Experimental investigation of nano-alumina effect on the filling time in VARTM process
In this research, by producing composite samples made of glass fibers and epoxy resin with different percentages of nanoparticles (Nano-alumina), the adding effect of nanoparticles of alumina Alpha and Gamma grade on filling time in the vacuum assistant resin transfer molding process (VARTM) is investigated. The grade Alpha and Gamma of Nano alumina were added to the epoxy system with the weight percentage of 1, 2, 3, 4, 5 and 6. The experimental results show that increasing nanoparticles lead to increase the filling time which is caused by increased fluid viscosity and consequently more resistant to vacuum pressure applied to flow fluid in porous media of preforms. By adding of nanoparticles, an optimal limit exists to prevent a significant increase in the filling time which is 3% for Nano-composite samples of alumina with grade of Alpha and Gamma. Also, in the first, the movement speed of the resin into the preform is about one centimeter per second, and by increasing flow this speed gradually decreases (close to zero).
Keywords: Nano-composite, VARTM, Nano-Alumina, displacement-time curve, die filling time