A glass sheet forming and annealing system disclosed provides control of edge stresses by maintaining a press formed glass sheet on an annealing ring (72) below a heated upper forming mold (58) within a forming station (12) for slow cooling toward the glass strain point temperature.

Embodiments of thermally and chemically strengthened glass-based articles are disclosed. In one or more embodiments, the glass-based articles may include a first surface and a second surface opposing the first surface defining a thickness (t), a first CS region comprising a concentration of a metal oxide that is both non-zero and varies along a portion of the thickness, and a second CS region being substantially free of the metal oxide of the first CS region, the second CS region extending from the first surface to a depth of compression of about 0.17.Math.t or greater. In one or more embodiments, the first surface is flat to 100 m total indicator run-out (TIR) along any 50 mm or less profile of the first surface. Methods of strengthening glass sheets are also disclosed, along with consumer electronic products, laminates and vehicles including the same are also disclosed.

There is provided a tempered glass plate, wherein a thickness of the tempered glass plate is less than or equal to 2.7 mm, wherein on a surface of the tempered glass plate, a plurality of stress marks are formed, wherein a distance between closest stress marks of the plurality of stress marks is less than or equal to 20 mm, wherein the surface of the tempered glass plate includes a first virtual circle that is formed by connecting points that are separated from a center of one of the plurality of stress marks by 2.5 mm, wherein the tempered glass plate includes a non elastic-wave region that is not affected by an elastic-wave generated during fracturing, and wherein, in the non elastic-wave region, an average number of cracks that exist in the first virtual circle is greater than or equal to 3.4.

A laminated glazing comprising a first ply of glazing material and a second ply of glazing material joined by at least one ply of adhesive interlayer material is disclosed. The first ply of glazing material comprises a sheet of glass having a first composition and the second ply of glazing material comprises a sheet of glass having a second composition different to the first composition. The laminated glazing has (i) a peripheral region extending around the periphery of the laminated glazing, the laminated glazing having a surface compression stress in the peripheral region and (ii) an edge compression, wherein the magnitude of edge compression is greater than the magnitude of the surface compression stress in the peripheral region. A method of making such a laminated is provided. A glass sheet suitable for being incorporated in such a laminated glazing is also disclosed.

Glass sheet forming and annealing disclosed provides control of edge stresses by maintaining a press formed glass sheet on an annealing ring (72) below a heated upper forming mold (58) within a forming station (12) for slow cooling toward the glass strain point temperature.

A method for evaluating the sensitivity of a glazing to forming quench marks depending on its anisotropy, the sensitivity being evaluated by computing parameter .sub.v, the quench marks resulting from different optical phase shifts in different regions of the glazing for a vision in transmission or reflection and from either side of the glazing, the method including computing a transmission parameter T1, T2 through face 1 or 2 or a reflection parameter R1, R2 from face 1 or 2, this computation being done for a region of the glazing without optical phase shift and for a region of the glazing inducing an optical phase shift ; computing a parameter E() corresponding to the color difference between said regions, based on at least one of T1, T2, R1, R2, and computing .sub.v by applying a function G dependent on computed E() and where appropriate on the one or more corresponding .

A laminated includes two bent glass substrates, a polymer interlayer between the glass substrates, and a notch or orifice cut in an entire thickness of the glazing. The glazing includes a border of compressive edge stresses obtained by general controlled cooling of the substrates in a paired state so that compressive stresses are generated at the border, and a local compression zone, different from the border, and obtained by local controlled cooling of a local area of a main surface of the glazing so that compressive stresses are generated in theid local compression zone. The notch or orifice is located in the local compression zone and made in the substrates in a paired state after forming the local compression zone so that cut contours of the substrates in the notch or orifice have a perfect superposition. The compressive edge stresses of the cut contours are greater than 4 MPa.

A strengthened glass sheet product as well as process and an apparatus for making the product. 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 having improved breakage properties.

A strengthened glass sheet product along with a process and an apparatus for strengthening a glass sheet are 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 having improved breakage properties.

A pre-stressed structure and a method for forming a pre-stressed structure are provided. The pre-stressed structure comprises a panel including a first region pre-stressed into a condition of membrane tension, resulting in the panel having increased transverse stiffness. The pre-stressed structure may further comprise a second region pre-stressed into a condition of membrane compression. The panel may be a plate or a shell and may form part of an insulating glass unit, which in turn may form part of a curtainwall unit.