SGL Group is showcasing newly innovated pre-impregnated textile semi-finished products also called tooling prepregs at Composites Europe, which begins on October 7, 2014.

“These prepregs are shaped and cured to make carbon fiber-reinforced plastic (CFRP) molds, which are then used to produce fiber-composite components,” SGL said.

“The Brazilian aircraft manufacturer Embraer has already qualified the new tooling prepregs,” SGL Group added.

“The special properties of this prepreg system give optimum drapability and so ensures reliable mold construction and the extended lifetime of the mold also ensures increased productivity,” Dr Andreas Wöginger, Vice President Product & Technology Management - SGL Group.

SGL explained, “Compared with conventional steel or aluminium molds, the CFRP molds offer significantly lower thermal expansion, lighter weight, and higher stiffness.

“In the production of CFRP components, particularly, a CFRP mold ensures that complex components can be produced without warpage thanks to the homogeneous thermal expansion.”

The epoxy prepreg system developed for mold manufacture also has a long shelf life, despite a low curing temperature and short curing time, and causes minimal odor. This greatly facilitates use of the new prepregs.

Carbon tooling prepregs are also suitable for moldmaking in other industrial applications. SGL Group uses state-of-the-art facilities to produce pre-impregnated carbon and glass fiber materials.

The material properties can be optimized through suitable choice of the textile component and matrix material (resin).

The fiber type basically determines mechanical properties, while by modifying the epoxy resin system it is possible to adjust viscosity and curing temperature (between 80 and 180°C).

Depending on the matrix type, the areal density of the new tooling prepregs varies between 150 g/m² and 1200 g/m². (AR)