Effects of curing time and de-molding temperature on the deformation of glass fiber/epoxy resin prepreg laminates fabricated by rapid hot press

The present article focused on the residual strains and deformation of the laminates fabricated by rapid hot press process using prepreg. Strain gauges and laser tracker were utilized to measure the residual strains and deformation of the laminates. By studying the effects of curing time and de-molding temperature on residual strains and deformation of composite laminates, the efficient curing conditions were proposed and good processing quality was ensured. The results indicate that the laminates with low curing degree incline to generate high residual stresses during curing and cooling processes. The effects of cure duration and de-molding temperature on the deformation degree and type of laminates are significant. In order to ensure both curing efficiency and low deformation, the curing time of the resin and de-molding temperature should be designed cautiously. The experimental results suggest that the curing duration longer than 12 min is needed, and the de-molding temperature should be no less than 40°C lower than glass transition temperature of the cured matrix.