Compression resin transfer moulding (CRTM) in polymer matrix composites

Abstract

This chapter discusses the compression resin transfer moulding (CRTM) process for the manufacture of composite materials. The process is particularly suited to the rapid production of high-quality composite parts. CRTM grew out of the need to reduce production cycle-times, and this is achieved by reducing resistance to resin flow in high fibre content reinforcing materials. The reduction in fill time is offset by the necessity for larger mould-closing forces. The benefits of CRTM are highlighted and the impediments facing a more widespread use are also discussed, including the careful process design required. A number of different variants of CRTM currently in use are examined. Process dependence on the material properties of the fibrous reinforcement are discussed, including material permeability and viscoelasticity. Modelling and analysis, based on the work of Terzaghi and Darcy, is carried out and experimental validation of numerical models as applied to planar and non-planar geometries is presented. Optimisation of the CRTM process is discussed and it is shown how the results of such analyses can be used for design purposes by the manufacturer. The chapter ends with a short review of current challenges facing CRTM and possible future trends.