Infra-red radiation is also utilized for drying of ceramic articles. The infra-red radiation is largely reflected or transmitted by ceramic materials, where as water adsorbs it and converts it into sensible heat. Special lamps with comparatively low filament temperature radiate 80% of their energy in the infra-red.
This type of drying is suitable for green ware and for unfired glazed ware, sprayed or dipped. Because of the danger of cracking in green ware, a preliminary drying of bodies containing more than 21.5 % water at temperatures below the critical temperature is recommended, after which drying can proceed faster at higher temperature.
To be contd……
