Monthly Tech-Tip | No tracking! No ads! |
These samples were part of a project to compare two sodium bentonites, using our standard procedures to characterize the physical properties of clays for use in bodies in traditional ceramics. These samples were taken from different spots in the same location in Nevada, USA. We were interested in dry-state properties: Shrinkage and deformation, water permeability, plasticity and related water requirements. And also firing: LOI, shrinkage, porosity and color at various temperatures. The DFAC test disk of L4122 (right) is still wet in the center (very slow and difficult drying is characteristic of bentonites). Its SHAB test bars have shrunk and curled much more. And cracked badly (expected of bentonites).
While these tests were mainly about comparing the two materials, they were also an absolute indicator - it would be impossible to even make these specimens from a pure bentonite, so these are simply montmorillonitic clays, containing differing percentages of bentonitic particles.
Materials |
Bentonite
Bentonite can make a clay body instantly plastic, only 2-3% can have a big effect. It also suspends slurries so they don't settle out and slows down drying. |
Buy me a coffee and we can talk