Edge stress using differential cooling

Patent metadata

Field	Value
Publication number	US-2022185717-A1
Application number	US-202017602324-A
Country	US
Kind code	A1
Filing date	Mar 30, 2020
Priority date	Apr 11, 2019
Publication date	Jun 16, 2022
Grant date	—

Abstract

A cold-formed glass laminate may include a first ply of 3D formed glass with a first thickness and a first strength. The first ply may include pre-formed residual compressive stresses in a peripheral edge portion adapted to offset tensile stresses resulting from a cold-forming process. The laminate may also include a second ply of 3D formed glass with a second thickness less than the first thickness and a second strength greater than the first strength. An adhesive may be arranged between the first ply and the second ply and post-formed residual stresses in the peripheral edge portion of the first ply of the laminate may remain compressive. A method of forming a glass laminate with compressive edge stresses is also described.

First claim

What is claimed is:

1 . A cold-formed glass laminate, comprising:
a first ply of glass with a first thickness and a first strength, the first ply having pre-formed residual compressive stresses in a peripheral edge portion adapted to offset tensile stresses resulting from a cold-forming process; a second ply of glass with a second thickness less than the first thickness and a second strength greater than the first strength; an adhesive arranged between the first ply and the second ply; and wherein post-formed residual stresses in the peripheral edge portion of the first ply remain compressive.

2 . The glass laminate of claim 1 , wherein the pre-formed residual compressive stresses range from approximately 10 MPa to approximately 25 MPa.

3 . The glass laminate of claim 1 , wherein the post-formed residual compressive stress in the peripheral edge portion of the first ply after the cold-forming process ranges from approximately 7 MPa to approximately 28 MPa.

4 . The glass laminate of claim 1 , wherein the peripheral edge portion comprises a substantially uniform ribbon around the perimeter of the glass laminate.

5 . The glass laminate of claim 4 , wherein the ribbon has a width from approximately 3 mm to approximately 7 mm.

6 . The glass laminate of claim 5 , wherein the width is approximately 5 mm.

7 . The glass laminate of claim 1 , wherein the first ply is soda lime glass and the second ply is at least one of chemically strengthened glass, thermally strengthened glass, or mechanically strengthened glass.

8 . The glass laminate of claim 1 , wherein the glass laminate is configured as at least one of a roof or a windshield for a vehicle.

9 . A method of forming a glass laminate, comprising:
hot-forming a first ply of glass; inducing residual compressive stresses in a peripheral edge of the first ply of glass by cooling the first ply of glass and, during the cooling, establishing a temperature differential between a peripheral edge of the first ply of glass and a center portion of the first ply of glass, wherein a temperature of the peripheral edge is cooler than a temperature of the center portion; and after cooling, cold-forming a second ply of glass to the first ply of glass and adhering the second ply of glass to the first ply of glass with an adhesive, the cold-forming causing tensile stresses in the peripheral edge of the first ply of glass that are counteracted by the residual compressive stresses such that post-forming residual stresses in the first ply of glass remain compressive.

10 . The method of claim 9 , wherein the temperature differential ranges from approximately 10° C. to approximately 40° C.

11 . The method of claim 10 , wherein the temperature differential ranges from approximately 12° C. to approximately 30° C.

12 . The method of claim 11 , wherein the temperature differential ranges from approximately 14° C. to approximately 25° C.

13 . The method of claim 9 , wherein the hot-forming of the first ply of glass comprises heating the first ply of glass beyond the glass transition point.

14 . The method of claim 13 , wherein establishing a temperature differential comprises providing additional cooling at edges of the first ply of glass.

15 . The method of claim 14 , wherein providing additional cooling comprises blowing cold air on the edges.

16 . The method of claim 15 , wherein blowing cold air comprises blowing cold air with a cooling channel arranged at or near the edges.

17 . The method of claim 16 , wherein hot-forming the first ply of glass comprises hot-forming the first ply of glass into at least one of a roof or a windshield shape.

18 . The method of claim 17 , wherein the cold-forming the second ply of glass comprises heating the second ply of glass to an elevated temperature below 140° C.

19 . The method of claim 18 , wherein the cold-forming the second ply of glass comprises pressing the second ply of glass against the first ply of glass at the elevated temperature.

20 . The method of claim 19 , wherein a strength of the second ply of glass is greater than a strength of the first ply of glass.

21 . The method of claim 9 , further comprising partially hot-forming the second ply of glass prior to cold-forming the second ply of glass to the first ply of glass.

Assignees

• Corning Inc

Inventors

• Bhatia Vikram
• Park Ah-Young
• Qaroush Yousef Kayed
• Zheng Zheming

Classifications

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• C03B23/0302

  between opposing full-face shaping moulds · CPC title

• C03C27/10

  with the aid of adhesive specially adapted for that purpose · CPC title

• B32B17/10889

  shaping the sheets, e.g. by using a mould (B32B17/10816 takes precedence) · CPC title

• B32B17/10816

  by pressing · CPC title