New approach in the characterization of the melting process in single screw plasticizing units using a model experiment

The melting behavior of polymeric materials in single screw plasticizing units is a crucial factor for the further process steps. A new method for characterization of the melting of polymers in a single screw plasticizing unit using a model experiment is presented in this paper. Polymer granules and solid samples are pressed onto a heated, rotating shaft whereas the thickness distribution of the melt film is measured according to the principle of optical triangulation (light intersection). Using this experiment the influence of the properties of the polymeric material, the processing conditions such as circumferential velocity, pressure and temperature as well as geometry parameters such as the flight gap on the formation of the melt film can be analyzed. The shear force or frictional force, the normal force and the thickness of the sample are measured during the experiments as well as the thickness distribution of the melt film, so the melt film and the difference in the volume of the sample can be measured at the same time.