Csúszóréteg kialakulása agyagkeverékek extrudálásakor.

The production of heavy-clay products demands a huge amount of plastic ceramic pastes. During extrusion the clay-compound flow through the extrusion die and this flow mainly show plug flow with extensive wall slip. The viscosity and the thickness of the slipping layer were investigated in this study. Brick-clay from Malyi (Hungary) deposit was applied as a raw material. Clay was characterised by XRPD, BET, SEM and granulometry. By the help of sedimentation of clay minerals content of the clay (d<2μm), the viscosity of suspension with different water content were measured by means of rotational viscositymeter. Based on thickness calculating process from former studies, it was integrated with measurement of viscosity. The thickness values were calculated from viscosity data and from data of former measurements with capillary reometer. The thickness of the slip layer showed a tendency to reach a limit value by increasing the extrusion speed. [ABSTRACT FROM AUTHOR]