An integrated process model for air evacuation and tow impregnation in out-of-autoclave prepreg consolidation

Out-of-autoclave (OOA) prepregs are an attractive alternative to conventional autoclave materials in terms of costs, sustainability and size constraints. However, due to low compaction pressure during cure, voids and porosity remain the main issue in OOA fabrication leading to reduced performance. To achieve the bench mark quality of autoclave structures, flow and compaction phenomena occurring during the consolidation of OOA materials have to be well understood in order to bring process and material parameters into optimal agreement. A basic understanding of void formation during consolidation may be gained by modelling the change of thickness of the prepreg as a function of fibre, resin and gas behaviour during cure.