Cure cycle optimization of infrared cured composites using Taguchi method

Knowing that cure cycle has a significant effect on the mechanical properties of the composite materials, determining the effects of cure cycle parameters - such as heating rate, maximum temperature, and dwell time, has gain importance. This study addresses the optimum cure cycle of an infrared cured carbon fiber pre-preg material. An infrared oven equipped with 1 kW halogen infrared heating unit and vacuum system was used. Different cure cycles determined by means of Taguchi experiment design approach and a cure cycle was found maximizing the tensile strength of the material. Results showed that infrared curing is a strong alternative to the autoclave despite its shortcomings regarding the product geometry. The optimized cure cycle showed 23% increase in the tensile strength comparing the tested cure cycle which is resulted with the minimum tensile strength. Besides, comparing the specimens cured with the optimum cure cycle, the infrared cured specimens showed slightly higher tensile strength than the autoclave cured counterparts. According to Taguchi optimization, optimum values for maximum tensile strength were found as 10 degrees C/min, 130 degrees C for heating rate and 60 min for plateau time. According to the analysis of variance, the most effective parameter affecting the tensile strength was the heating rate.