The role of the forming die is to achieve compaction, forming and curing of the billet. The cross-sectional dimension of the mold should take into account the molding shrinkage of the resin. The length of the mold is related to the curing speed, the mold temperature, the product size, the pultrusion speed, and the properties of the reinforcing material. The usual length of the mold is 600-1200 mm. The cavity finish is high to reduce friction, extend service life, and ease release. Microwave heating is used for high performance composites, usually by electric heating. Cooling devices are required at the mold population to prevent premature curing of the banana leaves. The dipping process mainly controls the relative density (viscosity) and immersion time of the glue. Its requirements and influencing factors are the same as prepregs.

The curing molding process mainly grasps the molding temperature, the mold temperature distribution, and the time when the material passes through the mold (pultrusion speed), which is the key process of the pultrusion process. In the pultrusion process, the prepreg through the mold is a series of physical, chemical and physicochemical complex changes that have not been known so far. In general, the mold can be divided into three regions according to the form when the prepreg passes through the mold. The reinforcing material passes through the mold at a constant speed, and the resin is different. The behavior of the resin in the mold population approximates the Newtonian fluid, and the viscous resistance at the surface of the resin and the inner wall of the mold slows down the advancement speed of the resin and gradually returns to a level comparable to the fiber as the distance from the inner surface of the mold increases.