Natural fiber

Thermoplastic

Composite number

Engineering

Breakage

Materials science

Ultimate tensile strength

Mold

Polypropylene

Compression molding

SISAL

Izod impact strength test

Microstructure

Glass fiber

Composite material

Fiber

Pulp and paper industry

Flexural strength

Extrusion

Retting

Composites Science and Technology

The aim of the study was to investigate the influence of fibre morphology of different natural fibres on the composites mechanical properties and on the fibre breakage due to extrusion process. The composite materials were manufactured using LTF (long fibre thermoplastic) extrusion and compression moulding and the used fibres were sisal, banana, jute and flax, and the matrix was a polypropylene. The results showed that sisal composites had the best impact properties and the longest fibres after the extrusion. Generally, the composites flexural stiffness was increased with increased fibre content for all fibres, being highest for flax composites. The flexural strength was not affected by the addition of fibres because of the low compatibility. The addition of 2 wt.% maleated polypropylene significantly improved the composites properties. Unlike the other three fibres, flax fibres were separated into individual elementary fibres during the process due to enzymatic retting and low lignin content.

The influence of fibre microstructure on fibre breakage and mechanical properties of natural fibre reinforced polypropylene