An apparatus and method for manufacturing a glass sheet are disclosed. The apparatus includes a glass delivery device, a puddle forming device positioned to contact and redirect at least a portion of a stream of molten glass as it falls from the glass delivery device, and a side roller configured to contact the stream falling from the glass delivery device and redirected from the puddle forming device at a target position and lose contact with the stream at a departure position to form a ribbon of glass. The puddle forming device and the side roller can be relatively positioned to form a puddle of molten glass on a surface of the side roller positioned upstream from the target position and a thickness control gap between the puddle forming device and the side roller.

The present invention provides a glass substrate in which in a heat treatment step of sticking a silicon substrate and a glass substrate to each other, an alkali ion is hardly diffused into the silicon substrate, and a residual strain generated in the silicon substrate is small. A glass substrate of the present invention has: an average thermal expansion coefficient α.sub.50/100 at 50° C. to 100° C. of 2.70 ppm/° C. to 3.20 ppm/° C.; an average thermal expansion coefficient α.sub.200/300 at 200° C. to 300° C. of 3.45 ppm/° C. to 3.95 ppm/° C.; a value α.sub.200/300/α.sub.50/100 obtained by dividing the average thermal expansion coefficient α.sub.200/300 at 200° C. to 300° C. by the average thermal expansion coefficient α.sub.50/100 at 50° C. to 100° C. of 1.20 to 1.30; and a content of an alkali metal oxide being 0% to 0.1% as expressed in terms of a molar percentage based on oxides.

Disclosed are various methods and apparatus for forming sheet glass from molten glass whose liquidus viscosity is <5 kP. Also disclosed is a roller for receiving and cooling continuously-fed ribbon of glass whose liquidus viscosity is <5 kP onto the roller's outer surface, where the roller is configured to be maintained at a predetermined temperature and can be rotated at a predetermined speed so that the glass ribbon comes in contact with the roller for a set duration of time and rolls off the roller at the end of the set duration of time.

An apparatus for making a glass sheet including a forming apparatus, a transition member, and a heat transfer device. The forming apparatus forms a glass ribbon from a supply of molten glass. The transition member encloses the glass ribbon adjacent the forming apparatus, and defines an interior space through which the glass ribbon passes. The heat transfer device is disposed within the interior space, and comprises a tube and a fin. The tube defines an exterior surface and an interior passage. The fin projects from the exterior surface. With this construction, the heat transfer device functions to extract heat radiated by the glass ribbon while minimizing the formation of flow vortices.

The present invention discloses improved methods and apparatus for forming sheet glass. In one embodiment, the invention introduces a counteracting force to the stresses on the forming structure in a manner such that the thermal creep which inevitably occurs has a minimum impact on the glass flow characteristics of the forming structure.

An apparatus for making a laminate glass ribbon, the glass ribbon having: a center laminate region, a first edge, a second edge, and first, second, third, and fourth, beads portions as defined herein, the apparatus includes: a bead thermal conditioning region including: a fluid source for selectively applying a fluid to one or more of the first, second, third, and fourth bead portions. Also disclosed is a method for bead thermal conditioning in the disclosed laminate fusion apparatus.

A method and apparatus for manufacturing a glass article includes flowing a glass ribbon through a transition region, heating the glass ribbon with a heating mechanism housed in the transition region, cooling the glass ribbon with a cooling mechanism housed in the transition region, wherein the cooling mechanism extends between the heating mechanism and the glass ribbon, and shielding the glass ribbon with a shielding mechanism that extends between the cooling mechanism and at least one of first and second bead regions of the glass ribbon.

A method for controlling the thickness of a glass ribbon and an article produced thereby are provided. The method includes: providing a glass ribbon by drawing from a melt or redrawing from a preform; predefining a nominal thickness of the glass ribbon; determining the thickness of the glass ribbon over its entire net width; determining at least one deviation of the thickness of the glass ribbon from the predefined nominal thickness; identifying the area of the thickness deviation in the glass ribbon; and heating the area of the at least one thickness deviation in the glass ribbon using a laser, so that the glass ribbon attains the predefined thickness.

An alkali-free glass substrate which is a glass substrate includes, as represented by molar percentage based on oxides, 0.1% to 10% of ZnO. The alkali-free glass substrate has an average coefficient of thermal expansion α.sub.50/100 at 50 to 100° C. of from 2.70 ppm/° C. to 3.20 ppm/° C., an average coefficient of thermal expansion α.sub.200/300 at 200 to 300° C. of from 3.45 ppm/° C. to 3.95 ppm/° C., and a value α.sub.200/300/α.sub.50/100 obtained by dividing the average coefficient of thermal expansion α.sub.200/300 at 200 to 300° C. by the average coefficient of thermal expansion α.sub.50/100 at 50 to 100° C. of from 1.20 to 1.30.

Provided is a glass ribbon manufacturing apparatus in which at least one of support rollers configured to support both sides of a glass ribbon (G) in a width direction in an annealing region and a cooling region is a shape stabilization roller configured to stabilize a shape of the glass ribbon (G) curved in the width direction. The shape stabilization roller includes a first roller (11) arranged on one surface side of the glass ribbon (G) and a second roller (12) arranged on another surface side of the glass ribbon (G). Inner end portions (11c) of rollers (11a) of the first roller (11) are all positioned on an outer side, in the width direction, of outer end portions (12c) of rollers (12a) of the corresponding second roller (12) in the width direction.