# US 2019/0169059 A1 · Methods for forming thin glass sheets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169059 A1 - Document ID: US20190169059A1 - Status: Published application - Kind: A1 - Application number: 16/184,101 - Filed: 2018-11-08 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Corning Incorporated - Applicants: Corning Incorporated - Inventors: Allan Mark Fredholm - Web page: https://patentgrep.com/patent/US20190169059A1 ## CPC - C03B 13/04: Rolling non-patterned sheets continuously - C03B 7/08: Feeder spouts, e.g. gob feeders - C03B 13/16: Construction of the glass rollers - C03B 17/06: Forming glass sheets - C03B 21/02: by cutting (C03B9/46 takes precedence) - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES ## Abstract According to one or more embodiments disclosed herein, a glass sheet may be formed by a method which includes supplying a feed of molten glass to an upper surface of a pair of forming rolls, and rotating the pair of forming wheels to continuously form a glass sheet from the molten glass. The pair of forming rolls may be spaced apart by a forming gap, and the forming gap may have a width of less than or equal to about 800 microns. The molten glass may have a viscosity of less than or equal to about 200 poise. The glass sheet may have a thickness of less than or equal to about 800 microns immediately upon passing though the forming gap. ## Claims ### Claim 1 A method for forming a glass sheet, the method comprising: supplying a feed of molten glass to an upper surface of a pair of forming rolls, the pair of forming rolls spaced apart by a forming gap, the forming gap having a width of less than or equal to about 800 microns, wherein the molten glass has a viscosity of less than or equal to about 200 poise; rotating the pair of forming rolls to continuously form a glass sheet from the molten glass, the glass sheet having a thickness of less than or equal to about 800 microns immediately upon passing though the forming gap. ### Claim 2 (depends on 1) The method of claim 1, wherein the glass sheet comprises a glass composition with a refractive index of about 1.7 or greater. ### Claim 3 (depends on 1) The method of claim 1, wherein the glass sheet has a width measured in a direction perpendicular to the forming gap width, and wherein the ratio of the width of the glass sheet to the thickness of the glass sheet is about 100 or greater. ### Claim 4 (depends on 1) The method of claim 1, wherein the glass sheet comprises a glass composition having a liquidus viscosity of about 200 poise or less. ### Claim 5 (depends on 1) The method of claim 1, wherein the thickness of the glass sheet varies by about 30 microns or less. ### Claim 6 (depends on 1) The method of claim 1, wherein the forming rolls are positioned horizontally relative to one another. ### Claim 7 (depends on 1) The method of claim 1, wherein no portion of the forming rolls contact one another. ### Claim 8 (depends on 1) The method of claim 1, wherein the molten glass forms a pool on the upper surface of the pair of forming rolls. ### Claim 9 (depends on 1) The method of claim 1, wherein the molten glass is supplied from a single point source. ### Claim 10 (depends on 9) The method of claim 9, wherein the single point source is a pipe. ### Claim 11 (depends on 1) The method of claim 1, wherein the molten glass is supplied from a plurality of point sources. ### Claim 12 (depends on 11) The method of claim 11, wherein the plurality of point sources are positioned along a major length of the forming gap. ### Claim 13 (depends on 1) The method of claim 1, further comprising cutting the glass sheet. ### Claim 14 (depends on 13) The method of claim 13, wherein the glass sheet is cut into a wafer. ### Claim 15 (depends on 1) The method of claim 1, further comprising directing the glass sheet to a heater, the heater configured to operate at a temperature greater than 100° C. ### Claim 16 (depends on 15) The method of claim 15, wherein the glass sheet has a viscosity less than 1010 poise at a distance of at least 0.75 m from the forming gap. ### Claim 17 A method for forming a high refractive index glass sheet, the method comprising: supplying a feed of molten glass to an upper surface of a pair of forming rolls, the pair of forming rolls spaced apart by a forming gap, the forming gap having a width of less than or equal to about 800 microns, wherein the molten glass has a viscosity of less than or equal to about 200 poise; rotating the pair of forming rolls to continuously form a glass sheet from the molten glass, the glass sheet having a thickness of less than or equal to about 800 microns immediately upon passing though the forming gap; wherein the glass composition of the glass sheet has a refractive index of about 1.7 or greater and a liquidus viscosity of about 200 poise or less. ### Claim 18 (depends on 17) The method of claim 17, wherein the molten glass has a viscosity of about 50 poise or less. ### Claim 19 (depends on 17) The method of claim 17, wherein glass composition of the glass sheet has a liquidus viscosity of about 50 poise or less. ### Claim 20 (depends on 17) The method of claim 17, further comprising directing the glass sheet to a heater, the heater configured to operate at a temperature greater than 100° C.