Method for producing air-quench-toughened glass plate

摘要

In a process for producing an air-quench-toughened glass plate, defective glass plates containing nickel sulfide (NiS) are removed by compulsory breaking the glass plates. Such compulsory breakage is carried out in the course of a batch-manner soaking process carried out after a toughening step; in the course of a toughening step carried out after generation of cracks in an annealing step; in the course of a toughening step carried out after generation of cracks in a pretreatment step; or in the course of a continuous annealing step carried out after a toughening step. Through the method, NiS-free toughened glass plates of high quality can be produced.