INTERFACE FORMATION MECHANISMS IN FIBRE REINFORCED THERMOPLASTIC TAPES
Topic(s) : Manufacturing
Co-authors :
Rami ALAWAR (FRANCE), Pierre-Jacques LIOTIER (FRANCE), Romain RAVEL (FRANCE), Patrick IENNY , Monica PUCCI (FRANCE)Abstract :
The future of composite materials consists in obtaining lighter parts using more sustainable materials. Bio-based and/or circular materials reinforced thermoplastics could represent a good solution for composites acceptability and increased uses. For instance, reclaimed carbon fibres and biodegradable flax fibres could respectively reinforce high performant Poly Ether Ether Ketone (PEEK) and biodegradable PolyLactic Acid (PLA) matrix depending on industrial applications. However, changing the nature of fibers and matrix requires first an advanced control of composite manufacturing and particularly of the fiber/matrix interface formation. The quality of interface, minimizing defects and voids inside composites, plays a primordial role on its mechanical behavior [1].
Continuous fibers composite tapes increasingly used in the transportation industry opening the possibility to process light composite structures with complex shapes, using large variety of materials. Process steps and parameters of Automated Fibre Placement (AFP) and/or Automated Tape Laying (ATL) are then studied at the macroscale of composites, in order to reduce inter and intra-plies porosity and increase adhesion between plies [2]. At the mesoscale of tape, interface formation and voids mechanisms are less investigated and still misunderstood, even if they constitute a non-negligible part of total porosity of composites manufactured with those processes.
The adhesion phenomena at the local fibre/matrix interface depend on different properties of constituents, but questions remain open about which are discriminant parameters affecting this adhesion (surfaces energies, fibre roughness…). Moreover, the effect of temperature has to be considered since the polymer is submitted to a thermal cycle during the process of interface formation. Then, the first objective of this study is to understand fibre/matrix adhesion phenomena depending of intrinsic properties of fibres and matrix as a function of temperature. Furthermore, another aspect has to be taken into account during this interface formation: the polymer flow occurring on and between fibres is a dynamic wetting phenomenon. It occurs with temperature and depends not only on the intrinsic properties of constituents, but also on the interaction between the fluid and the fibre arrangement during the flow, driven by a competition between capillary and viscous effects [3]. Actually, there is no methodology to study and deep understand fibre impregnation phenomena as a function of temperature. Development of reliable methods as well as predictive models to characterize these phenomena constitute the second objective of this study.
This study is a part of a research project funded by ANR (ANR JCJC DUINTACOS). The final aim will be the deep understanding of fiber/matrix interface formation and consolidation, considering high temperatures and the consequent cooling, at micro and mesoscopic scales, to simulate the process conditions (Fig.1).
Continuous fibers composite tapes increasingly used in the transportation industry opening the possibility to process light composite structures with complex shapes, using large variety of materials. Process steps and parameters of Automated Fibre Placement (AFP) and/or Automated Tape Laying (ATL) are then studied at the macroscale of composites, in order to reduce inter and intra-plies porosity and increase adhesion between plies [2]. At the mesoscale of tape, interface formation and voids mechanisms are less investigated and still misunderstood, even if they constitute a non-negligible part of total porosity of composites manufactured with those processes.
The adhesion phenomena at the local fibre/matrix interface depend on different properties of constituents, but questions remain open about which are discriminant parameters affecting this adhesion (surfaces energies, fibre roughness…). Moreover, the effect of temperature has to be considered since the polymer is submitted to a thermal cycle during the process of interface formation. Then, the first objective of this study is to understand fibre/matrix adhesion phenomena depending of intrinsic properties of fibres and matrix as a function of temperature. Furthermore, another aspect has to be taken into account during this interface formation: the polymer flow occurring on and between fibres is a dynamic wetting phenomenon. It occurs with temperature and depends not only on the intrinsic properties of constituents, but also on the interaction between the fluid and the fibre arrangement during the flow, driven by a competition between capillary and viscous effects [3]. Actually, there is no methodology to study and deep understand fibre impregnation phenomena as a function of temperature. Development of reliable methods as well as predictive models to characterize these phenomena constitute the second objective of this study.
This study is a part of a research project funded by ANR (ANR JCJC DUINTACOS). The final aim will be the deep understanding of fiber/matrix interface formation and consolidation, considering high temperatures and the consequent cooling, at micro and mesoscopic scales, to simulate the process conditions (Fig.1).