Methodologies for the characterisation of glass fibre orientation and distribution in large components moulded from sheet molding compounds (SMC)

Sheet Moulding Compounds (SMC) made of unsaturated polyester resin and other additives, reinforced with glass fibres, have emerged as a substitute for steel automotive outer panels. For a better understanding of the compression moulding of SMC, it is necessary to characterise the flow of material and particularly of the glass fibres. The aim of this work is to develop methodologies for characterising local mass fraction and orientation of short glass fibres in compression moulded composite components such as SMC. Pyrolysis, photographs by transmission of visible light and X-ray photographs analysed with homemade software for characterising the orientation give valuable and interesting information concerning the flow of fibres.