GLASS SHEET BENDING

• Main Authors: MEYERS, Michel, DEGAND, Etienne, DURY, Bertrand
• Format: Patent
• Language: English; French; German
• Published: 14.11.2018
• Subjects: CHEMISTRY; GLASS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL

The process for bending a glass sheet (1) by gravity, comprises disposing the sheet on a framework (2) between a microwave transmitter and a reflector element to provide a final outer shape, modifying the temperature of the sheet to a softening temperature by passing the sheet through a tunnel, initially bending the glass sheet, and subjecting the sheet to a localized and controlled microwave generator before the temperature reaches a value of greater than 500[deg] C to facilitate the bending in the exposed areas. The microwave heating is applied to form a temperature gradient of 5[deg] C/cm. The process for bending a glass sheet (1) by gravity, comprises disposing the sheet on a framework (2) between a microwave transmitter and a reflector element to provide a final outer shape, modifying the temperature of the sheet to a softening temperature by passing the sheet through a tunnel, initially bending the glass sheet, and subjecting the sheet to a localized and controlled microwave generator before the temperature reaches a value of greater than 500[deg] C to facilitate the bending in the exposed areas. The microwave heating is applied to form a temperature gradient of 5[deg] C/cm between the treated areas and surrounding areas, and is maintained for a time period of less than 100. The temperature of glass in the application area is measured to initiate and monitor the localized application of microwaves. Power delivered by microwave beam per kg of treated glass is 10W/kg for increasing the temperature of sheet in exposed area to 2[deg] C/s. The microwave generator has a frequency of 2.45 GHz.