Effect of pressure and reinforcement type on the volume chemical shrinkage in thermoset resin and composite

The diverse use of thermoset composite materials is increasing day by day in industrial applications. This has led to the development of several fabrication techniques, use of various reinforcement types, and different fabrication conditions to achieve a composite part with required properties. Despite all these technological advancements, there is a shear need to investigate and understand the effect of all these factors on the curing process. Volume chemical shrinkage of resin is one such property, which has been studied by several authors for a given value of applied pressure. A few studies have reported results on volume chemical shrinkage of composites for one type of reinforcement and for a single applied pressure. In the present work, experiments on vinylester resin and associated glass fibres composites were conducted under two different pressures. The tested composites were containing unidirectional fibres ([0] and [0/90]) and plain woven fabric with two different fibre volume fractions. The results of these experiments, carried out in a plunger type dilatometer, led us to show the effect of fibre fraction, type of reinforcement, and applied pressure on the volume chemical shrinkage of vinylester resin.