High performance natural fiber composites from mat and UD flax reinforcements backed with a mat Binder: A study of mat fiber surface fibrillation

The natural fiber composites (NFC) market is growing at fast rate in markets such as automotive interiors, construction and wind energy. The major driving force is the rise in demand for lightweight and environmentally sustainable materials. This research aims at developing high performance NFC, made from hybridizing short flax fibers and unidirectional flax filaments in the fabrication of mat and combined UD flax-mat reinforcement, by studying the mechanical surface fibrillation of the short flax fibers to improve the fiber–matrix load transfer. The results show an increase in the longitudinal tensile properties up to about 500 mill revolutions, after which a deterioration of the fiber structure occurs with corresponding reductions on properties. However, fibrillation reduces permeability to liquid resin, except in the transverse direction of UD flax-mat reinforcement. Globally, the mechanical fibrillation has a positive impact on mechanical properties and fracture behavior while impregnation can be further improved to ease manufacturing.