Study on re-pull force in pultrusion processes-I. Experimental observations

This paper presents experimental observations of re-pull force which was assessed in conjunction with the validation of a numerical model to predict pull-forces in the pultrusion process. The re-pull force was measured after a previously pultruded composite component was placed into a pultrusion die and re-pulled, with a period of delay of several days. Five re-pull experiments were conducted on the same composite component, under similar heating conditions. It was observed that the re-pull force, which was quite large during the first run, gradually decreased with each re-pull. The heat of reaction for the composite was also found after each experiment, providing information on the degree of cure at each re-pull stage.