Das Projekt "Gegentaktverarbeitung von kurzfaserverstaerkten Thermoplasten und Fluessigkristallpolymeren" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Fakultät für Verfahrenstechnik, Institut für Kunststoffprüfung und Kunststoffkunde durchgeführt. General Information: It is proposed to investigate and model the properties of highly anisotropic short fibre composites (glass fibre reinforced LCP's and 'long fibre' reinforced thermoplastic materials). These advanced composites are compared to standard short fibre composites. 'Push-Pull' injection moulding is used to process these materials and to come to a quasi-multilayered laminate structure in the parts. The properties of these composites are highly determined by processing parameters, design of part and gating and especially by the local fibre and matrix orientation and fibre length distribution. The proposal is intended as fundamental research to provide novel tool for designing, processing and quality control of highly anisotropic materials. These tools are morphology-based and pay attention to the high gradients in fibre and matrix orientation. These objectives are achieved by three principal tasks: 1. Modelling of the 'Push-Pull' injection moulding process will provide tools to predict fibre and matrix orientation in the layers, that are formed while the melt flows several times through the mould. Crystallisation and viscous heating effects in the solidifying boundary are important for the process-related morphology. 2. Modelling of local material properties (tensors of stiffness and thermal expansion) based on measured local matrix and fibre orientation tensors, local fibre volume fraction, matrix crystallinity and local fibre length distribution. 3. Developing and application of new 2D and 3D image analysis methods to measure morphological parameters of the fibre reinforcement. Confocal Laser Scanning Microscopy using optical and physical sectioning combined with pattern matching will provide fibre orientation and length data in a one-step 3D analysis. Successful completion should strengthen the European position in the market of these advanced composites by a reduction of the development time for new parts of more than 30 per cent. This will result in a corresponding reduction of product costs. Material properties of advanced composites are improved significantly (e.g. weldline strength by more than 50 per cent) by the new 'Push-Pull' process. Achievements: A new Push-Pull mould was developed to produce different plate geometries with different grades of nylon-6.6 and LCP. Fibre orientation measurements proved that Push-Pull processing can be used to produce highly oriented glass fibre reinforced samples. The influence of non-constant thickness, diverging and converging flow respectively was investigated by fibre orientation measurements and tensile tests in these parts. A range of fibre reinforced samples has been characterized by 2D image analysis, 3D confocal laser scanning microscopy (CLSM) and ultrasonic, time of flight measurements. Significant sample regions have been scanned by these techniques.