Apparatus and methods for producing a glass ribbon

A method of producing a glass ribbon including the steps of:

• (I) drawing molten glass in a draw direction into a viscous zone to form a glass ribbon including opposed edges extending in the draw direction, wherein the opposed edges are spaced apart along a width of the glass ribbon that is transverse to the draw direction;
• (II) drawing the molten glass from the viscous zone into a setting zone downstream from the viscous zone, wherein the glass ribbon is set from a viscous state to an elastic state;
• (III) drawing the glass ribbon into an elastic zone downstream from the setting zone;
• (IV) at least periodically sensing a stress characteristic of the glass ribbon at respective lateral locations along the width of the glass ribbon;
• and
• (V) at least periodically changing a transverse temperature profile of the glass ribbon by independently adjusting operation of a plurality of temperature adjustment elements positioned along the width of the glass ribbon in at least one of the viscous zone, the setting zone and the elastic zone, wherein the temperature adjustment elements are independently adjusted based on stress characteristic information obtained during the step (IV) of sensing the stress characteristic.

A method of producing a glass ribbon including the steps of:

• (I) drawing molten glass in a draw direction into a viscous zone to form a glass ribbon including opposed edges extending in the draw direction, wherein the opposed edges are spaced apart along a width of the glass ribbon that is transverse to the draw direction;
• (II) drawing the molten glass from the viscous zone into a setting zone downstream from the viscous zone, wherein the glass ribbon is set from a viscous state to an elastic state;
• (III) drawing the glass ribbon into an elastic zone downstream from the setting zone;
• and
• (IV) measuring a parameter associated with mechanically induced stress in the glass ribbon, and only if the measured parameter is within an operating range associated with the parameter, then changing a transverse temperature profile of the glass ribbon by independently adjusting operation of a plurality of temperature adjustment elements positioned along the width of the glass ribbon in at least one of the viscous zone, the setting zone and the elastic zone, wherein the temperature adjustment elements are independently adjusted based on stress characteristic information obtained by sensing the glass ribbon at respective lateral locations along the width of the glass ribbon.