Search Results (1,527)

Wood–plastic composites (WPCs) are polymeric materials, usually thermoplastic, filled with wood flour or fibers. They are relatively durable and stiff and resistant to water. They are also, importantly, relatively cheap compared to materials with similar properties. The WPCs market has grown significantly in recent years, mainly thanks to the increasing construction and automotive markets. Currently, the global WPCs market is forecasted to reach about USD 15 billion by 2030, increasing at an impressive compound annual increase rate of about 12% until 2030. There are some review articles on WPCs written from many different points of view, e.g., the type of materials used (polymers, fillers, auxiliaries), the method of manufacturing and processing, processing properties (thermal and rheological) and functional properties, methods of designing composite products and designing (modeling) forming processes. In this article, we will summarize these different points of view and will present a thorough literature review of rheology and material processing, and more specifically, the modeling of WPCs processing. This work will be presented in relation to state-of-the-art research in the field of modeling the processing of other polymeric materials, i.e., standard (neat) polymers and polymer blends. The WPCs’ processing is significantly different from that of standard plastics due to the differences in thermo-rheological properties, diverse structures, etc. So far, the global WPCs processing models have only been developed for both gravity-fed and starve-fed single-screw extrusion. The models for twin-screw extrusion, both co-rotating and counter-rotating, as well as for injection molding, have still not been developed. WPCs show a yield stress and wall slip when extruding, which must be considered when modeling the process. As the slippage on the screw and barrel grows, the process throughput and pressure diminish, but as the slippage on the die grows, the throughput grows and the pressure diminish. As the yield stress in the screw grows, the process throughput and pressure grow, whereas as the yield stress in the die grows, the throughput diminishes and the pressure grows. Full article

Mechanochemical methods have received much attention in the synthesis and design of all-solid-state battery materials in recent years due to their advantages of being green, efficient, easy to operate, and solvent-free. In this review, common mechanochemical methods, including high-energy ball milling, twin-screw extrusion (TSE), and resonant acoustic mixing (RAM), are introduced with the aim of providing a fundamental understanding of the subsequent material design. Subsequently, the discussion focuses on the application of mechanochemical methods in the construction of solid-state electrolytes, anode materials, and cathode materials, especially the research progress of mechanical energy-induced polymerization strategies in building flexible composite electrolytes and enhancing interfacial stability. Through the analysis of representative work, it is demonstrated that mechanochemical methods are gradually evolving from traditional physical processing tools to functional synthesis platforms with chemical reaction capabilities. This review systematically organizes its development and research trends in the field of all-solid-state battery materials and explores potential future breakthrough directions. Full article

Understanding the combined effects of edge width and cutter ring shape on the rock-breaking performance is critical for optimising disc cutter design. The intrusion test serves as an effective approach for investigating the rock-breaking mechanism of disc cutters. In this study, a two-dimensional discrete element method (DEM) model was established to simulate the intrusion process of a single disc cutter. Three commonly used disc cutter types were analysed: disc cutter with flat edge (FEDC), disc cutter with rounded edge (REDC) and disc cutter with alloy tooth (ATDC). The edge widths ranging from 10 mm to 24 mm were examined to assess their influence on rock crack propagation, stress distribution, cutting force and specific cutting energy. The FEDC and REDC exhibited face-contact extrusion breaking, whereas the ATDC was line-contact embedding breaking. The crack extension range, crack number, force chain intensity, stress distribution, rock-breaking force and specific cutting energy ranks are as follows: FEDC > REDC > ATDC. The ATDC generated a higher proportion of tensile cracks compared to the FEDC and REDC, though with fewer long cracks. The rock-breaking efficiency of the FEDC was lower, whereas the REDC and ATDC exhibited higher efficiency. With the increase in edge width, the force chain distribution became more concentrated, leading to greater internal rock damage, and the number and length of cracks increased significantly. Cracks initially expanded laterally at smaller edge widths but extended downward as edge width increased. The peak force and specific cutting energy increased with increasing edge width; the peak force at an edge width of 24 mm is approximately 3.5 times that of an edge width of 10 mm. The REDC is preferable in hard rock formations, and the ATDC is more effective in soft rock formations. The edge width should be determined based on rock properties and thrust capacity. Full article

Current research and technical standards primarily rely on observational methods to evaluate the printability of 3D printing materials. There is a lack of quantitative assessment metrics for extrudability and supportability, and experimental data cannot be used to characterize extrudability and buildability. Further research is needed. Based on traditional workability parameters (such as flowability), this study explored the influence of printability characteristics and adopted two quantitative indicators—extrusion uniformity and cumulative deformation rate—to comprehensively evaluate material performance from two aspects, while observing the trend of changes in traditional workability indicators and print quality under experimental conditions. The experimental results showed that the extrusion uniformity of 3D-printed mortar initially improved and then gradually deteriorated as flowability increased, and was inversely proportional to dynamic yield stress. The cumulative deformation rate decreases with the improvement of height retention capability and the increase in static yield stress. Through parameter analysis, the optimal printing performance conditions were determined: when the extrusion uniformity is below 3.3% and the cumulative deformation rate is ≤6%, the corresponding dynamic yield stress range is 200 Pa to 800 Pa, and the static yield stress range is 1800 Pa to 3300 Pa. Under these parameters, the mortar exhibits excellent printing performance, including high-layer stacking capability (≥30 layers) and enhanced structural stability. This experiment demonstrates that using these two quantitative indicators can simply and efficiently evaluate the performance metrics of 3D-printed materials, while also revealing the relationship between the workability and printing quality of 3D-printed recycled micro-powder geopolymer materials. Full article

Background and Objectives: Cochlear implantation (CI) is a surgical procedure that offers significant benefits to individuals with sensorineural hearing loss, particularly in pediatric patients, as it can prevent long-term cognitive impairment. Despite the devices being designed for lifelong use, complications may necessitate explantation and subsequent reimplantation. Materials and Methods: Our retrospective study analyzes the incidence and causes of such procedures in pediatric CI patients over a period of 15 years, from May 2009 to June 2025. The study included patients aged between 8 months and 17 years, recording their age, the manufacturers of their first and second implants, the reasons for explantation and reimplantation, and the type of electrode array used during the second surgery. Results: During the study period, a total of 440 cochlear implantations were performed in our department. The primary causes of explantation in our study group were device hardware failures in 2.27% of cases, seromas over the implant body or antenna in 0.68% of cases, spontaneous extrusion in 0.22% of cases, and local trauma with electrode displacement in 0.22% of cases. The study confirmed that hardware failures were the most common reason for reimplantation, with an incidence influenced by the device manufacturer and the extent of trauma to the device. Surgical observations highlight the challenges regarding electrode reimplantation and available electrode choices for the surgeon. Conclusions: The use of superior materials and advanced research in manufacturing can enhance implant reliability and reduce the number of surgical procedures required in the long term for pediatric patients. Any type of electrode array can be utilized in reimplantations if meticulous surgical techniques are applied. Full article

Following the trend of food waste valorization to produce innovative bio-based materials, this study proposes the conversion of brewer’s spent grain (BSG) into added value edible, high oxygen barrier, flexible, active packaging films via an extrusion molding compression method. Gelatin (Gel) was used as both a reinforcement and barrier agent and glycerol (Gl) as a plasticizer. Eugenol was nanoencapsulated on natural zeolite (EG@NZ), and pure clove powder (ClP) was used as an active agent to obtain BSG/Gel/Gl/xEG@NZ and BSG/Gel/Gl/xClP (x = 5, 10, and 15 %wt.) active films. Both BSG/Gel/Gl/xEG@NZ and BSG/Gel/Gl/xClP films show enhanced tensile, oxygen barrier, antioxidant, and antibacterial properties, and low toxicity and genotoxicity values. All BSG/Gel/Gl/xEG@NZ films presented a higher oxygen barrier, higher total phenolic content (TPC) values, higher antioxidant activity according to a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, higher inhibition zones against Staphylococcus aureus and Escherichia coli, and lower toxicity and genotoxicity than all BSG/Gel/Gl/xClP films. Thus, the superiority of the nanoencapsulated EG in NZ as compared to the physical encapsulated EG in ClP is proved. Briefly, BSG/Gel/Gl/15EG@NZ active film exhibited ~218% higher tensile strength, ~93% higher TPC value, and ~90% lower effective concentration for a 60% antioxidant activity value (EC₆₀) as compared to the pure BSG/Gel/Gl film. The zones against S. aureus and E. coli were 45 and 30 mm, respectively, and the oxygen barrier was zero. The use of this film extended the shelf life of fresh minced meat by two days and exhibited the high potential to be used as active packaging material. Full article

The present study offers a systematic review of the current state of research on lattice structures manufactured by additive technologies for biomedical applications, with the aim of identifying common patterns, such as the use of triply periodic minimal surfaces (TPMS) for bone scaffolds, as well as technological gaps and future research opportunities. Employing the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology, the review process ensures methodological rigor and replicability across the identification, screening, eligibility, and inclusion phases. Additionally, PRISMA was tailored by prioritizing technical databases and engineering-specific inclusion criteria, thereby aligning the methodology with the scope of this field. In recent years, a substantial surge in interdisciplinary research has underscored the promise of architected porous structures in enhancing mechanical compatibility, fostering osseointegration, and facilitating personalized medicine. A growing body of literature has emerged that explores the optimization of geometric features to replicate the behavior of biological tissues, particularly bone. Additive manufacturing (AM) has played a pivotal role in enabling the fabrication of complex geometries that are otherwise unachievable by conventional methods. The applications of lattice structures range from permanent load-bearing implants, commonly manufactured through selective laser melting (SLM), to temporary scaffolds for tissue regeneration, often produced with extrusion-based processes such as fused filament fabrication (FFF) or direct ink writing (DIW). Notwithstanding these advances, challenges persist in areas such as long-term in vivo validation, standardization of mechanical and biological testing, such as ISO standards for fatigue testing, and integration into clinical workflows. Full article

Background: The limited aqueous solubility of BCS Class II drugs, exemplified by itraconazole (ITR), continues to hinder their bioavailability and therapeutic performance following oral administration. The present study investigated the development of amorphous solid dispersions (ASDs) of ITR via continuous manufacturing technologies, such as hot melt extrusion (HME) and spray drying (SD), to improve drug release. Methods: Polymer selection was guided by Hansen solubility parameter (HSP) analysis, film casting, and molecular modeling, leading to the identification of aminoalkyl methacrylate copolymer type A (Eudragit^® EPO), polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus^®), and hypromellose acetate succinate HG (AQOAT^® AS-HG) as suitable carriers. ASDs were prepared at drug-to-polymer ratios of 1:1, 1:2, and 2:1. Comprehensive characterization was performed using ATR-FTIR, NMR, DSC, PXRD, SEM, PLM, and contact angle analysis. Results: HME demonstrated higher process efficiency, solvent-free operation, and superior dissolution enhancement compared to SD. Optimized HME-based ASDs were formulated into tablets. The ITR–Eudragit^® EPO formulation achieved 95.88% drug release within 2 h (Weibull model, R² > 0.99), while Soluplus^® and AQOAT^® AS-HG systems achieved complete release, best described by the Peppas–Sahlin model. Molecular modeling confirmed favorable drug–polymer interactions, correlating with the formation of stable complex and enhanced release performance. Conclusions: HME-based continuous manufacturing provides a scalable and robust strategy for improving the oral delivery of poorly water-soluble drugs. Integrating predictive modeling with experimental screening enables the rational design of ASD formulations with optimized dissolution behavior, offering potential for improved therapeutic outcomes in BCS Class II drug delivery. Full article

This review investigates how process parameters and material choices influence the mechanical performance of parts produced by material extrusion additive manufacturing, with a particular focus on Material Extrusion (ME). Through a systematic bibliometric analysis of literature between 2015 and 2025, the study identifies key factors affecting mechanical strength, anisotropy, and structural reliability, including printing temperature, speed, orientation, layer thickness, and interlayer bonding. Emphasis is placed on emerging techniques such as 4D printing, fiber-reinforced composites, and novel monitoring methods like real-time vibration sensing and thermal imaging, which offer promising pathways to improve part performance and process stability. Three research questions guide the analysis: (1) how printing parameters affect micro- to macrostructure and failure behavior, (2) how optimization strategies enhance part quality, and (3) how material and process selection aligns with functional requirements. The review highlights both advances and persistent limitations in process control, material compatibility, and anisotropic strength. It concludes with a call for further integration of predictive modeling, hybrid material systems, and closed-loop process monitoring to unlock the full potential of additive manufacturing in high-performance engineering applications. Full article

This article presents the wear characteristics of the working surface of WC-Co (Tungsten Carbide–Cobalt) tungsten carbide tools obtained using the innovative U-FAST (Upgraded Field-Assisted Sintering Technology) method for particleboard machining. Three groups of tools with a similar chemical composition but differing WC (Tungsten Carbide) grain sizes were tested. Milling tests were carried out on a CNC (Computer Numerical Control) machine tool with the following cutting parameters: spindle rotation at 15,000 rpm, a feed rate of 0.25 mm per tooth, and a feed rate of 3.75. The experimental results show that tools with submicron WC grit sizes of 0.4 µm and 0.8 µm have the longest tool life. Wear of the cutting edges occurred through the removal of the cobalt bond between the tungsten carbide grains, leading to fracture and mechanical removal of the grains from the cutting edge surface. The similarities in the relative wear characteristics of blades with submicron tungsten carbide grain sizes suggest that micro-abrasion and bond phase extrusion may be the main wear mechanisms under the experimental conditions. Nanometric WC grain size significantly influences tool wear through chipping and cracking. Full article

Twin-screw extrusion is a promising method to transform medicinal herbs into functional food ingredients. However, limited research has focused on the application of this technique to ginseng–astragalus compounds. In this study, the response surface methodology (RSM) was used to optimize the extrusion process (screw speed, temperature, and moisture content). The optimal parameters (208 rpm, 128 °C, 29%) significantly increased ginsenoside, polysaccharide, phenolic content, and antioxidant capacities (DPPH•, OH•, O₂⁻•). Furthermore, extrusion improved the aroma profile while reducing bitterness, as revealed by electronic nose and electronic tongue, and PCA. The treated product also exhibited enhanced antibacterial activity. These findings demonstrate that twin-screw extrusion is an effective tool for developing medicinal food products with improved quality and biofunctionality. The response surface methodology model showed high reliability (R² > 0.95) with prediction errors and relative standard deviations below 5%, confirming the robustness of the optimization. Full article

This study aims to compare the carbon footprints associated with the fabrication of two types of alumina-based tubular ceramic membranes used in microfiltration (MF): a multichannel membrane produced by extrusion and dip-coating, and an asymmetric hollow fiber membrane fabricated via phase inversion. The multichannel process involves two sintering steps but uses no organic solvents, whereas the phase-inversion method simplifies production through single-step shaping and sintering but requires organic solvents that increase environmental burdens. Using a functional unit of 1 m² effective membrane area, carbon emissions were quantified from raw material extraction to waste disposal. The results showed total emissions of 8.57 kg CO₂-eq/m² for the multichannel membrane and 10.67 kg CO₂-eq/m² for the hollow fiber membrane. Although the hollow fiber process consumed less energy, its extensive use of solvents, particularly NMP, led to significantly higher emissions. This study provides the first quantitative comparison of these two common ceramic membrane fabrication routes and underscores the importance of considering both energy use and solvent impacts when evaluating the environmental sustainability of membrane production. A sensitivity analysis further evaluated the influence of key parameters, including alumina emission factor, regional electricity carbon intensity, alumina recycling, and solvent substitution or NMP recycling. The analysis demonstrated that each factor could significantly influence the total carbon footprint and, under favorable conditions, narrow or even reverse the gap between the two fabrication routes. This study provides the first quantitative comparison of these two common ceramic membrane fabrication methods and highlights the importance of considering energy use, solvent impacts, and potential mitigation strategies when assessing the environmental sustainability of ceramic membrane production. Full article

This study investigates the effect of rice husk content (0–60 wt.%) on the thermal, mechanical and rheological properties of polypropylene composites prepared by extrusion and injection molding. A temperature-invariant approach was applied to analyze the viscoelastic properties, allowing the combination of data obtained at different temperatures. The results show that as the husk content increases, the elastic modulus and hardness rise linearly, while the impact strength and elongation at break significantly decrease. Composites with 40–50% filler exhibit a balanced combination of strength and stiffness, as confirmed by the summary data in the table (provide references). The application of the temperature-invariant viscosity method confirmed its effectiveness in evaluating the flow properties of composite melts. The obtained results have practical significance for the development of eco-friendly polymer materials with natural fiber fillers. Full article

Multimaterial 3D printing is transforming the landscape of additive manufacturing, enabling the production of advanced, functional parts with tailored properties for sectors like automotive, aerospace, and engineering. However, achieving strong interlayer adhesion between different polymers remains a significant challenge, limiting the mechanical reliability. This study investigates adhesion properties of widely used materials—polycarbonate (PC), acrylonitrile styrene acrylate (ASA), polylactic acid (PLA), and polyethylene terephthalate glycol (PETG)—and enhances mechanical performance of structural joints through optimized interlayer bonding techniques. Using the Material Extrusion (MEX) method, tensile testing was employed to evaluate the mechanical strength of joints by co-depositing and bonding material layers during the printing process. The results demonstrate that specific material combinations and joint design strategies, particularly increasing the interfacial contact area and applying interlayer bonding pressure, significantly enhance tensile strength. For instance, the strength of PC/PTEG composite joints increased from 15.2 MPa (standard joint) to 29.9 MPa (interlayer bonding strategy), nearly doubling the bond strength. These findings provide valuable insights into the behavior of multimaterial joints and propose practical approaches for improving the durability and functionality of 3D-printed structures. This research lays the groundwork for advancing multimaterial additive manufacturing, with implications for high-performance applications in engineering, aerospace, and beyond. Full article

The study aimed to evaluate the influence of ink composition, a blend of blueberry and banana purée with hydrocolloids such as xanthan gum and carrageenan in concentrations ranging from 1 to 4%, on various physical properties. These parameters included dry matter, water activity, density, syneresis index, and rheological and textural attributes of fruit inks. Additionally, the stability of the inks post-printing and after 60 min was examined using image analysis method. Increased hydrocolloid additives from 1 to 4% caused the increase of the viscoelastic modulus G′ and G″, force and extrusion work values extrudability of inks. The stability and fidelity of the inks were enhanced, resulting in a notable reduction in syneresis during storage. The modulus of elasticity exceeded the modulus of viscosity for all ink formulations evaluated, thereby ensuring structural stability. Notably, the formulation comprising 4% xanthan gum and 4% carrageenan exhibited the highest values in both viscoelasticity and extrudability indices, indicating superior performance characteristics within the studied parameters. The shape of the printed objects remained comparable to the designed model over time. Considering the constraints associated with the use of carrageenan, it is possible to attain a comparable effect by utilising reduced concentrations of hydrocolloids. For instance, formulations incorporating 3% xanthan gum in tandem with either 3% carrageenan or 2% carrageenan can achieve similar functionalities. The 3D printing of fruit purées, including blueberries and bananas, represents a significant innovation in personalising food products in terms of consistency. This is particularly relevant for individuals with dysphagia, children, and the elderly. Full article