<![CDATA[The development of technical materials, especially polymer composites including high-tech materials, manufacturing processes and engineering applications has shown a significant improvement. The problem that arises along with the development of the technology of polymer composite materials is how to utilize materials whose sources are of sufficient availability and are able to be regenerated to anticipate material crises. Especially the type of polymer plastic, where the availability of material sources is influenced by petroleum sources that cannot be renewed. Based on these considerations, a study of composites with fillers from natural fibers was carried out. Natural fibers used are coconut fiber and palm sugar fibers that are widely available in Indonesia. In this study using an experimental method, by varying the composite raw materials of coconut fiber (0%, 5%. 10%, 15%, 20%) and palm sugar fibers (40%, 35%, 30%, 25%, 20 %), and polyester resin at 6%. The testing standard used is JIS K 7113, which is testing tensile strength in the composite. From the results of the research conducted, it can be concluded that the addition of coconut fiber and palm fiber can affect the composite tensile strength. The value of the largest tensile strength reached an average of 17.67 MPa with a fraction of the volume of coconut coir fiber 20% and palm sugar fibers 20% and the modulus of elasticity 257,1183 Gpa. this shows that the higher the composition of the mixture of coconut fiber to the palm fiber fiber composite, the greater the strength of the tensile strength, due to the nature of the palm fiber fibers that are strong, flexible and not hollow because the cellulose content in the palm tree fibers is lower than the lignin content.]]>
