Validation of Paste Mixing for Pouring Operations in the Ceramic Sector Using CFD Simulations in SolidWorks

Abstract

This study aims to determine the optimal parameters for preparing ceramic slip intended for casting in gypsum molds, with the goal of improving its rheological properties (density, viscosity, flowability) and enhancing the quality of the final product. Key variables were evaluated, including water volume, mixer rotation speed (RPM), number and arrangement of blades, mixing time, and resting time.

The methodology was based on a fractional factorial design 2⁷⁻³ (1/8 fraction) with 16 experimental runs, allowing the analysis of both individual and combined effects of the variables. Data were collected through measurements of viscosity (using a Ford Cup No. 4), density, flowability, and paste homogeneity. Statistical tools such as ANOVA and response optimization graphs (using Minitab) were employed for data analysis.

Results showed that increasing the water volume to 152 liters and raising the mixer speed to 350 RPM favored better particle dispersion and homogenization. Increasing the number of blades to 6, evenly spaced, improved the distribution of mixing energy. Reducing the mixing time to 1 hour lowered energy consumption and helped prevent air entrapment. An extended resting period of 8 hours proved essential for stabilizing the paste and enhancing its fluidity. The ideal density achieved was 1.9625 kg/L, with an average viscosity of 266 centistokes.

Although the statistical analysis indicated that not all variables were significant at a 95% confidence level, a useful predictive model was obtained with a coefficient of variation of 100%, indicating high consistency among the data. Therefore, this model can be confidently used to optimize the ceramic slip mixing process, enabling more efficient and higher-quality production in both artisanal and industrial settings.