The utilization of coconut fibers as reinforcement in polymer composites has been increase significantly due to their low cost and high specification of mechanical properties. Whereas kevlar fibers has widely used as the core material in flexible body armors due to its great mechanical properties, such as high strength, light weight, good chemical resistance and thermal stability. The research work is concerned with the evaluation of high speed impact and flexural test of hybrid textile reinforced epoxy composites. Samples were prepared from coir yarn, kevlar yarn, interlaced of coir and kevlar yarn with different warp/weft orientation and pure epoxy as control specimen. The woven samples were produced using handloom and the composites specimens were prepared using hand lay-up technique. From the results obtained, it was found that woven kevlar composites samples displayed the highest impact properties while it exhibits the lowest flexural properties. Results also showed that the composite plate for woven coir yarn (warp) and kevlar yarn (weft) has the flexural strength and impact strength of 17 MPa and 67 kJ/m², which presented as the nearest properties to woven Kevlar composite respectively. These results indicate that coir as a natural fiber can be used as a potential reinforcing material for high impact resistance such as body armors in order to reduce the usage of synthetic materials whilst utilizing the natural resources.

Abstract. This research focuses on the study of oblique impact on kenaf reinforced composite plate. This study summarizes modeling analysis of targets subjected to certain angle of collisions which ranging from 0"-45". Due to the low density, natural fiber such as kenaf fiber provides relatively good mechanical properties than glass fiber. Thus, natwal fibers have high potential for better reinforcement in light weight structures such as aircraft, automobile. In this research, the velocity impact analysis is conducted by using the commercial finite element analysis software, ANSYS. A few finite element models of the nonwoven composite panel and a rigid impactor is developed using ANSYS software. Experimental investigations in determining mechanical properties and validating purposes are conducted in earlier study by using Universal Testing Machine and High Speed Impact Puncher. Total force, total energy, deformation, and energy absorption of kenaf reinforced composite for oblique impact are analyzed and discussed. The rise of oblique angle will increase the energy absorption of the composite. IntroductionOver the past few decades, there has been a growing interest in the use of natural fibers in composite applications. These types of composites present many advantages compared to synthetic fibers, such as low tool wear, low density, cheaper cost, availability, and biodegradability [I-21. The response of composite materials to ballistic impact has been investigated by many researchers [3-61. It is obvious from the open literature that research on ballistic impact has been focused on the high performance fibres, metals and ceramics. In replacing metals and ceramics, syntactic fiber such as aramid fiber was used to produce more lightweight composites. But, it's consumes to increasing cost of composite to be produced. Therefore, many researches had been done on natural fiber based composite [4-71. Producing composite samples and performing the experimental will consume much time and cost. By using finite element analysis software, the natural composite model can be numerically created in short time and many tests can be virtually performed. But, it is important to do a validation process by comparing the experimental and numerical results obtained before any hither work conducted. Natural impacts in which the projectile strikes the target vertically (90" towards plane) are virtually nonexistent. Its normally occurs in oblique impact by which the impacting occurs in a certain angle of collision.

The interest in utilizing natural fiber as reinforce in polymer composites has increased in recent years due to their advantages like availability, cheap, renewable, lightweight, and biodegradable. However, the main challenge of natural fiber to be used as reinforcement in polymer is their hydrophobic nature. One of the solutions is via chemical modification like mercerization treatment. In this study, the effect of alkali concentrations at 2 and 10 w/v %; and soaking temperature at 30°C and 80°C on a kenaf fiber bundles mean diameter was investigated. Untreated kenaf fiber was used as a control unit. Kenaf fiber diameter was measured using a Leica video analyzer. Microstructure change of kenaf fiber before and after mercerization treatment conditions was identified using JOEL scanning electron microscopy (SEM). Finally, an interaction of alkali treatment conditions on kenaf fiber bundles mean diameter value was statistically analyzed using a commercially available statistical software package. The results showed that kenaf fiber bundle mean diameter was reduced by 30.12% to 42.92% after mercerization treatment. From analysis of variance, the main effect of alkali concentration value was 6.075 and the temperature value was 1.135. The main effect plots reveal that alkali concentration had a higher impact on mean diameter changes compared to soaking temperature factor.

is present project investigated the impact penetration response of woven jute fiber reinforced composites subjected to wide range of low impact velocities. Hand layout woven jute fibers are thermally compressed to ensure no internal defects formed in the composites. Six layers of woven jutes are stacked together using different fiber orientations [0/q/0]s. Low impact velocities are used ranging between 5 – 20 m/s. Force-time, force-displacement and energy-time curves are obtained automatically during the impact tests. The results are then discussed with considering the composite fragmentations and failure mechanisms. It is found that 00composite orientations capable to absorb sufficiently impact energy for 5 m/s but not for velocity greater than 10 m/s. When fiber orientations used between 15 – 450, the composite impact resistance increased indicating two significant peak forces. These peak forces represent different type of failure mechanisms occurred during the striker progresses.

Abstract. The increase of environmental issues awareness has accelerated the utilization of renewable resources like plant fiber to be used as reinforced material in polymer composite. However, there are significant problems of compatibility between the fiber and the matrix due to weakness in the interfacial adhesion of the natural fiber with the synthetic matrices. One of the solutions to overcome this problem is using chemical modification like alkali treatment. In this study, the impact of alkali treatment conditions on short randomly oriented kenaf fiber reinforced polyester matrix composite tensile strength was investigated. The experimental design setting was based on 2 level factorial experiments. Two parameters were selected during alkali treatment process which are kenaf fiber immersion duration (at 30 minute and 480 minute) and alkali solution temperature (at 40 o C and 80 o C). Alkali concentration was fixed at 2% (w/v) and the kenaf polyester volume fraction ratio was 10:90. The composite specimens were tested to determine the tensile properties according to ASTM D638-10 Type I. JOEL scanning electron microscopy (SEM) was used to study the microstructure of the material. The result showed that alkali treatment conditions setting do have the impact on tensile strength of short randomly oriented kenaf polyester composite. The interaction factors between immersion time and temperature was found to have prominent factors to the tensile strength of composite followed by the immersion time factor.

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This research work was concerned with the evaluation of mechanical properties; flexural strength and impact strength of coconut coir textile composites. The coir fabric reinforcement was in a form of woven and cross ply structure. The two types of laminates orientations for cross-ply structures were 0/90 degrees and 45/-45 degrees. Composites with fibre weight fraction of 30% were prepared by hand lay-up and vacuum bagging technique. Mechanisms of composites failure were examined using scanning electron microscopy (SEM). Results have shown that the woven coir reinforced composites exhibited higher impact resistance and flexural strength (warp woven) compare to cross-ply composites. Moreover, 0/90 degrees orientations demonstrated better strength performance compare to 45/-45 degrees. However, damage propagation on woven composites was found to be larger than cross-ply composites. Normality test of data distribution were evaluated using Minitab software and it was proven that all samples were in a very stable behaviour (p > 0.05). Experimental results were also validated using one way analysis of variance technique (one way-ANOVA) and it revealed there was statistically significant difference (p < 0.05) between all different fabric structures of coir fabric as reinforcement in composite.

This review paper reports the studies available on the characteristics and applications of the henna (Lawsonia inermis) as a natural dye. Textile materials are mainly from synthetic dyes and fibers which are not renewable and not biodegradable. Around 30 million of tonnes was estimated for the global consumption of textiles and was expected to grow up to 3% per annum while 70,000 tonnes of dyes were released to the environment. The population of people who will have allergic to the chemicals will grow up to 60% by year 2020 which was stated in business week. Apart from that, natural dyes can be extracted and process from various sources such as plants, leaves, minerals, roots, barks and insect sections. Plants that was found in the world approximately 20% were for the pharmaceutical or biological test and new antibiotics were introduced in the market are obtain from natural or semi-synthetic resources. For the biological test, henna oil was tested against Staphylococcus aureus which was 870 μg/mL and Neisseria gonorrhoeae was 87 μg/mL respectively while henna leaves extraction using methanol of 95% showed significant in-vitro antihyperglycemic effect. Chemical contains in the henna are carbohydrates as 33.62%, fibers as 33.5%, fatty oils as 10–11% and essential oil as 0.01–0.02%. Moreover, the good UV absorbency for the henna dyed cotton was at 900 °C for 60 minutes and the colour fastness for the fabric which was dyed with henna is 4 which is good. Henna dye has slightly negative charge for the higher pH 9 for the washing fastness. The optimize condition for the pre-mordant is 4% for the copper sulphate (CuSO4) for cotton with the extraction of henna leaves. Furthermore, the optimum condition for the henna to remove lead Pb (II) from wastewater are pH 6, contact time is 80 minutes, 10 ppm for the initial metal concentration and 0.75 g/L for adsorbent dosage.