20 th International Conference on Composite Materials Copenhagen, 19-24 th July 2015 ASSESSEMENT OF DIFFERENT TECHNIQUES FOR ADDING THERMOPLASTIC MATRIXMATERIAL IN THE REINFORCEMENT STRUCTURES Ruben Geerinck 1 , Ives De Baere 1 , Geert De Clercq 2 , Jan Ivens 3 and Joris Degrieck 1 1 Department of Materials Science and Engineering, Ghent University Technologiepark-Zwijnaarde 903, 9052 Zwijnaarde, Belgium Email: Ruben.geerinck@ugent.be web page: http://www.composites.ugent.be 2 Department of Textiles, Ghent University Technologiepark-Zwijnaarde 907, 9052 Zwijnaarde, Belgium Email: geert.declercq@ugent.be web page: http://www.ugent.be/ea/textiles/en 3 Department of Metallurgy and Materials Engineering, KU Leuven Kasteelpark Arenberg 44 bus 2450, 3001 Leuven, Belgium Email: Jan.Ivens@mtm.kuleuven.be web page: http://www.mtm.kuleuven.be/English Keywords: Woven fabrics, Knitted fabrics, Thermoplastics, Fibre reinforced thermoplastics ABSTRACT Fibre reinforced thermoplastics (FRTP) are becoming more and more an alternative for thermoset composites. Due to the viscosity of thermoplastics the production methods for thermoset composites cannot always be used. Therefore, new techniques have to be developed in order to obtain a high quality thermoplastic composite. This paper will give three possible manufacturing processes for these composites with the aid of textile processes. The different manufacturing processes of the fabrics all have in common that the thermoplastic matrix inserted during the production of the fabric (woven or knitted). As a result, this reduces the flow distance of the thermoplastic matrix which can increase the quality of the impregnation. The first manufacturing process is pultruding the reinforcement yarns so the thermoplastic matrix is already in and around every yarn. A leno woven fabric is made from these yarns to test the impregnation. The second process is inserting thermoplastic weft yarns in a non-crimp multilayer fabric woven on a face-to-face loom. The third and last examined process is knitting a thermoplastic matrix around straight reinforcement yarns using a flat knitting machine. All fabrics are then pressed under high pressure and temperature to make a composite plate. To conclude, all these studied techniques provide positive results that textile structures can be a good alternative for the production of FRTP. 1 INTRODUCTION Fibre reinforced thermoplastics (FRTP) are a fast growing market. Production technologies for thermoset based FRP’s are not always usable for thermoplastics as they are too viscous. However, textile technology can provide solutions such as mixing reinforcement fibres with thermoplastic fibres so that the flow distance is reduced and the impregnation speed and quality is improved. This mixing can be done either within a yarn or by combining yarns of both types in textile structures such as woven or knitted fabrics. Another way to achieve these goals is coating the fibre bundles. These preforms offer two ways of producing composites (i) indirect one in which fabrics are first transformed into solid sheets by heating them under pressure, after which they are transformed into their final shape by thermoforming processes; and (ii) a direct one in which textile structures themselves are thermoformed into the final structure. A first technology being assessed is yarn coating. Multifilament glass yarns were coated with PVC and used as weft yarns in leno woven fabrics. By adapting the warp tension, fabrics without any crimp