Modelling face-core bonding in sandwich manufacturing: Thermoplastic faces and rigid closed-cell foam core

A model to predict the bond strength between thermoplastic faces and rigid, closed-cell foam cores in structural sandwich components is presented. The model is based on the assumption that the bond strength is proportional to the amount of resin that flows during manufacturing into the open surface cells of the core to bond the constituents to each other. Following model formulation, a numerical example considering bonding of glass reinforced polyamide 12 faces to an expanded polymethacrylimide core is used to illustrate the relative influence of the independent processing parameters. The numerical example is compared to a preliminary experimental investigation carried out with the same material system and a favourable, albeit preliminary, correlation between model predictions and experimentally determined bond strengths is found.