1. Introduction and objectives A great variety of rubber parts is produced for the automotive industry. To minimize problems during the assembly of the cars and to ensure best performance, the parts have to be manufactured with the smallest possible variation in size and shape. The size can be controlled by the extrusion and injection parameters – the shrinking of the material can often be well estimated. But what about the shape? The problem is not only the relaxation of the rubber after leaving the mold – this can be controlled by an appropriate design of the injection process. There can also be variation of the shape before entering the oven for vulcanization, which takes typically half an hour. Due to gravitational force there can be

significant changes in shape of an injected part depending on the rubber formulation used. To avoid such effects and to improve production perfomance, it would be highly appreciable to predict the respective properties of the sample. The presentation will show, that prediction of shape stability is possible with appropriate rheological investigations.