Hydraulic Press Research Articles

Influence of Silicon Carbide Incorporation on Thermal and Ablation Properties of Carbon Fabric-Phenolic Resin Composites

To shield re-entry spacecraft from the extreme heat experienced during hypersonic flight through a planet's or the earth's atmosphere, thermal protection systems (TPS) were developed. This work involved the fabrication of composites using a polyacrylonitrile (PAN) based carbon fabric (Cf)-phenolic resin matrix (PR) modified with different weight percentages (wt.%) of silicon carbide (SiC), namely 0 wt.% (Cf/PR), 1wt.%, 3wt.%, and 5wt.%. The composites were prepared using the hydraulic hot press method. The manufactured composites were analyzed for their thermal conductivity and resistance to ablation using an oxyacetylene torch test. Furthermore, the ablated composites underwent X-ray diffraction (XRD), revealing a SiO2 compound layer on the ablated composite surface. The experimental results demonstrated that the Cf/PR composites modified with 3wt.% of SiC exhibited superior characteristics. The composites consist of 3wt.% Cf/PR-SiC exhibited a thermal conductivity value of 0.57 W/m K. Additionally, these composites showed a noticeable decrease in the mass ablation rate (MAR) at 0.0052 mm/sec and linear ablation rates (LAR) at 0.025061 gm/sec. This study proposed an effective way to improve the thermal and ablation characteristics of TPS materials.

Mechanical, thermal, and water absorption properties of HDPE/barley straw composites incorporating waste rubber

This study investigates the mechanical, thermal, and water absorption properties of high-density polyethylene (HDPE) composites filled with barley straw and varying amounts of waste rubber. The research aims to develop sustainable materials that repurpose agricultural and industrial waste while addressing resource scarcity and waste management challenges. Composites were prepared using a twin-rotor mixer and hydraulic press, with waste rubber content varying from 0 to 20 wt%. Mechanical properties were evaluated through tensile testing, thermal behavior was analyzed using TGA, DTG, and DSC, and long-term water absorption was measured. Results show that increasing waste rubber content from 0 to 20% led to a decrease in tensile strength (11.3 to 8.9 MPa) and tensile modulus (1760 to 790 MPa), while relative extension increased (2.4–5.9%). Thermal analysis revealed a slight reduction in onset degradation temperature (270 °C to 240 °C) and increased char residue (8–18%) with higher rubber content. Water absorption decreased significantly, from 12 to 13% to 6–7% after 600 h of immersion, as waste rubber content increased. These findings demonstrate that incorporating waste rubber into HDPE/barley straw composites results in materials with enhanced flexibility and water resistance at the cost of some strength and stiffness. In conclusion, the results of this study offer a clear pathway for the development of sustainable polymer composites that have broad potential applications across industries like construction, marine infrastructure, automotive, and packaging. By replacing traditional, resource-intensive materials with eco-friendly alternatives, these composites not only provide functional benefits but also support global efforts toward sustainable development and environmental conservation.

Efficiency of Ceramic Composite Filter Produced Using Nano Particulate Carbonaceous Material

Millions of people have no access to safe water. This has led to continued incidence of waterborne diseases with severe cases of complications and sometimes death. Attempts to use silica sand-based materials for the production of filters by researchers are still evolving. In this study a novel hybrid clay-nanoparticulate agro-waste blend water filter with appropriate pore size and flow rate for contaminant-free water filtration was produced. The composite filters were produced using hydraulic pressing and sintering process. Four different ratios of clay, activated carbon and nanoparticle coconut shell (60:30:10, 60:20:20, 60:10:30, and 60:0:40 wt %) were mixed and fired at 700 °C, 750 °C, 800 °C, 850°C, 900 °C, 950 °C, and 1000 °C respectively at the rate of 75 °C/hr. E. Coli, Total Coliform, and turbidity tests were carried out on the influent water collected from Lagos Lagoon, and effluent water samples were filtered using the produced samples. The result of water tests revealed that all the filters produced removed between 86.81 % to 99% Escherichia Coliform (E. coli), and 81.81% to 93.31%% total coliform in the water sample. The blend of 60:10:30 fired at 850 °C and 900 °C showed improved properties with a flow rate value of 2.83 l/hr and 2.77 l/hr. In conclusion, the study established that synthesis of nanoparticle coconut shell and activated carbon is a suitable material for producing clay composite filters that can purify water to Nigerian Standards for Drinking Water Quality (NSDWQ) acceptable level.

Protocols for bulk off-line fluid inclusion extraction for the analysis of δ13C-CH4 and δ13C-CO2 using a cavity ring-down spectroscopy (CRDS) analyser

Fluid inclusions are a window into deep geological fluids, providing unique access to their nature and composition. The isotopic composition of CO2 and CH4 hosted in fluid inclusions is a powerful proxy to assess the origin and transformation of deep geological fluids, giving insights into carbon sources, fluxes, and degassing in a wide variety of geodynamic settings. Over the last 5 decades, techniques have been developed to extract fluid inclusions from their host minerals and measure their bulk composition. These techniques are often challenged by analytical artifacts including high blank levels of CO2 and CH4, fluid re-speciation, gas adsorption, and diffusion. Since these processes may alter the pristine composition of gases liberated from fluid inclusions, rigorous protocols are needed in order to evaluate the isotopic integrity of the extracted volatile species. In this study, we introduce new protocols for bulk off-line fluid inclusion extraction for the analysis of δ13C-CH4 and δ13C-CO2 using a Cavity Ring-Down Spectroscopy (CRDS) analyser (Picarro G2201-i). Two mechanical fluid extraction techniques are compared: ball milling in ZrO2 jars and sample crushing in a stainless steel sealed tube under a hydraulic press. Blanks and isotopically labelled tests with the ball milling technique suggest that rotation speed, grinding stock filling degree and filling type alter the CH4 and CO2 concentrations and isotopic compositions measured by the CRDS analyser. In contrast, the crushing technique does not generate measurable quantities of blank CH4 and CO2. The protocols presented in this study allow to extract, detect, and analyse δ13C of CH4 and CO2 for concentrations above 10 and 1,000 ppm respectively. Interlaboratory experiments allowed to replicate previously measured δ13C-CH4 values in natural fluid inclusions within 1‰ with both extraction techniques. This study highlights the potential of combining simple bulk off-line fluid inclusion extraction techniques with a CRDS analyser for δ13C analysis of CO2 and CH4 without gas separation being required.

Do Video Games Enhance Competencies & Skills? Study Case: Civil Engineering Students

The following article is a text that shows the relevance of including video games as part of an academic technique that promotes coexistence, communication, teamwork, develop some skills, competencies, and creativity among members of the university community -professors and students-. The objective of this research is to show the results obtained in a dynamic organized by the Civil Engineering department of a private university in Puebla, Mexico. The idea is to hold a private session and play “Call of Duty: Warzone II”. It should be noted that with this activity the students can learn a specific content, in this case, the analysis of a hydraulic press, how it is built and how it works. In addition, the activity carried on, helped to create a better bond between teachers and students, but above all, showed the possibilities to generate greater interest in learning and to get the students actively involved in one topic. The theoretical framework on which this research lies in the following topics: Game-Based Learning -GBL-, innovative education focused on video games as community generators, and the importance of the development of certain skills among college students. The methodology that this study has, is quantitative. Particularly, a questionnaire -Likert scale-, is carried out to the students who participated in this dynamic. The main results show that the people who were in the virtual session are excited to interact under another type of scenarios that goes beyond the classroom, and that “breaking” the barrier between teacher and alumni becomes a differentiating and innovative element. In educational matters, they consider that the learning obtained from a video game is something that they had not contemplated; Added to this, the students ensure that working as a team, communicating their needs and doubts between peers, and getting involved in this kind of forums helps generate greater interest in engineering and acquire new knowledge. Finally, it can be concluded that video games nowadays are an indispensable tool not only to foster an online community but to take the teaching and learning process to another level.

Antibacterial performance of biodegradable polymer and hazelnut husk flour antibacterial biofilm with silver nanoparticles

The antibacterial performance of biocomposite films prepared from lignocellulosic waste (hazelnut husk or hazelnut leafy green cover) modified with silver nanoparticles and polylactic acid (PLA) was determined. The amount of hazelnut husk in the PLA matrix ranged from 10 to 40% by weight in 10% increments. The composite pellets were produced using a twin-screw extruder. Biocomposite films of 0.6 mm x 40 mm x 200 mm were produced from the pellets in a laboratory hydraulic hot press. The surfaces of the modified hazelnut husk and biocomposite specimens were analyzed by scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectrometry (ICP-OES). The antibacterial activity of the biocomposite films against Staphylococcus aureus bacteria was determined using the ASTM E 2149 (2020) method. The antibacterial activity of the biocomposite films increased noticeably with the addition of hazelnut husk modified with the silver nanoparticles. Compared to the pure PLA film, the biocomposite films with 10 wt% modified husk flour showed the lowest antibacterial activity (31.3%) against S. aureus over 24-h while the films with 40 wt% showed the highest antibacterial activity (99.9%). The biocomposite films made of hazelnut husk flour with silver nanoparticles and PLA matrix could be considered for food packaging applications.

Analisis kekuatan pembebanan frame mesin press hidrolik kapasitas 3 ton

This study examines the safety and stress factors to determine the maximum dynamic load that can be supported by the press machine frame. Dynamic loads occur due to the working mechanism of the press machine that presses the bearing. Stress analysis test simulation using the Solidwork 2020 computer program with the finite element method in the simulation test of the hydraulic press machine frame material structure with dynamic load treatment. The frame design model uses U-profile iron material UMP 50 with a thickness of 3-5mm with dimensions of 50 mm x 38 mm. The simulated variable load is 3000 kg. The simulation results show the yield strength of the material = 521.927 N / m² (Mpa) and the stress, displacement, strain values ​​at a load of 3000 kg = simulation Stress = 620.422 N / m² (Mpa), Displacement = 1.232mm, Strain = 0.001. The von Mises stress value is 29,500 N = 620.422N; 521.927 N = 1.88. The simulation results show that the hydraulic press machine frame design has a safety factor of 0.001 and can withstand dynamic loads of up to 3000 kg.

Perancangan Perancangan Sistem Trasmisi Mesin Pres Hidrolik Kapasitas 3 Ton Dengan Penggerak Motor listrik

Technological advances have encouraged improvements in the industrial sector in developing countries, including Indonesia. This is of course supported by several factors, including the use of modern equipment as a substitute for human labor. It can be said here that the more modern an industry is, the more machine power is used while the less human power is needed. As human needs become increasingly greater, the machine industry is currently also developing very rapidly. Developments in the industrial sector are marked by the creation of various types of machines that can assist human activities. The use of machines can help human activities or work to be more efficient in terms of completion time, as well as reducing the risk of work accidents. Currently, machines are used as tools that have high automation and precision. Therefore, many people use machines for everything, one of which is a pressing machine. A pressing machine is a tool made to compress or press an object, the power source can come from hydraulics, human power, electric motors and others. The aim of this final project is to design a transmission system for a 3 Ton Semi-Automatic Hydraulic Press Machine with an electric motor drive. It can increase the author's knowledge, insight and experience regarding planning a machine. Conclusion Ball bearings with type 6203 require an installation time of 1 minute 35 seconds and removal of 1 minute 32 seconds. Ball bearings of type 6305 receive a pressure of 400 psi to be installed on the shaft, and when released the pressure produced is the same, namely 400 psi to be able to leave the shaft. A type 6206 ball bearing with a shaft length of 77 mm takes 3 minutes 32 seconds to install, while the same shaft length takes 3 minutes 22 seconds to remove from the shaft.

Peningkatan teknologi bagi agroindustri pliek-u sebagai upaya pelestarian kearifan lokal di Aceh [Technology improvement on pliek-u agroindustry as an effort to maintain a local wisdom in Aceh

Pliek-u is a specialty food product in Aceh with local wisdom values that should be preserved. The Program of Community Service Based Product (PKMBP) aimed to improve the pliek-u agro-industry by adapting simple processing technologies so that it could lighten work, produce quality products, and attract the interest of the younger generation as pliek-u entrepreneurs in future. The method applied consist of surveys, preparation of tools and materials, assembly of a solar tunnel dryer type Hohenheim Aceh and a hydraulic press, training and dissemination of technology through field schools, and evaluation of the program with pre-tests and post-tests. Data analysis was carried out using the Wilcoxon rank test with alpha of 5%. The results of the program were the construction of 1 unit of Hohenheim Aceh tunnel dryer, 1 unit of hydraulic press, and the implementation of training and dissemination activities which have been published in the form of videos on YouTube media and press releases through online media. The results of the Wilcoxon rank test also showed that of the 13 participants whose data were valid, 100% of participants received positive rankings and the pre-test scores were significantly different from the post-test scores. Thus, it can be concluded that the program carried out has contributed to increasing the knowledge, expertise capacity, and interest of participants in pliek-u processing technologies since the profile of conventional agroindustry can be transformed to be better agroindustry by the use of solar tunnel dryer type Hohenheim Aceh and hydraulic press. In addition, the use of technologies will ensure the halal requirement of pliek-u.

Synthesis and characterization of metakaolin-based geopolymers doped with CRT waste glass for radiation shielding applications

This study presents the influence of CRT glass on the gamma-ray interaction processes in metakaolin-based geopolymers. Four batches of G-CRT composites (namely, G, G-10CRT, G-20CRT, and G-30CRT, which represent geopolymer (G) samples doped with 0, 10, 20, and 30 wt% of CRT glass) were prepared using the cold hydrostatic press method. The mass attenuation coefficients of the prepared C-xCRT samples were computed using XCOM and FLUKA simulations for photons within the energy range of 15 keV–15 MeV. The density of the pristine geopolymer increased from about 1.86 g/cm3 to 2.09, 2.26, and 2.34 g/cm3 for G-10CRT, G-20CRT, and G-30CRT, respectively. The photon mass and linear attenuation coefficients of the geopolymers increased with CRT glass concentration. The half-value layer and mean free path were within the ranges 0.070–18.079 cm and 0.101–26.083 cm for G; 0.036–15.110 cm and 0.052–21.799 cm for G-10CRT; 0.024–13.197 cm and 0.014–19.039 cm for G-20CRT; and 0.018–12.074 and 0.026–17.419 cm for G-30CRT. The G-30CRT had the best gamma attenuating prowess in contrast to other G-xCRT. CRT-rich G-xCRT had a higher effective atomic number. For 10 mm thick geopolymer, the absorbed dose rates were 0.211 μR/h, 0.66 μR/h, 1.11 μR/h, and 1.55 μR/h for G, G-10CRT, G-20CRT, and G-30CRT, respectively, for 100 keV photons. The introduction of CRT glass into the geopolymer matrix improved their photon interaction cross-section. The geopolymers showed outstanding photon interaction ability compared to ordinary concrete and some shielding glasses at low photon energies. The CRT glass-doped geopolymer samples are useful for preparing radiation shielding concrete.

Development of cement slurries with additives of nanoclay particles for the construction of oil wells at elevated temperatures

Relevance. Strength decrease is a phenomenon that becomes more pronounced as the temperature rises above 110°C. It is characterized by significant chemical and microstructural changes that Portland cement undergoes at high temperatures. Adding silica particles (SiO2) to cement can significantly increase cement resistance to strength reduction when the temperature exceeds 110°C. Nanoclays are currently used in the cement industry to increase the strength of the cement matrix due to their ability to fill capillary micropores and due to their relatively small particle size. Aim. To investigate the effect of adding nanoparticles (nanoclay) to Saudi grade G cement on compressive and tensile strength, and cement stone permeability under high temperature conditions (300°С). Objects. Six samples of cement mortars with different concentrations of nanoclay, cement stones from, tested after 7 and 28 days of hardening at 25 and 300°C. Methods. Cement chemical composition was evaluated by the X-ray fluorescence method with the WORKSTN-V Olympus Vanta X-ray fluorescence analyzer. Cement physical composition was evaluated by the method of ray diffraction on the Mastersizer 2000 laser particle size analyzer. The test of the grouting stone samples was carried out in accordance with ISO 10426-2:2003 on a hydraulic press 65-L1132. The tensile strength of the samples by the Brazilian method was tested in accordance with ASTM D 3967-08 standard on a hydraulic press 65-L1132. The permeability of the samples was determined by single-phase stationary filtration at a facility for studying the filtration and capacitance properties of the PIK-OFP-UCH core in accordance with ISO 10426-2:2003. Results. The data obtained showed that cement destruction at extremely high temperatures can be avoided by using nanoclay (up to 3% by weight of cement). The microstructure of the cement matrix was significantly affected due to the aggregation of nanoparticles when more than 3% of nanoclay was added. All rheological characteristics of the cement slurry were improved by the addition of nanoclay particles.

Effect of the mechanical densification process in wood material on the surface adhesion strength of varnishes

This research aimed to determine the impact of the mechanical densifying process of wood material on the varnish surface adhesion strength. Specimens from black pine (Pinus nigra) and Uludag fir (Abies bornmuelleriana Mattf.) were subjected to densification in a hydraulic press at 140 °C to the extent of 25% and 50% in the radial direction. While densification increased the surface adhesion strength of the varnish layer in black pine, the value decreased in fir. Regarding the interaction between densification ratio, surface treatment, and wood type, the highest surface adhesion strength of the varnish layer was found in black pine + unsanded surface + 25% densification, and the lowest was in Uludag fir + unsanded surface + 50% densification. It can be stated that the densification process creates high adhesion values for the polyurethane varnish in the black pine wood type. The sanding process has an intensifying effect on these values, and the products that were obtained from the polyurethane varnished samples do not require sanding. Considering these situations can provide significant advantages in projects with wood materials subjected to the densification process.

Electro-Mechanical Behavior of Copper-Based Electrical Motor Brushes

This study was mainly performed in order to examine the properties of electric motor brushes (EMB). EMBs are electrically conductive and work under wear conditions due to direct contact with the moving part (rotor) of electric motors. In accordance with the scope of the study, EMB characteristics were investigated in two different groups and reproduced with a new technique at the end of this phase. New EMBs were produced via varying proportions of copper matrix, graphene, and silicon carbide reinforcements. The composite-alloy powder elements were carefully squeezed by a cold and single-axis hydraulic press under a pressure of 500 MPa (±5 MPa) following 8 hours of mechanical alloying (MA). The molded composite product (sample) was sintered at 900° C for 1 hour in a reducing gas atmosphere. 100 kPa spring pressure was tested on each sample thrice with 8, 16, 24, and 32 m/s rotational speeds and densities of 4, 8, 12, and 16 A/cm2. Following this process, the electrical conductivity, porosity, hardness, wear loss, surface roughness, and temperature changes were investigated for each sample. It was determined that the electrical conductivity decreased with increasing reinforcement ratio and, in terms of electrical conductivity, affected the brushes’ properties negatively.

Reconstituted Bamboo Scrimbers Prepared from Bambusa tulda with Phenol Formaldehyde (PF) Adhesive for Structural Applications

Abstract: This study investigates the physical and mechanical properties of reconstituted bamboo scrimbers prepared from Bambusa tulda bamboo, also known as Indian timber bamboo or Bengal bamboo. The preparation involves varying pressure levels (21.0, 24.5, 28.0, and 31.5 kg/cm2 ) with phenol formaldehyde (PF) adhesive using a hydraulic hot press. The study explores the change in mechanical and physical properties of bamboo scrimbers under varying specific pressures, which significantly reduces moisture content, increases density, and enhances resistance to water absorption and swelling. Mechanically, it improves properties such as modulus of rupture (MOR), modulus of elasticity (MOE), compression parallel to the grain, hardness, and screw-holding capacity. The results position the reconstituted bamboo scrimbers in the super group (IS:3629-1986) in stress grading (MOR & MOE) at all tested specific pressures, surpassing raw bamboo strength properties as well as conventional standard timber, including Teak (Tectona grandis). The results demonstrate remarkable properties comparable to species like Sal (Shorea robusta), Khair (Acacia catechu), and Teak (Tectona grandis) in various mechanical properties. This research highlights the potential of bamboo-based materials over conventional timber in construction and for sustainable development. Future studies on different adhesives and pressure levels could further enhance their economic sustainability.

Ultrasonic diagnostics of concrete destruction under the influence of corrosion environment

Introduction. Modern methods of studying the corrosion damage of concrete are quite lengthy and time-consuming, which makes their use difficult. This necessitates the search for new approaches to study the destruction of concrete under the influence of aggressive media. Currently, the ultrasound diagnostic method is effectively used to identify various structural defects, but the possibility of its use for concrete corrosion studies is poorly understood. This work is devoted to filling this gap.The methods of research. Concrete samples of 2.5x2.5x10 cm and 2.5x2.5x16 cm of various composition (cement: placeholder = 1:9, 1:7, 1:5). The control samples hardened under normal conditions, the test samples were stored in various aggressive environments. The samples of all storage media were subjected to periodic tests on the Pulsar-2.2 ultrasound diagnostic device. In parallel, the strength parameters obtained by the destructive method on the PGM-100MG4 hydraulic press, as well as the resistance coefficient, were determined.Results. The relationship between the growth periods, extremes and abrupt changes in the velocity of passage of ultrasonic waves and the stages of strength gain, the conditions of hardening of samples, and time factors has been established. It is shown that ultrasound diagnostics is quite sensitive to the processes caused by the corrosion destruction of concrete and allows us to obtain reliable data, while the strength and coefficient of resistance do not always adequately reflect the development of corrosion processes. It has been established that the use of ultrasound diagnostics makes it possible to increase the reliability of the results of concrete corrosion studies.Conclusion. The use of the ultrasound diagnostic method enables to obtain new data on the processes of concrete destruction under the influence of aggressive media, which makes it possible to increase the reliability of the results of concrete corrosion studies.

Thermally Active Medium-Density Fiberboard (MDF) with the Addition of Phase Change Materials for Furniture and Interior Design.

No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth's climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. Phase change materials (PCMs) can store and release heat when it is abundant during the day (e.g., from solar radiation), for use at night, or on chilly days when buildings need to be heated. As a consequence, buildings use less energy to heat and cool, which lowers greenhouse gas emissions. Consequently, research on thermally active medium-density fiberboard (MDF) with PCMs is presented in this work. MDF is useful for interior design and furniture manufacturing. The boards were created using pine (Pinus sylvestris L.) and spruce (Picea abies L.) fibers, urea-formaldehyde resin, and PCM powder, with a phase transition temperature of 22 °C, a density of 785 kg m-3, a latent heat capacity of 160 kJ kg-1, a volumetric heat capacity of 126 MJ m-3, a specific heat capacity of 2.2 kJ kgK-1, a thermal conductivity of 0.18 W mK-1, and a maximum operating temperature of 200 °C. Before resination, the wood fibers were divided into two outer layers (16%) and an interior layer (68% by weight). Throughout the resination process, the PCM particles were solely integrated into the inner layer fibers. The mats were created by hand. A hydraulic press (AKE, Mariannelund, Sweden) was used to press the boards, and its operating parameters were 180 °C, 20 s/mm of nominal thickness, and 2.5 MPa for the maximum unit pressing pressure. Five variants of MDF with a PCM additive were developed: 0%, 5%, 10%, 30%, and 50%. According to the study, scores at the MOR, MOE, IB, and screw withdrawal resistance (SWR) tests decreased when PCM content was added, for example, MOE from 3176 to 1057 N mm-2, MOR from 41.2 to 11.5 N mm-2, and IB from 0.78 to 0.27 N mm-2. However, the results of the thickness swelling and water absorption tests indicate that the PCM particles do not exhibit a substantial capacity to absorb water, retaining the dimensional stability of the MDF boards. The thickness swelling positively decreased with the PCM content increase from 15.1 to 7.38% after 24 h of soaking. The panel's thermal characteristics improved with the increasing PCM concentration, according to the data. The density profiles of all the variations under consideration had a somewhat U-shaped appearance; however, the version with a 50% PCM content had a flatter form and no obvious layer compaction on the panel surface. Therefore, certain mechanical and physical characteristics of the manufactured panels can be enhanced by a well-chosen PCM addition.

AC conductivity, dielectric and thermal properties of hybrid composite: bagasse cellulose carbon nanofibers composite

AbstractThis study investigates the impact of incorporating carbon nanofibers (CNFs) into sugar cane cellulose at a high weight ratio (6 wt.%). Composite samples were prepared using a hot hydraulic press technique, and their thermal stability was analyzed through thermal gravitational analysis in a nitrogen environment. The results indicate that the cellulose-CNF composite exhibits a simplified single-stage decomposition compared to the more complex behavior observed in pure cellulose. FTIR analysis reveals the presence of –OH bonds, indicating enhanced hydrophilic properties in the composite. Dielectric spectroscopy, conducted over a frequency range of 100 Hz to 1 MHz, explores the effects of CNFs on the relaxation and conduction mechanisms at different temperatures. Parameters such as dielectric permittivity, AC conductivity, electrical modulus, and complex impedance were studied, incorporating Jonscher’s equation, and the Havriliak–Negami model. The interplay between interfacial charge and cellulose crystallinity emerged as a crucial factor in the observed dielectric behavior. Overall, this research provides insights into the thermal and dielectric properties of cellulose/CNF composites, offering potential applications in diverse fields.

Open-source cold and hot scientific sheet press for investigating polymer-based material properties

To produce samples for both material testing and molded sheets/parts, this article details an open-source scientific cold and hot press design. It consists of two independent and modular upper and lower plate (929 cm2) assemblies each containing four 125 W insulated steel strip heaters. The steel housing for these heaters is entirely modular and designed for ease of manufacture, assembly, and customization. This system allows a researcher with access to a hydraulic press to repurpose existing equipment into a multipurpose hot and cold press, or if an independent machine is warranted, an additional welded support frame and commercially available bottle jack offer standalone operation. By utilizing this small-scale hot press either in conjunction with a hydraulic press or on its own, samples can be produced to determine the critical material properties of any polymer, composite, or polymer blend. A series of modular molds allow for the rapid production of flat sheet stock and solid testing samples adhering to the ASTM D695 standard for rigid plastics tested in compression and ASTM D638 standard for testing plastics in tension. The sheet mold offers the user the ability to produce stock sheets that can be cut and assembled into 2.5-D applications with post processing.

Effect of Using Alkoxy - Silane (ethoxy silane) Coupling Agent to Enhance the Mechanical Properties of Bio-Composites

This research work investigated the effect of alkoxy silane (ethoxy silane) on the mechanical properties of polyethylene/ dried powdered pine apple peels composite. The pine apple peels was washed in distilled water, sun dried for about eight hours and later oven dried at a temperature of 60oC for about three hours. The dried pine apple peels was pulverized and sieved using a mechanical sieve arranged in descending order of fineness. The alkoxy-silane (ethoxy-silane) coupling agent (2%) was first hydrolyzed in ethanol to deliver the alkoxy functional silane to the interior of the pineapple peels and ion-free water at room temperature for 6 hours. This was followed by addition of the dried powdered pineapple peels into the hydrolyzed coupling agent solution in a reactor at a temperature of about 80 ◦C for 20 minutes. The formed product was oven dried at 110 ◦C for 3 hours and pulverized using a locally made grinding machine and sieved using a set of sieves arranged in descending order of fineness in accordance with BS1377:1990 standard as was reported by Rajan et al., (2007) to obtain pineapple peels coated with the coupling agent (150mμ). The recycled polyethylene waste was washed using distilled water, sun-dried and shredded in a shredding machine. The pineapple peels powder coated with alkoxy silane and the shredded recycled polyethylene waste were blended using a two-roll rheo-mixer at 50°C and a rotor speed of 60 rpm. The percentage of the powdered pineapple peels coated with coupling agent in the recycled polyethylene matrix was varied from 10% to 40% to produce four different compositions. A hydraulic pressing machine was used to compress the produced composites for about ten minutes applying a pressure of about 25 tons at 130°C. The produced composite samples were allowed to cool to room temperature under sustained pressure before being removed from the hydraulic press for various mechanical tests. The impact tests were performed according to ASTM D256 standard using Impact testing machine model EXT94064/6705CE, 300 J. Flexural test was performed using Universal Testing Machine model TUE-C-100, according to ASTM D790. The hardness tests were performed according to ASTM D785 standard using Rockwell Scale K hardness testing machine. The results showed that maximum flexural strength of 10.8MPa and 384Hv were recorded at 40wt.% reinforcement. The developed composite can be used applications where moderate strength will be required.

Optimizing calliandra (Calliandra calothyrsus) biomass pellets: Impact of particle size and bark composition

Calliandra biomass pellets offer a promising alternative energy source to replace fossil fuels. Typically, these pellets are produced by directly processing the stem and bark of the calliandra (Calliandra calothyrsus) plant without separation, aiming for manufacturing efficiency. This study investigated the quality differences between calliandra biomass pellets with and without bark and varying particle sizes. Particle sizes used were 20 mesh, 40 mesh, and 60 mesh. The pellets were made using a 12 mm diameter biomass pellet mold and a manual hydraulic press with a pressure of 3 tons. Characterization involved assessing proximate analysis, calorific value, physical and mechanical properties, and Fourier Transform Infrared analysis. The test results were compared with biomass pellet standards from Indonesia, Japan, Korea, and Germany. Results indicate that bark affects several properties, with higher ash content observed in pellets with bark due to the higher mineral content in bark. Volatile matter decreases with finer particle size, influencing combustion rate. Moisture content is higher in pellets with bark, impacting combustion efficiency and smoke production. Fixed carbon values are influenced by moisture and volatile matter content. Calorific values are generally higher in pellets without bark and smaller particle sizes. Density and compressive strength increase with decreasing particle size. FTIR analysis reveals differences in functional groups between pellets with and without bark, indicating variations in chemical composition. Overall, this research provides insight into the potential of calliandra biomass pellets with bark and without bark along with particle size as a renewable energy source.