The current experimental investigation examines the effect of the warp/weft orientation of jute/sisal and flax/kenaf fibers on the static and dynamic mechanical characteristics of intra-woven hybrid composites. Jute (J), sisal (S), flax (F), and kenaf (K) hybrid woven mats were explicitly designed to keep fibers in the warp and weft directions. Intra-hybrid-composites with JJ, JS, SJ, SS, FF, FK, KF, and KK type hybrid woven mats with polypropylene matrix were processed using the compression molding/film stacking method. The tensile and flexural, and the dynamic mechanical behavior was investigated. Utilizing a scanning electron microscope, the fractured surface of tensile test specimens was examined. The results indicate that combining jute with sisal and flax with kenaf improved the mechanical properties of pure sisal and kenaf based composites. Hybridized composites exhibited the maximum increment in tensile strength (5.95% and 31.16%), tensile modulus (4.20% and 66.64%), flexural strength (12.59% and 5.69%), and flexural modulus (47.10% and 19.72%) for JS and FK composites, when compared with unhybridized SS and KK composites, respectively. The fiber hybridization and warp/weft sequence have a substantial effect on the dynamic mechanical performance of woven fiber laminated composites. It was identified that composites of JS and FK possess a higher storage modulus than pure SS and KK based composites, respectively. In addition, at a temperature of 50°C, the storage modulus was improved by 37.63% and 136.63%, for JS and FK hybrid composites, respectively in comparison to the unhybridized SS and KK composites, respectively. 

Static and dynamic mechanical behavior of intra‐hybrid jute/sisal and flax/kenaf reinforced polypropylene composites

Microwave drying optimization and kinetic modeling of fly ash from municipal solid waste incineration

https://eprints.whiterose.ac.uk/189393/1/1-s2.0-S2666682022000573-main.pdf

Novel composite curing methods for sustainable manufacture: A review

ABSTRACT Microwave processing of polymer composites is gaining attention as a viable alternative to traditional thermal processing techniques owing to several reasons, including faster and environment-friendly processing. In the present study, High-density polyethylene (HDPE) reinforced with jute and sisal fibers (10 wt.%) composites were fabricated using microwave energy at 2.45 GHz frequency. The mechanism of microwave molding of the composites has been explained. To understand and compare the performance of the fabricated composites, mechanical (tensile and flexural), thermogravimetric (TGA), and X-ray diffraction (XRD) analyses were employed to evaluate the performance of the composites. The composites exhibited significant improvement in tensile strength (29.25% and 48.69%), flexural strength (19.22% and 27.47%), and crystallinity (6.41% and 13.02%) for HDPE/Jute and HDPE/Sisal, respectively while compared to pure HDPE. The fractography confirmed that the fiber pull-out was the major mechanism of failure of the composites under mechanical loading. The processing data show that the application of microwave energy is a potential method to process natural fiber-based polymeric composites in a relatively low processing time.

Microwave Hybrid Heating for Moulding of Sisal/Jute/HDPE Composites

Over the last 70 years, pultrusion has matured into an industry-leading process when it comes to providing high throughput and automated composite manufacture at a competitive price point. In this paper, we review recent innovations that have advanced pultrusion to a versatile manufacturing technology and thereby allowed composite materials to penetrate markets in, e.g., the automotive, construction, aerospace, and wind turbine industries. We accompany our review with discussions on how pultrusion has enabled new innovations within additive manufacturing and sustainable composite manufacturing, and finally, we provide an outlook and suggestions for where we see the potential for research and new industrial applications of pultrusion technology. 

Cost-efficient, automated, and sustainable composite profile manufacture: A review of the state of the art, innovations, and future of pultrusion technologies

Search for novel energy-efficient, eco-friendly, and time-saving manufacturing techniques has gained momentum in the recent times. Polymer composites have been increasingly adapted for variety of industrial applications, however, their efficient processing remains challenging. Microwave curing technique has been employed to process thermoset-based composites since 1980, however, processing of thermoplastic-based composites with natural-fibers as reinforcement, calls for additional data and hence investigations. The current work presents an overview of the basics of microwave heating and the physics behind the microwave processing of polymer composites. A state-of-the-art on microwave processing of thermoset and thermoplastic-based composites and developments in microwave joining has been reviewed. The major constraints in adopting microwave technology for curing composites at the industry scale are highlighted. The article also highlights the challenges during microwave processing of sustainable thermoplastic-based polymer composites. Future scope of work to 3D print the polymer matrix composite parts, through microwave scanning route has been indicated. 

Processing of polymer matrix composites using microwave energy: A review

Fused deposition modeling is preferred to fabricate the biodegradable poly lactic acid (PLA) parts, owing to its impeccable characteristics, such as, customization, waste minimization and scalability. However, limited printing volume constraint restricts the ubiquitous applications of this technique. The current experimental investigation is focused on the employment of ultrasonic welding technique to address the printing volume challenge. The effect of infill density, type of energy directors (triangular (TED), semicircular (SCED) and cross energy directors (CED)) and different levels of welding parameters have been investigated on the mechanical and thermal behavior of welded joints. Presence of rasters and gap between them plays a pivotal role in overall heat generation at weld interface. The joint performance of 3D printed parts has also been compared with injection molded specimens of same material. All printed/molded welded specimens with CED recorded higher tensile strength than equivalent specimens with TED and SCED. Moreover, These specimens also performed better than specimens without energy directors and recorded higher tensile strength, that is, 317, 73.5, 59.7 and 42% higher for injection molded (IM), 80%, 90% and 100% infill density (IF) specimens without energy directors at lower level of welding parameters (LLWP). These specimens also exhibited higher tensile strength at optimal levels of welding parameters. Although, at medium and higher levels of welding parameters, both printed/molded specimens with CED observed comparatively more degradation of joints due to higher concentration of energy at weld interface. The dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and field emission scanning electron microscopy (FESEM) analysis have been performed to substantiate the experimental results.

Apurbba Kumar Sharma

Papers

Processing of polymer matrix composites using microwave energy: A review

Ultrasonic welding of printed/molded sustainable polymer specimens with energy directors.