Void Prediction During Liquid Composite Molding Processes: Wetting and Capillary Phenomena

TL;DR

This paper investigates void formation during Liquid Composite Molding by modeling pore networks and analyzing wetting and capillary effects to improve impregnation quality.

Contribution

It introduces simplified pore network models to study bubble formation influenced by capillary and wetting phenomena in LCM processes.

Findings

Capillary forces significantly affect bubble formation.

Pore network models help predict void locations.

Microfluidic approaches reveal wetting dynamics.

Abstract

The aim of this work is to contribute in improving fibrous preforms impregnation for Liquid Composite Molding (LCM) processes. The void prediction in LCM sparks off interest within the Composite Material elaboration because it represents a significant issue to keep the expected mechanical properties of the final product. The liquid properties, the preform geometry and the flow conditions impact the void or bubble entrapped inside and outside the yarns. Nevertheless, due to the complex geometry of the reinforcement, experimental characterization of bubble formation remains delicate. Thus, our study deals with two simple model networks representing connected pores so called "Pore Doublet Model". A first is considering two capillaries converging on a node (T-junction) and a second is representing two capillaries interconnected with a supplying principle. In this paper, we emphasize on microfluidic and millifluidic approaches where wetting and capillary forces are significant during bubble formation mechanism.