Mohd Iqbal Misnon

Comparison of electrical physical and mechanical properties of textile composites using microwave nondestructive evaluation

Composites are expensive and destructive test methods are normally applied to determine their physical and mechanical properties. For textile composites, a nondestructive test (NDT) could save time and save cost if the physical properties such as moisture content, weave architecture, void content and fiber volume fraction can be deduced from electrical properties. Also, there would be savings if mechanical properties such as tensile stress and elastic modulus could be determined by NDT methods. In this research, microwave NDT (MNDT) techniques such as measurement of complex permittivities are used for correlation with physical and mechanical properties. For textile composites made from E-glass, Kevlar and carbon fiber, we have measured reflection coefficients, transmission coefficients and dielectric properties using a free-space microwave measurement system. Epoxy has been used as a resin. Experimental results are reported for dielectric constants and loss tangents of textile composites. Also, measured physical and mechanical properties of textile composites are reported.

Tensile and Flexural Properties of Composites Made from Spinning Waste

ABSTRACT Spinning especially combed yarn produces considerable waste fibre. These fibres are sold at very low price for fillings. An investigation of converting these wastes to some form of value-added material was successful in forming a composite material made from natural fibre. Cotton combing noils and blowing waste were fabricated into thin composite boards using polyester resin at room temperature utilising a compression method. Tests on tensile and flexure properties of these composites were evaluated against 100% polyester resin plaques. It was found that composites made from cotton waste were stronger than polyester without the reinforcement. Some possible applications of these composites are thin boards or panels that can be used to replace wood and fibre-board products.

Water exposure, tensile and fatigue properties of treated hemp reinforced vinyl ester composites

Recently, due to the safety issue, the incorporation of fire retardant in natural fibre composites is becoming necessary. Nevertheless, since it is potentially utilised as low load bearing material, less work has been done on the fatigue properties and the effect of water to its mechanical properties. In this work, untreated and fire retardant treated (FR) composites made of woven hemp fabric (WHF) were investigated for their tensile and fatigue properties. Tensile properties of fabricated composites were studied with an addition of water absorption factors. Both composites were immersed in the water for up to 2688 hrs and tensile properties were analysed periodically. Based on the results, tensile properties of both fabricated composites are reduced after being immersed in the water for 2688 hrs. Comparing both samples, the FR treated composites exhibited lower tensile properties than the untreated. In terms of fatigue test, each sample was tested at 50, 60, 70 and 80% stress levels in tension-tension mode for both composites. It was observed that, as the number of fatigue cycles increased, the fatigue strengths of both composites gradually decreased. Their fatigue strength coefficient was also similar (0.12) indicates that the treatment did not affect the fatigue strength of composites. The safety limits for these fabricated composites to be utilised for any application is about 24 to 30 MPa.Recently, due to the safety issue, the incorporation of fire retardant in natural fibre composites is becoming necessary. Nevertheless, since it is potentially utilised as low load bearing material, less work has been done on the fatigue properties and the effect of water to its mechanical properties. In this work, untreated and fire retardant treated (FR) composites made of woven hemp fabric (WHF) were investigated for their tensile and fatigue properties. Tensile properties of fabricated composites were studied with an addition of water absorption factors. Both composites were immersed in the water for up to 2688 hrs and tensile properties were analysed periodically. Based on the results, tensile properties of both fabricated composites are reduced after being immersed in the water for 2688 hrs. Comparing both samples, the FR treated composites exhibited lower tensile properties than the untreated. In terms of fatigue test, each sample was tested at 50, 60, 70 and 80% stress levels in tension-tension mo...

Flammability Characteristics of Chemical Treated Woven Hemp Fabric

Woven hemp fabric was treated with sodium hydroxide, commercial flame retardant chemical, and combination of both to increase its fire-retardant properties. Treatments of fire-retardant changed the properties of woven hemp fabric such as increased its fabric shrinkage and density of fibres which ranges from 0.67 to 5% and 1.43 to 1.53 g/cm3 respectively. After the treatment, the fire retardancy of the fabric increased tremendously which was observed by the burning, thermogravimetry and limiting oxygen index tests. Some of the samples were not burnt when exposed to flame source and the burning rate needed to be measured under exaggeration of flame at longer time. The limiting oxygen index value increased from 18.6 to 51 after the treatments which explained the scenario happened in the burning tests. Nevertheless, its mechanical properties decreased slightly that ranges from 18 to 32% and 23 to 39% for warp and weft respectively compared to untreated fibre.

Utilization of Eco-Colourant from Green Seaweed on Textile Dyeing

Synthetic dyes are toxic and harmful to the living things. Therefore, the demand for natural dyes is emerging globally due to the fact that they are safer and more environmental friendly, and thus, the application of natural dyes should be considered as a better alternative to synthetic dyes. Using natural dyes contributes to the acceptability of the product by the customers and also responses to the increasing demand of compatibility with the environment. Along the Malaysian coast, stretching along Peninsula, Sabah and Sarawak are the habitats for marine plants and algae. Previously, seaweeds are used for food, processed products and medicinal usage by local ethnics. However, this research focuses on the extraction of natural dye from green seaweed of Caulerpa lentillifera as textile colourant. Caulerpa lentillifera was extracted using boiling water and ammonia fermentation methods. The dyeing was then performed by exhaustion at 85 °C for 60 min. Three types of mordant were used by metachrome or simultaneous addition of mordant and dye in the dyebath. The dyed samples were then measured using spectrophotometer to analyse the shades obtained with regard to L*a*b* values and K/S values (colour strength). The dyed samples were also compared in terms of their ability to withstand washing, perspiration, rubbing/crocking and light. The results showed that the natural dye obtained from boiling water extraction method gave higher K/S values in comparison with the dye obtained from ammonia fermentation method. Fastness properties of the dyed samples were evaluated according to MS ISO standard and ranged from good to excellent rating except for lightfastness which is poor.

Integration of textile fabric and coconut shell in particleboard

In this study, cotton fabric and coconut shell were integrated in particleboard to reduce the use of wood. Particleboards containing mixed rubberwood and coconut shell with an equal weight ratio have been integrated with various layers of cotton fabric. These materials were bonded by urea formaldehyde with a content level of 12% by weight. Flexural and water absorption tests were conducted to analyze its mechanical properties and dimensional stability. Results of flexural test showed an increment at least double strength values in fabricated materials as compared to control sample. The existence of fabric in the particleboard system also improved the dimensional stability of the produced material. Enhancement of at least 39% of water absorption could help the dimensional stability of the produced material. Overall, these new particleboards showed better results with the incorporation of cotton fabric layers and this study provided better understanding on mechanical and physical properties of the fabricated particleboard.

Some Properties of Kenaf and Kenaf Combined Waste Composites

Kenaf is one of the most promising fibers for composite conversion. In this work, kenaf is being combined with and combing waste or sheared polyester waste and polyester resin as matrix. The comparison of properties are based on tensile strength and flexural strength of 100% resin, 100% kenaf and 50/50 kenaf/cotton combing waste 50/50 kenaf/sheared polyester waste in three types of lay-ups of longitudinal, cross-laid and transverse. The highest results of tensile strength are from 100% longitudinal kenaf and 100% cotton combing waste but the highest results of flexural strength are 50/50 cross-laid lay-ups of composites. The tensile and flexural strength properties are also compared with similar properties on glass composites.