Natural fibres, such as sisal, flax and woodfibres, are relatively inexpensive and originate from renewable resources. Thermoplastic polymers, such as polypropylene (PP), high density polyethylene (HDPE) and waste plastics, possess shorter manufacturing cycle times and reprocessability. Natural fibre-reinforced thermoplastic composite materials exhibit favourable values of modulus and strength when the fibres are properly compounded with the polymers. Common methods for manufacturing natural fibre-reinforced thermoplastic composites, injection moulding and extrusion, require pre-compounding of the fibres and the thermoplastic due to the large difference in densities of the loose fibres and thermoplastic materials. Development and analysis of a screwless extruder that employs a reliable and low technology process for melt blending natural fibres and thermoplastic polymers is the main objective of this study.