process for the production of glasoder glaskeramikscheiben with erhoehter widerstandsfaehigkeit against rapid heating

摘要

Flat or curved glass or glass-ceramic sheets with improved resistance to thermal gradients from the centre to the edges, are produced by introducing stressed regions in the edge portions. The stress may be introduced by heat-treatment or by an ion-exchange process. Thus only the edge portions of the glass sheets crystallize and become opaque.