Cyanate ester resins offer significant advantages as composite matrices because of their high thermal stability, their improved toughness, low outgassing, low moisture uptake and radiation resistance due to their low dielectric constant. Towards the direction of incorporating these materials in the aerospace industry, a new glass/cyanate ester material system was characterized for use in the plenum of the air-cooling unit of aircrafts. However, the first trials with this new prepreg to manufacture real parts (plenum housing) in an autoclave, highlighted some heterogeneity issues in the reliability and reproducibility of the manufacturing process.

PLENOPTIMUM project aimed to address the reasons that lead to the aforementioned heterogeneities and through a novel Design of Experiments approach identify a number of possible influential factors that affect the manufacturing process (in autoclave and out-of-autoclave) and potentially cause deviations and heterogeneities. For the first time, factors additional to temperature profile and pressure examined according to their effect on the final quality of the composite materials and the actual plenum. Process modelling as well as online curing monitoring technologies assisted the optimisation task and the quest of the optimum curing cycle.

Manufacturing trials for plenum manufacturing in an autoclave as well as out-of-autoclave process took place in the final part of the project taking into account the results of a test campaign specially designed to highlight the effect each one of the identified influential factors has. Guidelines and recommendations to the topic manager and manufacturer that ensured and optimised the manufacturing process are the final outcome.

Both participants that form PLENOPTIMUM consortium have a strong background and experience on processing/manufacturing optimization and have the proper infrastructure to meet the targets set.