Comparative Studies of Tensile Strength on Polyester Resin Matrix Composites with Planar and Random Orientation Fibers

摘要

Composites have become the chosen material for new engineering materials specially in the areas of aerospace applications, military weapon and automotive components, due to its unique mechanical properties, like: high strength weigh ratio, extreme thermal shock resistance, low coefficient of thermal expansion, oxidation and wear resistance Polyester resin matrix composites reinforced with coconut fibers are being utilized as replacement synthetic fiber in fiberglass products. The high price of synthetic fiber, which is use as fiber reinforcement on fiberglass products, makes its products price become expensive. One alternative to reduce its prices is by replace fiber synthetic with other fiber, which have similar mechanical properties but cheaper and still not abandon regional potency. Coconut fiber are regional potency that still not used optimally, moreover they often considered as waste that doesn't have economic values. These research use experimental methods with control variables are percentage of coconut fiber and polyester resin by Planar and Random orientation fiber. Specimen testing makes by hand lay up fabrication. The research result shows that the optimum composition is on 40% fiber: 60% polyester resin, with value of tensile strength is 20.75 N/mm{sup}2 and value of strain is 0,7% by planar orientation fibers, while optimum composition on random orientation is on 30% fiber: 70% polyester resin, with value of tensile strength is 30.73 N/mm{sup}2 and value of strain is 1.4%.