Description:
<jats:title>Abstract</jats:title><jats:p>By adding different fillers to polymers, both the mechanical and optical properties of the composite can be influenced. The addition of wood flour or fibers results in wood‐polymer composites (WPC), which are industrially processed into deckings by means of an extrusion process. As part of this project, the melt of high density polyethylen (HDPE) and fine wood flour is extruded into a square hollow profile.</jats:p><jats:p>By means of thermo‐rheological measurements, the shear thinning behaviour as well as the solidification behaviour of WPC at various degrees of filling levels of the wood and different temperatures could be determined. At high fill levels of wood, removal by means of a crawler belt is no longer possible due to the low elongation, so that a partial solidification of the melt prior to exiting the extrusion die by cooling is necessary. In addition to solidification, wall slip effects in the area of cooling occur as a function of shear stress, which could also be measured and modeled using the Mooney method [1]. This contribution deals wih the numerical flow field calculations of such WPC in special extrusion dies. From the thermo‐rheological data a non‐linear viscous model is created. The aims of the numerical simulations with OpenFOAM are to reduce pressure loss and create a uniform velocity field at the outlet. Different parameters such as the mass flow of the melt and the temperatur of the cooling medium are varied.</jats:p>