Die Inlet Contour Impact on the Pressure Rise in a Pultrusion Die

Abstract

The quality of a pultruded composite depends on many process control parameters and variables. The pressure rise in the pultrusion die inlet is one such variable which can impact the quality of a pultruded product. An appreciable die inlet pressure rise can suppress void formation and enhance fiber "wet out." In this study, a model based on Darcy's law for flow in a porous medium and which employs the finite volume solution method is developed to predict the pressure and velocity fields as a function of various die inlet contours. Investigating the behavior of the pressure rise in the pultrusion die inlet as a function of the shape of the die inlet contour can be a very useful and effective tool for analyzing and designing pultrusion die inlets. Various die inlet contours such as the wedge, circular tapered die inlet, and some hypothetical die inlet contours were investigated to determine the impact on die inlet pressure rise. The original contributions of this paper are results which are useful for designing pultrusion dies and for producing an optimum pressure rise which will enhance the quality of the pultruded product.