Assessment of capillary phenomena in liquid composite molding. (May 2019)

• Record Type: Journal Article
• Authors: Caglar, Baris; Tekin, Cem; Karasu, Feyza; Michaud, Véronique
• Is Part Of: Composites. Volume 120(2019)
• Page Start: 73
• Page End: 83
• Publication Date: 2019-05
• Subjects: B. Wettability -- C. Transport phenomena analysis -- E. Liquid composite molding -- E. Surface treatments; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2019.02.018
• Languages: English
• ISSNs: 1359-835X

Abstract

Abstract: The interplay between capillary and viscous forces plays a significant role for optimal part quality in fiber-reinforced composites manufactured by Liquid Composite Molding (LCM); these are however difficult to analyze during flow. Two approaches are proposed in this study: (i) a woven glass fabric's surface was modified by corona treatment to improve its wetting characteristics without altering its permeability, (ii) flow of a UV-curable resin was stopped during LCM by fast radiation cure. Capillary rise experiments and unsaturated/saturated permeability measurements confirmed the wetting improvement by corona treatment. Flow front morphology analysis of cured pristine and treated fabrics, processed under various pressure differentials, revealed the enhancement of dual-scale flow at capillary-dominated regime and improvement of intra-tow flow in viscous-dominated regime. Furthermore, the obtained results provide insight into the so-called optimal capillary number to attain the minimal void content in composites and its alteration by surface treatment of fiber reinforcements.