The pultrusion of powder-impregnated thermoplastic composites

A numerical and experimental research study is performed on the pultrusion technology of powder-impregnated thermoplastic composites. A numerical model of the impregnation process is developed, modelling the resin both through Newtonian and power-law approaches. The model is implemented into a numerical algorithm and then a computer code. The results of the numerical simulation are compared to the values measured on an instrumented pultrusion line in terms of pulling force. The results show a certain agreement (less than 15% error), the experimental findings are comprised between the two corresponding numerical results, the Newtonian model providing the upper limit and the power-law model the lower limit. Several other simulations are performed in order carry out a sensitivity analysis and to evaluate the influence exerted by the main technological parameters, such as pultrusion velocity, curing temperature and die length. The model proves to be a powerful tool to be used during the preliminary phases of technology set-up and assessment. (C) 1997 Published by Elsevier Science Limited.