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Nowadays, sustainable and eco-friendly products are gaining more attention in various engineering industries owing to their considerable strength-to-weight ratio, abundant availability, and recyclability. The properties of biofibers depend on the cultivation method, environmental conditions, and extraction method. Biofibers are hauled out by dew retting, water retting, and mechanical decortication methods. The properties of natural fiber–reinforced composites can be enhanced by proper physical and chemical treatments. The aim of this study is to propose a complete evaluation of the different extraction methods applied on natural fibers. Various physical and chemical treatment methods were used to ascertain the properties of optimized natural fiber-reinforced composites for various industrial applications. The key findings derived from various existing data and the chemical treatment results of the biofiber-reinforced composite are specifically highlighted with critical assessment. The properties and use of natural fiber-reinforced composites in the various fields of applications have made them candidates of choice over synthetic petroleum–based fibers.

Development of the plant fiber-reinforced composites from renewable sources is a sustainable alternative material for emerging engineering fields like automotive, aerospace and marine. This experimental work aims to study the effect of weight fraction on the mechanical properties of flax (Linum usitatissimum) and jute (Corchorus olitorius) fibers reinforced hybrid composites. Five different hybrid composites based on fiber weight fraction were prepared by compression molding method. The mechanical properties of hybrid composites such as tensile, flexural, impact and interlaminar shear strength were tested according to ASTM standard. Failure of hybrid composites generally occurs due to the reduced adhesion bonding between fibers and epoxy matrix and fibers pull out. It was observed that the maximum tensile strength, flexural strength, interlaminar shear strength and impact strength were obtained only for a composite having 30 wt% flax fiber reinforcement. The values for the same were recorded as 36.38 MPa, 112.25 MPa, 4.45 MPa and 36.78 kJ/m2 respectively. These composites are having high compatibility to be incorporated in the application like automobiles, sheet roofs, etc.

Natural fiber reinforced composites are gaining more consideration by automakers and researchers to exploit in industrial applications due to lightweight, eco-friendly and sustainability. The aim of this paper is to provide an overview of natural fiber reinforced composites, effect of chemical treatments on natural fibers, manufacturing techniques and potential applications. The effects of various chemical treatments on natural fibers leads to altering the mechanical and thermal properties are studied. The applications of natural fibers reinforced composites are used in various industries such as automobile, aircraft, building, musical, sports and household applications are presented. The conclusion reveals that chemical treatment of the natural fiber enhances bonding between the fiber and matrix which ultimately improved the mechanical and thermal properties of the composites.

The solar dryers are playing a pivotal role in the food industries for preserving edible items such as grains, vegetables, fish, etc., through the removal of moisture content from them. They are having benefit over the open air drying by protecting the food items from dust, insects and other detrimental things. Further, they are attributed to save a greater amount of energy and protect the ecosphere from degradation. The indirect type solar dryers are primarily consisting of a solar collector and a space to place sliced potatoes. Their moisture removal rate is high and the quality of the end product would also be improved by them. In this present work, an indirect type single-pass forced convection solar dryer was fabricated and paraffin was integrated with solar collector as phase changing material (PCM) to improve the off-sunshine hour performance of the solar dryer. The process parameters such as, moisture removal rate, moisture ratio and the dryer inlet temperature were investigated for drying sliced potatoes in two cases, namely, solar dryer without PCM (Plain Dryer) and solar dryer with PCM (PCM Dryer). The mass flow rate of air was maintained as 0.065 kg/s and the dryer was operated from 10.00 a.m. to 7.00 p.m. The obtained results were compared and the influence of amalgamating PCM with the solar dryer was analyzed and presented. The results demonstrated that the presence of PCM within the solar collector enhanced the drying room temperature significantly, two more hours after solar period. In addition, the percentage weight of moisture removal from potato slices was enhanced by 5.1% per day with the aid of paraffin.

Developing sustainable products from renewable materials represents a large dispute in the last few years. Bio-fibers obtained by retting process from plants are receiving more attention from material experts owing to their sustainability, bio degradability, renewability and recyclability nature. The physical and mechanical properties of natural fibers depend on the cultivation method, environmental condition, extraction method and microfibrillar angle. Plant fibers are separated either by dew retting, water retting and/or mechanical decortications method. The properties of natural fiber reinforced composites could be enhanced by suitable chemical treatment processes. This literature survey proposes an in depth review of the extraction methods, chemical treatments and applications for natural fiber composites. We recapitulate the conclusion from the various recent literatures and the chemical treatment outcomes on the mechanical performance of the natural fibers are being highlighted.

In the present research, work focus has been given to determine mechanical properties of biodegradable industrial waste tea leaf fiber (WTLF), banana and flax fiber reinforced hybrid polymer composites using experimental approach. Banana fibers and WTLF were alkali treated with 5% NaOH solution. The hybrid composite laminates were manufactured using manually operated compression moulding machine with the volume fraction of 40:60 (Fiber: Matrix). As per ASTM standard, the mechanical characteristics were studied. The experimental results showed excellent mechanical characteristics for 5 wt% WTLF and 25- wt% banana fiber reinforced hybrid composites. The fractography analysis of untreated and alkali treated composites were examined using Scanning Electron Microscopy (SEM) and results revealed that superior mechanical bonding existed between fiber and polymer in case of alkali treated fiber composites.

The present research work investigates the influence of SiC and Al2O3 on the mechanical and morphological properties of flax dispersed epoxy composites. Composites were fabricated via compression moulding by adding ceramic fillers like SiC and Al2O3 in different proportions for improving tensile, flexural and impact properties of flax fiber incorporated with ceramics filler epoxy composites. Scanning Electron Microscopy is performed to analyse the microstructure and modes of failure of the composites. A tensile strength of 44.56 MPa, flexural strength of 112.56 MPa and impact strength of 28.57 kJ/m2 are the results for 20 wt% of flax fiber and 8 wt% of SiC and were the maximum values. The increase of SiC upto 8 wt% had a significant influence on the mechanical properties of the composites.

The mix of two different type of fibres, one is natural and another one is synthetic fibres were employed as reinforcing media in this study, and epoxy based polymer resin was employed as the matrix phase. S-glass and luffa fibres had been bonded with epoxy matrix to create a novel composite by compression moulding and to measure the effect of this hybridization in composite laminate utilising five different sequencing. To determine the mechanical characteristics of this composite material using tensile, flexural, and compression strength, a specimen named 'SL4' had shown the highest mechanical strength, resulting in a tensile properties of 253 MPa, compression strength of 234 MPa, and flexural characteristics of 237 MPa. The increment in mechanical characteristics is found to exhibiting around 20% increase comparing to the specimen having next higher value in all the properties. The results evidenced that the presence of luffa fibre layers at the interior most portion of the composite displayed the progressive values in all the investigated mechanical characteristics.

The aim of this paper is to study the effect of volume fraction on mechanical and physical properties such as tensile, flexural, impact, interlaminar shear strength, void content and water absorption of flax and bamboo fibers reinforced hybrid epoxy composites. Flax and bamboo fibers reinforced epoxy resin matrix hybrid composites have been fabricated by compression molding techniques. The hybrid composites were fabricated with different volume fraction of fibers. SEM analysis on the hybrid composite materials was performed to analyze the bonding behavior of materials and internal structure of the fractured surfaces. The effect of chemical treatment of flax and bamboo fibers was verified by FTIR analysis. The results showed that the tensile, impact, flexural and ILSS are maximum for 40:0 (flax: bamboo) hybrid composites. The void content decreased for 20:20 (flax:bamboo) composites due to tightly packed flax fiber and more compatibility towards epoxy resin.

Many solar energy utilizing techniques are present and PV modules are one among them which is having widespread applications. But, the main disadvantage of this is high cost and less efficiency. The efficiency of photovoltaic solar panel decreases with increase in operating temperature. This is because, the photo voltaic modules take only the visible light intensity for converting it to electrical energy and rest of the spectrum of light is converted to heat leading to the increase in operating temperature. Reflection from top surface is another reason for increase in operating temperature. The main aim of this project is to reduce the operating temperature using finned heat pipe. Experiments have been done on a prototype and the results have been compared with a computational study. Results have shown a maximum decrease of 13.8K by adopting this method. The results of experimental study and computational study are in good agreement.

Shortage of energy is increasing day by day and we have to store energy for our future. Storage is a challenge in the current scenario and lot of research is being conducted to find an effective way to store energy. Packed beds are one of the promising and potential methods to store thermal energy. This paper describes an attempt that has been made to study the fluid flow and heat flow characteristics in porous media. CFD analysis and experiments have been carried out with air-alumina as the porous medium. Pressure drop, velocity distribution, temperature distribution and Effective thermal conductivity have been found out. Parametric studies have been done both in experimentation and in the CFD analysis. Both experimental and computational results seem to be in good agreement.