Resin Mold Research Articles

On the Fabrication Processes of Structural Supercapacitors by Resin Transfer Molding and Vacuum-Assisted Resin Transfer Molding

This study investigated the manufacturing processes for structural supercapacitors (SSCs) using smear molding (RS), resin transfer molding (RTM), and vacuum-assisted resin transfer molding (VARTM). Woven carbon fibers were used as the electrode, woven glass fibers as an insulating layer, and an alkaline/epoxy compound as the electrolyte. In the RTM process, due to the vacuum and the high-pressure injection of the electrolyte, the electrochemical and mechanical properties of the SSC can be greatly improved, and the void contents in the SSC can be reduced. The balanced electrochemical performance and mechanical properties of SSCs were observed in the range of epoxy content from 15 wt% to 30 wt%. This study contributes to the development of SSCs through the establishment of the fabrication process for improvements in part quality. The fabrication method demonstrated here can be directly applied by industries to produce even larger-scale SSCs, opening up new possibilities for practical implementation and scalability.

Effect of Screw Length in Volar Plating for Intra-articular Distal Radius Fractures: A Biomechanical Study

PurposeThe purpose of this study was to compare the effect of varying screw lengths on load to failure and retention of the dorsal ulnar corner fragment after fixation of comminuted intra-articular distal radius fractures in a cadaveric model. MethodsTwenty-four fresh frozen cadaveric forearms were subjected to a standardized distal radius osteotomy to mimic an intra-articular fracture pattern. Dual X-ray absorptiometry scans were performed to ensure minimal variability in bone density. All fractures were fixed with a volar locking plate and distal locking screws. Three different lengths of distal locking screws were used in each group of eight specimens to simulate the clinical decision of different distal screw lengths. The screw lengths tested were bicortical, 100% of the width of the bone but unicortical, and 75% of the width of the bone and unicortical. All specimens were preconditioned with cyclic axial loading and then axially loaded using matching acrylic resin molds to clinical failure and fragment displacement as detected by a motion analysis system. Retention or loss of the dorsal ulnar corner fragment during loading was recorded as a binary variable. ResultsBetween the three groups, there were no statistically significant differences in precycling stiffness, postcycling stiffness, load at 2 mm displacement of the dorsal ulnar corner, or force at failure. The group with 75% length screws had a significantly higher loss of reduction of the dorsal ulnar corner (86%) compared with the other groups (0%). ConclusionsVarying screw lengths did not affect the stiffness or overall loads to failure of axially loaded specimens. However, the 75% length screws did not reliably secure the dorsal ulnar corner fragments. Although this did not significantly affect the overall load to failure of the construct, displacement of this fragment may have implications for rotation of the forearm through the distal radioulnar joint. Clinical relevanceSurgeons should consider the utilization of full-length unicortical locking screws to ensure adequate fixation of the dorsal ulnar corner. Type of study/level of evidenceBiomechanical study V.

Repair Bond Strength of Composite Resin to Dental Ceramic Using Various Surface Treatments: An In Vitro Study

Abstract Aim: This research aims to evaluate and compare the effect of various surface treatments and adhesive types on the bond strength between composite resin and two types of ceramic materials. Materials and Methods: A total of 98 disk-shaped of 10 mm diameter and 4 mm thickness were fabricated for each of the zirconia (H. C. Starck) and lithium disilicate (IPS E-Max computer-aided design), which were implanted individually in the acrylic resin mold leaving one surface exposed. The disks in each group were sub-divided according to the surface treatments into seven groups (n = 14): [hydrofluoric acid (HF, 9.5%), air abrasion, bur, laser, HF + bur, HF + air abrasion, HF + laser]. Each sub-group was further divided into two groups (n = 7) according to the type of adhesive used for the repairing procedure [G-Premio Bond universal adhesive group and intraoral repair kit (BISCO) group]. Each adhesive was applied depending on manufacturer instructions and, then, the composite cylinder (4 mm in diameter and 4 mm in height) was built on the pre-determined treated ceramic surface area by the addition of rubber mold. Then the samples were stored in distal water for 24 h. After that, all groups were submitted to a shear bond test using an Instron testing machine (TSTM 02500; Elista Ltd., Istanbul, Turkey) at 0.5 mm/min a crosshead speed. The data were analyzed by three-way analysis of variance and Tukey post hoc test at (P ≤ 0.05). Results: The HF + air abrasion groups registered the higher bond strength but with no statistically significant difference from groups of HF + bur. While the laser groups showed the lowest mean bond strength. Generally, E-Max registered significantly higher bond strength in comparison to zirconia. Finally, the BISCO repair system registered a significantly higher bond strength value in comparison to G-Premio. Conclusion: Combined surface treatment of HF + air abrasion with an intraoral repair kit can provide a promising method for repairing cracked ceramic restorations. However, repairing lithium disilicate is more predictable and successful than zirconia.

3D-printed neck phantoms with detailed anatomy for ultrasound-guided procedure and device testing.

With rapid advances in ultrasound-guided procedures, there is an unmet need for echogenic phantoms with sufficient anatomical details for artificial intelligence and ultrasound-guided device testing. We developed a method for creating neck phantoms for novel otolaryngology-related device testing. To achieve accurate representation of the anatomy, we utilized CT scans and 3D printing technology to create customized agar molds, thus providing high-fidelity yet cost-effective tools. Based on previous studies, the key components in our neck phantom include the cervical vertebrae, trachea, common carotid arteries, internal jugular veins, thyroid gland, and surrounding soft tissue. Open-source image analysis software were employed to process CT data to generate high fidelity 3D models of the target structures. Resin molds were 3D printed and filled with various agar mixtures to mimic anatomical echogenicity. Following the method proposed, we successfully assembled the neck phantom which provided a detailed representation of the target structures. To evaluate the results, ultrasound data was collected on the phantom and living tissue and analyzed with ImageJ. We were able to demonstrate echogenicity comparable to that of living tissue. The proposed method for building neck phantoms with detailed anatomical features offers a valuable, detailed, low-cost tool for medical training and device testing in otolaryngology, particularly for novel devices that involve artificial intelligence (AI) guidance and robotic-based needle insertion. Additional anatomical refinements and validation studies could further enhance the consistency and accuracy, thus paving the way for future advancements in ultrasound training and research, and ultimately benefiting patient care and safety.

Comparative Evaluation of Surface Roughness and Color Stability Between Single-Shade Composite and Multi-Shade Composite: An In Vitro Study.

Introduction Composite resin materials are a popular choice for direct tooth-colored restorative purposes due to their excellent aesthetic qualities and versatility. The key determinants that impact the visual aspect of the restoration are gloss, surface roughness, and color stability. Research indicates that there is a direct correlation between the level of roughness on a composite resin surface and the likelihood of discoloration. The aim of this study was to compare and evaluate the surface roughness and color stability of a single-shade and multi-shade composite resin after subjecting it to toothbrush simulation and immersion in coffee and an aerated drink. Materials and methods Ten single-shade composite resinsand 10 multi-shade composite resins were packed into a Teflon mold and light cured. Pre-operative surface roughness values were evaluated using a surface profilometer. Toothbrush abrasion was simulated using a toothbrushing simulator. All these resin molds were then evaluated for initial color using a spectrophotometer machine (Konica Minolta, Japan). Five resin molds were then immersed in a beaker containing coffee for seven days and five resin molds were immersed into a beaker containing an aerated drink for seven days. Following this, the resin molds were re-evaluated for color stability using a spectrophotometer machine. Results The results of this study show that single-shade composite showed increased discoloration when compared with multi-shade composite resin. Also, there is a statistical difference between the single-shade composite and multi-shade composite when it comes to surface roughness and discoloration. Conclusion With the limitations of the present study, it can be concluded that single-shade composite resins have more discoloration potential in beverages than multi-shade composite resins.

Investigation of The Effect of Molding Material Difference on Design in GGG70 Ductile Cast Iron Production

The casting process involves filling a prepared mould cavity with molten metal, which takes the shape of the container. While the liquid metal takes the shape of the container it is in, the method is attractive, while the volumetric changes during the liquid-solid transformation reveal the importance of moulding design for the manufacture of solid parts. Especially in cast irons, moulds with the same design may produce different results depending on the changing casting and foundry conditions because the volumetric change that occurs during the solidification of ductile cast irons is affected by many parameters and develops differently than in steel and aluminium castings. This study used model wet and resin molding materials to create single and double-riser moulding and castings with different section thicknesses. The importance of the type of mold material used in castings and the number of feeders for the robust production of the cast part was evaluated using experimental and modeling techniques. When the results were examined, it was seen that the shrinkage risk was lower with resin mould than with green sand moulding. In addition, depending on the riser connection point, the importance of the riser neck has emerged.

Effect of polymerisation protocols on water sorption, solubility and hygroscopic expansion of fast-cure bulk-fill composite

ObjectiveThis study examines the effect of two light-curing protocols from a LED polywave light curing unit (LCU) on water sorption, solubility, and hygroscopic expansion of fast and conventional bulk-fill resin-based composites (RBCs) aged in distilled water for 120 d. MethodsThree bulk-fill RBCs materials were studied: Tetric PowerFill® (fast photo-polymerised composite) (TPF), Tetric EvoCeram bulk-fill (EVO), and GrandioSo x-tra bulk-fill (GSO) (conventional photo-polymerised composites). Specimens were prepared within a 3D-printed resin mold (8-mm diameter x 4-mm height) and light-cured from one side only with 2 modes of polywave LCU (Bluephase® PowerCure): 3 s mode and for 20 s in “Standard” mode. Water sorption and solubility were measured at fixed time intervals for 120 d of distilled water storage, then reconditioned to dry to measure desorption for 75 d, all at 37 ± 1 °C. Hygroscopic (volumetric) expansion was recorded at the same time intervals up to 120 d. Data were analysed through SPSS using Two-way ANOVA, One-way ANOVA, independent t-tests, and Tukey’s post-hoc correction tests (p < 0.05). ResultsTPF, when irradiated for 3 s demonstrated minimal water sorption (0.83%), solubility (1.01 μg/mm3), and least volumetric expansion (1.64%) compared to EVO and GSO. While EVO showed the highest water sorption (1.03%) and solubility (1.95 μg/mm3) at 3 s. GSO had the lowest sorption (0.67%) and (0.56%) in 3 s and 20 s protocols, respectively. Nevertheless, all the sorption and solubility data were within the ISO 4049 limits. SignificanceFor TPF, fast (3 s) polymerisation did not increase either water sorption or solubility, compared with 20 s irradiation. However, with the two comparative bulk-fill composites, fast cure increased water sorption by 15–25% and more than doubled solubility. These findings were consistent with the lesser volumetric expansions observed for Tetric PowerFill at both the fast and standard protocols, indicating its relative stability across polymerisation protocols.

Evaluation of thermal contact resistance of molten resin–mold interface during high-thermal-conductivity polyphenylene sulfide filling in injection molding

Evaluation of thermal contact resistance of molten resin–mold interface during high-thermal-conductivity polyphenylene sulfide filling in injection molding

Process Optimization of the Morphological Properties of Epoxy Resin Molding Compounds Using Response Surface Design.

An epoxy compound's polymer structure can be characterized by the glass transition temperature (Tg) which is often seen as the primary morphological characteristic. Determining the Tg after manufacturing thermoset-molded parts is an important objective in material characterization. To characterize quantitatively the dependence of Tg on the degree of cure, the DiBenedetto equation is usually used. Monitoring polymer network formation during molding processes is therefore one of the most challenging tasks in polymer processing and can be achieved using dielectric analysis (DEA). In this study, the morphological properties of an epoxy resin-based molding compounds (EMC) were optimized for the molding process using response surface analysis. Processing parameters such as curing temperature, curing time, and injection rate were investigated according to a DoE strategy and analyzed as the main factors affecting Tg as well as the degree of cure. A new method to measure the Tg at a certain degree of cure was developed based on warpage analysis. The degree of cure was determined inline via dielectric analysis (DEA) and offline using differential scanning calorimetry (DSC). The results were used as the response in the DoE models. The use of the DiBenedetto equation to refine the response characteristics for a wide range of process parameters has significantly improved the quality of response surface models based on the DoE approach.

Abstract 6035: Fluoride effects on thermal properties of irradiated dentin and enamel

Abstract Aim: Radiation therapy to treat oral cancer introduces various harms, including decreased hardness of dentin and enamel. Fluoride treatments, including silver diamine fluoride (SDF), have been used as a tool to combat these harms, but its influences on the thermal properties of dentin and enamel prior to and after radiation therapy are not well understood. Thus, this study analyzed how SDF influences the thermal stability of dentin and enamel that has been exposed to radiation therapy intended for head and neck cancer patients. Methods: Forty human posterior teeth were collected, cleaned of debris and soft tissue, and then mounted into acrylic resin molds. The teeth were divided into two equal groups, with one group being the control (no treatment) and the other group receiving SDF treatment. Using an X-Rad 320ix biological irradiator, all teeth were subjected to two grays of radiation therapy every day for six weeks. Afterwards, the dentin and enamel were pulverized a SPEX freezer mill. Samples were heated in a NETZSCH Thermal Analysis instrument, and the amount of carbon dioxide and water released was determined. All teeth were heated to 1429 °C from room temperature. Results: The SDF-treated dentin released the most carbon dioxide (49,611.82 ppm/mg), followed by irradiated dentin (47,672.76 ppm/mg) and untreated dentin (45,249.66 ppm/mg). In contrast, the SDF-treated enamel released less carbon dioxide (7,367.62 ppm/mg) than the control enamel (8,172.01 ppm/mg). The pattern of release of water was different from that of carbon dioxide. The control dentin group released the most water (45.56 ppt/mg), followed by the SDF-treated (39.72 ppt/mg) and irradiated dentin (23.51 ppt/mg). Similarly, the control enamel also released the highest amount of water (0.83 ppt/mg), as well as the highest amount of carbon dioxide. The SDF-treated enamel released around 65% of the water compared to the control enamel group (0.54 ppt/mg). Furthermore, the irradiated dentin had the largest heat reversal temperatures for carbon dioxide (85.19 °C) and water (86.57 °C). Conclusions: The impacts of SDF treatment and radiation vary between dentin and enamel. Comparatively, dentin has a higher content of combustible material than enamel. Radiation treatment reduces the water content of both enamel and dentin, which may make teeth more susceptible to fracture. Therefore, regular dental check-ups and frequent fluoride treatment to increase the strength of the teeth are recommended for patients undergoing radiation therapy. Citation Format: Rachel J. Kulchar, Yusuke Kakiuchi, Vania Sanchez-Gamarra, Jie Deng, Francis Mante. Fluoride effects on thermal properties of irradiated dentin and enamel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6035.

Comparative Analysis of Strength of Differently Activated Denture Base Materials Including Recent Acetal Resin-Based Biodentaplast.

The aim of this study is to comparatively analyse the compressive and tensile strength of different types of record base materials made of different materials and processing techniques. The compressive and tensile strength of 4 types of injection moulded materials were compared with a control of conventional compression moulded material. Twenty test specimens (10 tensile and 10 compressive) were fabricated from each material. A test was done using the Instron 3382 (Norwood, MA, USA) universal testing machine. Compressive and tensile test values showed significant differences between the record base resin groups tested for both compressive and tensile strength tests (p=0.00). The mean tensile strength value was greatest for Group V (66.0 MPa) and lowest for Group III (41.9MPa) and the mean compressive strength value was greatest for Group I (74.5 MPa) followed by Group V (70.2 MPa) and lowest for Group III (10.8 MPa). Injection moulded acetal resin showed the highest tensile strength value; it was comparable to that of conventional compression moulded polymethyl methacrylate (PMMA). Compression moulding is reported to have the highest compressive strength values followed by injection moulded acetal resin material. Injection moulded acetal resin material attributed to its advantages and superior strength value, can be used as a material of choice in various clinical scenarios.

Simulation and Process Analysis of DLP 3D Printing with High-strength Resin

By utilizing digital light processing (DLP) printing equipment and technology, this study investigates the temperature field, stress changes, and the impact of various process parameters on the formation and strength characteristics of high-strength resin during the printing process. Abaqus birth-death element method simulation and related process tests are employed for this purpose. The simulation results demonstrate a gradual decrease in the temperature field through wavy diffusion from the center to the boundary during printing. The node temperature, displacement, and stress curves are observed to fluctuate frequently due to the subsequent printing layers, with the maximum stress point located close to the printing platform. The experimental results reveal that the test parameters possess different effects on the surface quality and tensile strength. Inappropriate parameters tend to result in surface defects. The influencing factors on the tensile strength of the sample are ranked in the following order: layer thickness, exposure time, and exposure light intensity. The molded resin sample achieves a tensile strength of 58.5MPa, which is comparable to the tensile properties of traditionally injection-molded parts.

Evaluation of fracture resistance of teeth with Class II Mesio-Occluso- Distal cavities restored by three different esthetic restorative materials: An In-vitro study

Aim - The aim of present investigation was to assess fracture resistance of teeth with Class II Mesio-Occluso-Distal (MOD) cavities filled with Microhybrid composite, Nanohybrid composite and Cention-N. Materials and Methods - 40 extracted maxillary premolars were kept in 0.1% thymol solution for 7 days, then subsequently in normal saline until use. All specimens were embedded 2mm below Cemento-enamel junction (CEJ) in self cure acrylic resin molds. They were then arbitrarily divided in 4 groups, each with 10 specimens (n=10). Group 1 consisted of intact teeth (Control group), whereas Group 2,3 and 4 contained prepared teeth with standardized class II MOD cavities filled with Microhybrid composite, Nanohybrid composite and Cention-N respectively. All the specimens were finished using composite finishing &amp; polishing kit and were stored in 100% humidity at 37℃ for 24 hours. Each specimen was subjected to Fracture resistance (N) under Universal Testing Machine. Data collected was subjected to One-way analysis of variance and then subsequently to Tukey’s post-hoc test. Differences in groups were considered significant at p ≤ 0.05. Results - The results showed that Cention-N exhibited highest fracture resistance whereas Microhybrid composite had least fracture resistance when compared to other restorative groups. Conclusion - It can be inferred that Cention-N can be preferred for restoration of Class II MOD cavities in maxillary premolars over Nanohybrid composite or Microhybrid composite. Keywords - Cention-N, fracture resistance, Mesio-Occluso-Distal cavities, Microhybrid composite, Nanohybrid composite, Universal testing machine

Minimal-surface-based multiphase metamaterials with highly variable stiffness

Variable-stiffness materials have a unique ability to change their stiffness reversibly in response to external stimuli or conditions. However, achieving ultrahigh stiffness change is often constrained by the geometric organization of the microstructures in most materials that exhibit variable stiffness. Therefore, to overcome this limitation, we introduce a metamaterial design inspired by triply periodic minimal surfaces for fabricating multiphase metamaterials. The specific geometric features of minimal surface designs facilitate interlocking bi- or tri-continuous interpenetrating phases such as air, resin, and alloy within a single multiphase metamaterial. These multiphase metamaterials are constructed by injecting a low-melting-point alloy (LMPA) into a 3D-printed elastic resin mold. The thermally-induced solid-liquid phase transition of the LMPA governs the stiffness change in multiphase metamaterials, ranging from Kilopascals to Gigapascals. Further contributing to this phenomenon, the superior resilience of the elastic resin enhances the shape-memory effect of the multiphase metamaterials. Applications of these materials in origami and deployable structures have been successfully demonstrated, highlighting their reconfigurability and volume compressibility. This innovative design strategy provides the foundation for crafting other metamaterials with intricately arranged internal phases. In conclusion, the proposed multiphase metamaterials have promising potential for various engineering applications where adaptability and morphing capabilities are essential.

Anti-Adhesive Surfaces Inspired by Bee Mandible Surfaces.

Propolis, a naturally sticky substance used by bees to secure their hives and protect the colony from pathogens, presents a fascinating challenge. Despite its adhesive nature, honeybees adeptly handle propolis with their mandibles. Previous research has shown a combination of an anti-adhesive fluid layer and scale-like microstructures on the inner surface of bee mandibles. Our aim was to deepen our understanding of how surface energy and microstructure influence the reduction in adhesion for challenging substances like propolis. To achieve this, we devised surfaces inspired by the intricate microstructure of bee mandibles, employing diverse techniques including roughening steel surfaces, creating lacquer structures using Bénard cells, and moulding resin surfaces with hexagonal patterns. These approaches generated patterns that mimicked the bee mandible structure to varying degrees. Subsequently, we assessed the adhesion of propolis on these bioinspired structured substrates. Our findings revealed that on rough steel and resin surfaces structured with hexagonal dimples, propolis adhesion was significantly reduced by over 40% compared to unstructured control surfaces. However, in the case of the lacquer surface patterned with Bénard cells, we did not observe a significant reduction in adhesion.

Accuracy of fit for cobaltchromium bar over two implants fabricated with different manufacturing techniques: an in-vitro study

ObjectiveThe purpose of the invitro research was to compare the fit of Cobalt Chromium customized bar fabricated with different manufacturing processes cast metal bar, milled bar and 3D printed bar using scanning electron microscope.Materials and methodsClear epoxy resin molds were prepared. In each mold two parallel implants with a 14 mm distance from each other were embedded. Thirty Co-Cr custom bars were constructed and were divided equally into three groups: Group (I) (Co-Cr conv), group (II) milled bar (Co-Cr milled), and group (III) printed bar (Co-Cr print). The marginal fit at implant-abutment interface was scanned using scanning electron microscope (SEM).ResultsThere was a significant difference between the three studied groups regarding marginal misfit the between implant and fabricated bars with p-value < 0.001. The highest value of micro-gap distance was found in Co-Cr conventional group (7.95 ± 2.21 μm) followed by Co-Cr 3D printed group (4.98 ± 1.73) and the lower value were found in Co-Cr milled (3.22 ± 0.75).ConclusionThe marginal fit of milled, 3D printed and conventional cast for Co-Cr alloy were within the clinically acceptable range of misfit. CAD/CAM milled Co-Cr bar revealed a superior internal fit at the implant-abutment interface. This was followed by selective laser melting (SLM) 3D printed bar and the least fit was shown for customized bar with the conventional lost wax technique.

Water Sorption in Hybrid Polyester/Glass/Jute Composites Processed via Compression Molding and Vacuum-Assisted Resin Transfer Molding.

The aim of this work is to analyze water sorption in hybrid polyester/glass fabric/jute fabric composites molded via compression and VARTM (Vacuum-Assisted Resin Transfer Molding). The laminates were produced with five different stacking sequences and subjected to water sorption testing at room temperature, 50 °C and 70 °C. This study consisted of two stages: experimental and theoretical stages. The composites had a fiber volume content ranging from 30% to 40%. Water absorption and diffusion coefficient in the hybrid composites were intermediate to those reinforced with a single type of fiber. There were no significant differences in these properties based on fiber arrangement once the composites reached saturation. Diffusion coefficient values were higher for specimens with jute fiber on at least one of the outer surfaces. Water sorption rates increased with higher immersion temperatures. The water sorption at saturation point was not affected by the manufacturing process. Among the hybrid composites, those with jute on the surfaces showed the highest diffusion coefficient, while those with glass on the surface had the lowest values. Higher diffusion coefficient values were observed at temperatures of 50 °C and 70 °C. The main influencing factors on the absorbed moisture content for composites are the presence and content of jute fibers in the system and the immersion temperature. The manufacturing process does not affect the water sorption at saturation point.

“Generating a eco friendly reinforced composite using human hair and analyzing it for commercial use”

This paper delves into the development and characterization of natural hair fiber-reinforced polymer composites, with a focus on their physical and mechanical attributes. Composite materials encompass ceramic matrix composites (CMC), metal matrix composites (MMC), and polymer matrix composites (PMC), with PMC being favored for its cost-efficiency and ease of production, notably employing thermoplastic polymers for recyclability. Natural fibers are gaining traction, especially in the automotive industry across Asia and Europe, due to their low density and environmental friendliness. Human hair stands out as a reinforcing material owing to its impressive tensile strength, sustainability, abundance, and keratin content. The paper addresses challenges linked to natural fibers in composites, including moisture resistance and dimensional availability. The research involves creating composites using human hair fibers, epoxy resin (polypropylene), and specific molds, varying hair fiber percentages. Detailed methodology covers materials, equipment, mold prep, specimen prep, and mathematical modeling. Tensile, flexural bending, and impact strength tests reveal insights into composite mechanics. Hair fiber additions strengthen the polymer matrix, particularly at 5 to 15 weight percentages, though flexural strength diminishes compared to non-reinforced composites. Higher hair fiber percentages enhance hardness. In conclusion, this study showcases human hair fiber's potential as a reinforcement in polymer composites, emphasizing the need for further exploration of matrix-fiber adhesion to boost composite performance. These findings contribute to the growing interest in natural fiber composites for sustainable and economical applications.

A novel recycling framework for transforming uncured aerospace prepreg offcuts into a strand-based compression moulding compound with adjustable flow-compaction and curing behaviours

Aerospace composites manufacturers discard anywhere from 30 to 50% of their uncured prepreg during the ply-cutting phase of manufacturing. This waste is attributed to nesting pattern inefficiencies caused by restrictive production schedules, fixed prepreg roll widths, and limited material out-life. Previous studies have explored the possibility of transforming offcuts into strand-based compression moulding compounds, but have been limited by the processing mismatch between autoclave curing and compression moulding. This article introduces a recycling framework which employs comprehensive material characterization and targeted elevated temperature staging to produce a recyclate with tailorable processing characteristics without the need for additional resins or fillers. The influence of resin viscosity on prepreg flow-compaction is presented and a software tool is introduced which generates process maps for selecting optimal staging based on desired moulding temperature, cure time and resin viscosity.

Interfacial Behavior Between Mold Resin and Sputtered Film Deposited on Electromagnetic Shield Packages

Interfacial Behavior Between Mold Resin and Sputtered Film Deposited on Electromagnetic Shield Packages