Search results for "natural fibre"
showing 10 items of 22 documents
Durability of basalt/hemp hybrid composites
2017
This study focused on the performance of injection-molded short hemp fibre and hemp/basalt fibre hybrid high density polyethylene composites. Results showed that hybridization with basalt fibre enhanced the performance properties. Analysis of fiber length distribution in the composite and fracture surface was performed to study the fiber breakage and fracture mechanism. Prolonged moisture absorption and accelerated ageing of short hemp fibre and hemp-basalt hybrid reinforced thermoplastic composites was addressed. Ageing in water did not result in a reduction of the strength of the composite samples, while it was found to decrease stiffness of hemp fibre reinforced composites. Mechanical pr…
Durability of Basalt/Hemp Hybrid Thermoplastic Composites
2019
The Achilles heel of thermoplastic natural fibre composites is their limited durability. The environmental degradation of the mechanical properties of hemp and hemp/basalt hybrid-reinforced high-density polyethylene (HDPE) composites has been investigated with a special focus on the effects of water ageing and accelerated ageing, including hygrothermal and UV radiation. Modification of the matrix was carried out using a maleic anhydride high-density polyethylene copolymer (MAPE) as a compatibilizer. Hybridization of hemp fibres with basalt fibres and the incorporation of MAPE were found to significantly decrease the water uptake (up to 75%) and increase the retention of mechanical propertie…
Thermal characterisation of Bio Based Building Materials
2006
This paper describes how the characterization of indigenous renewable biomass sources that are applicable for making bio-based building (BBB) materials is crucial as it can significantly affect the cost of production and the quality of material. Nowadays, in any specific area, wide ranges of biomass sources are usually available but only a few sources may be suitable for making BBB material. Therefore the suited sources should be determined. In this paper, the use of BBB materials is focused on Insulation Materials which are widely used in the buildings. Compared with currently used materials, these materials are bio-degradable. Insulation material with a good energy-adsorbing property and …
Effectiveness of Flax-TRM composites under traction
2023
The scientific research in the field of masonry structures is increasingly welcoming the adoption of innovative and sustainable rehabilitation techniques aimed at the safeguarding of the Built Cultural Heritage. Textile Reinforced Matrix (TRM) composites are the most widely investigated strengthening systems for ancient masonry structures, thanks to their high compatibility level with the material substrates in terms of fire resistance, chemical/physical aspects, reversibility property, little impact on dimensions, stiffness and weight. Nevertheless, in the last years, the growing concern on sustainability increased the interest in products with low environmental impact, for promoting circu…
Environmentally Friendly Composites and Surface Treatments for Metal-to-Composite Hybrid Joints for Marine Application
2022
In this study, the use of natural fibres (flax and basalt) in combination with a recyclable epoxy matrix based on cleavable amines is suggested for improving the sustainability of marine industry. In addition, a new and eco-friendly anodizing process based on tartaric sulfuric acid solution (TSA) and a pore widening step in a NaOH aqueous solution was carried out on aluminium alloy (AA5083) to evaluate its effect on the adhesion strength and damage tolerance after low velocity impact of co-cured adhesive joints with a basalt fibre reinforced and recyclable laminate. The durability in marine environment was simulated by exposing samples to salt-fog spray conditions over a period of 90 days. …
Modelling the structure-property relationships of high performance PBAT-based biocomposites with natural fibers obtained from Chamaerops humilis dwar…
2022
Two fibrous fillers were achieved from stalks and leaves of Chamaerops humilis dwarf palm and tested as reinforcing agents for poly(butylene adipate co-terephthalate) (PBAT)-based composites. The influence of filler type and content on the morphomechanical properties of the green composites was assessed. The outcomes of tensile tests pointed out that both fillers are strong candidates to overcome the two main limiting aspects of PBAT, that is, the lack of both stiffness and cost-effectiveness, while preserving its stretchability and environmental sustainability. The remarkable stiffness increments (up to 300%), combined with fair retention of stretchability (33%) and doubled resistance, led…
Failure mechanisms of flax/epoxy laminates with open hole: a failure map
2017
Aim of this paper is the investigation of the pin/hole contact stress and failure mechanisms of flax/epoxy composite laminates underwent to tensile bearing tests. In particular, the maximum loads and failure modes are evaluated at varying joint geometry. In order to optimize the use of composite materials in structural applications, an experimental failure map, identifying main failure modes of mechanically fastened joints, is obtained by evaluating failure modes (i.e., net tension, shear out, cleavage and bearing) as a function of the pin diameter and the position of the hole from the free edge of the laminate. Main goal of this paper is give a simple experimental methodology to support th…
Mode I translaminar fracture toughness of high performance laminated biocomposites reinforced by sisal fibers: Accurate measurement approach and lay-…
2022
Abstract The present work performs a systematic experimental analysis of the translaminar fracture behavior of high performance biocomposites constituted by green epoxy reinforced by sisal fibers, by varying the main influence parameters as fiber concentration and lay-up. Despite the corrective function properly introduced to take into account the anisotropy as well as the use of the equivalent crack length, the study shows that the LEFM does not give accurate estimations of the fracture toughness, because the extension of the near tip damaged zone is higher than the singular dominated one. Accurate estimations can be obtained instead by the proposed modified area method that takes into acc…
Study of fatigue behavior of plant fiber reinforced composites : taking into account the variability of properties
2012
The present study focuses on the characterization and comparison of the quasi-static and fatigue properties of flax and glass fibre reinforced composites with an epoxy matrix. An extensive experimental campaign of fatigue tests have been performed using the measured quasi-static tension and in plane-shear properties. It appears that the static and fatigue characteristics of the glass/epoxy composites are higher than that of flax/epoxy ones with similar fibre volume fraction and lay-ups. However, due to the low density of flax reinforcements, the differences between the specific properties of the two materials are low. The measurement of the evolution of the fatigue properties has highlighte…
Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties
2021
Abstract In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, c…