The effect of vacuum pressure during autoclave curing on tensile strength of epoxy composite reinforced natural fiber of Cordyline australis with sea water surface treatment

Abstract

In this work, the composite made from epoxy resin as a matrix and natural fiber of Cordyline australis was used as reinforcement. The fiber was prepared from the process of water retting in fresh water for 1 weeks followed by drying. The final process was soaked in sea water to understand the effect of soaked in sea water to the adhesion of the fiber and matrix. The fiber was immersed in 5 hours and also 7 hours in sea water to be compared with the fiber that is was not immersed in sea water. The curing process also consists of 2 variation processes namely hand layup and vacuum pressure. The tensile test is conducted to investigate the final product of composite. It is found that the vacuum process resulting in better tensile strength (34.610 MPa) in the sample of epoxy without fiber reinforcement (19.818 MPa for hand layup). In general for composite that are made with fiber without immersion in sea water, the tensile strength for the hand layup increase with addition of fiber fraction. On the other hand the tensile strength decreases with addition of fiber fraction for vacuum process. For the fiber reinforcement, the hand layup resulting in better reinforcement comparing the vacuum process.