Effect of layering pattern on thermal and mechanical properties of lyocell/rayon fabric reinforced textile composites

The influence of different layering pattern on the thermal and mechanical properties of the hybrid lyocell/rayon woven fabric reinforced polyester composites is demonstrated in this research work. The effect of different layering pattern was studied and characterized with tensile, open hole tensile, flexural, and impact testing. Composites manufacture with rayon/rayon/lyocell pattern reinforcement has the best tensile and flexural properties. The tensile and flexural strength increased by 36.5% and 43.79%, respectively, with reference to neat resin. It is also noted that the tensile modulus reduced by 31.1% when compared to neat resin. This represents an increase of material ductility in comparison with neat resin. It is observed that placing of high strength lyocell fabric at the extreme layer as reinforcement would result in enhanced properties. In case of rayon/lyocell/rayon hybrid tensile composites it can be seen that there is only 8% increase in tensile properties in comparison with neat resin due to rayon fabric placed as a skin rather than core. A negative effect of 6-26% reduced tensile strength was observed for the open hole (6mm diameter) samples of all pattern of textile composites. This was due to fiber and inter fiber (matrix) fracture. A more detailed microfractography analysis was used to determine the crack growth direction and initiation. While in impact properties the lyocell/lyocell/lyocell pattern reinforcement showed the best impact strength of 3.36kJ/m(2) compared to rayon/rayon/rayon and other tri-layer composites. Thermal analysis showed higher thermal stability for the rayon/rayon/lyocell pattern reinforcement.