Microwave processing of porcelain tableware using a multiple generator configuration

In this work we developed a microwave oven capable of processing porcelain tableware, with different sizes and shapes. We used a multimode cavity fed by 6 magnetrons with 1 kW each one, operating at 2.45 GHz, as the only heating source. Controlling the radiation power, in each stage of the process, we can create a more homogeneous electromagnetic field, avoiding the natural inhomogeneity which is a critical problem in the sintering process with microwave radiation.To characterize the quality of the sintered porcelain we measured the rupture energy, impact resistance, porosity, water absorption and concentration of undesired elements. These measurements have been compared with the obtained in similar porcelain pieces prepared by conventional methods, showing equivalent features and with parameters in the acceptable limits. It was observed that the sintering process is faster, with consequent lower costs and lower local emissions of harmful gases into the atmosphere.

► We present a microwave oven capable of processing porcelain tableware.
► Material dielectric properties are critical due to its natural inhomogeneity.
► Thermal runaway can be controlled by the field distribution during the sintering.
► Samples show equivalent properties compared with conventional fired porcelain.