Materials Waste Research Articles

Remaining useful lifetime prediction for predictive maintenance in manufacturing

Traditional maintenance approaches often result in either premature replacement of machine parts or downtime in production lines due to malfunctions. Consequently, these lead to significant amount waste in material, time and, ultimately, money. In this study, a machine learning-based predictive maintenance approach is proposed to predict the Remaining Useful Life of production lines in manufacturing. Using data collected from integrated IoT sensors in a real-world factory, we attempted to address the problem of predicting potential equipment failures on assembly-lines before they occur through machine learning models in real-time. To evaluate the effectiveness of the approach, we developed several predictive models using ML algorithms, including Random Forests (RF), XGBoost (XGB), Multilayer Perceptron (MLP) and Support Vector Regression (SVR) and compared the results for all possible variations. Furthermore, the impact of noise filtering, smoothing and clustering techniques on the performance of ML models were investigated. Among all the methods evaluated, RF, an ensemble bagging method, showed the best performance, followed by XGB and implemented in production systems. The implemented prediction model achieved successful results and was able to prevent about 42 percent of actual production line failures.

Novel Sustainable Composites Incorporating a Biobased Thermoplastic Matrix and Recycled Aerospace Prepreg Waste: Development and Characterization.

Carbon fiber-reinforced polymer (CFRP) composite materials are widely used in engineering applications, but their production generates a significant amount of waste. This paper aims to explore the potential of incorporating mechanically recycled aerospace prepreg waste in thermoplastic composite materials to reduce the environmental impact of composite material production and promote the use of recycled materials. The composite material developed in this study incorporates a bio-based thermoplastic polymer, polyamide 11 (PA11), as the matrix material and recycled aerospace prepreg waste quasi-one-dimensionally arranged as reinforcement. Mechanical, thermal, and thermomechanical characterizations were performed through tensile, flexural, and impact tests, as well as differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Compared to previous studies that used a different recycled CFRP in the shape of rods, the results show that the recycled prepregs are a suitable reinforcement, enhancing the reinforcement-matrix adhesion and leading to higher mechanical properties. The tensile results were evaluated by SEM, and the impact tests were evaluated by CT scans. The results demonstrate the potential of incorporating recycled aerospace prepreg waste in thermoplastic composite materials to produce high-performance and sustainable components in the aerospace and automotive industries.

A Review on Progress, Challenges, and Prospects of Material Jetting of Copper and Tungsten.

Copper (Cu) and tungsten (W) possess exceptional electrical and thermal conductivity properties, making them suitable candidates for applications such as interconnects and thermal conductivity enhancements. Solution-based additive manufacturing (SBAM) offers unique advantages, including patterning capabilities, cost-effectiveness, and scalability among the various methods for manufacturing Cu and W-based films and structures. In particular, SBAM material jetting techniques, such as inkjet printing (IJP), direct ink writing (DIW), and aerosol jet printing (AJP), present a promising approach for design freedom, low material wastes, and versatility as either stand-alone printers or integrated with powder bed-based metal additive manufacturing (MAM). Thus, this review summarizes recent advancements in solution-processed Cu and W, focusing on IJP, DIW, and AJP techniques. The discussion encompasses general aspects, current status, challenges, and recent research highlights. Furthermore, this paper addresses integrating material jetting techniques with powder bed-based MAM to fabricate functional alloys and multi-material structures. Finally, the factors influencing large-scale fabrication and potential prospects in this area are explored.

Quantitative comparison of low-cost electrical machines with soft magnetic composite and ferrite magnet materials

Because of its special structure and manufacturing process, the soft magnetic composite (SMC) material has shown its advantages over silicon sheets, including magnetic and thermal isotropy, low high-frequency core loss, low material wastes during its manufacturing process, etc.. Considering the price of SMC raw material can be very cheap in the future, it is an ideal material for developing the low-cost electrical machine. Combined with SMC cores and low-cost ferrite magnets, some electrical machines with SMC and ferrite magnets for low-cost applications were developed in the past decades, which include the transverse flux flux switched permanent magnet motor (TFFSPMM), axial flux claw pole permanent magnet motor (AFCPM), axial flux vernier motor (AFVM), dual rotor axial flux permanent magnet motor (DRAFM) and axial radial flux permanent magnet motor (RAFM). To better utilize SMC material, all these machines are designed following the design guidelines of SMC machines. Though both of them with good performance for low-cost applications, it is necessary to know the main advantages of each machine. The main target of this paper is to compare these machines quantitatively. For obtaining the comparison results fairly all these machines are optimized by using the sequential robust Taguchi method. Finally, it can be seen that the AFVM and TFFSPMM are with relatively high torque ability and the DRAFM is with high efficiency and power factor ability.

Assessing benefits and risks of incorporating plastic waste in construction materials

Plastic pollution and climate change are serious and interconnected threats to public and planetary health, as well as major drivers of global social injustice. Prolific use of plastics in the construction industry is likely a key contributor, resulting in burgeoning efforts to promote the recycling or downcycling of used plastics. Businesses, materials scientists, institutions, and other interested stakeholders are currently exploring the incorporation of plastic waste into building materials and infrastructure at an accelerated rate. Examples include composite asphalt-plastic roads, plastic adhesives, plastic-concrete, plastic/crumb rubber turf, plastic lumber, plastic acoustic/thermal insulation, plastic-fiber rammed earth, and plastic soil reinforcement/stabilizers. While some believe this to be a reasonable end-of-life scenario for plastic waste, research shows such efforts may cause further problems. These uses of plastic waste represent an ongoing effort at “greenwashing,” which both delays and distracts from finding real solutions to the plastic pollution crisis. Hypothesized effects of incorporating plastic waste in construction materials, including economic, environmental, human health, performance, and social impacts, are evaluated in this mini review. We compare known impacts of these treatments for plastic waste and provide recommendations for future research. Evidence shows that such practices exacerbate the negative ecological, health, and social impacts of plastic waste and increase demand for continued production of new (virgin) plastics by creating new markets for plastic wastes. We urge caution—and more research—before widely adopting these practices.

Special Issue on “Recycling Waste in Construction Materials, Volume II”

Recycling plays a key role in decreasing present-day waste [...]

Development of Greener and Stable Inkjet-Printable Perovskite Precursor Inks for All-Printed Annealing-Free Perovskite Solar Mini-Modules Manufacturing.

Inkjet-printing is considered an emerging manufacturing process for developing perovskite solar cells (PSCs) with low material wastes and high production throughput. Up-to-now, all case studies on inkjet-printed PSCs are based on the exploitation of toxic solvents and/or high-molarity perovskite precursor inks that are known to enable the development of high-efficiency photovoltaics (PVs). The present study provides a new insight for developing lower-toxicity, high performance and stable (for more than 2 months) inkjet-printable perovskite precursor inks for fully ambient air processed PSCs. Using an ink composed of a green low vapor pressure noncoordinating solvent and only 0.8m of perovskite precursors, the feasibility of fabricating high-quality and with minimum coffee-ring defects, annealing-free perovskite absorbent layers under ambient atmosphere is demonstrated. Noteworthily, the PSCs fabricated using the industry-compatible carbon-based hole transport material free architecture and the proposed ink present an efficiency >13% that is considered on the performance records for the under-consideration PV architecture employing an inkjet-printed active layer. Outstanding is also found the stability of the devices under the conditions determined by the ISOS-D-1 protocol (T95 = 1000h). Finally, the perspective of upscaling PSCs to the mini-module level (100cm2 aperture area) is demonstrated, with the upscaling losses to be as low as 8.3%rel dec-1 per upscaled active area.

Use of bacterial cellulose obtained from kombucha fermentation in spent coffee grounds for active composites based on PLA and maleinized linseed oil

Spent coffee grounds have been successfully used as an alternative infusion for kombucha fermentation (spent coffee kombucha, SCK). The obtained by-product of this fermentation consists of a kombucha bacterial cellulose (KBC) matrix. The bacterial cellulose was also fermented in pristine coffee grounds infusion for comparison (coffee kombucha, CK). The bacterial cellulose obtained from both infusion fermentations (SCK and CK) was used as filler in PLA matrix plasticized with a 5 wt% of maleinized linseed oil (MLO). Two different content of SCK and CK (3 and 5 wt%) were introduced in the PLA-MLO matrix to produce a film using a conical twin-screw microextruder to simulate the industrial processing conditions. The resultant bio-based films were studied in tern of morphological, tensile, and thermal properties, UV–visible absorption, water vapor permeability, and wettability. The antioxidant activity of the obtained materials was tested in contact with a fatty food simulant demonstrating antioxidant activity. In addition, disintegrability tests under composting conditions confirmed the compostable character of all films. The obtained results suggest the potential applicability of these bio-based materials obtained by the revaluation of HoReCa waste in antioxidant materials with interest as food packaging or for agricultural uses.

STUDY OF THE APPLICATION OF PELLETS FROM TEXTILE MATERIAL WASTE AND BIOMASS MIXTURE IN INDUSTRIAL AND RESIDENTAL HEATING SYSTEMS

The efficient waste management hierarchy is based on four priorities, reuse, recycle, energy recovery, deposit.Efficient energy recovery from non-recyclable textile materials (waste to energy) principles we study in this paper. Energy recovery from the fuel pellets consisting of waste textile materials and biomass depends on many factors. One of the main is to create a competitive form for the newly offered fuel (pellets from a mixture of biomass and textile), as well using a new generation of small-scale energy production facilities. Using already existing applications for efficient waste management is one of the circular economy aspects we lay on in this paper.Roughly estimated that the quantities of textiles separately collected will increased from 65 000 to 90 000 tons per year across the EU-27 from 2025. Reuse and recycling outlets will need to be created, as the current sorting and recycling capacities are not sufficient to process the anticipated volumes. However, it is also expected that at least half of these additional volumes will comprise non-reusable textile waste with specific flame retardant (FR) treatment. It is known that flame retardant is hazard by its adverse environmental impacts of FRs in their production and disposal phases.The objective of the paper is to review opportunities of elaboration a new type of the fuel pellets, and using them in industrial heat pellet boilers and combined heat and power CHP systems.Elaborated the new pellets from biomass (prepared by plasticization method) and chopped textile waste sized till 2-3 mm (by method separative milling) were tested in controlled combustion processes.Experiments were carried out by adding different proportions of textile waste to biomass pellets and the results obtained are summarized in the article

The synergistic hydration mechanism and environmental safety of multiple solid wastes in red mud-based cementitious materials

Red mud (RM) is a solid waste material with high alkalinity and low cementing activity component. The low activity of RM makes it difficult to prepare high-performance cementitious materials from RM alone. Five groups of RM-based cementitious samples were prepared by adding steel slag (SS), grade 42.5 ordinary Portland cement (OPC), blast furnace slag cement (BFSC), flue gas desulfurization gypsum (FGDG), and fly ash (FA). The effects of different solid waste additives on the hydration mechanisms, mechanical properties, and environmental safety of RM-based cementitious materials were discussed and analyzed. The results showed that the samples prepared from different solid waste materials and RM formed similar hydration products, and the main products were C–S–H, tobermorite, and Ca(OH)2. The mechanical properties of the samples met the single flexural strength criterion (≥ 3.0 MPa) for first-grade pavement brick in the Industry Standard of Building Materials of the People's Republic of China-Concrete Pavement Brick. The alkali substances in the samples existed stably, and the leaching concentrations of the heavy metals reached class III of the surface water environmental quality standards. The radioactivity level was in the unrestricted range for main building materials and decorative materials. The results manifest that RM-based cementitious materials have the characteristics of environmentally friendly materials and possess the potential to partially or fully replace traditional cement in the development of engineering and construction applications and it provides innovative guidance for combined utilization of multi-solid waste materials and RM resources.

THE POSSIBILITY OF USING SILICATE-CONTAINING WASTE IN THE PRODUCTION OF BUILDING MATERIALS

The solution to the problem of reducing the resource intensity of the construction industry is possible due to the involvement of large-tonnage waste in the production of building materials as a feedstock. Despite the fact that this task has been standing for a long time, the share of waste in raw materials for the production of building materials is still not large today. The article presents the results of research on the properties of concrete mixtures for self-leveling floors based on silicate-containing waste. In the course of experimental studies, the compositions of raw mixtures containing Portland cement, finely ground broken glass, concrete scrap, and liquid glass were optimized. The ratio of the composition of concrete mixes with the use of waste was revealed, at which the quality of the finished product is maintained. Keywords: cullet, concrete scrap, liquid glass, liquid glass, concrete mixtures.

CubeSat satellite patch antenna designed with 3D printable materials: a numerical analysis

The paper presents a compact patch antenna system designed using 3D printable materials and compatible with any CubeSat satellite structure. Small satellites are transforming the space industry, allowing space access with an important cost reduction for satellite industries and a shorter plan development time compared to bulky satellites. Moreover, using additive manufacturing, it is possible to design specific system components, also with a complex geometry of the inner part, without material wasting. Furthermore, a key point of 3D printing is to allow to go from design to construction straight, having an enormous effect on the supply chain. Generally, CubeSats count on Very High Frequency and Ultra High Frequency communication systems for low bit-rate uplink and downlink. Instead, S-band is among the favourite choices for high bit rates since the frequency range 2.40–2.45 GHz is one of the International Telecommunication Union (ITU) amateur satellite frequency range. An S-band printed antenna system is designed in the present paper, considering the limitations on size and the weight of CubeSat standard. The antenna system is simulated with an electromagnetic CAD, using the polylactic acid as substrate, or polylactide, a thermoplastic polyester widely used in 3D printing.

Optimization of plastic waste integration in cement bricks

Implementing plastic waste in construction materials is a sustainable disposal method to overcome plastic pollution. The current study aims to optimize the integration of plastic waste in cement bricks regarding their thermomechanical properties in order to develop an eco-friendly building material. Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) partially substituted cement with different ratios (0, 2.5, 5, 7.5, 10, 20%). The type that achieved better thermomechanical performance further replaced the other brick components; sand and coarse aggregates to determine the optimum replacement scenario and best design mix. Laboratory experiments have been carried out to measure the compressive strength, indirect tensile strength, bulk density, and thermal conductivity of the new composites. The measured results revealed better performance for the samples with HDPE than PET. A boost in the compressive strength and indirect tensile strength was noticed for the samples obtaining a limited amount (up to 7.5%) of HDPE. However, a reduction in the tested mechanical properties occurs with higher substitution levels. With respect to thermal conductivity and bulk density, they decreased with the increase of plastic waste. The best mechanical behavior and the highest thermal resistance were obtained by partial replacement of coarse aggregates with 7.5% and 20% HDPE respectively. The results represent a good contribution to energy conservation, waste management and sustainability.

A REVIEW PAPER ON INDUSTRIES REVOLUTION 4.0 POWERING THE FUTURE OF HEALTH CARE SECTOR

In the age of globalisation and digitization, the ability of computers to perform tasks normally associated with intelligent beings is known as artificial intelligence (AI), which can play a critical role in assisting in dealing with every type of business and function of human resource management in a proficient and timely manner. The unparalleled data processing capabilities of AI and ML in the pharmaceutical industry serve as a harness in the enhancement and improvement of efficiency in diagnostic assistance and clinical trials, pharmaceutical marketing, foster innovation, quality control, reduce materials waste, improve production reuse, perform predictive maintenance, and improve decision-making skills. The Fourth Industrial Revolution (industries 4.0) in Health Sector implement artificial technologies to performed functions by machines and small robotic systems programmed to do human-like tasks result great potential to transform drug discovery by accelerating the research and development timeline. This technology is being adopted by many pharmaceutical companies to help with the drug discovery and development process, which will enable them to work on a variety of research-oriented projects to improve health facilities and easily cure the diseases in the future. With the development of artificial intelligence and machine learning, the pharmaceutical industry is undergoing significant advancement like decrease the time interval gap from development of a drug product to its commercialization. We will discuss the various roles of AI and ML in health care sector and challenges in this article. As a result, this clearly demonstrates that artificial intelligence has a positive impact on the pharmaceutical industries.

Slope stability assessment of some waste rock dumps at a typical gold mine in Ghana

Mining results in both economic and uneconomic materials being generated. The uneconomic materials (wastes) are stacked in a convenient place for further use or stored permanently as a slope or embankment. In Ghana, a typical gold mine set up dumping sites to accommodate the waste generated from its operations. Samples were collected from three waste dumps and tested in the laboratory, and the parameters obtained were used as input for 2D model development. The Factor of Safety (FS) of the three waste dumps were determined using the Janbu Generalised slope stability analysis method. Path and slope surface (circular and non-circular) search methods were used for the three cases. The FS for the waste dumps were determined and ranged from 1.61-2.74, 1.49- 2.50 and 1.32-2.10 under dry, static and pseudo-static loading conditions, respectively. These values exceed the minimum requirements of 1.1-1.5 for stability conditions. The geometry of the waste dumps, Suraw Waste Dump (SWD), is within the standard and hence, does not require reshaping, while the slope angles for the remaining waste dumps, Tano Waste Dump (TWD) and Akoti Waste Dump (AWD) need to be reshaped to achieve the proposed slope angle of 3H:1V (18.40 degrees) as stipulated in the mine’s Environmental Impact Statement (EIS).

Effect of loading-induced damage on chloride ingress behavior of recycled aggregate concrete: A comprehensive review

The recycling technology of construction and demolition wastes is an inevitable choice towards the sustainable development of the construction industry, aiming at addressing the problems of raw materials shortage and waste disposal. The utilization of recycled coarse aggregate (RCA) in new concrete production has been identified as an effective way to reasonable application of natural resources replacement and environmental preservation. In service, external mechanical loading can easily cause the initiation and interconnectivity of microcracks inside concrete, specifically the complex multiple interface structures of recycled aggregate concrete (RAC) due to the old adhered mortar at the surface of RCAs, which can remarkably accelerate the process of water penetration and aggressive ions penetration into concrete. Thus, knowledge of mass transport properties in the loading-induced damaged RAC contributes to the durability evaluation of RAC and its extensive application in the practical engineering. This paper reviews the previous findings on the mechanical loading effects on the chloride transport properties of RAC. The effects of loading-induced damage on microstructure evolution of RAC as well as the damage characteristics were discussed. The research progress on the chloride ingress behavior of RAC subjected to mechanical loading was highlighted from the viewpoint of testing method, loading devices and numerical calculation, and the modified effects on the transport properties were further analyzed. On this basis, the future research on the durability-related properties of RAC would be finally proposed, which is helpful to further perfect theoretical development and technological innovation of RAC durability in the aggressive environment.

Analysis of carbon emission reduction potential of construction industry in Liaoning Province based on system dynamics

The rapid increase in carbon emissions is one of the main causes of environmental degradation, and the construction industry contributes 40% of carbon emissions. This paper uses system dynamics to analyze the carbon emission reduction potential of construction enterprises in Liaoning Province in order to realize the national "dual carbon" goal as soon as possible. First, the factors affecting carbon emissions are summed up by combining the calculation formula of carbon emissions of buildings in the whole life cycle and related literatures. Then use the environmental characteristics of Liaoning Province to establish a carbon emission reduction model, carry out simulation simulation and validity test, and obtain the relationship between the influencing factors and carbon emission reduction. Finally, a scenario analysis is carried out in four aspects: energy technology, building materials production technology, transportation technology and waste recycling technology. A series of conclusions are drawn, such as building materials production technology and energy technology are the key aspects of implementing carbon emission reduction in the construction industry in Liaoning Province. The whole work provides a theoretical basis for Liaoning Province to successfully achieve the "14th Five-Year" goal, and then achieve carbon emission reduction and sustainable development.

Reducing Reinforced Concrete Materials Waste in Construction Projects Using Building Information Modeling in Egypt

Reduced Reinforced Concrete Material Waste (RRCMW) is recognized as a major issue that must be controlled in building projects. The primary goal of the study is to demonstrate the significance of BIM in construction and the importance of BIM in reducing reinforced concrete material waste. To achieve the study's goal, a questionnaire survey is undertaken to estimate the benefit of using BIM in Egyptian building projects. According to the survey results, about 41% of respondents are believed that BIM may reduce project costs by 16% to 20% when compared to the traditional method. In addition, the proportion of variations in reinforced concrete amount survey between traditional methods (AutoCAD) and (Revit) is discovered to be 44%, with a range of 11% to 15%. Approximately 46% of respondents are believed that BIM eliminates design errors, with a percentage ranging from 21% to 25%, and about 51% are believed that BIM helps in reducing rework, with a total percentage ranging from 21% to 25%. Then, case studies of building ("Residential projects") and infrastructure ("Bridges projects") projects are analyzed to determine the difference between waste minimization using traditional methods and waste minimization using BIM. Waste management is a critical issue since it is the only approach to optimize waste throughout the project phases. As a result, factors managing (RRCMW) are extracted, and BIM software should be used to manage these factors in order to optimize waste. The relevant BIM applications are used in this case study: site utilization planning, quantity take-off, 3D coordination, visualization, digital prefabrication, design validation, "design review and clash detection," and optimized workflow and communication structure. So, based on the preceding case studies, it is discovered that using BIM is far more successful and economical than using the traditional method, because it aids in the resolution of many issues before and during construction, such as clash detection, material storage, material ordering, and so on. As a result, while BIM is not widely used in Egypt, engineers should be familiar with it because it will be a vital tool to reduce waste in the future.

DISCLOSURE INDEX OF HAZARDOUS TOXIC WASTE (LB3) IN INDONESIA

This research aimed to compile a toxic hazardous materials waste (LB3) disclosure index in Indonesia, knowing the difference between unweighted and weighted LB3 disclosures in manufacturing and oil and gas companies, mineral and coal mining management (Minerba). The data used was primary, sourced from FGD and questionnaires with the sampling technique used were accidental sampling. The secondary data used was the LB3 disclosure data of manufacturing and mining companies listed on the Indonesia Stock Exchange (IDX) in 2019 using purposive sampling techniques. The index preparation method used descriptive tests and independent t-test tests to look for differences in unweighted and weighted LB3 disclosures in manufacturing and mining companies. The results of this study in the form of LB3 disclosure index as many as 21 disclosure items with their respective weights. The test results were no different but the mean value of LB3 weighted disclosure (0.2945) was higher than the mean weighted value (0.283). The difference from the unweighted and weighted index is 0.0142, the difference is very small, so statistically there is no different LB3 disclosure in manufacturing companies and miners.

Physical and Chemical Properties of Organic Waste Reinforced Polyester Composites

Organic wastes constitute an important part of environmental pollution. Disposal of these wastes can be achieved either by using recycling methods or as reinforcement material. In this study, research has been carried out on the use of organic wastes in composite materials. For example, the effects of organic fillers on the physical and chemical properties of polyester composites have been investigated. Organic wastes (biomass) are prepared as fillers after drying and grinding. Especially, biomass samples with a fibrous structure improve the mechanical properties of composites. The use of such organic wastes in polyester composites is preferred for obtaining both economical and low-density materials. However, such fillers should be used in optimum proportions in the composite. Because the use of these wastes at a high rate negatively affects both the surface morphology and the pore structure of polyester composites. Besides, the evaluation of these wastes in the production of polyester composites reduces the carbon footprint. Such fillers interact physically in the polyester composite. If no chemical modification is made, it does not react with polyester components and does not make a chemical bond. According to the evaluated results, it reduces the density and hardness of the polyester composite. Also, it decreases the thermal conductivity coefficient and thermal stability, albeit slightly.