Cure cycle optimization for the resin infusion technique using carbon nanotube additives

• Published in: Carbon (New York) 2016-01, Vol.96, p.1043-1052
• Main Authors: Anil Kumar, A., Sundaram, Ramesh
• Format: Article
• Language: English
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2015.09.044

Cure cycle optimization of resin transfer molding grade epoxy resin system was studied for the manufacture of composite structures by the resin infusion technique. Cure cycle optimization necessitates resin viscosity optimization for appropriate wetting of fiber preform and to minimize excess resin bleed out, which results in an optimal fiber volume fraction of 58–60%. To achieve this, two different approaches were experimented: 1) resin aging, and 2) using multi-walled carbon nanotubes (CNT). Different sets of viscosity experiments with varying ‘aging temperatures’ and CNT concentration were studied on neat resin to arrive at an optimum viscosity profile. Carbon fiber reinforced test laminates were then manufactured by the resin infusion technique using the modified cure cycles based on optimized resin viscosity profiles. Ultrasonic non-destructive evaluation of cured test laminates showed uniform and relatively good consolidation. Mechanical properties evaluation showed that modified cure cycles resulted in similar results. The resin content analysis through acid digestion method ensured acceptable fiber volume fraction with void content less than 1%. Incorporation of CNT decreased the total cure cycle to a considerable extent. This novel approach of using CNT reduces processing time by a large margin, thereby reducing the final cost of the product.