Patent ID: 6408649
Filing Date: 2002-06-25
Classification: C03B,Y02P

Abstract:
A method of thermally treating at least one glass sheet for shaping, comprising placing the glass sheet having a temperature of up to the softening point of the glass sheet on a fixture and exposing the glass sheet to microwave radiation with uniformity &psgr; wherein &psgr; is greater than or equal to 100%{1â€”MoR/(Ks&Dgr;T)} where the temperature dependent MoR and Ks are selected at their minimum and maximum value respectively, said microwave radiation having an effective frequency and a sufficient power density to heat at least one selected area of the glass sheet from any initial temperature up to the softening point of the glass sheet to any required temperature in a selected time whereby a sufficient temperature distribution to allow shaping of the glass sheet is obtained in the selected area so that the glass sheet's internal thermal stress is prevented from exceeding its modulus of rupture.