Evaluation of slip in capillary extrusion of ceramic pastes

摘要: Abstract In this study, the capillary extrusion behaviour of an alumina paste material, made using submicron powder, hydroxy ethyl cellulose (HEC), a polyelectrolyte dispersant, poly (methacrylate), and water is described. It confirms that computed shear stress, obtained estabilished analytical procedures, depends upon both diameter length tube. Additionally, for given nominal rate, stress so calculated less smaller capillaries than corresponding larger capillaries. These trends are rationalised, along established lines, in terms preponderance material process slip at wall as opposed to cohesive or fully developed uniform flow. Moreover, tubes greater longer tubes. concluded these results not amenable meaningful analysis classical rheometery procedures based presumption The extensive which inevitably occurs interface between extrudate negates sensible application type procedures. Instead, attempt made, same data, interpret characteristics paste-wall quantity defined “reference thickness”, seen depend velocity (or apparent rate) but independent dimensions