Trade-off between curing energy and rate in incremental composite manufacturing by frontal polymerization

• Energy-time-efficient incremental curing of CFRP composites is achieved via FP. • Trade-off between curing energy and rate is analytically and numerically investigated. • Manufacturing parameters from the Pareto front are experimentally validated. • A normalized areal processing rate of 59.0 h −1 demonstrates scalable manufacturing. Manufacturing large carbon fiber-reinforced polymer (CFRP) composite structures requires autoclaves that accommodate bulky volumes. The large volume and modest heating rates lead to inefficient power use and manufacturing time to achieve fully cured thermoset composites. In this study, the trade-off between curing energy and curing cycle time is numerically studied and experimentally validated for a frontal polymerization (FP)-based CFRP manufacturing process. To produce high-quality CFRP, the exothermic FP is thermally triggered using a heated tooling plate, enabling through-thickness FP under normal compaction pressure. To progressively cure large areas, the cured CFRP is translated after each curing step until the large composite part is fully processed. Computational modeling is first employed to study the trade-off relationship between the heating energy and curing time, and to identify the Pareto front for the lowest energy and highest cure rate. In addition, thermal cycle of the incremental curing process is further adjusted to reduce energy input and curing time. Incrementally cured CFRP composites achieve full cure at a normalized areal processing rate of 59.0 h −1 , with a high fiber volume fraction ( ϕ = 0.63 ) and a glass transition temperature ( T g = 166 °C). These results demonstrate the potential for rapid, scalable, and energy-saving manufacturing of large composite structures.