Slip casting is the primary forming method for sanitaryware (toilets, washbasins, pedestals) and complex-geometry art ceramics.
Application Overview
The process involves pouring a liquid clay suspension (casting slip) into plaster molds, where the plaster absorbs water from the slip, building up a solid clay wall against the mold surface. The casting slip must have specific rheological properties: low viscosity at high solids content (typically 65-70% solids), good deflocculation response, controlled casting rate, and adequate green strength after demolding. Feldspar and nepheline syenite contribute to slip casting body formulations as flux materials, but their particle characteristics also influence the slip rheology and casting behavior. Fine-particle nepheline (K200, 200 mesh) deflocculates more easily than coarser grades, contributing to lower slip viscosity at the same solids content — a direct productivity advantage for sanitaryware casting.
Technical Details & Formulation
SY101 K-feldspar provides the high viscosity melt needed for shape retention during firing of complex sanitaryware geometries. A typical sanitaryware casting slip: 25-30% ball clay, 15-20% kaolin, 15-20% nepheline K200, 8-12% K-feldspar SY101, 15-20% quartz, 5-8% wollastonite, plus deflocculant (sodium silicate 0.2-0.4%)..
