Abstract The objective of this study is to determine the optimal cooling scheme to minimise the processing time during the cooling stage in press moulding. The optimisation is subject to the quality constraints concerning maximum allowable residual stress and recommended levels of crystallinity. Since they depend on temperature state, a one-dimensional transient heat transfer analysis was carried out using a finite difference method so as to obtain the transient temperature profile through the thickness of the laminate. The heat transfer analysis was then coupled with a crystallisation-kinetics model. Using a plane-strain viscoelastic model, residual stress distribution was obtained corresponding to a given cooling scheme. These models were then integrated into an optimisation algorithm called sequential simplex, to minimise the cooling time without compromising quality requirements. Significant reduction in processing time was obtained for APC-2 laminates.