The influence of the time of application of contact pressure onparticle adhesion to a substrate surface.
A centrifuge method has been employed to investigate the effect of the time of application of the preliminary pressing force on particle adhesion to a steel surface. The geometric median adhesion forces obtained for four powders (i.e. polyethyleneglycol (PEG) 4000, pregelatinised starch (Starch 1500), spray-dried lactose and calcium carbonate) increased with the length of time the adhering particles were subjected to the applied load before detachment was assessed. A more substantial increase in the median adhesion force was observed for the harder spray-dried lactose than for the softer PEG 4000 and for Starch 1500. This may be due to the inherent brittle structure of the lactose particles, rendering the solids more susceptible to the applied pressure at prolonged durations, which consequently gave rise to greater change in adhesion. On the assumption that the deformation occurring in the adhesion was predominantly plastic, the phenomenon of strain hardening was found to take effect sooner in a harder solid than in a softer material. © 1993 Elsevier Sequoia.
|Title:||The influence of the time of application of contact pressure onparticle adhesion to a substrate surface|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > School of Life and Medical Sciences > Faculty of Life Sciences > UCL School of Pharmacy
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