Development of a Portable Online Rheometer for the Characterization of PVC Melts

✍ Scribed by Andreas Limper; Gordon Fattmann; Stefan Seibel

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 154 KB
• Volume: 287
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200290001

✦ Synopsis

Abstract

Poly(vinyl chloride) (PVC) is a standard polymer with a world‐wide sales quantity of more than 20 Mio. t. From a rheological point of view, PVC is much more difficult to classify than for example polyethylene. Standard thermoplastics can be plasticized by the input of thermal energy, whereas for a sufficient plastification of PVC shear energy is needed. Hence, the PVC melt properties measured with the help of standard lab‐scale rheometers are not taking the shear history into account. Therefore, the melt behavior within an extruder cannot be described. In addition, PVC melts show wall slipping effects. A new rheometer concept especially developed to characterize PVC melt is presented. The rheometer takes a representative melt stream between the screw tip and the inflow of the die. The pressure gradient of this melt stream is measured within the geometry of the rheometer. Due to this the shear history and the wall slipping effects can be accounted for. Experimental data and results are presented and the application possibilities such as the design of profile dies and the development of PVC recipes are discussed.
The portable online rheometer in the assembled state.

magnified imageThe portable online rheometer in the assembled state.