Generally, ceramic tiles for building construction are manufactured by dry forming process using granular powders prepared by spray drying process after mixing and grinding of mineral raw materials. In recent years, as the demand for large ceramic tiles with natural texture has increased, the development of granule powders with high packing ratio and excellent flowability has become more important. In this study, ceramic tile granule powders are coated with hydrophobically treated silica nanoparticles. The effects of hydrophobic silica coating on the flowability of granule powders and the strength of the green body are investigated in detail. Silica nanoparticles are hydrophobically treated with GPTMS(3-glycidoxypropyl trimethoxy silane), which is an epoxy-based silane coupling agent. As the coating concentration increases, the angle of repose and the compressibility decrease. The tap density and flowability index increase after silica coating treatment. These results indicate that hydrophobic treatment can improve the flowability of the granular powder, and prevent cracking of green body at high pressure molding.

Abstracts
 1. Introduction
 2. Experimental Procedure
 3. Results and Discussion
 4. Conclusion
 Reference

• 김진호(한국세라믹기술원 이천분원) | Jin-Ho Kim (Ceramicware Technology Center, Korea Institute of Ceramic Engineering and Technology) Corresponding author
• 김응수(한국세라믹기술원 이천분원) | Ung-Soo Kim (Ceramicware Technology Center, Korea Institute of Ceramic Engineering and Technology)
• 한규성(한국세라믹기술원 이천분원) | Kyu-Sung Han (Ceramicware Technology Center, Korea Institute of Ceramic Engineering and Technology)
• 황광택(한국세라믹기술원 이천분원) | Kwang-Take Hwang (Ceramicware Technology Center, Korea Institute of Ceramic Engineering and Technology)