Method for bending a glass sheet in a complicated shape and apparatus therefore

摘要

A glass sheet, which has been heated to have a viscosity of not lower than 105 Pa·s and not higher than 108 Pa·s, is pressed against a mold having a certain bending surface to be bent. There are a step for controlling a bending temperature T and a bending time period t for the glass sheet so as to satisfy the following formulas 1 and 2, and a step for bending the glass sheet:        0.05 φ 2.00     Formula 1 where P(τ) is a surface pressure difference (unit: Pa) between a pressure applied on a primary surface of the glass sheet and a pressure applied on a rear surface of the glass sheet at a time τ, t is a bending time period (unit: s), η(T) is the viscosity (unit: Pa·s) of the glass sheet at a temperature T, and T is a bending temperature (unit: °C) at the time τ.The apparatus for carrying out the method is also claimed.