Study On Degradation Of Glass Fiber Sheet Moulding Compound Under Hot Water

Current study investigated the mechanical property of Sheet Moulding Compound (SMC) using25mm-long glass fiber as reinforcement for the possibility of producing bathtub materials. In this experiment SMC cuttings from the bathtub immersed into hot water (90℃) from250-1500hrs followed by tensile test with Acoustic Emission (AE) monitoring and microscopic investigation to evaluate its initial fracture and degradation mechanism. The specimens were prepared in two perpendicular directions determined as Y (resin flowing direction) and X direction in the paper. The initial fracture generated in tensile test was determined by both tensile stress-strain curve and AE measurement (140kHz and1MHz resonant frequencies).The result shows that different fiber orientation and mechanical property between Y and X are occurred due to the fiber flowing during molding. In most cases Y specimen tensile strength and modulus is higher than X specimen. Initial fracture stress from stress-strain curve and AE measurement were obtained and was proposed as an allowable products design.