Surgical Masks Research Articles

Remembering Medical Ventilators and Masks in the Days of COVID-19: Patenting in the Last Decade in Respiratory Technologies

Health systems, which have been under great pressure with the COVID-19 outbreak, encountered problems in accessing some urgently needed medical resources. One of these resources has been the medical ventilators needed in acute respiratory distress syndrome developing with COVID-19. As a result of the calls made, many manufacturers have modified their facilities to produce medical ventilators and the problem has been solved to a great extent. While we focus on the urgent requirement for ventilators in these troubled days of COVID-19, we do not seem to be worth discussing their technical developments. How did the countries perform in the development of novel respiratory technologies in the pre-COVID period? While patents are seen as a measure of inventive activity, we attempt to draw a general picture of patents granted in the field of medical respiratory technologies. Our study examines 27 397 respiratory patents listed in the Derwent Innovations Index database at the last 50 years and focuses on the last decade for further evaluation. In addition to the analysis of patent numbers, we identified the core ventilation technologies of the last two decades with the topic modeling technique and compared them. We used the claims section of the patents collected. It is seen that focus of ventilation patents granted between 2001 and 2010 was on oxygen, flow generation, and pressure sensors while it shifted to the pipes, measurement methods, and plates between 2011 and 2020.

Optimal Control Strategies for Assessing the Impact of Medical Masks on COVID-19 Dynamics: Global Perspectives and Societal Well-Being

Optimal Control Strategies for Assessing the Impact of Medical Masks on COVID-19 Dynamics: Global Perspectives and Societal Well-Being

Graphene Oxide–Pretreated Waste Medical Mask Microfiber-Reinforced Cement Composites: Frost Damage Modeling and Chloride Migration

Graphene Oxide–Pretreated Waste Medical Mask Microfiber-Reinforced Cement Composites: Frost Damage Modeling and Chloride Migration

Face Mask and Tear Film Stability: A Pilot Study of the Objective Measurement of Tear Break-Up Time.

(1) Background: Mask-associated dry eye (MADE) has been associated with increased dry eye symptoms, apparently due to reduced tear break-up time (TBUT). This study aimed to determine the short-term impact of surgical face mask (FM) on tear film stability by measuring non-invasive tear break-up time (NIBUT). (2) Methods: Twenty-six healthy participants had NIBUT evaluated without FM, with surgical FM and with a surgical FM secured to the skin with adhesive tape (TFM). NIBUT-first was measured with Keratograph 5M (K5M, Oculus, Wetzlar, Germany). Each participant had NIBUT measured in four sessions on four consecutive days. Session 1: without FM vs. with FM. Session 2: with FM vs. without FM. Session 3: without FM vs. with TFM. Session 4: with TFM vs. without FM (3). The time between each measured setting was 2 min. Results: The mean ± SD NIBUT without FM was 8.9 ± 3.7, with FM 10.2 ± 4.1, and with TFM 8.4 ± 3.8 s. No significant differences were observed in NIBUT in any of the evaluated settings: without FM vs. with FM (p = 0.247), without FM vs. with TFM (p = 0.915), and with FM vs. with TFM (p = 0.11). (4) Conclusions: This study did not find a significant short-term effect of FM on NIBUT. Other variables or longer periods of exposure might trigger the symptoms and ocular surface alterations in MADE.

Pengaruh Penggunaan Limbah Masker Medis dan Limbah Serabut Kelapa sebagai Substitusi Pasir dalam Pembuatan Bata Ringan

Lightweight brick is a type of lightweight brick that is superior to the previous one. The purpose of this study was to analyze variations in the optimal composition of lightweight bricks (CLC) innovation by utilizing medical mask waste and coconut fiber waste as a substitute for sand based on bulk density and water absorption, compressive strength test, and soundproof test. The method used is the experimental method. Test object with variations in composition, namely 0%, 5%, 10% and 15%. Each variation has 3 samples with a total of 12. The values for bulk density and water absorption are in accordance with SNI 8640-2018. The compressive strength test was carried out using a cube specimen with a side of 15 cm aged 14 days. Soundproof test using a sound level meter. The results obtained at 10% variation with a mixture of 10% medical mask waste and 10% coconut fiber waste are the optimal composition in the manufacture of innovative lightweight bricks. The bulk density and water absorption were 0.0741%, the compressive strength test was 11.86 MPa, and the soundproof test was 24.3 dB. This lightweight brick innovation of 10% variation can be an alternative to smart, environmentally friendly and economical building materials.Keywords : Lightweight Brick (CLC), Medical Mask Waste, Coconut Fiber Waste, Content weight and Water absorption, Compressive Strength Test, Soundproofing Test

Optical Microscopic Methods for Testing Face Mask Efficacy for COVID-19

COVID-19 has spread worldwide and it is leaving everyone wondering how to protect themselves or help those who are affected. Furthermore, the increased number of infectious diseases has become a significant health concern over recent decades. The respiratory droplets or airborne route, one of the transmission methods, impacts social relationships most significantly and can be avoided by using a face mask. Face masks are available in a variety of degrees of protection. Even in the face of the ongoing pandemic, individuals made their masks from household items due to the lack of face masks worldwide. In developing countries, surgical masks (SMs) and cloth masks (CMs) made of various cloth materials are very common. These types of masks are typically used for months after being repeatedly washed and dried. However, there is no indication of how washing, drying, or stretching practices affect the quality of CMs and SMs. Various efforts have been devoted to making effective face masks by using antimicrobial activity and super-hydrophobicity. This review article aims to discuss the mask efficiency of commercial SMs and homemade CMs from the public health and technical perspective. Recent advancements in mask engineering, disinfection, and material science have also been discussed. Optical microscopic methods were employed to assess the efficiency of different face masks and determine the quality of masks after washing, drying, and stretching. The filtration efficiency of CMs ranges from 63% to 84%. However, the SM had the highest filtering effectiveness and efficiency of 94%.

Reading Emotions Through a Surgical Mask

Reading Emotions Through a Surgical Mask

Importance of Dipole Orientation in Electrostatic Aerosol Filtration.

Electrostatic charge is a major part of modern-day aerosol filtration media (e.g., N95 respirators and surgical facemasks) that has remained poorly understood due to its complicated physics. As such, charging a fibrous material has relied on empiricism in dire need of a mathematical foundation to further advance product design and optimization. In this concern, we have conducted a series of numerical simulations to improve our understanding of how an electrostatically charged fiber captures airborne particles and to quantify how the fiber's dipole orientation impacts its capture efficiency. Special attention was paid to the role of Coulomb and dielectrophoretic forces in the capture of particles of different charge polarities (e.g., particles having a Boltzmann charge distribution). Simulation results were compared with the predictions of the popular empirical correlations from the literature and discussed in detail. Predictions of the empirical correlations better agreed with the simulation results obtained for fibers with a dipole perpendicular to the flow direction rather than for fibers with a dipole parallel to the flow. This indicates that such empirical correlations are more suitable for filters charged via contact electrification (friction charging), where the dipoles are mostly perpendicular to the flow direction, and less suitable for corona-charged media, where the fiber dipoles are generally parallel to the flow direction.

Exercising with a Surgical Mask is Safe but Decreases Performance in Both Athletic and Non-Athletic Individuals

Introduction: Upper respiratory tract infections (URTI) are common medical problems in athletes. Many athletes with URTI continue to train at high-levels and even compete. Using a mask as an additional measure may be beneficial to prevent the spreading of infection among teammates. However, there are many concerns about the effects of mask use on exercise safety and performance. Although some studies have investigated the effects of masks on performance in healthy individuals, studies in athletes are even more limited. Thus, we aimed to evaluate the impact of surgical masks on performance and safety during a cardiorespiratory exercise test (CPET) test applied to both athletes and non-athletes. Patients and Methods: A cross-over, non-randomized study was designed. The study was conducted in two phases. In phase 1, the CPET was performed without using a surgical mask. In phase 2, CPET was performed with a surgical mask in addition to the spiro mask 48 hours after the first test. Thirty participants aged 18-35 were included in the study. They were further divided as athletes (n= 17) and non-athletes (n= 13) subgroups. Results: Significant decreases were observed in some parameters of submaximal exercise [VEan, BFan, VE/ VO2 , VE/VCO2 (p< 0.001)] and in maximal exercise [VEmax, BFmax, TVmax, VE/VO2 , VE/VCO2 (p< 0.001)]. There were also significant decreases in VO2 levels (VO2 an, VO2 max) when compared with and without a surgical mask in both submaximal and maximal exercise (p< 0.001). Additionally, PETO2 decreased, and PETCO2 increased in maximum exercise (p< 0.001), whereas no significant changes were detected at the submaximal level. In subgroup analysis, VEan, VEmax, VO2 an, VO2 max parameters were decreased in athletes compared to non-athletes in surgical masked tests. Conclusion: Surgical masks for athletes and non-athletes decrease performance but have no detrimental effect on cardiorespiratory parameters. Athletes should be aware of this negative effect when high-level performance is demanded.

Impact of wearing a surgical facemask during exercise on dyspnea in patients with chronic pulmonary infections: A randomized crossover study

BackgroundWearing facemasks in public is effective in preventing viral transmission. However, no study has evaluated the impact of wearing facemasks during exercise on dyspnea in patients with chronic pulmonary infections from multifaceted aspects, including sensory qualities and emotional responses. The aim of this study was to evaluate facemask-related dyspnea during exercise in this patient population. MethodsWe conducted a randomized crossover study involving adult patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) or bronchiectasis who participated in exercise sessions, both with (mask-on) and without (mask-off) surgical facemasks. The sensory and emotional dimensions of dyspnea during each exercise session were assessed using the Multidimensional Dyspnea Profile. Statistical analyses were performed to identify factors associated with worsening scores for each dimension. ResultsThirty-four patients (mean age [standard deviation]: 71.6 [8.6] years) were included in the analysis. The median [interquartile range] total scores for the sensory and emotional dimensions of dyspnea were 3.5 [1, 9.5] (mask-off) vs. 10 [5.5, 23.8] (mask-on) (P < 0.001) and 0 [0, 5] (mask-off) vs. 3 [0.8, 10.3] (mask-on) (P = 0.115), respectively. “Air hunger” was the primary sensory descriptor of mask-related dyspnea. Vital capacity (VC) < 80% of the predicted value was a significant risk factor for worsening sensory dimension scores when wearing masks (odds ratio [95% confidence interval]: 5.5 [1.16–26.1], P = 0.038). ConclusionsThe findings of this study indicate that patients with NTM-PD or bronchiectasis, particularly those with VC <80% of the predicted value, are likely to experience the sensory dimension of dyspnea during exercise while wearing surgical facemasks.

Recycled Surgical Mask Waste as a Resource Material in Sustainable Geopolymer Bricks

With the advent of the COVID-19 pandemic, the global consumption of single-use surgical masks has risen immensely, and it is expected to grow in the coming years. Simultaneously, the disposal of surgical masks in the environment has caused plastic pollution, and therefore, it is exigent to find innovative ways to handle this problem. In this study, surgical masks were processed in a laboratory using the mechanical grinding method to obtain recycled surgical masks (RSM). The RSM was added in doses of 0%, 1%, 2%, 3%, and 4% by volume of geopolymer bricks, which were synthesized with ground granulated blast furnace slag (GGBS), rice husk ash (RHA), sand, and sodium silicate (Na2SiO3) at ambient conditions for a duration of 28 days. The developed bricks were tested for compressive strength, flexural strength, density, water absorption, efflorescence, and drying shrinkage. The results of the study reveal that compressive strength and flexural strength improved with the inclusion of RSM in the bricks. The highest values of compressive strength and flexural strength were 5.97 MPa and 1.62 MPa for bricks with 4% RSM, respectively. Further, a reduction in the self-weight of the bricks was noticed with an increase in RSM. There was no pronounced effect of RSM on the water absorption and efflorescence properties. However, the RSM played a role in reducing the drying shrinkage of the bricks. The sustainability analysis divulges the catalytic role of RSM in improving material performance, thereby proving to be a potential candidate for low-carbon material in the construction industry.

Differences in Facial Skin Acidity Levels of Nurses in Sebelas Maret University Hospital, Before and After Surgical Mask Use During the COVID-19 Pandemic

Background: Indonesia has reported more than 4 million confirmed COVID-19 cases as of November 2021. This has led to an increase in the use of personal protective equipment (PPE), for example, surgical masks in hospitals, especially referral hospitals for COVID-19 patients. The Potential Hydrogen (pH) or level of acidity plays an important role in the body's physiological functions and regulates the formation of an epidermal barrier (stratum corneum). Thus, the use of surgical masks is able to influence the pH of human skin. This study aimed to determine the difference in facial skin acidity (pH) levels of nurses at Sebelas Maret University Hospital before and after surgical mask use.&#x0D; Methods: The study utilized a cross-sectional observational method and was conducted at the Sebelas Maret University Hospital, Surakarta. A total of 55 subjects were involved in this study, and each subject’s facial skin Potential Hydrogen (pH) was measured before and after surgical mask use. Subsequently, all data were analyzed with a T-test using SPSS 21.00, and a p-value &lt;0.05 indicated statistical significance.&#x0D; Results: The results showed facial skin pH increased after surgical mask use for nurses at the Sebelas Maret University Hospital (p = 0.000).&#x0D; Conclusion: An increase in the physiological value of skin pH was observed in the nurses of Sebelas Maret University Hospital after surgical mask use.&#x0D;

Protecting healthcare workers and patients during the COVID-19 pandemic: a comparison of baseline and follow-up infection prevention and control needs in Nigerian military healthcare facilities delivering HIV services

BackgroundProtecting the HIV health workforce is critical for continuity of services for people living with HIV, particularly during a pandemic. Early in the COVID-19 pandemic, the Nigerian Ministry of Defence, in partnership with the US Military HIV Research Program, took steps to improve infection prevention and control (IPC) practices among staff working in select PEPFAR-supported Nigerian military health facilities.MethodsWe identified a set of IPC activities a priori for implementation at four Nigerian military hospitals in HIV and related departments in early 2021, including continuous medical masking, physical distancing, placement of additional hand washing stations and hand sanitizers throughout facilities, and training. We fine-tuned planned intervention activities through a baseline needs assessment conducted in December 2020 that covered eight IPC components: ‘IPC program structure, funding and leadership engagement’; ‘IPC policies, guidelines and standard operating procedures (SOPs)’; ‘infrastructure’; ‘triage and screening’; ‘training, knowledge and practice’; ‘personal protective equipment (PPE) materials, availability and adequacy’; ‘biosafety and waste management’; and ‘monitoring and remediation’ prior to implementation. Baseline results were compared with those of a follow up assessment administered in August 2021, following intervention implementation.ResultsIPC readiness remained high at both baseline and follow-up assessments for ‘IPC guidelines, policies, and SOPs’ (96.7%). The components ‘infrastructure’ and ‘monitoring and remediation’, which needed improvement at baseline, saw modest improvements at follow-up, by 2% and 7.5%, respectively. At follow-up, declines from high scoring at baseline were seen in ‘IPC program structure, funding and leadership engagement’, ‘training, knowledge and practice’, and ‘biosafety and waste management’. ‘PPE materials availability and adequacy’ improved to 88.9% at follow-up. Although unidirectional client flow was newly implemented, the score for ‘triage and screening’ did not change from baseline to follow-up (73%).ConclusionVariability in IPC component readiness and across facilities highlights the importance of building resilience and employing a quality improvement approach to IPC that includes regular monitoring, re-assessment and re-training at set intervals. Results can be used to encourage solutions-oriented dialogue between staff and leadership, determine needs and implement action plans to protect staff and people with HIV.

Physiological responses and molecular mechanism of Chlorella sorokiniana to surgical mask exudates in wastewater

Microalgae-based bioremediation is likely to be challenged by the microplastics (MPs) in wastewater induced by the widely use of surgical masks (SMs) during COVID-19. However, such toxic impact was generally evaluated under high exposure concentrations of MPs, which was not in agreement with the actual wastewater environments. Therefore, this study investigated the microalgal cellular responses to the surgical mask exudates (SMEs) in wastewater and explored the underlying inhibitory mechanism from the molecular perspective. Specifically, 390 items/L SMEs (including 200 items/L MPs which was the actual MP level in wastewater) significantly inhibited nutrient uptake and photosynthetic activities interrupted peroxisome biogenesis and induced oxidative stress which destroyed the structure of cell membrane. Moreover, the SMEs exposure also affected carbon fixation pathways, suppressed ABC transporters while promoted oxidative phosphorylation processes for the ATP accumulation These comprehensive processes led to an 8.5% reduced microalgae growth and variations of cellular biocomponents including lipid, carbohydrate, and protein. The increased carotenoids and consumed unsaturated fatty acid were considered to alleviate the SMEs-induced stress, and the enhanced EPS secretion facilitated the homogeneous aggregation. These findings will enhance current understandings of the SMEs effects in wastewater on microalgae and further improve the practical relevance of microalgae wastewater bioremediation technology.

Investigating the Effect of Different Disinfection Methods on the Efficiency, Pressure Drop and Quality Factor of Medical Masks

Background and Objective: This study was conducted with the aim of determining the effect of different disinfection methods on the efficiency, pressure drop, and quality of medical masks used by medical staff. The filtration efficiency of medical masks was also investigated in the present study. Materials and Methods: In the present study, four models of medical masks used by the treatment staff were selected. The masks were then disinfected with the disinfection methods recommended by the disease control and prevention centers, including heat methods, autoclaves, ultraviolet rays, immersion in 70% alcohol, and immersion in sodium hypochlorite. Finally, the effect of each disinfection method on the efficiency, pressure drop, and quality of the masks was checked using the test system. Results: Based on the results obtained from the study, disinfecting masks using thermal methods, autoclaving, ultraviolet radiation, immersion in sodium hypochlorite, and immersion in 70% alcohol caused changes in efficiency by 5.58%, 9.83%, 8.15%, 13.34%, and 20.38%, respectively. Additionally, changes in pressure drop were observed at rates of 12.9, 7, 6.92, 183.75, and 16.13 Pa, respectively. Moreover, the quality factor of masks improved after disinfection using thermal methods and autoclaving, in contrast to other methods. Furthermore, the assessment of filtration efficiency indicated that three out of four types of masks examined had efficiencies lower than 85%. Conclusion: Disinfection of medical masks using the heat method was chosen as the best disinfection method due to the least change in efficiency, a slight increase in pressure drop, and availability, and the 70% alcohol immersion method was chosen as the weakest disinfection method due to the decrease in efficiency, increase in pressure drop, and destruction of the mask's structure.

Effect of microfibers induced toxicity in marine sedentary polychaete Hydroides elegans: Insight from embryogenesis axis

Presence of surgical face masks in the environment are more than ever before after the COVID-19 pandemic, and it poses a newer threat to aquatic habitats around the world due to microfibers (MFs) and other contaminants that get discharged when these masks deteriorate. The mechanism behind the developmental toxicity of MFs, especially released from surgical masks, on the early life stages of aquatic organisms are not well understood. Toxicity test were developed to examine the effects of MFs released from surgical facemask upon deterioration using the early gametes and early life stages of marine sedentary polychaete Hydroides elegans. For MFs release, cut pieces of face masks were allowed to degrade in seawater for different time points (1 day, 30 days and 120 days) after which the fibers were obtained for further toxicity studies. The gametes of H. elegans were exposed to the MFs (length < 20 μm) separately for 20 min at a concentration of 50 MFs/ml before fertilization. In addition, we also analyzed the experimental samples for heavy metals and organic substances released from face masks. Our findings demonstrated that gametes exposed to MFs affected the percentage of successful development, considerably slowed down the mitotic cell division and significantly postponed the time of larval hatching and also produced an adverse effect during embryogenesis. When the sperm were exposed fertilization rate was decreased drastically, whereas when the eggs were exposed to MFs fertilization was not inhibited but a delay in early embryonic development observed. In addition the release of heavy metals and other volatile organics from the degrading face masks could also contribute to overall toxicity of these materials in environment. Our study thus shows that inappropriately discarded face masks and MFs and other pollutants released from such face masks could pose long-term hazard to coastal ecosystems.

Calibration of DustTrak and Low-Cost Sensors and Their Application for Assessment of Inhalation Exposures to Traffic-Related PM2.5 and PM1 in Ho Chi Minh City

The in-traffic microenvironment can enhance personal exposure to fine particulate matter (PM). With this study, we aimed to calibrate a DustTrak instrument (DustTrak 8533 DRX Aerosol Monitor, TSI Incorporated, Shoreview, MN, USA) and low-cost sensors (AS-LUNG-P sensors) and then assess inhalation exposure to PM2.5 and PM1 for different commuters in central areas of Ho Chi Minh City (HCM). The DustTrak instrument and low-cost sensors were calibrated using a gravimetric method under side-by-side conditions. Relationships between the DustTrak signals and PM concentrations measured by the gravimetric method were identified using simple linear regression models for PM2.5 (R2 = 0.998, p-value &lt; 0.05) and PM1 (R2 = 0.989, p-value &lt; 0.05). Meanwhile, PM concentrations determined by the AS-LUNG-P sensors and the gravimetric method were correlated using two-segmented linear regressions. To obtain the corresponding two-segment regression equations, the response of the AS-LUNG-P sensors was compared with the corrected DustTrak data. The coefficient of variation (CV) evaluated for all sensors was smaller than 10%, indicating that the data were applicable for particle assessment. For inhalation exposure assessment, the results showed that commuters using open transport modes, such as bikes, motorbikes, and walking, were exposed to more PM than those using closed transport modes (e.g., cars). Specifically, the bicyclists had the highest inhaled doses of PM among the open transport groups. PM exposure levels in the morning were higher than in the afternoon. Additionally, exposure levels to PM concentrations rapidly increased when passing through intersections of major roads and moderately decreased when using surgical facemasks.

A Comparative Evaluation of the Effects of N95 and Surgical Facemasks on Pregnant Women Performing Moderate-Intensity Exercise: A Prospective Randomized Study.

Background and objective A facemask is often indicated for the control of the spread of airborne pathogens. At the peak of the COVID-19 pandemic, there was mass enforcement of mask use across the globe. Pregnant women were not excluded. While several studies have been conducted to evaluate and compare the efficacy of various mask types, data on their effects on pregnant women during exercise are scarce. The objective of this study was to evaluate and compare the effects of N95 and surgical facemasks on the cardiopulmonary functions of pregnant women during moderate-intensity exercise. Methods A prospective randomized study was conducted among 104 healthy women with advanced singleton pregnancies performing moderate-intensity exercise wearing either surgical or N95 masks during routine antenatal care. Their respiratory rates were counted, and arterial oxygen saturation (SPO2) and radial pulses (heart rates) were recorded with a mobile digital pulse oximeter at baseline and after 30 minutes of exercise. The mean values were calculated. Data analysis was done using Statistical Product and Service Solutions (SPSS, version 25; IBM SPSS Statistics for Windows, Armonk, NY). An independent t-test was used to compare the mean SPO2 and radial pulse between the two groups. Chi-square was used to examine differences in categorical variables. The level of significance was set at 0.05. Results Their demographic profiles and measured baseline parameters were comparable. Following a 30-minute exercise, the N95 mask group had lowermean SPO2 compared to the surgical mask group (95.5% versus 97.0%; P=0.028, 95%CI; -2.607 to 0.15). Further, the N95 group recorded a higher mean heart rate than the surgical mask group ((97.23 b/m versus 95.02b/m, respectively, mean difference (MD)=2.212, P=0.021, 95%Cl: 1.249-3.672). The mean respiratory rates were also higher among women in the N95 mask group (32.1 c/m versus 29.08 c/m, MD=3.018, 95%CI: 1.392-4.662, P=0.001). Conclusion The study, comparing the relative effects of the surgical and N95 facemask on the cardiorespiratory functions of exercising pregnant women, findings suggest that surgical facemasks may be better tolerated in advanced pregnancy when performing routine antenatal aerobic exercise in comparison with N95 masks.

Potential Use of COVID-19 Surgical Masks and Polyethylene Plastics in Developing Sustainable Concrete

Managing disposable waste surgical face masks and plastic made from polyethylene (PE) resin is a real challenge. Thus, these are considered a great threat to the environment. Generally, surgical face masks are made of microplastic made of polypropylene materials. Both polypropylene and PE are not easily decomposable in the soil. Consequently, the presence of these waste materials can have detrimental effects on terrestrial and aquatic ecosystems, exacerbating the ongoing crisis faced by the animal kingdom and the broader biosphere. Hence, it is imperative to identify alternate and efficient methods for waste management. Given its significant economic importance, the construction industry holds a prominent position among many industries globally. Consequently, waste masks within the construction sector might assume a crucial role in mitigating plastic pollution. Concrete, one of the most widely used construction materials, is being adapted with various waste materials as the partial or complete substitutes for natural constituents, such as cement and aggregates. This study focused on using different percentages of used COVID-19 surgical masks in fiber form and PE as partial replacements of natural coarse aggregates in producing sustainable concrete. Mask fibers were used in concrete production at percentages of 0%, 0.5%, 1%, 1.5%, and 2% of the total volume of concrete. Similarly, PE aggregates replaced the coarse aggregates by volume at 0%, 5%, 10%, and 15% in concrete. The results showed that the strength of concrete reduced as the percentages of mask fiber and PE aggregates increased. However, the strength and crack-bridging capability of mask concrete are still acceptable for some structural and non-structural applications. The results obtained from this research could also help engineers to design sustainable concrete materials with mask fibers.

Synthesis and characterization of PET impregnated agro-medical waste: Novel approach for plastic substitute using hybrid composites

Composites are environmentally friendly materials made from natural fibers that have lightweight properties and improve the performance of synthetic parts. Medical waste has been identified as one of the biggest challenges recently in India due to COVID-19. More than 70% of medical waste is considered non-hazardous waste, obtained from crushing used surgical face mask (SFM) and surgical gloves (SG) as reinforcement materials chosen in this study. The research aim is to increase the strength and minimize the cost of production of polyethylene terephthalate (PET) matrix by employing hybrid waste fibers as particle reinforcement particles. Five fiber composites of 3% to 12% weight fractions of hybrid fiber (Kevlar Fiber/Glass fiber) and a constant 10% medical waste were fabricated using an injection moulding process to regulate the polymer structure and determine its thermal conductivity. Adding fibers improved mechanical properties such as tensile, flexural, and impact strength. TGA and thermal conductivity were analyzed. Tribological characteristics like a specific wear rate and coefficient of friction were conducted. Morphology is used to identify material behaviour by applying different weight fractions. Adding 9% (KF/GF) and 10% (SFM/SG) particles improves the wear and mechanical properties of the hybrid composite by 52%, respectively. Adding medical and fiber waste particles will improve the interfacial bonding between the matrix material and fillers. It is widely used as a leaf spring in ballistic and automobile applications suspension.