Patent ID: 9676650
Date: 2017-06-13
CPC Classifications: C03B,C03C

Claim:
1. A method for producing a glass sheet by down-drawing, the method comprising: an air pressure controlling step of controlling an air pressure of a furnace outside space formed between a furnace wall covering a whole furnace and a covering part that covers the whole furnace wall, the furnace including a forming furnace, a lehr, and a space that contains a cutting device for cutting the glass, a melting step of melting glass raw materials to form molten glass, a supplying step of supplying the molten glass to a forming cell disposed inside the forming furnace, a forming step of forming a glass sheet by allowing the molten glass to flow down the forming cell, an annealing step of cooling the glass sheet while allowing the glass sheet to flow in one direction in the lehr, and a cutting step of cutting the glass sheet that has been cooled, by the cutting device, the furnace outside space including a forming furnace outside space that includes a region corresponding to a position where the forming furnace is disposed, and a lehr outside space that includes a region corresponding to a position where the lehr and cutting device are disposed, in the air pressure controlling step, the air pressure control being carried out such that a temperature of an outer surface of the furnace wall covering the whole furnace is stabilized by an air pressure of the forming furnace outside space being higher than an air pressure of the lehr outside space, wherein the air pressure of the lehr outside space is higher than atmospheric pressure.