Modeling of Degree of Cure in Epoxy-glass Prepreg

Degree of cure is one of the most important properties of prepregs, so that the change in degree of cure will cause the changing the of other properties such as, mechanical properties, tack and resin flow. In order to predict and monitor degree of cure, the quantitative relation with processing parameters such as line speed, oven temperature and resin content have to be determined. In this paper, the heat transfer equation governing epoxy-glass prepreg curing systems, together with the equation for the rate of epoxy resin curing is solved using numerical methods and computer programs written in the MAPLE software. The kinetic parameters of the curing reaction of epoxy resin are also evaluated by using isothermal differential scanning calorimetry data. According to results, initially, the temperature and the degree of cure will be reduced by increasing the amount of resin. However, releasing of the heat of curing increases both the temperature variation rate and the degree of curing. Moreover, the fiber types affect the degree of curing; the higher the density and specific heat capacity of the fibers, the less the temperature and degree of curing. Finally, increasing the oven temperature raised the temperature and degree of cure, as expected. On the other hand, increasing the line speed decreased the temperature and the degree of cure.