A method for producing ultra-thin glass sheets is provided that results in glass sheets with high edge strength. The method includes: hot forming a continuous glass ribbon with a glass thickness from molten glass; annealing the glass ribbon with an annealing rate chosen based on the glass thickness; producing a laser beam focus area that is longer than the glass thickness; introducing filamentary defects into the glass ribbon using the laser beam so that the filamentary defects extend from one face to the opposite face and are spaced apart from one another along the breaking lines to produce transverse breaking lines and longitudinal breaking lines with margins each comprising a thickened bead; separating the beads along the longitudinal breaking lines and separating glass sheets by severing along the transverse breaking lines.

Laminated articles comprised of glass core and clad layers, more specifically, to compressively stressed laminated articles comprising a glass core sandwiched between first and second clad layers, the clad layers being formed from photosensitive glass.

A method of manufacturing a laminated glass article having a first clad layer, a second clad layer, and a core layer between the first clad layer and the second clad layer, by exposing an edge of the core layer. An etchant can be applied to the edge of the laminated glass article to form the recess. The recess can then be filled.

Methods for machining glass structures may be performed on fusion-drawn glass laminates having a core layer interposed between a first cladding layer and a second cladding layer. The core layer may be formed from a core glass composition having a core photosensitivity, the first cladding layer may be formed from a glass composition having a photosensitivity different from the core photosensitivity, and the second cladding layer may be formed from a glass composition having a photosensitivity different from the core photosensitivity. At least one of the core layer, the first cladding layer, and the second cladding layer is a photomachinable layer. The methods may include exposing a selected region of a photomachinable layer in the fusion-drawn laminate to ultraviolet radiation; heating the glass structure until the selected region crystallizes; and removing the crystallized material selectively from the photomachinable layer.

A method of making a glass article includes melting batch materials to produce molten glass, heating or cooling the molten glass to a temperature, forming a glass article from the molten glass. The batch materials include a plurality of viscosity-affecting components that become at least part of the glass article. Selection of the batch materials or the temperature was made at least in part using computer-implemented modeling where predicted equilibrium viscosity of the glass at the temperature is a function comprising concentrations of viscosity-affecting components and temperature-independent fitting coefficients for the viscosity-affecting components.

A glass substrate for a high-frequency device, which contains, in terms of mole percent on the basis of oxides: 40 to 75% of SiO.sub.2; 0 to 15% of Al.sub.2O.sub.3; 13 to 23% of B.sub.2O.sub.3; 2.5 to 11% of MgO; and 0 to 13% of CaO, and having a total content of alkali metal oxides in the range of 0.001-5%, where at least one main surface of the glass substrate has a surface roughness of 1.5 um or less in terms of arithmetic average roughness Ra. and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

A glass roll of band-shaped glass film is free of skew and single slack when a roll-to-roll mode is used. The band-shaped glass film is wound into a roll shape and has creases formed thereon. The band-shaped glass film includes an effective section with two side edges in a width direction extending parallel to each other, and leading and trailing end portions extending parallel to the width direction. When a length from the leading end portion to the trailing end portion along a surface of the effective section is measured along each of a first position along one side edge and a second position along another side edge, a difference between the first and second measurement lengths is 400 ppm or less of a longer measurement length of the first and second measurement lengths.

Provided is a manufacturing method for a glass article, including: a pre-heating step (S1) of heating a transfer pipe (7); and a transfer step (S4) of allowing a molten glass to flow inside the transfer pipe (7) after the pre-heating step (S1). The transfer pipe (7) includes: a main body portion (8) having a tubular shape; and a flange portion (9a, 9b) formed at an end portion of the main body portion (8). The main body portion (8) is retained by a refractory (10). The pre-heating step (S1) includes an external force application step of applying an external force (F) to the transfer pipe (7) to extend the transfer pipe (7).

A forming body of a glass forming apparatus may include a first conduit comprising a first conduit wall and at least one slot in the first conduit wall, and a second conduit disposed above and vertically aligned with the first conduit, the second conduit comprising a second conduit wall and a slot extending through the second conduit wall. The forming body may include a first vertical wall and a second vertical wall extending between an outer surface of the second conduit wall and an outer surface of the first conduit wall at a first side and a second side, respectively, of the forming body. The forming body may include a first forming surface and a second forming surface extending from an outer surface of the first conduit wall and converging at a root of the forming body. Methods of forming a continuous laminate glass ribbon are also disclosed.

A production apparatus that continuously produces plate glass, includes a molding member configured to mold molten glass to form a glass ribbon, wherein the molding member is (i) constituted with graphite or includes a portion constituted with graphite, and/or (ii) supported by a support member containing graphite, wherein in a case of (i), the molding member is surrounded by a fence, and in a case of (ii), the support member is surrounded by the fence together with the molding member, and wherein a space surrounded by the fence is adjusted to have an oxygen concentration of less than or equal to 100 ppm.