Studies on Slip Casting Control (IV)

Relationship between Slip Properties and the Fundamental Parameters of Whiteware Bodies

Abstract

Viscosity of casting slips, casting rate and thickness of remaining slip layer on draining were investigated to obtain equations expressed as functions of fundamental parameters, i.e. solid fraction (F₃), specific surface area (S_a) and hydration degree of solid (d_s). The results were summarized as follows.
(1) Viscosity of slips could be given by the equation η=I(AF₃^2/3)S_af(d/d_s), where (AF₃^2/3)S_a and f(d/d_s) related to the contact area of particles and the binding force at contact points depending on water film thickness d, respectively. Viscosity coefficient (I) was found to be rather constant except slips with different type of flow curves.
(2) Casting rate could be calculated from the viscosity and the fundamental parameters. The reliability depended largely upon accuracy of the measured viscosity.
(3) The thickness of remaining slip layer on draining could be expressed by the equation Δl=θ/(ρ_sgsinα), where ρ_s, θ and α denoted slip density, yield value and draining angle, respectively.