Since the benefits of composite materials have been demonstrated, particularly those relevant to the fields of transports and energy, increasingly high industrial expectations are emerging. As the control of the processes is complex, the thickness of the composite materials does not usually exceed a few millimetres. The aim of the work presented in this paper is to highlight new phenomena related to the oven/autoclave consolidation of thicker thermoplastic composites. In the case of such thick composites, the influence of certain phenomena that are usually neglected becomes important and a physical interpretation becomes necessary (the thermal contact resistance between mold and part and the influence of mold geometry). Here, an experimental approach is compared with numerical simulations of heat transfer and crystallization in order to validate the proposed thermokinetics model. Finally, some numerical observations are discussed and analyzed.