Spectral analysis of force fluctuations during probe penetration into cohesive powders
2008 (English)In: Powder Technology, ISSN 0032-5910, Vol. 187, no 1, 62-67 p.Article in journal (Refereed) Published
We investigate force fluctuations during probe penetration into cohesive powders consisting of ∼5 μm lactose particles with varying surfaceproperties prepared by spray drying. The results obtained for the more cohesive powders were remarkably similar to those previously reported fororders of magnitude larger noncohesive particles. For the less cohesive powders, the spectral densities were instead found to exhibit two distinctpower-law regions. Furthermore, the spectra were found to be independent of the geometry of the penetrating probe and dimensions of the diecavity. These findings suggest that the response is dominated by particle aggregate or agglomerate movement for the more cohesive powders,whereas the behaviour of the less cohesive ones is consistent with a response dominated by relatively weak force chains, with the fluctuations resulting from the recurring creation and collapse of jammed states being damped for length scales N0.1 mm.
Place, publisher, year, edition, pages
2008. Vol. 187, no 1, 62-67 p.
Granular materials, powders, cohesion, probe penetration, fluctuations, percolation
IdentifiersURN: urn:nbn:se:uu:diva-100068DOI: 10.1016/j.powtec.2008.01.011ISI: 000260052300008OAI: oai:DiVA.org:uu-100068DiVA: diva2:209343