Moulding Technique Research Articles

Development of Synthetic Lumbar Vertebrae using Custom-made Mould for Orthopaedics Training: Micro-Structural Analysis

Human vertebrae composed of cortical and cancellous bone are crucial to provide the structural support of human framework and protect the organs underneath. Vertebrae from the Lumbar 3 (L3) was selected for fabrication because it is the most commonly used for surgical training. The use of human vertebrae in the orthopaedic studies is necessary to investigate various complications such as vertebral compression fracture and to propose the most suitable medical intervention for the treatment. However, investigations of cortical and cancellous material properties and composition have been limited. Therefore, the main objective of this study was to design a custom-made mould for synthetic lumbar vertebrae using moulding techniques that could exhibit the same anatomical structure as real vertebrae. Then, this study was carried out to establish a process of cortical and cancellous synthetic bone development. Lastly, this study was done to compare the morphological properties of synthetic bone produced with human bone. Utilizing Polyurethane (PU) as the main material was used for the fabrication, where it could inhibit the morphological properties that could mimic the human bone. The methods to fabricate the vertebrae also varied from static mould and rotational mould. The fabricated lumbar produced was tested for the morphological properties, targeting the pore diameter, was performed using Scanning Electron Microscopy (SEM). From this study, it was identified that the analysis of pore diameter from specimen of Ratio 3 from rotational mould depicts the smallest pore diameter and standard deviation, 1.5 ± 0.3 mm. While this specimen has the smallest value, the results were still higher when compared to the pore diameter of human trabecular bone (which ranges from 0.3 mm to 0.6 mm). In conclusion, the use of silicone custom-made moulds could provide synthetic vertebrae with an anatomical structure mimicking real human vertebrae.

Determination of Mechanical Properties of Hybrid Composite

Abstract: Manufacturing of composite laminates is the peculiar member of science that encounter its immense utilization in various industrial areas such as sporting, automotive, aerospace and marine industries. The superior properties of composites such as stiffness, better mechanical properties, low density, and lightweight make it a candidate in engineering applications. The continuous research in this area is due to the need for seeking alternative materials with increased performance. In this report, the basalt fiber E-glass reinforced composite mechanical properties has investigated. The basalt fiber E-glass composite was formulated with hand layup moulding technique. Mechanical properties such as tensile, flexural strength and impact strength of the basalt fiber E-glass composite have been analysed

Treatment outcomes of digital nasoalveolar moulding in infants with cleft lip and palate: A systematic review with meta-analysis.

The aim of this systematic review was to compare the treatment outcomes of digital nasoalveolar moulding (dNAM) technique with conventional nasoalveolar moulding (cNAM) or non-presurgical intervention protocol in infants with unilateral (UCLP) or bilateral (BCLP) cleft lip and palate. A bibliometric search by MEDLINE (via Ovid), Embase, Cochrane Library, grey literature and manual method was conducted without language restriction until November 2023. Literature screening and data extraction were undertaken in Covidence. The risk of bias was evaluated using the Newcastle-Ottawa Scale and RoB-2. Pooled effect sizes were determined through random-effects statistical model using R-Software, and the certainty of evidence was assessed using the GRADE approach. Among 775 retrieved articles, nine studies were included for qualitative synthesis (6-UCLP, 3-BCLP), with only three eligible UCLP studies for meta-analysis. In the UCLP group, very low certainty of evidence indicated no difference in alveolar cleft width (SMD, 0.13 mm; 95% CI, -0.31 to 0.57; I2, 0%), soft tissue (lip) cleft gap, nasal width, nasal height, and columellar deviation angle changes between dNAM and cNAM. In the BCLP group, qualitative synthesis suggested similar changes in alveolar, lip, and nasal dimensions with dNAM and cNAM. In both cleft groups (UCLP, BCLP), reduced alveolar cleft width was observed in the dNAM group compared to the non-presurgical intervention protocol, along with fewer clinical visits and reduced chairside time for dNAM compared to cNAM. It can be concluded that the treatment outcomes with dNAM were comparable to cNAM in reducing malformation severity and were advantageous in terms of chairside time and clinical visit frequency. However, the overall quality of evidence is very low and standardization is needed for the virtual workflow regarding the alveolar movements and growth factor algorithms. Registration: PROSPERO-database (CRD42020186452).

Development of a facile, versatile and scalable fabrication approach of solid, coated, and dissolving microneedle devices for transdermal drug delivery applications

Nowadays, microneedles as novel transdermal delivery systems are interested in scientists for biomedical applications. This work aims to present a Cascade Microneedle Molding Technique (CMMT) for the reusable fabrication of polydimethylsiloxane (PDMS) molds to produce microneedle devices. To produce a positive master mold from epoxy resin, a negative PDMS mold was first fabricated. PDMS can be molded, and microneedles can be fabricated using this epoxy mold in a scalable and cost-effective manner. These molds were used to manufacture solid, coated, and dissolving microneedles, which were characterized comprehensively. Microneedle morphology and geometry were evaluated using Scanning Electron Microscopy (SEM). The mechanical integrity and ability to insert the microneedle device into the skin were assessed using compression strength analysis and force-displacement measurements. Drug penetration through animal skin was evaluated for Rhodamine B (RhB) loaded microneedles. The depth of needle insertion was also visualized using histological analysis while the spatial distribution of released cargo was determined by using confocal microscopy. Taken together, CMMT offers a simple, rapid, cost-effective, and scalable method for mass-producing microneedles with remarkable properties compared to direct 3D printing or laser ablation.

Development of lightweight and high-strength glass fiber and natural fiber hybrid composites using VARTM technique

This research paper presents the synthesis of Glass Fiber Reinforced Plastic (GFRP) and Natural Fiber Hybrid Composites (NFHC) utilizing Vacuum-Assisted Resin Transfer Molding (VARTM) techniques. Jute and flax fibers were strategically selected for their unique properties and potential synergistic effects when combined with glass fibers. The study systematically evaluates the influence of natural fiber incorporation on the mechanical performance of the composites, focusing on critical factors such as fiber type, orientation, and resin selection. A series of meticulously crafted laminate configurations were employed. These included combinations of glass and jute fibers (GJG, GJGJG), glass and flax fibers (GFG, GFGFG), and a reference laminate composed solely of glass fibers (GGGGG). The mechanical characterization involved rigorous Izod impact testing, hardness assessments, and water absorption tests to provide a detailed understanding of behavior of composite material. The results reveal that the incorporation of jute fibers resulted in a significant enhancement of impact resistance of up to 59 % compared to GFG laminates and hardness. Water absorption varied across the laminates, with GGGGG exhibiting the lowest value of 0.054 %. Scanning Electron Microscopy (SEM) was employed to gain valuable insights into the critical fiber-matrix interaction and microstructure of the composites, further elucidating the observed mechanical properties. These findings pave the way for lightweight, high-strength composites ideal for engineering applications, particularly automotive mono leaf springs. The resulting weight reduction promises significant gains in fuel efficiency and vehicle performance, advancing sustainable materials with exceptional mechanics.

Manufacturing of Bricks by using Waste Foundry Sand

The foundry is an industrial sector where various iron, scrap steel, and ferroalloys are melted down in arc furnaces or cupolas, shaped in sand, ceramic, or metal moulds, and the cast, steel, nodular, and tempered foundry products needed in industry are produced as raw or processed materials. Especially in establishments such as factories and workshops that produce parts of the automotive, construction, and machine and in steel industry, foundry sand is used to mould foundry products (iron-steel industry and aluminium- and copper-based alloys).Foundry sand is used to prepare metal foundry moulds. For 1 ton of production, 4-5 tons of sand is required. This ratio may be changed based on the type of the metal that needs to be casted, part size, and moulding technique. Sands that contain more than 90% of silica and 7–15% clay (bentonite or kaolinite clay) and have a sintering temperature of over 1500°C are defined as foundry sands. Foundry sand disposal is a herculean task for the industrial sector in today’s scenario. In order to overcome this problem to some extent, it is required to convert it into some useful products. Hence, this project gains its importance for the effective utilization of foundry sand into foundry sand bricks

Experimental Investigation of Date seed and Neem Powder Reinforced Natural Fiber Composites

Natural fillers have received great attention among researchers due their its light weight, high strength, degradability, and eco-friendly behavior. This work is focused on developing a laminate of date palm seed powder and neem gum powder reinforced epoxy resin. Epoxy resin is an excellent thermoset polymer with anoutstanding cost to performance ratio. Date palm seeds have highly competitive properties in improving the mechanical and thermal properties of composites by their good adherence to polymer matrix. Neem gum powder is used as a binder in increasing ratios of 0 %, 10 %, 15 %, 20 %, 25 %, and 30 % to test their strength in different compositions. Date seed powder has been reinforced in decreasing weight percent as 30 %, 25 %, 20 %, 15 %, 10 %, 5 %, and 0 %. The specimens prepared through the compression moulding technique were subjected to various mechanical tests like a tensile test, flexural test, and impact test as per the ASTM standards. Fractography analysis using FESEM (Field Emission Scanning Electron Microscopy) and FT-IR(Fourier Transform Infrared spectroscopy) test have determined the surface characteristics and chemical composition of the samples. The result shows that, by adding neem gum powder in increasing quantities the mechanical properties like tensile and flexural decreases. However, it does not affect the impact strength of the material. A detailed study of their behavior is discussed in this work.

Sapindus Mukurossi - An Effective Biocleanser for Removable Dental Prostheses? An In vitro Study.

This study aims to determine the efficient concentration of Sapindus mukorossi that can be used as a denture cleanser. 60 heat cure denture base resin specimens of dimensions 10*10*2 mm were fabricated. Among these, 30 were fabricated by compression moulding technique and the remaining 30 by an injection moulding technique. The samples inoculated with Candida albicans and Streptococcus mutans were subjected to denture cleansing protocols using a medicinal herbal extract from the Sapindus mukorossi, at various concentrations [15%, 20%, and 25%]. The colony-forming unit [CFU] values were evaluated using a microprocessor colony counter. The statistical analysis was performed. The intragroup comparison showed a statistically significant difference between all groups except the compression moulded samples inoculated with Streptococcus mutans. The intergroup comparison revealed no statistically significant differences between the compared groups. The reduction in CFU values is evident in the effective anti-microbial activity of Sapindus mukorossi. A concentration of 25% Sapindus mukorossi solution showed the greatest efficiency. The maximum anti-microbial activity was observed against Candida albicans in a 25% concentration of Sapindus mukorossi. Among all, injection moulded samples showed better results.

Analyzing the Tensile Strength of Carbon Fiber-Reinforced Epoxy Composites Using LabVIEW Virtual Instrument

Carbon fiber-reinforced polymer composites are widely used materials in the aircraft industry, automotive sector, marine applications, civil engineering, and daily consumer goods, due to their superior mechanical properties at a relatively low density compared to metallic materials. The studied composites are composed of an epoxy resin matrix in which three layers of carbon fiber fabric are embedded, oriented at 0 and 90 degrees. Carbon fiber-reinforced polymer composites were manufactured using the Vacuum Assisted Resin Transfer Molding technique. The tensile failure mechanism in carbon fiber-reinforced polymer composites is an extremely complex phenomenon influenced by numerous factors. This study aims to evaluate the mechanical behavior of carbon fiber-reinforced composites through tensile testing and to compare experimentally obtained results with those calculated using the mixture rule. Additionally, the behavior of the materials under tensile stress was analyzed using the digital image correlation method. Estimating mechanical properties based on the mixture rule is a common practice in the design phase of polymer composites. This study s novelty and originality lie in its anticipation of the tensile strength and modulus of elasticity of the studied composites. This anticipation was achieved using a virtual instrument developed in the LabVIEW graphical programming environment. The experimentally obtained results for the tensile characteristics of the studied materials are suitable for this type of composite. These results were compared with estimates derived from the mixture rule, and the absolute error was determined.

Evaluation of the Corrosion Resistance of Watch Links from 316L and 904L Austenitic Stainless Steels Obtained by the Metal Injection Molding (MIM) Technique Intended to Be in Contact with Human Skin

Watchmaking manufacturers obtain their bracelet links from machining drawn metal profiles. But, today, there is another process that represents an alternative to manufacture them: metal injection molding using metal powders (MIM technology). This process is less expensive than the machining of drawn metal profiles. The aim of this study was to evaluate the corrosion behavior and the nickel cation release of two stainless steel alloys: 316L MIM and 904L MIM. The general corrosion behavior was evaluated by the rotating electrode technique; the galvanic corrosion measurements were conducted with a 316L AISI bulk coupling partner. The pitting corrosion behavior was evaluated in FeCl3 0.5 M media (according to ASTM G48-11). For comparison, a complementary study was conducted on 316L and 904L bulk alloys. The Ni cation release tests were conducted on 316L and 904L MIM and bulk samples according to EN 1811. Different electrochemical parameters were measured and calculated (open circuit potential, polarization resistance, corrosion current and Tafel slopes, coulometric analysis). Generally, if MIM steels are compared with conventional steels, their corrosion resistance behavior is inferior. In the couplings studied, the galvanic currents generated are very important. The shape of the curves also reveals the presence of localized corrosion phenomena. According to tests in ferric chloride, MIM steels were noted to have inferior behavior compared to conventional steels. MIM type 904L steels are comparable in behavior to conventional type 316L steels. The quantities of nickel released according to EN 1811 were very significant (2 mg cm−2 week−1 up to 24 mg cm−2 week−1) and did not meet the requirements of the European directive (0.5 µg cm−2 week−1). In conclusion, conventional steels studied under the same experimental conditions revealed a better behavior compared to MIM steels independently of the phenomenological parameters chosen.

Jute and Flax Fiber Composites Enhancement through Carbon Nanotube Filler

This investigation primarily focuses on enhancing the sustainable jute/flax/epoxy nanocomposite with the use of carbon nanotubes (CNTs) as filler. The flax and jute natural fibres were treated with sodium hydroxide solution. The compression moulding technique was preferred for better fabrication. The CNTs were thoroughly mixed with epoxy resin with the help of a ball milling-type mixture. The nanocomposite samples were prepared by varying the reinforcement and filler content. Jute fibre varied from 59 to 99 wt%, Flax Fiber varied from 0 to 40 wt% and the filler was maintained as constant of 1 wt%. The five types of laminated and fabricated composites were characterized in terms of tensile strength, flexural strength and modulus of elasticity. The SEM examinations were carried for the composite samples to analyse the fibre diameter (µm), CNT dispersion and interfacial adhesion. The results revealed that the sample fabricated with 69 jute fibre, 30 wt% flax fibre, and 1 wt% CNT filler outperformed with 60.1 MPa tensile strength, 79.3 MPa flexural strength, 8.1 GPa modulus of elasticity.

Significance of Hemp Fiber on Mechanical and Thermal Performance of Polypropylene Nanocomposite Developed by Compression Mould Technique

Significance of Hemp Fiber on Mechanical and Thermal Performance of Polypropylene Nanocomposite Developed by Compression Mould Technique

High-performance Fe–6.5wt.%Si/CaCO3 soft magnetic composites prepared via the thermal decomposition of calcium acetate

Recent studies on inorganic salt compounds are predominantly directed towards their utilisation as reinforcements for resins. However, the use of salt compounds besides phosphates as insulating layers has not been widely explored. Therefore, this study focuses on using salt compounds as insulating layers for soft magnetic composites (SMCs), revealing their numerous potential advantages. Fe–6.5 wt%Si/(CH3COO)2Ca composite powders were successfully synthesised using a hydrothermal method. Then, SMCs powders of Fe–6.5 wt%Si/CaCO3 and Fe–6.5 wt%Si/CaO, along with their corresponding SMCs, were prepared using powder heat treatment and cold press moulding techniques. The effects of calcium acetate ((CH3COO)2Ca) addition on the structure and electromagnetic properties of Fe–6.5 wt%Si/CaCO3 SMCs were further explored via an in-depth investigation of the formation mechanism of CaCO3 and CaO insulating layers on the surface of the Fe–6.5 wt%Si matrix. Results showed that (CH3COO)2Ca, as a precursor, decomposed into CaCO3 at 300 °C and CaO at 900 °C during heat treatment. Compared with the CaCO3 insulating layer on the surface of the Fe–6.5 wt%Si matrix, the CaO insulating layer exhibited a tendency for flocculent agglomeration, with lower homogeneity and integrity. Furthermore, the addition of (CH3COO)2Ca considerably influenced the thickness of the CaCO3 insulating layer in the Fe–6.5 wt%Si/CaCO3 SMCs, thereby effectively modulating the magnetic properties of the materials. The prepared Fe–6.5 wt%Si/CaCO3 SMCs had optimal magnetic properties when 4 wt% (CH3COO)2Ca was added. Under the conditions of a 25 mT external magnetic field and 100 kHz frequency, the material exhibited a relative magnetic permeability as high as 37.2, a total loss of merely 125.06 kW/m³, a saturation magnetic induction intensity of 178.15 emu/g and an electrical resistivity of 125.4 Ω∙m. The innovative material design and the proposed preparation method considerably enhanced the comprehensive magnetic properties of Fe–6.5 wt%Si-based SMCs, opening up a new avenue for the research and development of high-frequency SMCs.

PREDICTION OF TORQUE IN DRILLING WOVEN JUTE FABRIC REINFORCED EPOXY COMPOSITES USING THE ADAPTIVE NETWORK-BASED FUZZY INFERENCE SYSTEM AND RESPONSE SURFACE METHODOLOGY

Jute fiber reinforced epoxy (JREp) composites were prepared by the compression moulding technique by varying the fiber content (0, 20, 30 and 40 wt%). Fabricated JREp composites were subjected to a drilling study to observe the impact of factors such as spindle speed (rpm), feed rate (mm/min) and fiber content (wt%) on the output response – torque. A set of experiments were designed and conducted as per Taguchi’s Design of Experiment. The obtained torque results were found in the range from 14.84 to 32.28 N-m. The minimum value of torque was achieved for the composite drilled using an HSS twist drill (90°-point angle) at a high spindle speed (3000 rpm), with low feed rate (25 mm/min) on low fiber loaded JREp composite (20JREp). ANOVA analysis showed that the developed regression model was fairly significant and torque was mainly influenced by the feed rate. Mathematical models were developed for drilling JREp composites using response surface methodology (RSM) and adaptive neuro fuzzy inference system (ANFIS), and compared for their efficacy. The coefficient of determination (R2) values for RSM and ANFIS were 0.9778 and 0.9982, respectively, which conveys that both models were beneficial to predict the torque. The average checking error percentage (0.0000222) was obtained for the ANFIS model trained using ‘gbellmf’ membership function with 100 epochs. FESEM images of the drilled surface were captured to analyse the mode of failure endured by the JREp composites.

Evaluation of mechanical and erosive wear properties of hybrid nano composites basalt/E-glass fiber + MWCNTs/SiO2

The extensive study conducted has revealed that the mechanical and other characteristics of hybrid composites are greatly influenced by several aspects, such as the kind of fibre reinforcement, nanofillers, matrix materials, and the manufacturing methods employed. In the context of structural applications, the incorporation of Multi-wall Carbon Nanotubes (MWCNTs) as fillers in E-Glass fibres had a significant impact on the rapid alteration of mechanical properties, particularly strength, in the composites. This study aimed to create hybrid nanocomposites by including multi-walled carbon nanotubes (MWCNTs) and silicon dioxide (SiO2) as filler materials, Basalt/E-glass as fibres, and epoxy with hardener as the matrix. This study utilises statistical methods, specifically the Taguchi L16 Orthogonal Array (OA), to analyse the impact of various operating factors. The parameters selected for this study include MWCNTs/SiO2 fillers at varying weight percentages (0 %, 1 %, 2.9 %, and 3 %), an epoxy matrix with decreasing weight percentages (40 %, 39 %, 38 %, and 37 %), compression pressures ranging from 5 MPa to 35 MPa, and moulding temperatures ranging from 40 °C to 100 °C. The mechanical parameters being examined are the tensile strength and erosive wear. The utilisation of the hand layup and compression moulding technique achieved the development of these composites. By optimising the moulding temperature, significant improvements were achieved in the tensile strength, which reached 184.38 MPa. Similarly, reducing the percentage of fillers resulted in a substantial decrease in erosive wear, with a value of 95.06 mg/kg.

Development of eco-friendly brake pads using industrial and agro-waste materials

There has been an increase in research over the past decades into the use of environmentally friendly materials in brake pads, such as natural fibres. This is due to the possibility that natural fibbers could serve as an alternative to the noxious asbestos materials in tribological applications like brake pads. As a result, utilizing the compacting mould technique, an asbestos-free friction material was developed using agricultural waste (coconut shell and oil bean stalk) as a filler element, alongside aluminium dross, metal chip industrial wastes and carbon black. The filler material considered had particles as small as 300 μm, with epoxy resin serving as the binding agent. Using these waste materials can help reduce environmental pollution and the risk to animal and plant life (Preeti et al., Pharma Innov J 7:94–102, 2018; Sajib, A Study on the effects of environmental pollution on human life in the riverbank area of Barishal City Corporation (Kirtankhola River), 2021). This research aimed to replace asbestos in brake pads due to its carcinogenic nature, reducing the health risks associated with manufacturing and using these brake pads. The brake pad materials were cast and produced using square wooden moulds. Four samples were created, comprising the same mixing ratio but varying in reinforcement fibre and particle size, with epoxy resin used as the matrix. Various tests were conducted on these samples, including a water absorption test, specific gravity test, compressive strength test, hardness test, thermal conductivity, SEM and EDX. The developed brake pads underwent microscopic characterization and structural examination using a scanning electron microscope (SEM) fitted with energy-dispersive X-ray spectroscopy (EDX) for elemental characterization. Thermal conductivity was obtained using automated Lee’s Disc apparatus. Comprehensive strength analysis was conducted using a universal testing machine (UTM).The specific gravity tests yielded values for the developed composites in the range of 1.136–1.257, while the commercial brake pad had a value of 2.081, indicating that the produced samples were lighter and less dense. The water absorptivity of the developed samples ranged from 0.95 to 2.174%, while the commercial brake pad had a value of 1.031%. For the hardness tests, at three different loads, the developed values ranged from 16.4HV3 to 19.4 HV3; 26.4HV30 to 28.7HV30; and 25.5HV100 to 29.6HV100, while the commercial brake pad had values of 16.5HV3, 28.4HV30 and 28.2HV100.Sample C (212 μm: coconut shell powder) exhibited the most desirable characteristics with five values: water absorptivity 0.95, compressive strength 120.5 MPa, hardness value 29.6 HV100, wear resistance 0.099 mm/mm3, specific wear rate 1.00 mm3/Nm. The outstanding values were attributed to the chemical composition, particle sizes and good interfacial bonding of the microstructure.The developed brake pads performed favourably when compared with the existing commercial brake pads. The chemical tests showed that the natural fibres bonded well with the epoxy matrix. The thermal and mechanical tests yielded comparable results with the values obtained from the commercial brake pads. Therefore, the developed materials for brake pads can be considered suitable replacements for asbestos brake pads.

Experimental investigation of conductive heat transfer and fire protection in a polymer-based plate heat exchanger

Polymer-based heat exchangers offer several attractive features for thermal management applications such as low-cost, lightweight, antifouling, and anti-corrosion characteristics. However, their thermal performance is compromised primarily by the low thermal conductivity and high-flammability. This work consists of developing new polymer-based plate heat exchangers, which are made from epoxy resin reinforced by banana fibres and manufactured using the vacuum bag resin transfer moulding technique. The aim of this research is to improve both the heat transfer efficiency and thermal protection. The proposed approach involves incorporating silicon carbide powder as charge into samples to increase their thermal conductivity, and applying an intumescent fire-retardant coating to improve their capacity to withstand heat and flames. To determine the efficacy of this approach, a cone calorimetry test was performed to examine the thermal distribution within the plate heat exchanger samples and to assess fire reaction parameters during a fire scenario. The results revealed a notable increase in thermal conductivity, due to the addition of silicon carbide powder. Furthermore, the intumescent fire-retardant coating substantially improved the samples’ thermal resistance. This result has been verified by thermogravimetric analysis conducted during this work. These findings suggest that using banana fibres-reinforced epoxy resin, combined with silicon carbide powder and intumescent fire-retardant coating, has the potential to enhance the overall thermal performances of plate heat exchangers. The addition of silicon carbide powder increases the thermal conductivity by 36%. This demonstrates the feasibility of utilizing sustainable and biodegradable materials to manufacture heat exchangers that are more efficient and eco-friendly.

Design of Sustainable Aluminium-Based Feedstocks for Composite Extrusion Modelling (CEM).

Additive manufacturing (AM) has become one of the most promising manufacturing techniques in recent years due to the geometric design freedom that this technology offers. The main objective of this study is to explore Composite Extrusion Modelling (CEM) with aluminium as an alternative processing route for aluminium alloys. This process allows for working with pellets that are deposited directly, layer by layer. The aim of the technique is to obtain aluminium alloy samples for industrial applications with high precision, without defects, and which are processed in an environmentally friendly manner. For this purpose, an initial and preliminary study using powder injection moulding (PIM), necessary for the production of samples, has been carried out. The first challenge was the design of a sustainable aluminium-based feedstock. The powder injection moulding technique was used as a first approach to optimise the properties of the feedstock through a combination of water-soluble polymer, polyethyleneglycol (PEG), and cellulose acetate butyrate (CAB) wich produces low CO2 emissions. To do this, a microstructural characterisation was carried out and the critical solid loading and rheological properties of the feedstocks were studied. Furthermore, the debinding conditions and sintering parameters were adjusted in order to obtain samples with the required density for the following processes and with high geometrical accuracy. In the same way, the printing parameters were optimised for proper material deposition.

Experimental Study on Mechanical, Chemical and Acoustical Properties of Waste Tea Leaf Fiber Reinforced Epoxy Composites

Fibre reinforced polymer composites are employed instead of metal and wood because they are stronger, more lightweight, have a favourable strength to weight ratio, and are noncorrosive. In the current research, sisal, carbon fibre, and industrial waste tea leaf fibre (WTLF) reinforced hybrid epoxy composites are being examined for their chemical, mechanical and acoustical properties with experimental study. The sisal and WTLF were chemically treated with 5% sodium hydroxide (NaOH) solution. By modifying the weight percentage of sisal and WTLF with a structure of 40 weight percent fibre and 60 weight percent matrix, five different compositions of natural fibre reinforced hybrid composites were fabricated using an automatic compression moulding technique. As per the ASTM standard the manufactured hybrid composites are tested for mechanical, chemical and acoustic characteristics. According to the experimental findings, sisal fibre with a 25 wt% and WTLF with a 5 wt% demonstrated superior mechanical properties, while these materials also demonstrated an excellent acoustic absorption coefficient (AAC) of 0.62 between the frequency range of 2000 to 6300 Hz. The morphology of failure samples revealed the matrix micro crack, void formation, fiber pullout and layers of fractured fibers which are being examined using Scanning Electron Microscopy (SEM). The superior bonding between fibre and matrix was seen in the FTIR study of 5% alkali treated composites.

Effect of silicon carbide particles on the mechanical, thermal and structural properties of recycled high-density polyethylene

In this research work, recycled high-density polyethylene (rHDPE)/silicon carbide (SiC) composites were produced by melt compounding followed by injection moulding technique. It has been revealed from the mechanical properties that the addition of SiC increases the hardness, density, flexural strength of the composite and tensile strength of the composite. The impact strength at 15 wt-% SiC composite gives the best results. From the thermal analysis, it was observed that the addition of SiC in rHDPE increases the melting point and total enthalpy of crystallisation. The residual value of rHDPE composites increases with the rise in filler loading which enhances the thermal stability of the composites. Melt flow index (MFI) decreases with the increased in silicon carbide. The heat deflection temperature (HDT) increased with the loading of filler content. The contact angle analysis revealed the hydrophilic nature of the composite. MFI reduced with the incorporation of filler content. The SEM images concluded the agglomeration of the composite at higher filler fractions. These results confirm the possibility of using rHDPE/SiC composite to produce various parts for household commodities and structural applications.