InFo – Integration of Thermoplastic Foils into the Manufacturing Process of Composite Parts

The project demonstrates the processing of fibrous material in the RTM process without release agent and confirms the practicability of combining fiber draping and injection in a single die.

Project Partners
DIEFFENBACHER GMBH Maschinen- und Anlagenbau, KraussMaffei Technologies GmbH, Roding Automobile GmbH, Voith Composites GmbH & Co. KG

Duration
01.06.2011 – 31.05.2014

Funding Authority
German Federal Ministry of Education and Research

Motivation
At the beginning of the project, numerous processes for coating composite shell parts with an organic layer were state of the art in automobile production. These were predominantly processes of coating from a liquid (painting, paint injection) and coating by plastic foils (foiling by inserts or subsequent foiling by a double vacuum chamber). These coating processes lead to longer and more complex process chains since the coating step is added sequentially to the existing process chain. The goal of the project was to plan, conceptualize and realize a foil-based process chain for composite shell parts. The foil is thereby multifunctional and allows to overcome the conflict of objectives between technical readyness to use (reduced need for surface finishing, weldability, no need for release agent) and shortened process chain.

Method
A holistic concept of industrialization was realized at the example of an actual geometry of an outer skin. An alternative, foil-based process was developed for the manufacturing and handling of fibrous preforms. Its degree of automation could be demonstrated at a test facility. The separation effect of foils in the injection process was succesfully validated. Moreover, demonstrators which were foiled, formed, injected with resin and finished were manufactured. A high-quality surface was achieved by only one grinding and painting step. A material system for the realization of all project goals within a short process chain was itentified. If comprises a polycarbonate multiple layer foil, a thermoset resin system on the basis of polyurethane and fibrous material with a tricot franse stitching pattern. The investigations led to a production machinery which is based on two processing modules. The first module puts a process for manufacturing flat and foiled fibrous inserts into pratcise, the second module grips the semi-finished products with improved handleability and processes them to composite parts with reduced need for finishing work.

Publications

Film-RTM. Film-RTM: Konzept. URL: www.youtube.com/watch


Film-RTM. Film-RTM: Der Effekt. URL: www.youtube.com/watch


Film-RTM. Film-RTM: Technologiedemonstrator. URL: www.youtube.com/watch

Acknowledgement
The chair thankfully acknowledges the funding of the project “Integration thermoplastischer Folien in den Herstellungsprozess von Faserverbundbauteilen – InFo” provided by the German Federal Ministry of Education and Research (funding code: 02PJ2061).