Patent ID: 9643875
Date: 2017-05-09
CPC Classifications: C03B

Claim:
1. A fusion draw method comprising the steps of: (I) flowing molten glass over a pair of downwardly inclined forming surface portions of a forming wedge, the downwardly inclined forming surface portions converging along a downstream direction to form a root; (II) drawing a glass ribbon from the root into a viscous zone, wherein the glass ribbon has a pair of opposed edge portions and a central portion in a viscous state laterally spanning between the opposed edge portions, and an outer end of each opposed edge portion including an edge bead with a thickness that is greater than a thickness of the central portion; (III) severing the edge portions from the central portion within the viscous zone prior to the central portion transitioning from the viscous state to an elastic state; then (IV) drawing the central portion of the glass ribbon from the viscous zone into a setting zone, wherein the central portion transitions from the viscous state to the elastic state in the setting zone; and then (V) drawing the central portion of the glass ribbon from the setting zone to an elastic zone, wherein the central portion is in the elastic state in the elastic zone.