One of the most important stages in the injection moulding cycle of plastics is ejection. This is the final stage of the part in the mould during the complex thermo-mechanical cycle. In this stage it is important to know the surface properties of the mould/moulding pair in contact, this being critical in situations where the moulding tends to shrink onto deep cores. The mould material, the moulding surface roughness, the injected material and the conditions at ejection, such as contact pressure and temperature, must be evaluated and characterized, if the prediction of the ejection force is required in the mould design.