Measuring the flowability of polyolefins
Polyolefins comprise one of the major building blocks of most plastics we use in everyday life. Gaining a better understanding of their physical behaviour could only aid our exploitation of these important materials. Sabic Europetrochemicals R&D, the research wing of a major polyolefin producer in Europe, participated in a GROWTH Programme project dedicated to advancing our knowledge of polyolefins. Their contribution focused on establishing a quantitative method for measuring the flowability of polyolefins. Polyolefins are often converted into power or pellet form prior to transport and usage in factory environments. This complicates flowability measurement, which is otherwise straightforward with materials in the liquid or gas phase. To extend beyond current empirical methods, the Dutch scientists employed a ring-shear test that properly addresses the undefined forces acting on the polyolefin particles. Extensive testing and tweaking has enabled a high level of accuracy, especially for large-scale production equipment (e.g. reactors). Incorporating this new knowledge as a factory design parameter will ensure maximum efficiency while minimising downtime. Considerable effort and money can also be saved by optimising production lines for flowability in existing plants.