Properties of Randomly Oriented Chopped E-glass Reinforced Unsaturated Polyester Based Resin Composite -Effect of Length/Content of E-Glass Fiber and Number of Stacking-

: To develop automobile parts, the unsaturated polyester based matrix resin(PR)/reinforcement(randomly orientedchopped E-glass fiber, GF) composites were prepared using sheet molding compound(SMC) compression molding. The effectsof GF length(0.5, 1.0 1.5 and 2.0inch)/content (15, 20, 25, 30wt%) and number of ply(3, 4 and 5) on the specific gravityand mechanical properties of PR/GF composites were investigated in this study. The optimum length of GF was found to beabout 1.0inch for achieving improved mechanical properties(tensile strength and initial modulus). The tensile strength andinitial modulus of composites increased with increasing GF content up to 30wt%, which is favorable content range for SMC.The specific gravity, tensile strength/initial modulus, compressive strength/modulus, flexural strength/modulus and shearstrength increased with increasing the number of ply up to 5, which is the maximum number of ply range for SMC. Theeffectiveness of ply number increased in the flexural strength > shear strength > compressive strength > tensile strength.