Fibre reinforcement of commodity polymers, such as polypropylene, is an established method for the manufacture of components with significantly increased mechanical properties compared to their unfilled counterparts. Glass fibre polymer composites incorporate short glass fibres, 250 m, or long fibres, up to 12 mm in length, within a polymer matrix. The mechanical performance of any moulded component is highly dependent on the final fibre orientation, in the case of short fibres, alongside fibre length distribution and overall fibre dispersion, long fibres. In this paper a 40 wt% long glass fibre filled PP has been used to investigate the effects of processing parameters, including nozzle geometry, on fibre degradation and dispersion during the injection moulding process. Results show that over 50% of 12 mm long fibres have reduced in length to between 0.25 and 1.25 mm by the time they enter the mould. Additionally, micro-CT images show a complex flow field within the nozzle section prior to the mould, which in some cases continues down the sprue.