Methods of producing glass sheets

A method of producing a glass sheet comprising the steps of:

• fusion drawing a glass ribbon along a draw direction into a viscous zone downstream from a root of a forming wedge, wherein the glass ribbon includes opposed edges and a lateral portion extending between the opposed edges along a lateral direction transverse to the draw direction;
• drawing the glass ribbon into a setting zone downstream from the viscous zone, wherein the glass ribbon is set from a viscous state to an elastic state;
• drawing the glass ribbon into an elastic zone downstream from the setting zone, wherein the lateral portion of the glass ribbon in the elastic zone includes a profile shape along the lateral direction comprising a substantially curved set profile shape;
• creating a vacuum to force the entire lateral portion of the glass ribbon to engage an anvil portion of a breaking device in the elastic zone, wherein the glass ribbon is held such that the profile shape of the lateral portion of the glass ribbon comprises a substantially planar engaged profile shape that substantially matches a shape of the anvil portion, and wherein the vacuum is provided by a plurality of pressure zones that are operated independent from one another;
• forming a score line along the lateral portion of the glass ribbon;
• breaking away a glass sheet from the glass ribbon along the score line while the entire lateral portion of the glass ribbon is forced against the anvil portion by the vacuum;
• and then
• releasing the glass ribbon from the anvil portion such that the profile shape of the glass ribbon does not match the engaged profile shape.