Analysis of void removal in liquid composite molding using microflow models

Abstract Void removal in liquid composite molding was studied. Two void removal mechanisms were observed during flow visualization. Owing to the complicated geometry in the fiber reinforcement, micron‐sized flow channels were fabricated in order to carry out quantitative analysis. The mobility of voids in both straight and constricted channels was investigated. It was found that the mobility of the bubble is related to both the bubble size and the wetting between the fluid and the solid surface (i.e. contact angle). A snap‐off effect of the gas bubble was observed when the bubble passed through the constricted channel. The snap‐off time was found to be a function of constriction geometry and the capillary number.