Apparatus and method for processing a glass substrate

Patent metadata

Field	Value
Publication number	US-11420895-B2
Application number	US-201716332670-A
Country	US
Kind code	B2
Filing date	Sep 11, 2017
Priority date	Sep 13, 2016
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

Disclosed are apparatuses and methods for non-contact processing a substrate, for example a glass substrate, overtop a gas layer. The support apparatus includes a plurality of gas bearings positioned on a pressure box supplied with a pressurized gas. Some embodiments are directed to a method of supporting and transporting softened glass. The method includes placing the glass in proximity to a gas bearing device having a support surface with a plurality of outlet ports disposed therein. Some embodiments are directed to a glass processing apparatus comprising an air table configured to continuously transport and support a stream of glass and a plurality of modular devices supported by a support structure and disposed above the air table. Some embodiments are directed to a method for flattening viscous glass using a two-sided gas bearing device or a one-sided gas bearing device.

First claim

What is claimed is:

1. An apparatus for supporting a substrate moving in a conveyance direction, comprising:
a. a pressure box enclosing a chamber in fluid communication with a source of pressurized gas;
b. a gas bearing positioned on the pressure box, the gas bearing including:
i. a plenum in fluid communication with the chamber and extending in a length direction of the gas bearing,
ii. an intermediate passage in fluid communication with the plenum through an impedance orifice sized to restrict a flow of gas between the plenum and the intermediate passage, and
iii. a slot in fluid communication with the intermediate passage and extending along the length direction of the gas bearing, the slot opening at a major surface of the gas bearing and configured to exhaust a gas along a length of the slot, and the major surface is substantially planar such that an opening of the slot is co-planar with the major surface; wherein the gas bearing comprises a plurality of edges defining the major surface of the gas bearing, the plurality of edges including a first pair of opposing parallel edges arranged at an angle α relative to the conveyance direction, wherein α is in a range from about 20 degrees to about 60 degrees, the plurality of edges including a second pair of opposing parallel edges connecting the first pair of opposing parallel edges, the second pair of opposing parallel edges orthogonal to the conveyance direction.

2. The apparatus according to claim 1 , wherein the apparatus comprises a plurality of gas bearings positioned on the pressure box, the plurality of gas bearings arranged in a plurality of rows extending orthogonal to the conveyance direction.

3. The apparatus according to claim 1 , wherein the pressure box comprises cooling passages in fluid communication with a source of cooling fluid.

4. The apparatus according to claim 1 , wherein a distance between an exit aperture of the impedance orifice and a major surface opening of the slot is equal to or greater than about 5 millimeters.

5. The apparatus according to claim 1 , wherein the impedance orifice extends along a longitudinal axis that intersects the major surface.

6. The apparatus according to claim 5 , wherein a second slot is in fluid communication with the intermediate passage and extends along the length direction of the gas bearing, the second slot opening at the major surface of the gas bearing and configured to exhaust a gas along a length of the second slot, the major surface positioned between the slot and the second slot with the slot on one side of the longitudinal axis and the second slot on an opposite side of the longitudinal axis.

7. The apparatus according to claim 1 , wherein the impedance orifice extends along a longitudinal axis that is parallel to the major surface.

8. A method for supporting a glass substrate, comprising:
a. conveying a glass substrate over a support apparatus in a conveyance direction, the support apparatus comprising a pressure box enclosing a chamber in fluid communication with a source of pressurized gas, the pressure box further including a plurality of gas bearings positioned on the pressure box, the plurality of gas bearings arranged in a plurality of rows extending orthogonal to the conveyance direction, each gas bearing of the plurality of gas bearings comprising:
i. a plenum extending in a length direction of the gas bearing,
ii. an intermediate passage in fluid communication with the plenum through an impedance orifice sized to restrict a flow of gas between the plenum and the intermediate passage,
iii. a slot in fluid communication with the intermediate passage and extending along the length of the gas bearing, the slot opening at a major surface of the gas bearing;

b. exhausting gas from each slot along a length of the slot, thereby supporting the glass substrate in a position spaced apart from the major surface of each gas bearing of the plurality of gas bearings; and
c. wherein the major surface of each gas bearing of the plurality of gas bearings is defined by a plurality of edges comprising at least a first pair of parallel edges arranged at an angle α relative to the conveyance direction, where α is in a range from equal to or greater than 20 degrees to equal to or less than 60 degrees, wherein a second pair of parallel edges connect the first pair of parallel edges, and the second pair of parallel edges are orthogonal to the conveyance direction.

9. The method according to claim 8 , further comprising heating the glass substrate to a temperature greater than an anneal temperature of the glass substrate as the glass substrate is conveyed over the support apparatus.

10. The method according to claim 8 , wherein a width of the glass substrate is at least 1 meter, and a maximum variation of a major surface of the glass substrate does not exceed 100 micrometers relative to a reference plane parallel with the major surface after conveying the glass substrate over the support apparatus.

11. The method according to claim 8 , wherein the glass substrate is a glass ribbon, the method further comprising drawing the glass ribbon from a forming body prior to supporting the glass ribbon with the support apparatus.

12. The method according to claim 11 , further comprising re-directing the glass ribbon from a first direction to a second direction different than the first direction prior to supporting the glass substrate with the support apparatus.

13. The method according to claim 8 , wherein a gas pressure exhausted from gas bearings positioned adjacent edge portions of the glass substrate is greater than a gas pressure exhausted from gas bearings positioned beneath a central portion of the glass substrate.

Assignees

• Corning Inc

Inventors

• Fournel Olivier
• Fredholm Allan Mark

Classifications

• C03B35/246 Primary

  Transporting continuous glass ribbons · CPC title

• C03B35/184

  Cooling · CPC title

• C03B23/0355

  by blowing without suction directly on the glass sheet · CPC title

• C03B17/062

  combined with flowing onto a solid or gaseous support from which the sheet is drawn · CPC title

• B65H2801/61

  Display device manufacture, e.g. liquid crystal displays · CPC title