Resin suitable for prepreg and heat curing – Hot cure system

Prepreg resin is used to make prepreg fibers. The hardener in this type of resin reacts with the resin and cures only when exposed to heat. Prepreg fibers are used to manufacture special parts with high mechanical strength and resistance, such as wind turbine blades. The heat-curing and prepreg resin produced by Mandegar Baspar Company is used in the production of prepreg fibers. Another application of this type of resin is in the filament winding system, which is widely used in pipe manufacturing industries.

What is Prepreg?

Prepreg is the common term for a reinforcing fabric that has been pre-impregnated with a resin system. This resin system (typically epoxy) has already been combined with a suitable hardener. As a result, the prepreg is ready to be placed into a mold without adding any other material. To achieve the best quality laminate, the application of combined pressure and heat is essential.

How do Prepregs work?

Fabrics prepared as prepregs are slightly sticky, so they are placed between two layers of plastic to prevent them from sticking together during transport and before use. By peeling off the two plastic layers, the prepreg is ready for use.

For complete curing of the prepreg, heat and pressure are required simultaneously. Although pressure can be applied using a press, the common method is to use a vacuum bag. First, the prepreg layers are placed in the mold. After applying sealant tape and a vacuum bag and connecting it to a vacuum pump, the mold is placed in an oven or furnace for heating. During the heating of the prepreg, the part must remain under vacuum and not lose vacuum until the end of the process. The vacuum helps remove excess resin and air bubbles from inside the part.

It should be noted that the ideal curing environment for prepreg is an autoclave, which has temperature and pressure control. However, prepregs are generally cured without an autoclave, in a conventional manner.

In general, it is better to use ovens with proper temperature control for heating prepregs, where the heating and cooling ramp rates can be controlled. Also, be sure not to use ovens used for cooking, as prepregs release vapors during curing that are harmful to food.