After successive use and acceptance of short fiber reinforced plastics and long fiber-reinforced plastics, the automotive industry faces the next challenge: using continuous fiber-reinforced composites to produce automotive components. This type of material and workpiece can further reduce vehicle weight and fuel consumption.

The future of lightweight structures, especially body and chassis components, depends on continuous fiber composites. In this form, BASF, Germany, has established a multidisciplinary team of lightweight composite materials.

They investigated the potential of the production of automotive components by using resin injection technology using three kinds of polymers, epoxy, and polyamide as continuous fiber-reinforced substrates.

The main aim of the study is to shorten the cycle time and improve molding efficiency. One of the molding processes is resin transfer molding (RTM).

This process can be used to manufacture large and complex composite products. The dry-State multilayer continuous fiber or textile structure is placed into the temperature-controlled mould, and the die is impregnated with a low viscosity resin.

Because the initial viscosity of the resin is low, it is enough to obtain a good impregnation effect. When using thermosetting resins (epoxy and polyurethane), the cross-linking reaction occurs rapidly and when thermoplastic polyamide is used, the polyamide is polymerized and crystallized in a short time.

In the area of epoxy resins and polyurethane resins, BASF has matured brands and solutions.

The two thermosetting resins use innovative curing mechanisms that allow them to be cross-linked within minutes.

They can be molded on conventional high-pressure and low-voltage equipment. The new polyurethane system is currently under development.

The system consists of very low viscosity of the Caprolactam (PA’s mother) advanced Activator and catalyst. Unlike the classic polyamide molding process, they react ⼀ as soon as they enter the mold. The molded thermoplastic composite can be fused and recycled.

As the continuous fiber-reinforced materials in RTM are distributed throughout the workpiece, their performance is even better than that of continuous fiber-reinforced injection-molded composite products.

The first model manufactured using BASF materials suitable for RTM is a multiple-segment foldable roof assembly. This is the sandwich structure with carbon fiber reinforced plastic as the surface layer and low-density polyurethane closed-cell foam as core material.

The roof has high stiffness and good adiabatic quality. The top section of the car is 2.9kg, lighter than the aluminum structure more than 35%, lighter than the steel structure more than 65%, and their carrying capacity is quiet.