Plastic Components Research Articles

혐오의 정치를 넘어선 연대를 위한 포스트휴머니즘

This study examines the politics of disgust facing contemporary democracy and the possibility of solidarity as its alternative from a posthumanist perspective. It demonstrates that the issues of disgust and solidarity extend beyond mere human emotions or political cooperation, encompassing complex sociopolitical implications, while critically examining the fundamental limitations of the autonomous subject concept presupposed by humanism. Recent neuroscientific findings reveal that brain plasticity operates in close conjunction with sociocultural practices, and the neurobiological mechanisms of affect are continuously reconstructed within sociopolitical contexts. This suggests that disgust is not an inevitable universal phenomenon but rather a component of brain plasticity, and the biological possibility of solidarity should also be understood in terms of the complexity of brain plasticity. The study concludes that within the posthumanist paradigm, genuine solidarity must be reconstructed at the point of actively affirming difference, discord, and the (im)possibility of disgust, and that this transition is an imperative task directly linked to the survival of contemporary democracy.

Exploring the Potential of Fungal Biomass for Bisphenol A Removal in Aquatic Environments

Bisphenol A is a plastic component, which shows endocrine activity that is detrimental to humans and aquatic ecosystems. The elimination of BPA from the environment is one of the solutions for BPA contaminant management. Adsorption is a cost-effective, easy-to-use method generating low harmful byproducts; nevertheless, contaminant sorbent treatment is a challenge that still needs to be addressed. Fungal fruiting bodies biomass is rarely studied sorbent but is promising due to its high polysaccharide content and availability. Our preliminary studies showed BPA sorption (100 mg/L) by 50 cultivated and wild fungi. The cultivated species: Clitocybe maxima (82%), Pholiota nameko (77%), and Pleurotus columbinus (74%), and wild fungi Cantharellus cibarius (75%) and Lactarius deliciosus (72%) were the most efficient. The biomass was able to sorb BPA over a broad range of temperature and pH levels, with an optimum at 20 °C and pH 7. Although saturation of sorbents was rapid, the regeneration process using ethanol was effective and allowed to recover up to 75% of sorbents’ initial efficiency. A single use of 1 g of sorbent would allow the treatment of 8.86 to 10.1 m3 of wastewater effluent, 16.5 to 18.7 m3 of surface water, and 411 to 469 m3 of drinking water, assuming the concentrations of BPA reported in the literature.

DFT-Based Permutationally Invariant Polynomial Potentials Capture the Twists and Turns of C14H30.

Hydrocarbons are ubiquitous as fuels, solvents, lubricants, and as the principal components of plastics and fibers, yet our ability to predict their dynamical properties is limited to force-field mechanics. Here, we report two machine-learned potential energy surfaces (PESs) for the linear 44-atom hydrocarbon C14H30 using an extensive data set of roughly 250,000 density functional theory (DFT) (B3LYP) energies for a large variety of configurations, obtained using MM3 direct-dynamics calculations at 500, 1000, and 2500 K. The surfaces, based on Permutationally Invariant Polynomials (PIPs) and using both a many-body expansion approach and a fragmented-basis approach, produce precise fits for energies and forces and also produce excellent out-of-sample agreement with direct DFT calculations for torsional and dihedral angle potentials. Going beyond precision, the PESs are used in molecular dynamics calculations that demonstrate the robustness of the PESs for a large range of conformations. The many-body PIPs PES, although more compute intensive than the fragmented-basis one, is directly transferable for other linear hydrocarbons.

Estimating the weight of consumed tobacco product waste in various Indian states: a novel method to assess the potential burden of tobacco product waste

IntroductionThe direct morbidity and mortality caused by tobacco are well documented, but such products also contribute to a range of environmental pollutants resulting from tobacco product waste. No previous studies...

Temperature Effects on Traffic Load-Induced Accumulating Strains in Flexible Pavement Structures

AbstractRutting is a major distress mode in flexible pavements, results from the repetitive loading caused by traffic movement. Pavement deformation consists of both recoverable (elastic) and unrecoverable (plastic) components. The continuous movement of vehicles contributes to the overall deformation in the flexible pavement system, involving all pavement components. In regions with hot climates or in the hot summer season, rutting tends to be more prominent due to the substantial reduction in the viscosity of the asphalt binder. This decrease in viscosity, which is inversely linked to rutting, occurs as temperatures rise, leading to a heightened susceptibility of the Hot Mix Asphalt (HMA) blend to rut formation. However, according to studies, a significant amount of permanent deformation takes place in the unbound layers beneath the asphalt course, it is therefore essential to prioritize attention on these layers. Temperature exerts besides viscosity a substantial impact on asphalt stiffness, leading to the transfer of higher vertical deviatoric stresses to the unbound layers beneath the asphalt course (base, subbase, subgrade). This research presents a study integrating the High Cycle Accumulation (HCA) model into a laminar model to determine permanent deformations in the unbound granular layer of flexible pavements and taking into account the temperature dependent stiffness of asphalt. Rutting depths at the end of the design lifetime were computed, accounting for seasonal stiffness variations. It was shown that the softer asphalt behavior significantly increases the development of ruts in the underlaying soil layers. The findings were compared with results obtained from mean annual temperature and the typical equivalent asphalt stiffness utilized in fatigue tests. Additionally, an analysis was conducted to assess whether the timing of road implementation influences settlements throughout the design lifetime. The results suggest that the sequence of seasons is most relevant during the first year of service, showing a distinct effect at that time. However, with a higher number of axle passes, the initial differences fade away, and the curves start to merge.

Iron bed accelerator for discharging cylindrical NCA battery in salt solution

This study examines the iron bed accelerator for discharging cylindrical NCA batteries in salt solution. The use of Li-ion batteries has increased due to the rise of e-mobility in computers, cell phones, and electric vehicles. Recycling Li-ion batteries for raw material in lithium-ion battery production is increasingly important as the revolution unfolds. When disposing of, transporting, and recycling the battery, it is important to crush it to separate the black mass, plastic, and metal components. However, there is a potential explosion risk due to the remaining voltage in the battery. In recycling, the discharge step is significant. The research aimed to test a new method for discharging cylinder batteries using saltwater and an iron bed. Higher NaCl content increases pH and lowers electrochemical potential for water electrolysis. This unique combination enables the battery to discharge at a high rate. In 6 hours, the battery discharged in a 20 wt.% salt solution with 99.6% efficiency. The battery discharge efficiency decreased when exposed to 25 wt% and 30 wt% salt solutions, attributed to reduced water electrolysis intensity. According to the results of various experiments, it has been observed that as the temperature of the salt solution rises, there is a slight increase in the rate of battery discharge; however, no significant difference has been observed. This article talks about how batteries are discharged. It shows the electrochemical reaction using the Eh-pH diagram for Fe-Na-Cl. It also has a schematic diagram that shows the process and a chemical analysis of the precipitate that forms during the discharge test.

Study of the interaction between low density polyethylene and TiO2 in different environments. Influence of the presence and absence of radiation, and of the atmosphere (O2, N2 or Ar)

In the process of photocatalytic degradation of plastics, the surface interaction between the plastic material and the photocatalyst results crucial. The present work focuses on using a specific TiO2 photocatalytic semiconductor whose hierarchical structure favours the interaction with low density polyethylene (LDPE), a key component in plastics. An exhaustive study of the nature of this interaction is conducted, analysing the influence of the atmosphere and radiation. The results obtained indicate that the observed interaction can be modulated by controlling the atmosphere, evolving into a degradation process whose mechanism also depends on the absence or the presence of light. This point is particularly relevant as it highlights the dual nature of TiO2 as both photocatalyst and catalyst.

Thermal and catalytic pyrolysis of automotive plastic wastes to diesel range fuel

This study investigated the pyrolysis of automotive plastic wastes (APW) for the production of diesel-grade oil products using a modified calcium bentonite clay catalyst. The research aimed to optimize the process for maximum oil yield and diesel range organics yield. The APW was characterized by its chemical composition and physical properties and the optimal temperature and catalyst amount were determined for maximum oil yield and diesel range hydrocarbons. The results showed that the APW contained mixed Acrylonitrile Butadiene Styrene (ABS), High/Low Density Polyethylene (H/LDPE), Polypropylene (PP), Polystrene (PS) and fiberglass, with a large quantity of volatiles and ash. The average oil yield was higher in the catalytic process compared to that in the thermal process. Generally, higher temperature above 450 °C produced waxy oil, thus lower temperature favoured more Diesel Range Organics (DRO). Both processes yield similar yields of C8–C24 DRO, and in both cases, lower temperature favoured high yield of C8-C24 hydrocarbons. The catalyst significantly increased the yield of oil, but did not significantly increase C8–C24 DRO yield. The optimal conditions for a maximum oil yield of 78.6 % and DRO yield of 79.5 % was a temperature of 416 °C and 24.3 wt% clay. Thus, the modified calcium bentonite clay can be used to improve oil yield from pyrolysis of APW. The oil produced had properties such as calorific value (49.85 MJ/kg), flash point (113 °C) and total aromatics 3.55 area%, similar to those of commercial diesel, and comprised mostly of 2,4-Dimethyl-1-heptene (25.37 ± 2.01 %) of thermal and 2, 4 – Dimethyl – 1 – heptane (23.44 ± 2.42) in the catalytic process. The study suggests further research to explore different catalysts, maximization of both DRO and gasoline range organics, recover energy from residues, and conduct techno-economic assessments for plant-scale operations. Additionally, policies on the management of end-of-life vehicles should include provisions for stripping and segregation of plastic components by accredited providers for the purpose of plastics recycling.

Development of a green microextraction procedure for determining polyaromatic hydrocarbons in electronic equipment plastics

The global proliferation of electronic devices, driven by technological advancements, has led to the release of organic pollutants from the plastic components of these devices, particularly in indoor environments. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs), which are emitted into the air from plastic components, play a critical role in the field of indoor environment pollution. Consequently, effectively monitoring the PAH content in plastics used in electronic equipment is crucial for preventing indoor contamination.In this study we aimed to develop a fast, inexpensive, easy, and environmentally friendly analysis method for determining PAH content in plastic equipment. A dispersive liquid liquid microextraction (DLLME) combined with solidified organic drop (SFO) microextraction technique was developed.Considering the eleven number of parameters that can affect the signal in the DLLME-SFO method, Plackett Burmann's design was applied to select the most three impactful parameters for 18 PAH species. A Box-Behnken experimental design was also applied to optimize the identified parameters. The optimal conditions for the most influential parameters such as solvent type, pH, and the sample weight were identified as 1-dodecanol, 12 and 0.24 g, respectively.The proposed method was validated under these optimized conditions, yielding low detection limits ranging from 0.004 to 0.11 ng mL−1. The calibration curves were linear with correlation coefficients above 0.98 and relative standard deviation (RSD) values ranging from 2.4% to 20%. This method was successfully applied to analyze PAH content in the plastic components of electronic devices. The extraction technique developed in this study is a newly developed technique and has not been previously used to analyze organic pollutants that may be present in electronic equipment plastic.

Concerns and Safety Evaluation Indicators for Compatibility Study of Injections with Prefilled Syringe

Abstract: Prefilled syringe is a multi-component injector drug packaging system in which liquid drugs are directly loaded for direct use by patients. It has two functions, drug storage and regular injection, which belongs to high-risk pharmaceutical packaging containers. In recent years, more and more injections have been packaged with prefilled syringes worldwide. However, no guidelines about compatibility of chemical injections and prefilled syringes was set up. In current review, studies related to the compatibility study was summarized. Structural composition, material composition and production technology are analyzed first. After that, extraction test, interaction study and safety study are summarized. Glass components, plastic components, seal elastomer components, other components and materials, adsorption test and physical properties are the main focusing points. Based on the studies mentioned above, together with the results of extraction test, migration test and adsorption test, safety evaluation indexes could be formed. The current review aims to provide strategies for the setting up of compatibility study guidelines.

Diagenesis Variation in Different Distributary Channels of Shallow Water Lacustrine Delta Deposits and Implication for High-Quality Reservoir Prediction: A Case Study in the Chang 8 Member in Caijiamiao Area, Sw Ordos Basin, China

Tight oil reservoirs are considered important exploration targets in lacustrine basins. High-quality reservoir prediction is difficult as the reservoirs have complex distributions of depositional facies and diagenesis processes. Previous research has found that the diagenesis process of tight oil sandstones varies greatly in different depositional facies. However, diagenesis variation in different depositional facies is still poorly studied, especially in distributary channels of shallow water delta deposits in lacustrine basins. Based on the description of core samples, the observation of rock slices, the interpretation of well logging data, and the analysis of porosity and permeability data, the differences in the lithofacies types, diagenesis processes, and pore structures of different distributary channels have been clarified. Ultimately, a model of diagenesis and reservoir heterogeneity distribution in the shallow-water delta of Chang 8 Member of the Yanchang Formation in the Caijiamiao area of the Ordos Basin has been established. This research indicates that the main distributary channels in the study area are dominated by massive bedding sandstone lithofacies, while the secondary distributary channels are primarily characterized by cross-bedding sandstone lithofacies. There are significant differences in the compaction, dissolution, and cementation of authigenic chlorite and carbonate among different parts of the distributary channels. Plastic mineral components, such as clay and mica, are abundant in sheet sands, and are more influenced by mechanical and chemical compaction. Influenced by the infiltration of meteoric water and hydrocarbon generation, dissolution pores are relatively well-developed in the underwater distributary channel reservoirs. A large amount of carbonate cementation, such as calcite and siderite, is found within the sandstone at the interface between sand and mud. The occurrence of authigenic chlorite exhibits a clear sedimentary microfacies zonation, but there is little difference in the kaolinite and siliceous cementation among different microfacies reservoirs. Finally, a model of diagenetic differences and reservoir quality distribution within dense sand bodies has been established. This model suggests that high-quality reservoirs are primarily developed in the middle of distributary channels, providing a theoretical basis for the further fine exploration and development of oil and gas in the study area.

Contribution of plastic solid components to volatile organic compounds formation during plastics combustion

The combustion of plastic waste releases volatile organic compounds (VOCs) that are harmful to human health. However, information on the micro-mechanisms of VOC formation remains lacking. Here, the study hypothesized and verified the relationship between VOC formation and solid component degradation during plastics combustion. The VOCs released during plastics combustion exhibit characteristics such as low carbon content (nc< 10), volatility (9μgm-3 < log10C0 < 11μgm-3), and medium oxidation degree (−1.5 <OSC¯ < −0.5). The dominant VOCs ketones/aldehydes/acids (33-43%) may be attributed to the depolymerization of the polymer structure of plastics, the oxidation of C-O/C=O groups, and the secondary cleavage of gaseous oxygen-containing macromolecules. The VOCs released from the combustion of polyethylene terephthalate (PET) and poly(butyleneadipate-co-terephthalate) (PBAT) contained more aromatics than polyethylene (PE) and polypropylene (PP). And the temperature response of aromatics released from PET and PBAT lagged other VOCs compared that of PP and PE. However, compared to biomass thermal conversion, combustion of plastics releases fewer aromatics and nitrogenous compounds. Collectively, this work shows that the formation mechanisms of VOCs contributed by the solid components during plastic combustion are similar for PET and PBAT due to their similar chemical structures. The proposed mechanism in this paper will provide insight into the control of contaminants during plastic combustion.

Comprehensive Investigation into the Impact of Degradation of Recycled Polyethylene and Recycled Polypropylene on the Thermo-Mechanical Characteristics and Thermal Stability of Blends.

The impact of degradation on plastics is a critical factor influencing their properties and behavior, particularly evident in polyethylene (PE) and polypropylene (PP) and their blends. However, the effect of photoaging and thermal degradation, specifically within recycled polyethylene (rPE) and recycled polypropylene (rPP), on the thermo-mechanical and thermostability aspects of these blends remains unexplored. To address this gap, a range of materials, including virgin polyethylene (vPE), recycled polyethylene (rPE), virgin polypropylene (vPP), recycled polypropylene (rPP), and their blends with different ratios, were comprehensively investigated. Through a systematic assessment encompassing variables such as melting flow index (MFI), functional groups, mechanical traits, crystallization behavior, microscopic morphology, and thermostability, it was found that thermo-oxidative degradation generated hydroxyl and carboxyl functional groups in rPE and rPP. Optimal mechanical properties were achieved with a 6:4 mass ratio of rPE to rPP, as validated by FTIR spectroscopy and microscopic morphology. By establishing the chemical model, the changes in the system with an rPE-rPP ratio of 6:4 and 8:2 were monitored by the molecular simulation method. When the rPE-rPP ratio was 6:4, the system's energy was lower, and the number of hydrogen bonds was higher, which also confirmed the above experimental results. Differential scanning calorimetry revealed an increased crystallization temperature in rPE, a reduced crystallization peak area in rPP, and a diminished crystallization capacity in rPE/rPP blends, with rPP exerting a pronounced influence. This study plays a pivotal role in enhancing recycling efficiency and reducing production costs for waste plastics, especially rPE and rPP-the primary components of plastic waste. By uncovering insights into the degradation effects and material behaviors, our research offers practical pathways for more sustainable waste management. This approach facilitates the optimal utilization of the respective performance characteristics of rPE and rPP, enabling the development of highly cost-effective rPE/rPP blend materials and promoting the efficient reuse of waste materials.

Bioaccessibility of plastic-related compounds from polymeric particles in marine settings: Are microplastics the principal vector of phthalate ester congeners and bisphenol A towards marine vertebrates?

Marine vertebrates are known to ingest significant amounts of microplastics (MPs). Once ingested, MPs might cause gastrointestinal injuries and serve as a path of harmful plastic components, such as phthalate esters (PAEs) and bisphenol A (BPA) in the food chain. However, there is a lack of standardized in-vitro methods capable of simulating fish uptake of chemicals from MPs in the environment as potential vectors of such contaminants. In this work, leaching and in-vitro oral bioaccessibility testing of PAEs and BPA from MPs were conducted batchwise using artificial seawater and gut fluids mimicking gastric, intestinal, and gastrointestinal compartments of marine vertebrates at physiological temperature. The environmental and physiologically relevant extraction tests were applied to medium-density polyethylene (PE) and polyvinyl chloride (PVC) certified reference materials containing eight PAEs of varying hydrophobicity, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate, benzylbutyl phthalate, diethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate and diisodecyl phthalate, and BPA (only in PE) as MP surrogates with realistic analyte concentrations of additives for primary MPs. The analysis of the leachates/gut fluid extracts was performed via dilute-and-shoot by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Only the most hydrophilic compounds, i.e. DMP, DEP and BPA, were found to get released significantly in saline waters, and exhibited the highest oral bioaccessibility rates (34–83 %). Based on our results, a dual-compartment physiologically relevant gastrointestinal test is recommended for appropriate estimation of fish bioaccessibility. The fish daily intakes of DMP, DEP and BPA from MPs, and seawater ingestion as well were estimated using several contamination scenarios (10th percentile as the low level, 50th percentile as the medium level and 90th percentile as the high level) based on probabilistic distributions and cumulative probability curves of measured environmental concentrations of (i) MPs in seawater throughout the world, (ii) DMP, DEP and BPA in beached MPs and those sampled in the open ocean (including both incurred and adsorbed contaminants), and (iii) DMP, DEP and BPA in seawater as reported in recent literature. Under a medium-level concentration scenario (50th percentile) in marine settings, and taking the gastrointestinal bioaccessibility factor into account, the daily intake of DMP, DEP and BPA from MPs accounted for a mere 0.02 % of the waterborne contribution. Hence, the ingestion of MPs should not be considered the primary route of fish exposure to BPA and the most polar PAEs in marine environments. However, more studies on the local and the global scales for mass concentrations of MPs and additives in marine settings are needed for further confirmation of our findings.

Status of Production, Consumption, and End-of-Life Waste Management of Plastic and Plastic Products in Nigeria: Prospects for Circular Plastics Economy

This study is motivated by the need to understand and proffer sustainable circular economy solutions to the persistent challenges associated with plastic waste management in Nigeria. Despite the emerging awareness and increased number of studies conducted on plastic and plastic products in Nigeria, the challenges and opportunities associated with their production, consumption, and post-consumption management are still poorly understood. Besides the large quantity of plastic and plastic products produced locally in Nigeria, a substantial quantity of these products in various forms and polymer types also comes into the country through importation. This results in a high consumption rate and, by extension, a huge volume of plastic waste generated daily exceeding the capacity and ability of the authorities to manage. In this work, we reviewed the available literature to analyze the status of the production, importation, consumption, and post-consumption management of plastic waste in Nigeria. It is estimated that out of 27.3 million tonnes of municipal solid waste currently generated in Nigeria’s urban cities per annum about 11.2 million tonnes is collected, of which about 1.1 million tonnes is plastics. It is further projected that by 2040, about 40.5 million tonnes of municipal solid waste will be generated, and only about 1.6 million tonnes of the plastic component will be collected for disposal. Based on the outcome of the analysis, the current study further suggested how adopting circular economy principles can help mitigate the impact of plastic waste on Nigerian society.

The Designs and Testing of Biodegradable Energy-Absorbing Inserts for Enhanced Crashworthiness in Sports Helmets.

This article addresses manufacturing structures made via injection molding from biodegradable materials. The mentioned structures can be successfully used as energy-absorbing liners of all kinds of sports helmets, replacing the previously used expanded polystyrene. This paper is focused on injection technological tests and tensile tests (in quasi-static and dynamic conditions) of several composites based on a PLA matrix with the addition of other biodegradable softening agents, such as PBAT and TPS (the blends were prepared via melt blending using a screw extruder with mass compositions of 50:50, 30:70, and 15:85). Tensile tests showed a positive strain rate sensitivity of the mixtures and a dependence of the increase in the ratio of the dynamic to static yield stress on the increase in the share of the plastic component in the mixture. Technological tests showed that increasing the amount of the plasticizing additive by 35% (from 50% to 85%) results in a decrease in the minimal thickness of the thin-walled element that can be successfully injection molded by about 32% in the case of PLA/PBAT blends (from 0.22 mm to 0.15 mm) and by about 26% in the case of PLA/TPS blends (from 0.23 mm to 0.17 mm). Next, the thin-walled elements (dimensions of 55 × 55 × 20 mm) were manufactured and evaluated using a spring-loaded drop hammer. The 60 J impact energy was tested in accordance with the EN 1078 standard. The dynamic crushing test included checking the influence of the materials' temperature (-20, 0, 20, and 40 °C) and the impact velocity. It was proven that the maximum deflection increases with increasing material temperature and an increase in the share of the plastic component in the mixture. The PLA15PBAT85 blend was selected as the most effective material in terms of its use as an energy-absorbing liner for sport helmets. Johnson-Cook and Cowper-Symonds material plasticizing models were constructed. Their use during dynamic FE simulation provided results that were in good agreement with those of the conducted experiment.

Multimodal optical ultrasound imaging: Real-time imaging under concurrent CT or MRI

Optical ultrasound (OpUS) imaging is an ultrasound modality that utilizes fiber-optic ultrasound sources and detectors to perform pulse-echo ultrasound imaging. These probes can be constructed entirely from glass optical fibers and plastic components, and as such, these devices have been predicted to be compatible with computed tomography (CT) and magnetic resonance imaging (MRI), modalities that use intense electromagnetic fields for imaging. However, to date, this compatibility has not been demonstrated. In this work, a free-hand OpUS imaging system was developed specifically to investigate the compatibility of OpUS systems with CT and MRI imaging systems. The OpUS imaging platform discussed in this work was used to perform real-time OpUS imaging under (separately) concurrent CT and MRI. CT and MRI imaging of the OpUS probe was used to determine if the probe itself would induce artifacts in the CT and MRI imaging, and ultrasound resolution targets and background measurements were used to assess any impact of CT and MRI on the OpUS signal fidelity. These measurements demonstrate that there was negligible interaction between the OpUS system and both the CT and MRI systems, and to further demonstrate this capability, concurrent OpUS-CT and OpUS-MRI imaging was conducted of a tissue-mimicking phantom and a dynamic motion phantom. This work presents a comprehensive demonstration of an OpUS imaging system operating alongside CT and MRI, which opens up new applications of ultrasound imaging in electromagnetically challenging settings.

Biodegradable Alternatives to Plastic in Medical Equipment: Current State, Challenges, and the Future

The use of plastic products or components in medical equipment and supplies results in challenges in terms of environmental sustainability and waste management for disposable, non-recyclable, and non-biodegradable materials. Medical plastic waste includes items ranging from syringes, tubing, intravenous (IV) bags, packaging, and more. Developing biodegradable replacements to petroleum-based plastics in medical equipment has not yet become an urgent priority, but it is an important endeavor. Examining alternatives involves several key themes, including material selection, testing, validation, and regulatory approval. To date, research includes studies on biodegradable polymers, composite materials, surface modifications, bacterial cellulose, three-dimensional (3D) printing with biodegradable materials, clinical trials and testing, collaboration with industry, regulatory considerations, sustainable packaging for medical devices, and life cycle analysis. The incorporation of bio-based and biodegradable plastics in the healthcare industry holds immense potential for reducing the environmental impact of medical plastic waste. The literature suggests that researchers and industry professionals are actively working towards finding sustainable alternatives that meet the stringent requirements of the medical industry. This paper reviews the efforts made so far to develop biodegradable and sustainable alternatives to plastic in medical equipment using a meta-analysis of resources, which include relevant papers published in English until June 2024. A total of 116 documents were found and screened by three reviewers for relevance. The literature reviewed indicated that various medical uses require plastics due to their unique properties, such as having strength and flexibility; being lightweight; and being able to prevent bacterial contamination. Among the alternatives, polycaprolactone (PCL), polylactic-co-glycolic acid (PLGA), starch-based acid, and polybutyric acid (PBS) have demonstrated favourable outcomes in terms of biocompatibility, safety, and efficacy. Additionally, a set of approaches to overcome these barriers and strategies is discussed alongside potential future solutions. This review aims to catalyze discussions and actions toward a more environmentally sustainable future in the medical industry by providing a comprehensive analysis of the current state, challenges, and prospects of this domain.

Research on the surface quality improvement of 3D-printed parts through laser surface treatment

This study investigates laser polishing as a post-processing technique to reduce surface roughness in ABS and Nylon parts produced via Fused Deposition Modeling (FDM). The research utilized CO2 and Nd:YAG lasers to polish these materials, achieving surface roughness reductions of 95.9 % and 96.0 % for CO2-treated ABS and Nylon samples, respectively, while Nd:YAG-treated samples exhibited reductions of 67.3 % and 68.6 %. Additionally, the study explores the impact of various laser parameters on surface quality through both single-factor and orthogonal experiments. It also introduces wet laser polishing as a novel method to mitigate color changes and enhance polishing effectiveness. This innovative approach demonstrates substantial improvements in performance metrics, underscoring its potential for industrial-scale production of plastic components and biomedical implants. The technique, in particular, shows promising applications in meeting the polishing requirements of 3D-printed parts.

Creep assessment of thermoplastic materials for non-structural components in marine engines

The substitution of metals with fiber-reinforced polymers represents a well-established practice in the automotive and aerospace industries, driven by advantages such as cost reduction, weight savings, and environmental benefits. In the marine engineering sector, there is a growing interest in this metal replacement trend, particularly for non-structural components of marine engines that can be produced by adopting proper fiber-reinforced thermoplastic polymers. However, evaluating the suitability of such materials for marine applications necessitates a thorough understanding of their creep behavior, given the demanding operational environments and strict safety standards. The material selection process must intricately consider the material's susceptibility to creep through tailored material design methodologies. Moreover, redesign activities should aim to leverage the material's creep-resistant properties while ensuring adequate strength and simplifying installation procedures. Unfortunately, unlike the automotive industry, testing innovative plastic components in real environments on working engines is quite impossible. Neither engine manufacturers nor owners would allow jeopardizing their machinery by installing technologies not yet certified in a delicate environment such as a ship's engine room. In this context, finite element simulations offer a valuable tool to assess the material's creep performance and validate the proposed design when experimental measurements cannot be performed, hence predicting the component behavior over its intended lifetime. This study aims to exploit finite element analysis to evaluate the creep behavior and suitability for marine engine applications of a fiber-reinforced thermoplastic material, focusing on a camshaft cover of a four-stroke marine engine currently manufactured from aluminum alloy. Through numerical simulations, a commercial 30 % wt GFs/PA6,6 thermoplastic composite emerges as a promising candidate, demonstrating adequate creep resistance while significantly reducing weight, processing costs, and energy consumption. The results obtained from the present study lay the foundations for the adoption of such material-based technology also in the marine engine sector despite the difficulties coming from the peculiarities of this industry.