The effect of soluble salt in bone ash and other factors on the rheological properties of bone china bodies

摘要

A dynamic stress rheometric technique was developed to determine the plasticity of bone china bodies. In addition, the effect of natural variations of commercial bone ash on the rheology and processability of bone china was examined. The plasticity was then related to the floc characteristics of the body. In carrying out this study the physical and colloidal characteristics of a wide range of commercial bone ash batches were determined. The effect of washing bone ash on the properties of bone ash was also determined. The preparation of bone china body followed accepted industrial processing. The extent of flocculation of the bone china body was determined using the Carmen-Kozeny model for filter pressed cakes. Dynamic mechanical analyses were conducted on all samples using a dynamic stress rheometer using a of parallel plate geometery. Stress sweep analyses were used to determine the linear viscoelastic range for other tests and the loss factor of the sample. Frequency sweep analyses were run to obtain the instantaneous modulus as the measurement of plasticity. Creep test analyses were carried out to find the steady viscosity. Mean relaxation time was calculated out from the measured instantaneous modulus and steady viscosity.