Coupling filtration and flow during liquid composite molding: Experimental investigation and simulation

Abstract

Molding composites constituted of fiber reinforcements, resin and fillers is of prime interest for many transportation applications. Dealing with the flow of particle-filled resin in a fibrous network raises the issue of particle retention and viscosity increase. The present study aims at simulating such molding through an efficient coupling between a filtration model, that has been previously described, and a flow model (Darcy's law). First, filling experiments are realized so as to separate cases: cake filtration, retention and no retention for two types of single-scale porous materials (polyester felt and glass fiber mat) injected with a resin filled with micro-beads. Then results of filler content, viscosity, permeability, pressure , retention profiles are simulated from the coupling between filtration and flow. Experimental data of filler profiles in the final parts, resin flow front evolution and injection times are compared with predictions obtained from the simulation.

Simulation of coupling filtration and flow in a dual scale fibrous media

“…The particle filtration phenomenon was investigated for the effect of, particles size, the particles concentration and the preform size. The comparison made between our numerical results and those experimental [5,6] shows a good agreement. In conclusion, we find that the addition of particles in resin injected into a fibrous media can significantly modify the rheological behavior of suspension and therefore its flow.…”

“…In order to validate the proposed modelling approach, we will make a comparison between the numerical results of our model and experimental results from Lefevre D. [5,6]. The author is interested to study the flow of particle-filled resin through a fibrous Table 1.…”

“…For the permeability determination of the filter system, we consider the same approach used by authors D. Lefevre et al [6]. By electrical analogy, the filter system is considered as the superposition of two sub-systems: the fibrous preform ( assumed constant) and the retained particles ( ) which evolves over time.…”

“…By electrical analogy, the filter system is considered as the superposition of two sub-systems: the fibrous preform ( assumed constant) and the retained particles ( ) which evolves over time. We adopt the Kozeny-Carman formula generally used to describe the permeability of particle deposition [6]:…”

“…For example Erdal et al [4] formulated an evolution equation for the particle concentration during infusion of particle filled resin and filtration kinetics, considering re-suspension of particles. Lefevre et al [5,6] argued that a proper retention function needs to be introduced to account for their experimental observation in typical particle concentration profiles. More recently, Hwang et al [12] proposed a two-dimensional direct numerical simulation technique to describe particulate flows in dual scale porous media to predict particle deposition on the permeable porous surface.…”