Composites for large-scale manufacturing

Continuous fibre-reinforced composites with thermoplastic matrix resins, which are well suited for use in automotive manufacturing, are themselvers complicated to manufacture. A new approach now makes it possible to use the injection moulding process.

To date, it has been very laborious to manufacture fibre-reinforced composites with a thermoplastic matrix in large quantities. On the one hand, the textile-like dense continuous fibre-reinforced structures are difficult to shape, on the other, joining the continuous fibres with a highly viscous thermoplastic matrix material is a highly complex process.

To date,  an economically profitable production technology for large-volume component series does not exist.

Adapted injection moulding process

Together with the injection moulding machine manufacturer Engel Austria GmbH, scientists of the Fraunhofer Institute for Chemical Technology ICT in Pfinztal, Germany, have, for the first time, brought a technology to production readiness that allows the series production of such continuous fibre-reinforced thermoplastic composites with an injection moulding process.

So far, it has only been possible to use the injection moulding process for fibre-reinforced composites made of short fibres or long fibres. ''Continuous fibre-reinforced composite structures with a thermoplastic matrix are becoming increasingly popular, and will be used increasingly in the automotive industry'', states Dr.-Ing. Lars Fredrik Berg, scientist and project manager at the ICT. ''With the injection molding process, components  that have high fibre contents by volume and therefore outstanding mechanical characteristics can be produced efficiently in high volume series.''