CPC B32B 3/263 (2013.01) [B32B 3/02 (2013.01); B32B 3/26 (2013.01); B32B 3/30 (2013.01); B32B 17/10036 (2013.01); B32B 17/10045 (2013.01); B32B 17/10119 (2013.01); B32B 17/10137 (2013.01); C03B 17/064 (2013.01); C03B 18/02 (2013.01); C03B 23/023 (2013.01); C03C 3/083 (2013.01); C03C 3/087 (2013.01); C03C 3/093 (2013.01); C03C 21/002 (2013.01); B32B 2315/08 (2013.01); B32B 2329/04 (2013.01); B32B 2329/06 (2013.01); B32B 2551/00 (2013.01); B32B 2571/00 (2013.01); B32B 2605/006 (2013.01); Y10T 428/24777 (2015.01)] | 11 Claims |
1. A method for producing a glass substrate, comprising:
melting a glass;
forming the glass into the glass substrate; and
adjusting a viscosity of the glass prior to fully forming the glass into the glass substrate so that:
the viscosity of the glass η immediately upstream of a flow rate control component has a maximum viscosity deviation (Δlg η/dPa·s) equal to at most 0.1; and
the viscosity of the glass η1 downstream of the flow rate control component at a distance y1 that is ≤1.5 m from a location immediately downstream of the flow rate control component has a maximum viscosity deviation (Δlg η1/dPa·s) equal to at most 0.2 and the following equation applies:
lg η1(y1)/dPa·s=(lg η01/dPa·s+a1(y1))
where η01 is a value of glass viscosity at y=0 m and lg η01 is a logarithm of the glass viscosity η1 at y=0 m,
0 m≤y1≤1.5 m being a distance of a location immediately downstream of the flow rate control component that is located at y=0 m,
3.75≤lg η01/dPa·s≤4.5 being a range of viscosities to be adjusted at y=0 m, and
a1(y1)=1.00/m*y1 being a positive change in the range of viscosities to be adjusted over 0 m≤y1≤1.5 m.
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