THz spectroscopy for the inline control of polymeric compounding processes

We present non-destructive and contactless inline measurements on the molten polymer polypropylene and on the polymeric compound polypropylene-CaCO₃ carried out with a THz spectrometer. The effect of temperature and pressure on the THz properties of the molten polymeric material is investigated. Additionally, we analyze the additive content of the compound during the extrusion processing and compare this data with offline results. Further measurements on wood plastic composites demonstrate the capability of detecting the degree of dispersion of compounds with THz-spectroscopy.