Effect of coconut shell powder filler on performance of polyester composites for ballistic application

This work reports the use of coconut shell powder filler with polyester resin for the development of Nylon 6,6 fabric reinforced composite panels. The impact resistance of the prepared composites against 0.22 caliber projectile has been studied at four different weight proportions (10%, 20%, 30% and 40%) of coconut shell powder filler. With an increase in filler proportion, the depth created on the clay backing after ballistic impact is found to decrease from 7.62 cm to 4.60 cm in the 25 m range and from 7.62 cm to 2.39 cm in the 30 m range. Consequently, the area involved in impact energy absorption is also found to increase from 0.44 cm2 to 2.27 cm2 in the 25 m range and from 1.86 cm2 to 4.9 cm2 in the 30 m range. The increase in the area due to the absorption of impact energy ensures effective distribution of the impact energy over the panels. Coconut shell powder filler added with resin has a significant effect in improving the impact resistance of the composite panels due to the changes in the inter-yarn frictional force of the reinforced fabrics. Further, the impact test results are based on the findings of tensile strength test and Rockwell hardness test. There is an increase in tensile strength by 25% and hardness by 41.6% as compared to the control sample.