Introduction
In an era prioritizing energy efficiency and premium user experience, the physical properties of ceramics are evolving from simple high density to "multi-functionalization." Low Thermal Conductivity Ceramics are not only critical for energy-saving industrial kilns but also essential for enhancing tactile comfort in smart sanitaryware. Leveraging years of Casting Slip R&D, Sunlets Technology analyzes how to "lock in" heat at the molecular level through strategic raw material selection.
1. Crystalline Engineering: Selecting Natural "Thermal Barriers"
Thermal conductivity is fundamentally governed by lattice vibrations (phonon transport).
The Utility of Mullite: Mullite possesses a complex network structure with significantly lower thermal conductivity than standard alumina ceramics. By precisely balancing Kaolin and siliceous materials in the Formulation, we induce the in-situ growth of needle-like Mullite crystals during firing to maximize phonon scattering.
Original Insight: While traditional sanitaryware typically exhibits thermal conductivity between 1.5~2.0W/(m.K) , Sunlets reduces this by approximately 20% through the strategic introduction of zircon sand, utilizing its naturally low thermal diffusivity.
2. Balancing Microporosity: The Contribution of High-Pressure Casting
While increasing porosity reduces thermal conductivity, it often compromises mechanical strength.
Closed-Pore Control: Utilizing Sunlets' proprietary Battery Casting Machine, the slip is molded under pressures of 10-12 bar. This high-pressure environment allows for the inclusion of trace hollow microsphere additives that maintain structural integrity within the Green Body.
Technical Data: Research indicates that a 5% increase in closed porosity can yield a 15% drop in thermal conductivity. Thanks to the isotropic alignment achieved via High-Pressure Casting, mechanical strength remains robust, declining by less than 3%.
3. Thermal Processing and Structural Integrity
Material selection must be paired with precise Firing curves.
Kiln Temperature Control: Within Sunlets' 96-meter Tunnel Kiln, we meticulously control the dwell time in the high-temperature zone (above 1250°C) to prevent excessive recrystallization of low-thermal-conductivity phases.
Vitrification: Despite optimizing for thermal insulation, Sunlets ensures full Vitrification with water absorption ≤0.5%, maintaining the product's hygiene and long-term durability.
4. Conclusion: From Material Science to User Experience
The development of low-conductivity ceramics demonstrates Sunlets' mastery over material fundamentals. As a global leader in OEM/ODM services, we empower our partners to differentiate in the energy-saving and comfort-focused markets through deep material innovation.