The Influence of Cooling Conditions on the Mechanical Properties of Commingled Yarn Composites

The influence of cooling conditions on the bending properties and Mode I interlaminar fracture toughness of commingled PET/GF and PA6/GF composites was investigated. The morphology and thermal properties of the composites were studied using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).The results show that cooling conditions had no major effect on bending properties, but the fracture toughness (GC) was affected; i.e., fracture toughness of gradual cooling was lower than rapid cooling. The bending properties are not significantly affected by crystallinity, but GC is strongly influenced by the level of crystallinity in the matrix resin.