Production of FRP with in-line-compounded thermoplastic matrix in the LFT-D-ILC direct process.

The relevance of long fiber reinforced thermoplastics in the automotive sector has grown significantly during the last few years. State of the art is the processing of semi-finished products like glass mat reinforced thermoplastics (GMT) and long fiber granulates (LFT-G). However, the so called direct process technologies (LFT-D) are about to gain a growing market share. These technologies enable the manufacturer to manufacture components based on the raw materials glass fibers, thermoplastic resin and additives by using the compression molding technique. Concerning the choice of materials, the LFT-D-ILC process technology with in-line compounding of the matrix polymer offers added value in regard of flexibility. The matrix polymer is tailored directly within the process by adding modifiers to affect mechanical and specific properties, e.g. heat stabilization, for each application individually. At the Fraunhofer Institute for Chemical Technology (ICT) in Pfinztal/Germany the LFT-D-ILC process technology is available at a pilot plant scale, which allows the development and scientific characterization of material combinations under almost large-scale processing conditions. The use of long fiber reinforced engineering thermoplastics for light weight components leads to improved mechanical properties. The combination of these materials with local reinforcement of components by continuous fibers, e.g. fabrics, non-wovens, and uni-directional profiles, enables the production of semi-structural and structural "Advanced LFT-D" parts. Investigations at the Fraunhofer ICT have shown that the LFT-D-ILC process technology is also qualified for the processing of engineering thermoplastics. In comparison with long glass fiber reinforced Polypropylene (PP) a significant increase in mechanical properties has been found. This paper shows mechanical and processing properties of different engineering thermoplastics that have been processed using the LFT-D-ILC equipment and a range of potential applications for the considered materials is included, e.g. a locally reinforced front-end carrier and an instrument panel carrier which includes a directly integrated system enabling the opening of the airbag. The development of large scale processing methods of these components was supported by the Federal German Ministry for Education and Research (BMBF) within a public funded project. For the covering abstract see ITRD E126782.