Search Results (307)

In the manufacturing of micro-scale components, geometric dimensional accuracy and product quality are critical factors that directly influence both production costs and efficiency. To meet the growing demands in this field, micro-extrusion technology has been developed and extensively applied, particularly in mass and bulk production. This technology is considered an optimal solution for improving dimensional accuracy, enhancing mechanical properties, increasing production efficiency, and reducing costs compared to traditional methods, while also aligning with the current trends of modern industrial development. This study investigates the influence of temperature and friction on forming force, formability, and product quality during the micro-extrusion process. A combined approach of simulation and experimentation was utilized to form cross-shaped coupling components using pure copper as the material. The results indicate a significant relationship between temperature, friction coefficient, and forming force. Furthermore, 550 °C is identified as the most suitable temperature for hot forming, providing a balance between force reduction and product quality. These insights enhance the predictability and control of the micro-extrusion process and contribute to reducing production defects. Ultimately, the findings support wider implementation of micro-extrusion in the manufacturing of high-accuracy small-scale parts and align with modern trends emphasizing miniaturization, automation, and cost efficiency. Full article

The microstructures and mechanical and corrosion properties of Mg-12Gd-2Zn-xNd-0.4Zr (x = 0, 0.5, and 1.0 wt.%) alloys after hot-extrusion have been studied by scanning electron microscope (SEM), transmission electron microscope (TEM), electron back scattered diffraction (EBSD), X-ray diffractometer (XRD), electronic universal testing machine, atomic force microscope (AFM), immersion, and electrochemical tests. The results show that all the alloys consist of an α-Mg matrix, β phase, and stacking faults (SFs). Obvious texture (<$\overline{1}2\overline{1}0$> parallel to the extrusion direction and the direction close to <0001>) can be found due to the introduction of the Nd element. The yield strength (YS) of the alloys with Nd additions in different testing conditions is higher than that without Nd addition. The addition of 0.5 wt.% Nd achieves the highest tensile YS at room temperature (262 MPa) and 180 °C (251 MPa), along with compression YS (246 MPa), attributable to grain refinement, stacking faults, texture, and solute atom strengthening. Moreover, the compression YS to tensile YS ratio of the as-extruded alloy increases from 0.87 to 0.98, indicating a significant improvement of tension–compression YS asymmetry. The Nd addition also plays a great role in the enhanced corrosion resistance of the alloys. Specifically, the corrosion potential of the different phases in the alloys shows the following order: β phase > SFs > α-Mg matrix. The alloy with 0.5 wt.% Nd addition exhibits the best corrosion resistance owing to its lower corrosion potential difference between the β phase and α-Mg matrix. Full article

Ice cream is a frozen aerated dessert composed of milk solids, sugars, stabilizers, and fat—with the latter being a key component in defining its structural and sensory properties. This study evaluated the influence of four fat sources—low-trans vegetable fat (T1), butter (T2), UHT cream (T3), and fresh cream (T4)—on the physical and structural characteristics of ice cream, including overrun, melting resistance, texture, color, and rheology, at different stages of processing (before and after maturation). Oscillatory rheological analysis revealed predominantly elastic behavior (G′ > G″) after maturation in all samples, indicating a stable viscoelastic solid structure. Formulations containing T3 and T1 showed the highest overrun values, indicating greater air incorporation, whereas the butter-based formulation (T2) showed the lowest overrun values. Melting resistance followed the following order: T3 > T4 > T2 > T1; therein, the UHT cream formulation exhibited the greatest thermal stability, which was likely due to protein denaturation and aggregation induced by high-temperature processing. Texture analysis showed that the T1 formulation required the lowest maximum extrusion force, while T2 required the highest, reflecting an inverse correlation with overrun values. T1 also displayed the most distinct rheological profile, which was likely due to its specific crystallization behavior and reduced destabilization of the fat globule membrane—which favored the development of a more structured internal network. These findings demonstrate that both the source and processing of fat have a significant impact on the formation of the structural matrix and the final functional properties of ice cream. The results offer technical insights for the development of formulations tailored to specific physical characteristics, optimizing texture, stability, and performance throughout the production process. Full article

Background/Objectives: Hospital compounding is essential for the delivery of patient-tailored therapies—particularly for pediatric and oncology patients and other groups requiring precise dosing. Its role is expected to grow as, for instance, the UK MHRA’s new Guidance on Decentralised Manufacturing promotes alternative manufacturing pathways that integrate hospital preparation units. However, drug substances that remain stable in commercial oral formulations may undergo rapid degradation under alternative conditions (e.g., aqueous suspension, light exposure, or in the presence of specific excipients). Despite these risks, formulation strategies in hospital compounding often rely on empirical practices and lack structured guidance regarding stability, impurity control, and reproducibility. Methods: This study proposes a risk-based scientific framework for formulation design, integrating degradation profiling with predictive toxicology. Potential degradation pathways (hydrolytic, oxidative, and photolytic) are systematically identified through forced-degradation studies combined with ab initio modeling. These risks are translated into formulation strategies using a structured decision tree encompassing solvent selection, pH adjustment, excipient compatibility, and packaging considerations, even in the absence of a pharmacopeial monograph. The toxicological relevance of degradation products is evaluated using in silico approaches aligned with ICH M7 guidelines, thereby defining critical quality attributes (cQAs) and critical process parameters (CPPs). Results: The applicability of the framework is demonstrated through hospital compounding case studies, with further extension toward advanced applications such as semi-solid extrusion (SSE) 3D printing. Conclusions: By integrating mechanistic understanding of drug degradation into formulation planning, the proposed framework enhances the safety, reproducibility, and quality of compounded preparations. This approach reinforces Good Preparation Practices (GPPs) and is consistent with international quality-by-design (QbD) principles in the context of personalized medicine. Full article

Background. Orthodontic extrusion (OE), or forced eruption, is a conservative technique used to recover teeth affected by coronal fractures, traumatic intrusions, or severe caries. It involves applying light, continuous forces to induce vertical tooth movement, promoting tissue remodeling through periodontal ligament stimulation. Materials and Methods. This narrative review included studies investigating OE as a therapeutic approach for the management of deep or subgingival carious lesions, traumatic dental injuries (such as intrusion or fracture), or for alveolar ridge augmentation in implant site development. OE is typically performed using fixed appliances such as the straight-wire system or, in selected cases, clear aligners. Forces between 30 and 100 g per tooth are applied, depending on the clinical situation. In some protocols, OE is combined with fiberotomy to minimize gingival and bone migration. Results. Studies show that OE leads to significant vertical movement and increases in buccal bone height and interproximal septa. It enhances bone volume in targeted sites, making it valuable in implant site development. Compared to surgical crown lengthening, OE better preserves periodontal tissues and improves esthetics. Conclusions. In this narrative review is analized how OE is effective for managing traumatic intrusions and compromised periodontal sites, particularly when paired with early endodontic treatment. It reduces the risks of ankylosis and root resorption while avoiding invasive procedures like grafting. Although clear aligners may limit axial tooth movement, OE remains a minimally invasive, cost-effective alternative in both restorative and implant dentistry. Full article

Background: Left bundle branch area pacing (LBBAP) has emerged as a physiological alternative to conventional pacing, offering improved ventricular synchrony and clinical outcomes. However, extraction of deeply implanted LBBAP leads remains challenging, particularly in the context of device-related infections. Case Summary: We report two cases of successful extraction of chronically implanted LBBAP leads using a novel technique based on femoral countertraction with pigtail catheters. In the first case, a deep septal implanted 3830 lead was extracted in a patient with persistent bacteremia and suspected device-related endocarditis. Continuous traction was applied to the mid-portion of the lead using a pigtail catheter introduced via femoral access, facilitating safe removal without the use of powered sheaths proximal to the distal tip of the lead. In the second case, three leads (RA, RV, LBBAP) from a cardiac resynchronization therapy with deffibrilation support (CRT-D) system were completely removed in a patient with device extrusion and pocket erosion, using a dual pigtail approach anchored to the atrial and septal leads. Results: In both cases, the technique enabled successful extraction without complications. Procedural times were approximately 70 and 65 min, respectively. In vitro testing suggested that the pigtail catheter applied a sustained moderate traction force (~0.06 kgf), translating to an estimated pressure of 0.85–1.91 kgf/cm² at the septal lead interface. Conclusions: This case series demonstrates that LBBAP lead extraction is feasible using a novel femoral countertraction technique with pigtail catheters. Steady, moderate traction over time may provide a safer alternative to forceful subclavicular extraction, especially in chronically implanted deep septal leads. Further studies are warranted to evaluate the reproducibility, safety, and clinical applicability of this approach. 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

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

The demand for modified packaging materials increases annually. At the same time, there is growing interest in the development of functional packaging. The incorporation of modifiers, stabilizers, and fillers into polymer matrices can enhance the functionality of the material but may also negatively affect its safety. Polymers are susceptible to degradation, which negatively affects their strength and tensile properties under external factors (physical, chemical or environmental). Packaging containing antimicrobial and antioxidant agents is among the most promising, as it contributes to the product quality during storage. Films based on calcium carbonate (CaCO₃) and dihydroquercetin (DHQ) remain insufficiently studied, despite their potential. Such materials are especially relevant for fatty products with a large contact surface area, including butter, cheese, and other solid high-fat foods. This study aimed to comprehensively investigate the structural and tensile properties of polyethylene films modified with varying contents of CaCO₃ and DHQ. The films were produced via blown film extrusion using a laboratory extruder (SJ-28). Surface analysis was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Fourier-transform infrared (FTIR) spectroscopy was used to examine the film’s composition. The results showed that the introduction of more than 40.0 wt.% of CaCO₃ into the polymer base affected the strength properties. The conducted studies of the physical and mechanical properties of LDPE film samples filled with CaCO₃ showed significant changes in the samples containing more than 50.0 wt.% of the filler, with an increase in strength of more than 40.0%. The relative elongation at break after 50.0 wt.% decreased by more than 75.0%. These results indicate that to achieve the best strength properties for packaging materials, it is recommended to fill them to a maximum of 40.0 wt.%. The introduction of the antioxidant DHQ had almost no effect on the strength of the modified films. SEM analysis of films with high CaCO₃ content and DHQ revealed visible antioxidant particles on the film surface, suggesting enhanced antioxidant potential at the interface between the film and dairy products. AFM analysis confirmed that a CaCO₃ 40.0 wt.% content altered the surface roughness and heterogeneity of the films. FTIR spectroscopy revealed that the incorporation of CaCO₃ influenced the overall spectral profile of polyethylene, resulting in decreased peak intensities depending on the concentration of the filler. Based on these results, the modified polyethylene-based film with CaCO₃ and DHQ shows potential for use as food packaging with antioxidant properties. Full article

In view of the lack of accurate model in the discrete element study during straw comprehensive utilization (crushing, mixing, and baling), wheat straw was taken as the research object to calibrate the simulation parameters using EDEM 2023. The intrinsic and contact mechanical parameters of wheat straw were measured, and a test of the angle of repose (AOR), extrusion test and bending test were carried out. On this basis, a discrete element model (DEM) of hollow flexibility by using cylindrical particles was developed. The optimal combination of contact mechanical parameters was obtained through AOR tests based on the Box–Behnken design (BBD), coefficients of static friction, rolling friction, and restitution between wheat straw and wheat straw-45 steel are separately 0.227, 0.136, 0.479, 0.271, 0.093, and 0.482, AOR is 18.66°. Meanwhile, optimal combinations of bond contact parameters were determined by the BBD. The calibrated parameters were used to conduct extrusion and bending tests. Results show that the average values of peak extrusion force and peak bending pressure are 23.20 N and 3.92 N, which have relative discrepancy of 3.25% and 3.59% compared to physical test measurements. The results can provide model reference for the optimization design such as feed processing equipment, baler, and mixer. Full article

The integration of functional ingredients into 3D food printing formulations presents both opportunities and challenges, particularly regarding the printability and structural integrity of the final product. This study investigates the effect of incorporating omega-3 fatty acids encapsulated in pea protein into a model food gel composed of gelatin and iota-carrageenan. Four formulations with varying concentrations of encapsulated omega-3 (0%, 3%, 3.75%, and 6%) were evaluated for their rheological, textural, and printability properties. Rheological analysis revealed a progressive increase in storage modulus (G′) from 1200 Pa (0%) to 2000 Pa (6%), indicating enhanced elastic behavior. Extrusion analysis showed a reduction in maximum extrusion force from 325 N (0%) to 250 N (6%), and an increase in buffer time from 390 s to 500 s. Print fidelity at time 0 showed minimal deviation in the checkerboard geometry (area deviation: −12%), while the concentric cylinder showed the highest stability over 60 min (height deviation: 9%). These findings highlight the potential of using encapsulated bioactive compounds in 3D food printing to develop functional foods with tailored nutritional and mechanical properties. Full article

In this paper, dedicated material models were developed and verified for three melts of EN AW-7021 alloy, differing in zinc and magnesium content, for tube extrusion conditions. Based on the plastometric tests, it was found that in the studied range of strain parameters, the analyzed melts of the same aluminum alloy showed different sensitivity to strain rate and temperature. In addition, a significant effect of magnesium and zinc content on the plasticity of the tested material was observed. Therefore, dedicated material models describing stress changes were developed for each melt analyzed. The models were then implemented into the material database of the QForm-Extrusion^® program, which was used for the theoretical analysis of the industrial extrusion process. In order to verify the results of numerical calculations, industrial tests of the extrusion process were carried out. The force parameters and the rate of the extrusion process were mainly analyzed. The use of dedicated material models for each melt contributed to the accuracy of numerical modeling. A high degree of compliance was obtained regarding the theoretical and experimental extrusion force and the velocity of metal flowing out of the die cavity, among others. Full article

This study explored the potential of insect proteins as an alternative to traditional meat and bone meals in nutritionally balanced dry expanded dog food. Four formulations containing black soldier fly larvae meal (BSFL), cricket flour (CF), poultry meal (PM), or fish meal (FM) at 30% inclusion were evaluated using powder rheology, extrusion trials, and analyses of kibble expansion and texture. BSFL and FM had lower specific basic flow energy (<13 mJ/kg) compared to PM and CF (>14 mJ/kg), leading to better flowability and improved extrusion stability and product consistency. High fat and chitin contents in CF and BSFL, respectively, resulted in higher bulk densities (328–382 g/L) than meat-and-bone-meal-based products (304–306 g/L). The insect-meal-based kibbles also had either a fragile (peak crushing force < 7 kg for BSFL) or very hard texture (force > 13 kg for CF). Results from a second experiment showed that including BSFL meal at lower levels (10%) alongside poultry meal mitigated the negative effects on kibble quality while improving process stability. Overall, the study suggests that defatting and partial, rather than complete, replacement of traditional proteins with insect meal could be more viable strategies for producing consistent, high-quality extruded pet food. Full article

Hyaluronic acid (HA) dermal fillers represent a cornerstone of modern esthetic medicine, providing a minimally invasive solution for facial volume restoration and skin rejuvenation. However, the diversity of available products, each utilizing distinct crosslinking technologies, presents a challenge for objective comparison and clinical decision making. This study introduces a scientific framework to evaluate and categorize the physicochemical properties of HA fillers based on two key parameter groups: dynamic parameters (e.g., rheology and gel content) and consistency parameters (e.g., extrusion force, water uptake, and gel particle size). Using standardized methodologies, 23 commercially available fillers from five major manufacturers were analyzed, enabling cross-technology comparisons. The findings reveal how specific crosslinking approaches influence the rheological behavior, handling characteristics, and potential clinical applications. By offering an integrated and reproducible assessment, this work helps practitioners select the most suitable filler for individualized treatment plans and encourages manufacturers to enhance product transparency through harmonized testing protocols. Full article

Extrusion-based printers have attracted much attention for their simplified printing process and broader material compatibility. Carbon fibers (CF), known for their excellent mechanical properties, are incorporated into polypropylene (PP) printing materials. This study presents a shear screw printer (SSP) with a modified screw design. The SSP generates torsional shear forces, enabling helical orientation of CFs within PP/CF composites. The study also compares the SSP’s performance with that of a conventional screw printer (CSP). PP/CF composite specimens containing 15% CF were printed at four different layup angles: 0°, 45°, 90°, and ±45° (net). The results show that combining CFs’ helical orientation with a net printing arrangement can effectively enhance tensile properties while reducing anisotropy. Furthermore, this approach can significantly mitigate warping in printed parts. Full article