Effect of loading rate, viscosity, and binder activation on the bending response of an infiltrated UD-NCF

Assessing the bending response of infiltrated reinforcement fabrics is crucial in wet compression molding (WCM) as it affects macroscopic wrinkling. Binder-stabilized fabrics may be used in WCM to improve handleability and reduce defects, necessitating their characterization. This study examines the bending behavior of an infiltrated binder-stabilized carbon fiber unidirectional non-crimp fabric (UD-NCF), focusing on the effects of viscosity, loading rate, and binder pre-activation. Infiltration reduces bending stiffness compared to dry fabric owing to lubrication and lower tow-stitch friction, while higher loading rates increase bending stiffness for all considered conditions. Moreover, binder pre-activation increases fabric stiffness by enhancing tow-stitch cohesion and friction. As the first investigation on infiltrated binder-stabilized UD-NCF bending, this work advances understanding of the complex bending response.