Study on fibre orientation of weld line parts during injection moulding of fibre reinforced plastic by image processing

In injection moulded products using fibre reinforced plastics, weld line was unavoidable due to mould shaping factors such as the position and size and number of mould gates. The weld line leads to fibre orientation perpendicular to resin flow direction, sudden reduction of the reinforcement effect and consequently degrading of the mechanical properties of moulded products. Until now, there has been no research on the measurement of fibre orientation in the weld line using image processing. Using the image processing method, the fibre orientation distribution of weld line in injection moulded products was assessed. The effects of fibre content and injection mould gate conditions on the fibre orientation were also discussed.