Mechanical properties of natural-fibre-mat-reinforced thermoplastics based on flax fibres and polypropylene.

Thermoplastic composites based on flax fibres and a polypropylene (PP) matrix were manufactured using (i) a film-stacking method based on random fibre mats and (ii) a paper making process based on chopped fibres. The influence of fibre length and fibre content on stiffness, strength and impact strength of these so-called natural-fibre-mat-reinforced thermoplastics (NMTs) is reported and compared with data for glass-mat-reinforced thermoplastics (GMTs), including the influence of the use of maleic-anhydride grafted PP for improved interfacial adhesion. In addition some preliminary data on the influence of fibre diameter on composite stiffness and strength is reported. The data is compared with the existing micro-mechanical models for strength and stiffness. A good agreement was found between theory and experiment in case of stiffness whereas in the case of strength the experimental values fall well below the theoretical predictions. Results indicated that NMTs are of interest for low-cost engineering applications and can compete with commercial GMTs when a high stiffness per unit weight is desirable. Results also indicated that future research towards significant improvements in tensile and impact strength of these types of composites should focus on the optimisation of fibre strength rather than interfacial bond strength

Natural-fibre-mat-reinforced thermoplastic composites based on flax fibres and polypropylene

Natural-fibre-mat-reinforced thermoplastics (NMTs) based on flax fibres and a polypropylene (PP) matrix were manufactured using a film-stacking method. The influence of fibre content on stiffness and strength is reported and compared with data for glass-mat-reinforced-thermoplastics (GMTs), including the influence of improved fibre/matrix adhesion as a result of the use of maleic-anhydride grafted PP. Additionally, unidirectional and random-flax-mat composites based on epoxy resin were manufactured as reference materials. Results indicated that NMTs are of interest for low cost engineering applications, especially when a high stiffness per unit weight is desirabl

Natural-fibre-mat-reinforced thermoplastic composites based on flax fibres and polypropylene

Natural-fibre-mat-reinforced thermoplastics (NMTs) based on flax fibres and a polypropylene (PP) matrix were manufactured using a film-stacking method. The influence of fibre content on stiffness and strength is reported and compared with data for glass-mat-reinforced-thermoplastics (GMTs), including the influence of improved fibre/matrix adhesion as a result of the use of maleic-anhydride grafted PP. Additionally, unidirectional and random-flax-mat composites based on epoxy resin were manufactured as reference materials. Results indicated that NMTs are of interest for low cost engineering applications, especially when a high stiffness per unit weight is desirabl