| Three frit compositions were formulated and studied by varying the major constituents – alkalis (K2O + Na2O) and alkaline earth oxide (CaO) with minor changes in ZnO, SiO2, Al2O3 and B2O3 content. The frits produced were characterized with respect to fusion, flow and thermal expansion properties and compared with a frit of imported origin. It is observed that fusion and flow characteristics of the frits are strongly influenced by the combined fluxing effect of CaO and calcium borate. The thermal expansion value increases with the increase in alkali content. The performance of the frits in rapid once-fired wall tile glaze was also studied by preparing a slip made of 90 wt% frit and 10 wt% white burning clay applied on green wall tile sample and fired at 1100°C. The performance of one formulation produced in the present study was almost on a par with imported frit. |
