According to one embodiment, a method for thermally treating glass articles may include holding a glass article at a treatment temperature equal to an annealing temperature of the glass article =15° C. for a holding time greater than or equal to 5 minutes. Thereafter, the glass article may be cooled from the treatment temperature through a strain point of the glass article at a first cooling rate CR1 less than 0° C./min and greater than −20° C./min such that a density of the glass article is greater than or equal to 0.003 g/cc after cooling. The glass article is subsequently cooled from below the strain point at a second cooling rate CR.sub.2, wherein |CR.sub.2|>|CR.sub.1|.

A glass substrate for a high-frequency device, which contains SiO.sub.2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na.sub.2O/(Na.sub.2O+K.sub.2O) in the range of 0.01-0.99, and the glass substrate having a total content of alkaline earth metal oxides in the range of 0.1-13% in terms of mole percent on the basis of oxides, wherein at least one main surface of the glass substrate has a surface roughness of 1.5 nm 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.

An isothermal drop speed cooling method and an apparatus for same. A glass ribbon carried with glass passes through the forced convection area of the glass annealing lehr, and the glass ribbon is moving while the glass is being air-cooled in the forced convection area. The glass is air-cooled by different air volume according to the temperature of the glass, so that the glass is allowed to be cooled at isothermal drop speed during the moving process of the glass. According to the cooling method and apparatus, the specification size of the opening section of multi-row air nozzles longitudinally arranged is increased along the moving direction of the glass ribbon, so that the cooling air volume from the front to the rear can be gradually increased, thereby allowing the temperature drop speed of a glass plate to be uniform from the front to the rear.

An isothermal drop speed cooling method and an apparatus for same. A glass ribbon carried with glass passes through the forced convection area of the glass annealing lehr, and the glass ribbon is moving while the glass is being air-cooled in the forced convection area. The glass is air-cooled by different air volume according to the temperature of the glass, so that the glass is allowed to be cooled at isothermal drop speed during the moving process of the glass. According to the cooling method and apparatus, the specification size of the opening section of multi-row air nozzles longitudinally arranged is increased along the moving direction of the glass ribbon, so that the cooling air volume from the front to the rear can be gradually increased, thereby allowing the temperature drop speed of a glass plate to be uniform from the front to the rear.

A system for forming a glass panel includes a mixing apparatus for weighing and mixing glass particles and additives, an oven for melting and holding molten glass, a float chamber for floating molten glass thereover, an annealing lehr, and at least a nozzle for delivering compressed air at least of one of a first pressure and a second pressure.

A system for forming a glass panel includes a mixing apparatus for weighing and mixing glass particles and additives, an oven for melting and holding molten glass, a float chamber for floating molten glass thereover, an annealing lehr, and at least a nozzle for delivering compressed air at least of one of a first pressure and a second pressure.

Processes and methods for preparing glass panels for use with automobiles include mixing and melting glass particles. Molten glass is passed along into a lehr, where the molten glass is annealed. Annealed glass is cut into glass panels. A nozzle systems delivers compressed air to the glass panels to form a curvature for providing a top seal contact area. A nozzle system delivers a second blast of compressed air, which marks the glass panel to identify characteristics of the glass panel.

Processes and methods for preparing glass panels for use with automobiles include mixing and melting glass particles. Molten glass is passed along into a lehr, where the molten glass is annealed. Annealed glass is cut into glass panels. A nozzle systems delivers compressed air to the glass panels to form a curvature for providing a top seal contact area. A nozzle system delivers a second blast of compressed air, which marks the glass panel to identify characteristics of the glass panel.

A windshield according to the present invention includes an outer glass plate, an inner glass plate that faces the outer glass plate, and an intermediate film disposed between the outer glass plate and the inner glass plate, and in at least a partial region of the outer glass plate and the inner glass plate, compressive principal stress on a surface on a vehicle exterior side of the outer glass plate is larger than compressive principal stress on a surface on a vehicle interior side of the inner glass plate.

A strengthened glass article (100), such as a substrate for a p-Si based transistors, includes first and second glass cladding layers (104, 106) and a glass core layer (102) disposed therebetween. A coefficient of thermal expansion [CTE] of each cladding layer (104, 106), which can be made of the same glass, is at least 1×10.sup.−7° C..sup.−1 less than that of the core layer (102). Each of the core and cladding layers has a strain point less than 700° C. A compaction of the glass article (100) is at most about 20 ppm [see FIG. 1]. A method includes forming a glass article and/or heating a glass article to a first temperature of at least about 400° C. The glass article has a glass core layer (102) and a glass cladding layer (104, 106) adjacent to the core layer. The glass article is maintained at a temperature within a range of from 400° C. to 600° C. for a holding period from 30 to 90 minutes and subsequently cooled to a temperature of at most 50° C. over a cooling period from 30 seconds to 5 minutes. The glass article (100) for heat strengthening may have been produced by the fusion overflow down draw process, e.g. as depicted in FIG. 3.