FLOAT PROCESS FOR PRODUCING FLOAT PLATE GLASS AND FLOAT PLATE GLASS

摘要

PROBLEM TO BE SOLVED: To provide a method based on float process for producing a float plate glass which is chemically strengthened in a high grade.SOLUTION: A glass ribbon with a specified width, which has a tin bath side facing molten metal and an upper side facing opposite to the molten glass, is formed by continuously sending the molten glass and drawing to a drawing direction. Then, the glass ribbon is cooled along a drawing zone and lifted up from the molten glass and forwarded into a slow cooing furnace. In that float process, atmosphere including Ois prepared in a part A of the drawing zone of down stream of the molten glass in view of drawing direction, and gas flow including SOis supplied at least at a first position S, and preferably at another position S. Thereby, the atmosphere at the part A has a higher SOdensity at the upper side than at the tin bath side of the glass ribbon.