Analytical investigation of the effect of fibrous tow position and radius on impregnation, pulling force and pressure profile in pultrusion process of thermoplastics

This paper presents a numerical model for predicting pressure, impregnation and pulling force in pultrusion die which circular cross section witch two reinforcement fibrous tows pass through it. Pulling force and degree of impregnation are the most important parameters associated with pultrusion process that determine production cost and quality of pultruded profile respectively. Main idea in this approach is obtaining characteristic equations in purely polymer region and purely fibrous region and establishing relations between them by using conservation law. The superiority of this approach compared to other methods is ability to considering both straight and conical part of the die, calculating pulling force, ability of investigating influence of a variety of parameters such as those associated with die geometry, material rheology and process parameters. In this paper the influence of fibers position and fibers radius on pulling force, impregnation and pressure inside die is investigated. Due to the ability of simultaneous calculation of force and impregnation, this model can be used to establish an optimum condition between cost and quality of produced profiles.