Effects of fabric counts and weave designs on the properties of laminated woven kenaf carbon fibre reinforced epoxy hybrid composites

The effects of different fabric materials namely weave designs (plain and satin) and fabric counts (5 × 5 and 6 × 6) on the properties of laminated woven kenaf/carbon fibre reinforced epoxy hybrid composites were evaluated. The hybrid composites were fabricated from two types of fabric, i.e., woven kenaf that was made from a yarn of 500tex and carbon fibre, by using vacuum infusion technique and epoxy resin as matrix. The panels were tested for tensile, flexural, and impact strengths. The results have revealed that plain fabric is more suitable than satin fabric for obtaining high tensile and impact strengths. Using a fabric count of 5 × 5 has generated composites that are significantly higher in flexural modulus as compared to 6 × 6 which may be attributed to their structure and design. The scanned electron micrographs of the fractured surfaces of the composites demonstrated that plain woven fabric composites had better adhesion properties than satin woven fabric composites, as indicated by the presence of notably lower amount of fibre pull out

Mechanical Properties and Water Absorption Behaviour of Durian Rind Cellulose Reinforced Poly(lactic acid) Biocomposites

Environmental concerns have resulted in replacing petrochemically derived polymer with biodegradable renewable resource. In this study, mechanical properties and water absorption behaviour of durian rind cellulose reinforced poly(lactic acid) biocomposites were investigated. Poly(lactic acid) was mixed with 25 and 35 wt. % of durian rind cellulose that was derived from durian consumption wastes. The biocomposties were melt-blended at 165 and 175 °C with 15 min using a Brabender internal mixer followed by a hot compression moulding technique. The results showed that impact strength and modulus of Young increased with increasing of cellulose content but decreased at higher mixing temperature. Water absorption behaviour of biocomposites as function of days was also investigated. It was found that the water absorption amount of biocomposites increased with increasing of cellulose content and exposure time.   

Mechanical and physical properties of kenaf-derived cellulose (KDC)-filled polylactic acid (PLA) composites

Kenaf-derived cellulose (KDC)-filled poly(lactic acid) (PLA) composites were prepared via melt blending and compression molding to improve the properties of PLA by introducing a natural cellulose that was chemically derived (chlorination and mercerization processes) from plant-based kenaf bast fibers. The effect of KDC content (0-60 wt.%) on the tensile elongation at the break point and during flexural and impact testing and on the water absorption and density of the composites was investigated, while the neat PLA polymer (without the addition of cellulose) served as a reference for the composites. The elongation at the break point of the composites was 9% on average, making it less elastic than the neat PLA. The flexural strength and modulus also increased by 36% and 54%, respectively. The impact strength of the composites was improved at KDC contents below 40 wt.%, but the impact strength was reduced above 40 wt.%. The composite containing the highest amount of KDC (60 wt.%) was denser than the neat PLA and had a water uptake of approximately 12%, which is notably low for a biocomposite system

Water absorption behaviour of kenaf reinforced unsaturated polyester composites and its influence on their mechanical properties

Fibre reinforced composites have gained use in a variety of applications. The performances of these composites may suffer when the material is exposed to adverse environments for a long period of time. Kenaf fibre reinforced unsaturated polyester composites were subjected to water immersion tests in order to study the effects of water absorption on the mechanical properties. Composites specimens containing (10%, 20%, and 30%) weight percentages of fibre were prepared. Water absorption tests were conducted by immersing these specimens in a distilled water bath at 25°C for four months. The tensile properties of the specimens immersed in water were evaluated and compared with the dry composite specimens. A decrease in the tensile properties of the composites was demonstrated, indicating a great loss in the mechanical properties of the water-saturated samples compared to the dry samples. The percentage of moisture uptake was also increased as the percentage of the fibre weight increased due to the high cellulose content. The water absorption pattern of these composites was found to follow the Fickian behaviour

Combined effects of water absorption due to water immersion, soil buried and natural weather on mechanical properties of kenaf fibre unsaturated polyester composites (KFUPC)

Kenaf Fibre reinforced composites have been gaining wide use in the variety of applications. The performance of these composites may suffer when the material is exposed to adverse environments for long periods of time. Kenaf fibre unsaturated polyester composites (KFUPC) were subjected to three environmental tests: water immersion, soil buried and natural weather tests, in order to study the effect of water/relative humidity absorption on the mechanical properties of specimens containing 10, 20 and 30% by weight of fibre content. Tensile strength and modulus of the composites were determined. A decrease in tensile properties of the composites was demonstrated, showing a great loss in mechanical properties of the humid samples compared to the dry samples. The percentage of moisture uptake increased as the weight percentage of fibre is increased due to the high cellulose content. The water absorption pattern of these composites was found to follow Fickian behavior

Optimisation of processing variables of Kenaf derived cellulose reinforce polylactic acid

Optimisation of composite processing variables (temperature and time) was carried out by monitoring both the stabilisation zone (to ensure composite is well mix at sufficient duration) and the maximum mixing temperature (below 200 °C to avoid fibre degradation) by analysing mixing torque curves upon compounding 5 wt % KDC/PLA using Brabender internal mixer at 160-180 °C for 10, 20 and 30 min., respectively. The composites were pressed and cut into tensile test specimens prior to testing. The 5 wt % KDC/PLA composite demonstrated an optimum tensile strength at three combinations of variables, however the best condition was chosen at 170 °C for 30 min for preparation of composites at various KDC loading (0-60 wt %). The effect of KDC loading on the tensile strength and modulus of composites were investigated. The results demonstrated that increasing KDC loading from 0-60 wt % enhanced the tensile strength and the tensile modulus up to 34 and 107 %, respectively. The a-cellulose was initially derived from kenaf fibre (from bast) by removal of lignin and hemicellulose via chemical (chlorination and mercerization) processes. The absence of these components in the FTIR spectral peaks confirms their removal after been chemically treated

Review of kenaf fiber reinforced polymer composites

General characteristics of kenaf fibers and mechanical properties of its polymer composites (dependently on the environmental conditions) as well as applications directions of such materials have been presented

The effects of weathering on mechanical properties of kenaf unsaturated polyester composites (KFUPC).

Kenaf Fibre reinforced composites have been gaining wide use in the variety of applications. The performance of these composit es may suffer when the material is exposed to adverse environments for long periods of time. Kenaf fibre unsaturated polyester composites (KFUPC) were subjected to three environmental tests: water immersion, soil buried and natural weather tests, in order to study the effect of water/relative humidity absorption on the mechanical properties of specimens containing 10, 20 and 30% by weight of fibre content. Tensile strength and modulus of the composites were determined. A decrease in tensile properties of the composites was demonstrated, showing a great loss in mechanical properties of the humid samples compared to the dry samples. The percentage of moisture uptake increased as the weight percentage of fibre is increased due to the high cellulose content. The water absorption pattern of these composites was found to follow Fickian behavior

Biological durability of injection moulded wood plastic composite boards

The steadily growth of Wood Plastic Composite (WPC) in exterior applications resulted a need to understand their durability. In Malaysia, the durability of WPC is not only affected by mold and decay fungi as biodegradation agents but also due the termites attack. Therefore, this study was carried out to investigate the durability of WPC produced from different wood fine loadings (60, 65 and 70%) and MAPP (1, 2, 3 and 4%) concentration. The aim of this study is to determine the optimum WPC formulation associate with higher durability against biodegradation agents. Commercial polypropylene, wood fines and coupling agent premixed in dumper mixer for 30 min prior to extrusion process at temperature of 190°C using 110 mm counter-rotating twin-screw extruder. The premixed raw materials were then subjected to injection moulded using 40 ton press moulding machine and pressed into size of 30 mmx30 mm and 3 mm thick board. Biological durability tests were carried out according to ASTM D4445 for mold, ASTM method D 2017 for decay fungi and ASTM D 3345 for termites. From the result, 70% wood fine loading showed significantly lower durability due to the insufficient encapsulation of wood fine with polymer matrix. Higher percentage of coupling agent (MAPP) used in the WPC boards will provide higher durability of WPC. Conclusively, the optimum formulation for WPC i.e., 4% MAPP and 60% wood fine loading gave the highest protection against mold, decay fungi and termites

Thermoplastic impact property improvement in hybrid natural fibre epoxy composite bumper beam

Utilization of thermoset resin as a bumper beam composite matrix is currently more dominated in car manufacturer suppliers, because of availability, easy processing, low material cost and production equipment investment. Moreover, low viscosity, shrinkage and excellent flow facilitate better fibre impregnation and proper surface resin wetting. Three-dimensional cross linking curing increase impact, creep and environmental stress cracking resistance properties. Low impact properties of natural fibre epoxy composite, are main issues in its employment for automotive structural components. Impact properties in epoxy composite bumper beam could be increased by modifying the resin, reinforcement and manufacturing process as well as geometry parameters such as cross section, thickness, added ribs and fixing method optimizations could strengthen impact resistance. There are two main methods, flexibilisation and toughening, as modifying the resin in order to improve the impact properties of epoxy composite, which form single phase or two-phase morphology to make modifier as epoxy or from separate phase to keep the thermo-mechanical properties. Liquid rubber, thermoplastic, core shell particle and rigid particle are different methods of toughening improvements. In this research, thermoplastic toughening has used to improve impact properties in hybrid natural fibre epoxy composite for automotive bumper beam and has achieved reasonable impact improvements