Quantitative Assessment of Reactive and Non-Reactive Binder Systems on First Ply Adhesion for Dry Fiber Placement Processes

Abstract

Dry fibers or fabrics do not possess an inherent tack, when compared to prepreg materials. In order to fixate dry fiber fabrics onto tooling geometries, auxiliary binder systems are necessary. These tackifying agents vary in terms of chemical composition and reactivity, processing parameters and appearance. One key aspect for most automated fiber placement technologies (incl. Dry Fiber Placement; Abr. DFP) is the adhesion of reinforcement materials on tooling surfaces, also referred to as first ply adhesion. Insufficient prepreg or binder adhesion will lead to fiber slippage thus increased scrap rates and is therefore crucial for high class composite performance. This study reveals quantitative insights on binder performance and indicates that the treatment with solvent-based release agents reduces first ply adhesion by up to 78%. Furthermore, it shows, that elevated tooling temperatures reduces binder adhesion by up to 49%.