Abstract
In this study, the effect of heating sources on the temperature profiles of soda-lime silicate glass was investigated. Conventional heating created an extreme thermal gradient (the surface temperature > the interior temperature) when glass which is a poor thermal conductor was heated. As a result, an adequate soaking time depended on the thickness was required for the interior of the glass to become as hot as those surface. On the other hands, microwave heating which was employed to rapidly and homogenously heat the glass, showed an inverted temperature gradient that the surface temperature is cooler than the interior temperature of the glass. When using microwave energy, critical temperature (Tcri) at which the glass can be self-heat, was observed to be at 370°C. At this temperature, the heating rate which is the interior temperature of glass increased from 8 to 16°C/min. On a cross section of glass, the thermal gradient (ΔTheating, the interior–the surface) and the heating rate of glass were successfully manipulated by introducing a hybrid heating method which combined microwave heating with conventional heating. The results were 0°C ≤ ΔTheating ≤ 180°C and ∼3°C/s, respectively.
