Method and system for forming shaped glass articles

Patent metadata

Field	Value
Publication number	US-9550695-B2
Application number	US-201414183938-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Feb 20, 2013
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A method of forming a shaped glass article includes placing a glass sheet on a mold such that a first glass area of the glass sheet corresponds to a first mold surface area of the mold and a second glass area of the glass sheet corresponds to a second mold surface area of the mold. The first glass area and the second glass area are heated such that the viscosity of the second glass area is 8 poise or more lower than the viscosity of the first glass area. A force is applied to the glass sheet to conform the glass sheet to the mold surface. During the heating of the second glass area, the first mold surface area is locally cooled to induce a thermal gradient on the mold.

First claim

The invention claimed is:

1. A method of forming a shaped glass article, comprising:
placing a glass sheet on a mold having a mold surface with a select shaped glass article profile, the placing being such that a first glass area of the glass sheet corresponds to a first mold surface area of the mold surface, wherein the first mold surface area is substantially flat, and a second glass area of the glass sheet corresponds to a second mold surface area of the mold surface, wherein the second mold surface area comprises a bend;
heating the first glass area and the second glass area to a glass viscosity between 10 10.1 poise and 10 9 poise;
locally heating the second glass area to a glass viscosity at or below 10 9.9 poise such that the glass viscosity of the second glass area is 8 poise or more lower than the glass viscosity of the first glass area;
applying a force to the glass sheet by creating vacuum at the second glass area through at least one vacuum opening located in the bend to conform the glass sheet to the mold surface when the second glass area is at a glass viscosity at or below 10 9.9 poise; and
locally cooling the first mold surface area using a cooling chamber positioned underneath the first mold surface area so that it does not extend underneath the bend to induce a thermal gradient on the mold surface that results in the glass viscosity in the first glass area remaining above 10 9.9 poise during the local heating of the second glass area.

2. The method of claim 1 , wherein the local cooling of the first mold surface area is such that the glass viscosity in the first glass area is maintained at or above 10 10.9 poise during at least a portion of the local heating of the second glass area.

3. The method of claim 1 , wherein local cooling of the first mold surface area results in a maximum thermal gradient across the first mold surface area of less than 20° C. during the local cooling.

4. The method of claim 3 , wherein local cooling of the first mold surface area is such that a temperature of the first mold surface area is below a temperature corresponding to a glass viscosity of 10 11.3 poise.

5. The method of claim 1 , wherein a temperature of the second mold surface area is above a temperature corresponding to a glass viscosity of 10 11.7 poise when the force is applied to the glass sheet.

6. The method of claim 1 , wherein the bend has a radius less than 20 mm.

7. The method of claim 1 , wherein creating vacuum comprises creating vacuum with a first vacuum pressure for a first time period followed by creating vacuum with a second vacuum pressure for a second time period, wherein the second vacuum pressure is reduced compared to the first vacuum pressure.

8. The method of claim 1 , further comprising cooling the conformed glass sheet to a glass viscosity above 10 13 poise.

9. The method of claim 1 , wherein heating of the first glass area and second glass area to a glass viscosity at or above 10 10.1 poise occurs in a first furnace or a first set of furnace zones and local heating of the second glass area to a glass viscosity at or below 10 9.9 poise occurs in a second furnace or second set of furnace zones that is different from the first furnace or first set of furnace zones.

10. The method of claim 1 , wherein at least one vacuum opening is located only in the bend.

Assignees

• Corning Inc

Inventors

• Immerman Jacob
• Keebler Thomas A
• Saltzer Jr John Robert
• Ukrainczyk Ljerka

Classifications

• Y10T428/24628

  Nonplanar uniform thickness material · CPC title

• G06F1/1626

  with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs] · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C03B23/0235 Primary

  involving applying local or additional heating, cooling or insulating means · CPC title

• C03B23/0357 Primary

  by suction without blowing, e.g. with vacuum or by venturi effect · CPC title