Thermotropic liquid crystal polymers comprise rigid chain segments, which are called mesogens. Those mesogens are oriented due to shear in melts flows and the degree of orientation determines the local mechanical properties of the product such as elastic modulus and tensile strength. In this lecture, a new model is presented to calculate the orientation of the mesogens in a slit die flow. With this model, the influence of the power law index, the die height, pressure loss and wall slip on the orientation of the mesogens is studied. As an approach, the mesogens are considered as rigid rods with finite length and an initial orientation angle in the flow field. The shear thinning behaviour of the polymer melt is considered using a power law model. First, the rigid rod performs a differential translational movement in the flow direction in a differential time step. In addition, due to the velocity distribution and shear rate, a differential rotation of the rigid rod takes place. An analytical equation is obtained which enables the calculation of orientation dependent on the position in the die and the local residence time. After a short flow path, the mesogens are oriented in flow direction close to the die wall due to the high shear rate. The orientation of the mesogens decreases with increasing distance from the die surface towards the centre of the flow. With decreasing power law index the differences in orientation between the centre of the flow and the boundary layer increase.