A novel model for resin infiltration in pin-assisted pultrusion

Abstract

Based on the results of a comprehensive numerical study of pin-assisted pultrusion, we present a simple explicit model, which allows for the estimation of the infiltration depth as a function of measurable parameters. The numerical approach on which the infiltration model is based combines use of Stokes equation within the resin pool, Brinkman equation for flow inside the porous roving and a predictor-corrector iterative scheme to determine the location of the advancing resin front inside the roving. As a result of each computation we obtain a value for the infiltration depth hf, which depends on process and material parameters, such as roving speed V, pin radius R, resin viscosity μ, and substrate permeability K. The results of hundreds of such calculations are analyzed in terms of a dimensionless number Λ = μVLoδ/ (Formula presented.) KR and a master curve is obtained, according to which hf is a power function of Λ, namely, hf=C/(1+AΛB), where A, B, and C are known parameters, obtained from non-linear data fitting. Following this, we extend the model to incorporate the tensioning force as well as present a procedure for its use in multiple-pin arrangements. Finally, we present result of an extensive parametric analysis as well as comparisons with published experimental data; the agreement with the latter is very encouraging, the model being in all cases in semiquantitative agreement with experiment. POLYM. COMPOS., 38:2653–2662, 2017. © 2015 Society of Plastics Engineers. © 2015 Society of Plastics Engineers