The current paper documents the development of an apparatus to produce continuous fibre reinforced thermoplastic tow-preg filament. The apparatus was developed at Deakin University to process the raw materials, namely, a dry fibre bundle (or tow) and a polymer matrix, to produce a continuous fibre tow-preg filament. The processing speed is a critical factor in achieving high fibre volume fraction tow-preg filaments. Fibre volume fractions ranging from 30–60% have been produced in our laboratory. This fibre volume fraction (60%) is greater than that of commercially available thermoplastic tow-preg filaments and is expected to result in improved tensile modulus and strength compared to similar filaments with lower fibre content. The novelty of this research lies in the precise control over processing parameters to customize the material properties of continuous fibre reinforced tow-preg filaments by controlling the fibre volume fraction. While the present work has focused on producing carbon fibre reinforced tow-preg filaments, the apparatus is sufficiently flexible to allow a range of fibre types and matrix materials to be processed. This research represents a significant step towards the development of the next generation of composite materials and will pave the way for the broader adoption of AM composites.