4_A_0930 Doc

The dimensioning of injection heads for the extrusion of rubber profiles is exclusively based on empiric knowledge of the non-linear viscoelastic flow behaviour of elastomers especially of the so-called die swell.Thus, the design of injection heads is carried out with subject to the used rubber blend, whereas the geometry of the appropriate profile is achieved by empiric adaptation of the extrusion die. This adaptation process is mainly influenced by the swelling after the extrusion of rubber and is carried out in several steps.The disadvantages of the current production process are the process technology which is non-reproducible over a long timeframe and the design of dies which is connected with long development time. This relevantly affects the capacity of the running production. This fact was one of the motivations for a research project concerning the characterisation of the die swell properties of rubber blends. The research work is performed in cooperation with Semperit Technische Produkte Ges.m.b.H. & Co KG.