A glass sheet thermally strengthened such that at the first major surface is under compressive stress; the sheet having an a characteristic 2D autocorrelation matrix c(x,y) given by c(x,y)=F.sup.1(F(g).Math.F(g)) where F is a 2D Fourier transform and represents a complex conjugate operation and g is a high pass filtered data array given by g(x,y)=F.sup.1(F(f(1F(h)) where h is a spatial 2D low pass filter array and f is a square data array of Shear 0 and Shear 45 data, taken over an area away from any birefringence edge effects on the sheet, wherein an autocorrelation peak maximum width of the matrix c(x,y) at 40% of peak height, for the c(x,y) matrices from both the Shear 0 and Shear 45 data, is between 1 and 5 mm.

A strengthened glass or glass ceramic sheet has a roughness of greater than 0.05 nm Ra and less than 0.08 nm Ra over an area of 10 m10 m and has the property that, excluding areas within three sheet thicknesses of the outer edge surface of the sheet, the slope of a measured value of a thermally affected property of glass over distance along the first major surface of the sheet is higher bordering one or more lower-cooling-rate-effect-exhibiting areas on the first surface of the sheet than elsewhere on the first surface of the sheet, and at least one of said one or more areas has a shortest linear dimension, in a direction parallel to the first major surface, of less than 100000 m.

A strengthened glass or glass ceramic sheet has a roughness of greater than 0.05 nm Ra and less than 0.08 nm Ra over an area of 10 m10 m and has the property that, excluding areas within three sheet thicknesses of the outer edge surface of the sheet, the slope of a measured value of a thermally affected property of glass over distance along the first major surface of the sheet is higher bordering one or more lower-cooling-rate-effect-exhibiting areas on the first surface of the sheet than elsewhere on the first surface of the sheet, and at least one of said one or more areas has a shortest linear dimension, in a direction parallel to the first major surface, of less than 100000 m.

A process of strengthening a glass sheet by cooling a sheet or portion of a sheet, the sheet comprising or consisting of a glass having a glass transition temperature, given in units of C., of T, wherein the cooling is performed starting with the sheet at a temperature above T, with more than 20%, 30%, 40% or 50% or more of said cooling, at some point during said cooling, being by thermal conduction through a liquid to a heat sink surface comprising a solid.

An apparatus for processing a glass web can include a gas nozzle to generate a curtain of gas to entrain debris generated during a separation procedure. In further embodiments, apparatus for processing a glass web includes a washing device including a housing with a partition dividing an interior of the housing into a first area and a second area. In still further embodiments, apparatus for processing a glass web includes a coating chamber positioned down-stream from a washing device, wherein the coating chamber includes at least one port configured to dispense a coating on at least one major surface of the glass web. Methods can include entraining debris generated during a separation procedure into a gas curtain. Further methods include washing a glass sheet within a housing including two interior areas and coating a washed glass sheet with a protective coating.

A strengthened glass or glass-ceramic sheet or article as well as processes and systems for making the strengthened glass or glass-ceramic sheet or article is provided. The process comprises cooling the glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened glass sheets.

A strengthened glass or glass-ceramic sheet or article as well as processes and systems for making the strengthened glass or glass-ceramic sheet or article is provided. The process comprises cooling the glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened glass sheets.

A strengthened cover glass or glass-ceramic sheet or article as well as processes and systems for making the strengthened glass or glass-ceramic sheet or article is provided for use in consumer electronic devices. The process comprises cooling the cover glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened cover glass sheets for use in or on consumer electronic products.

A strengthened cover glass or glass-ceramic sheet or article as well as processes and systems for making the strengthened glass or glass-ceramic sheet or article is provided for use in consumer electronic devices. The process comprises cooling the cover glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened cover glass sheets for use in or on consumer electronic products.

A strengthened architectural glass or glass-ceramic sheet or article as well as processes and systems for making the strengthened architectural glass or glass-ceramic sheet or article is provided. The process comprises cooling the architectural glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened architectural glass sheets that may be incorporated into one or more panes in single or multi-pane windows.