for a 3D printed object from the GF/rPP composite at 30 wt% GF additive would have printing accuracy of 0.54% +/- 0.0014 and 21.1 +/- 0.76 mu m, respectively, and no clogging phenomenon was observed in the printer nozzle channel during the printing processing, suggested that this recycling method for a large number of non-woven waste masks was potentially applicable in serving as a FDM 3D printing material.
ABSTRACT
During the global pandemic of COVID-19, the term 'N95' is frequently encountered in our daily life. 'N95' is the abbreviation of facepiece respirators that meet the class 95 standard of US National Institute for Occupational Safety and Health (NIOSH). The number '95' means that the N95 respirator can filter >95% of airborne particles. Numerically, 95% or 0.95 is very close to the function value of f(x)=1-e-x, when x=3. Intuitively, there might be some underlying relationship between f(3) and the filtering rate 0.95. In this paper, a constant-law model is presented, giving clear physical picture for the filtering rate of non-woven fabrics. The derived physical model may also be used as a standard for particulate-filtering non-woven fabric products such as facepiece respirators.
ABSTRACT
The recent COVID-19 outbreak has led health authorities to recommend at least the use of surgical masks, most preferably respirators (FFP2 or KN95), to prevent the spread of the virus. Non-woven fabrics have been chosen as the best option to manufacture the face masks, due to their filtration efficiency, low cost, and versatility. Modifying the mask filters with graphene has been of great interest due to its potential use as antibacterial and virucidal properties. Indeed, some companies have commercialized face masks in which graphene is coated and/or embedded. However, the Canadian sanitary authorities advised against using the Shandong Shengquan New Materials Co. graphene masks because of the possibility of pulmonary damage produced by graphene inhalation. Thus, we have analyzed the stability of the graphene filter of these masks and compared it with two other commercially available graphene mask filters, evaluating the morphological and spectroscopical change of the fibers, as well as the particles released during the endurance tests. Our work introduces the necessary tools and methodology to evaluate the potential degradation of face masks under extreme working conditions. These methods complement the present standard tests ensuring the security of the new filters based on composites or nanomaterials.
ABSTRACT
In the context of the COVID-19, the co-pyrolysis of waste cotton swabs and non-woven masks is a promising way of biomass utilization. On the one hand, it alleviates the energy crisis to some extent, and on the other hand, it is conducive to the proper disposal of medical waste. In this paper, the pyrolysis process and kinetic behavior of two materials under different conditions including mixing ratios, heating rates and catalyst additions were studied. The results show that the heating rate has little effect on the pyrolysis process. Mask has better pyrolysis performance than cotton swabs and could promote the decomposition of biomass as an auxiliary material. All the blends show a certain synergistic effect. The difference between the actual mass loss and the theoretical mass loss (ΔW) is positive and the activation energy is lower than that of any single component. The addition of catalyst can further promote the pyrolysis reaction, and the residual mass is greatly reduced. This paper aims to provide some suggestions for further exploration in related fields.
ABSTRACT
The World Health Organization has declared the coronavirus an emergency of international importance. In this regard, non-woven materials (NM) are recommended to be actively introduced and used to stop the spread of coronavirus in products for various purposes, including medical devices. Synthetic polyester fillers in pillows, blankets, mattresses, insulation in clothes and buildings are nonbiological non-cellular structure. It does not spread bacteria, which, in turn, like living organisms, microorganisms, can be a medium for viral spread. The fibers used in the production of Hollofiber® materials have a hygroscopicity of less than 1%, they do not have a protein component or a plant cell, which can be a nutrient medium for microorganisms and, accordingly, viruses spread through them. However, the issues of viral transfer and virulence remain relevant and problematic. One effective solution is radiation sterilization. The problem is that not all nonwoven materials (NM) are able to withstand exposure to radiation sterilization. In connection with this object of research, a high-tech NM of domestic production was selected. Thus, the study of the effect of radiation sterilization on Hollofiber® material is an urgent task. As a result of studying Hollofayber® NM after radiation in the dose range from 20-60 kGy, there were no significant changes in consumer characteristics. Thus, NM Hollofayber® PROFI, article P 35191, Hollofayber® SOFT, article P 5197, Plollofayber® SOFT, article P 5200 are recommended for the manufacture of medical devices. © 2021 Ivanovo State University of Chemistry and Technology. All rights reserved.
ABSTRACT
Personal protective equipment, used extensively during the COVID-19 pandemic, heavily burdened the environment due to improper waste management. Owing to their fibrous structure, layered non-woven polypropylene (PP) disposable masks release secondary fragments at a much higher rate than other plastic waste types, thus, posing a barely understood new form of ecological hazard. Here we show that PP mask fragments of different sizes induce morphogenic responses in plants during their early development. Using in vitro systems and soil-filled rhizotrons, we found that several PP mask treatments modified the root growth of Brassica napus (L.) regardless of the experimental system. The environment around the root and mask fragments seemed to influence the effect of PP fabric fragment contamination on early root growth. In soil, primary root length was clearly inhibited by larger PP mask fragments at 1 % concentration, while the two smallest sizes of applied mask fragments caused distinct, concentration-dependent changes in the lateral root numbers. Our results indicate that PP can act as a stressor: contamination by PP surgical masks affects plant growth and hence, warrants attention. Further investigations regarding the effects of plastic pollution on plant-soil interactions involving various soil types are urgently needed.
Subject(s)
COVID-19 , Masks , Humans , Pandemics , Plastics , Soil/chemistryABSTRACT
The COVID-19 epidemic increases the uncertainty of energy demand. This paper aims to study the impact of containment measures due to the COVID-19 epidemic on the energy demand of a group of buildings in a neighborhood and evaluate the different techniques studied on thermal performance and energy savings. Indeed, this study shows the importance of using natural and recycled waste-based materials and nighttime radiative cooling during the summer period. For this purpose, a full-scale cell located in Casablanca was considered a case study to build a simulation model performed on TRNSYS, validated using the experimental results. This model is then used to impact the techniques studied on energy performance and hours of discomfort inside another cell in Marrakech. As a result, this study has shown that the passive techniques integrated into the cell, using the material based on sisal/wool nonwoven, and night-time radiative cooling during summer, reduce energy requirements compared to the reference configuration. © 2022 IEEE.
ABSTRACT
BACKGROUND: Aluminium reduces severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) survival in experimental settings. It is unknown whether adding an aluminium gauze to a mask reduces the SARS-CoV-2 RNA load in the mask and whether SARS-CoV-2 is detectable in the breath that permeates through such a mask in clinical settings. METHODS: Patients admitted to Kishiwada City Hospital, Osaka, Japan, between July 2021 and September 2021 were enrolled in the study. Non-woven masks comprising filters with 99% viral filtration efficacy and aluminium and cotton gauzes attached to plastic collection cases were developed. All participants wore the experimental mask models for three hours. RESULTS: Twenty-nine patients who wore the final model masks were analysed in this study. The Ct values of the nucleocapsid gene and envelope gene of SARS-CoV-2 were significantly higher in the aluminium gauze than in the cotton gauze. SARS-CoV-2 RNA was detected in the masks of 8 out of 12 vaccinated patients (66.7%). Although breath condensates were collected behind both aluminium and cotton gauzes, SARS-CoV-2 RNA was not detected in these condensates. CONCLUSIONS: Our study indicated that non-woven masks with an aluminium gauze may obstruct SARS-CoV-2 transmission in clinical settings better than non-woven masks with cotton gauzes.