| Abstract: | The rheology of polystyrene powder beds was examined by two kinds of experiments. From stress relaxation measurements during powder compaction, it was found that relaxation at the shorter times could be attributed to sliding between particles. This is followed by a relaxation attributed to the deformation of the polystyrene particles themselves. From dynamic mechanical measurements, an increase was found in the value of vibrational absorption coefficient (Q?1 value) at a temperature below that of the main relaxation dispersion of bulk polystyrene, attributed to the slipping around tight particle junctions. These phenomena appear characteristic of powder-like materials. |
