Utilization of grey Taguchi method to optimize the mechanical properties of hemp and coconut shell powder hybrid composites under liquid nitrogen conditions

Through this work an attempt was made to improve the mechanical properties of composite materials by using a process called Gray-Taguchi. Hand lay-up approach has been adopted for manufacturing. Here, Woven Hemp fiber diameter, Number of hemp layer, coconut shell powder content and cryogenic temperature ranges at different levels were incorporated as result parameter. ASTM specifications were set for the manufactured laminates to perform the mechanical tests. Hemp and coconut shell powder material are exposed to 5 percent NaOH treatment to create the matrix-fiber interface exchange. To optimize composite, the Taguchi method is combined with the Gray relational analysis. The quality targets are set for mechanical properties that include compressive strength, tensile strength, impact strength and flexural strength. This study involved nine experiments on the orthogonal array of the L₉ (3⁴) Taguchi method. A combination of the composite, Gray relational analysis was applied to obtain the optimal parameter. The results of optimum parameters were verified using Conformation test. The maximum prescribed parameters are 0.7 mm woven hemp diameter, two hemp layers, 10 percent CSP content weight, and -130°C cryogenic temperature range provides the maximum energy of impact, tensile strength and flexural strength.