Effect of material internal pressure in curing process of SMC roll forming

Sheet molding compound (SMC) is applied to mass-production of FRP. SMC is usually formed in compression molding. However, this molding method needs huge forming energy and is not suited for long-sized products by restriction of mold sizes. So I have attempted to apply roll forming, which is known as metal rolling, to SMC. SMC roll forming has many advantages compared with other molding method, for instance the lower forming energy, and the short production time. The SMC roll forming method has two procedures of the forming process and the curing process. Now, the curing oven of the batch type of the boxy shape is used for the curing process. But, it is not suitable for continuous curing system, because of rising of the material internal pressure. In the present research, in order to develop and design the curing system applied the roll-shaped curing oven, the expansion history of the specimens caused by the material internal pressure in curing was investigated in detail.