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The low-velocity impact response of Napier grass fibre/polyester composites was investigated. Napier grass fibre was used as the reinforcing material in polyester composite laminates. Napier/polyester composites specimens of 10%, 15%, 20%, 25% and 30% fibre volume fraction were produced using a compression moulding machine. The specimens of the mentioned fractions were impacted with a 5 J energy level using an instrumented drop weight impact tester (IMATEK IM10). The fracture damage of the impacted specimen was analysed using a field-emission scanning electron microscope (FESEM). The experimental result shows the relationship between the volume fraction percentage of Napier fibres and the impact force, energy absorbed and stiffness of the composites. Pure polyester specimens displayed brittle behaviour with a lower peak force, lower energy absorption and less time to failure compared to Napier reinforced composites. The impacted Napier/polyester composites with fibre loading of 30% show higher absorbed energy, peak force and longer time to failure. Furthermore, the experiments on each fibre volume fraction revealed increasing load-bearing capability and energy absorption with an increase in the volume fraction of Napier fibre. The FESEM observation exhibits various failure mechanisms such as fibre breakage, fibre pull-out, matrix cracking and fibre splitting.

This paper describes the experimental investigation of the tensile and flexural strength of untreated Napier grass fibre reinforced polyester composites. Napier grass fibres were extracted trough conventional water retting process and used as reinforcing materials in the polyester composite laminates. Tensile tests were then conducted for the composite specimens from the laminates at 25% fibre loading using the electronic extensometer setup to obtain the tensile properties. The results show significant differences in tensile strength between random short fibres laminates and random long fibrelaminates with the long fibres yield over 30 % higher in strength.Both the short and long fibre composites exhibits similar strength with short fibres having slightly higher flexural strength to long fibres The laminate also shows higher maximum strength compared to other commonly available natural fibre composites with almost 75 % improved in the maximum strength compared to the short kenaf fibre reinforced composites.

This paper presents an overview of a natural fibre, namely Pennisetum purpureum, which is commonly known as Napier grass. This paper's intention is to analyse Napier grass fibre to assess the effect of alkaline treatment on the tensile properties, thermal stability, and morphology of the fibres. These fibres were extracted by a water retting process from the internodes of Napier stems. The fibres were later subjected to alkaline treatments with NaOH at 5, 10, 15 and 20% concentrations for a period of 24 h at 25°C (RT). The tensile strength, thermal stability and crystallinity of the fibres were seen to upsurge upon conducting the alkaline treatments. Thus, the experimental results demonstrate that the 10% NaOH concentration has the strongest tensile test compared to untreated Napier grass fibre. The surfaces of the fibres after the treatment were observed with a scanning electron microscope (SEM), TM-3000. SEM investigation showed that the surfaces of the fibres become rougher after NaOH treatment. Moreover, from XRD, the amount of crystallinity is also higher in the 10% alkaline treated fibres, and DSC thermograms proved that they have better thermal stability. From this study, Napier grass fibres show potential to be used as reinforcing fibres in composite structures.