Apparatus and method for dynamic thermal tempering of glass
AssigneeCorning Incorporated
InventorsDouglas Dale Bressler, Brian Christopher Sheehan, John Thomas, Kevin Lee Wasson
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Abstract
A process for thermally strengthening a glass article comprising first conveying a glass article, having a temperature above a transition point of the glass of the article, into position between two fluid bearing surfaces then moving the fluid bearing surfaces toward the glass article and cooling the glass article, with at least 20% of said cooling taking place by conduction from the glass article to the fluid bearing surfaces. Apparatuses for performing the process and products resulting are also disclosed.
Claims30
A process for thermally strengthening a glass article, the process comprising
- first conveying a glass article, the article having a temperature above a transition point of the glass of the article, into position between a first two fluid bearing surfaces;
- second moving one or both of the first two fluid bearing surfaces toward the glass article and cooling the glass article, with at least 20% of said cooling taking place by conduction, from the glass article to the fluid bearing surfaces, during at least some point in time during the cooling.
A process for thermally strengthening a glass article, the process comprising
- first, heating a glass article positioned in a hot zone between two hot zone fluid bearing surfaces while moving one or both of the two hot zone fluid bearing surfaces toward the glass article without contacting the glass article, said heating to a temperature above a transition point of a glass of the article with at least 20% of said heating taking place by conduction during at least some point in time during said heating;
- second, conveying the glass article into position in a cold zone between a two cold zone fluid bearing surfaces.
An apparatus for thermal tempering of glass, the apparatus comprising:
- a cold zone comprising two cold zone fluid bearing surfaces, one or both of the cold zone fluid bearing surfaces being moveable, under automated control, toward and away from the other of the two cold zone fluid bearing surfaces so as automatically vary a gap between the two cold zone fluid bearing surfaces;
- and
- a conveyor moveable under automated control between the hot zone and the cold zone so as to be capable to move a glass article under treatment from the hot zone to the cold zone;
- wherein the moveable cold zone fluid bearing surface(s) and the moveable conveyor are moveable independently and wherein the automated control of the moveable cold zone fluid bearing surface(s) is programmed and/or designed so as to move the moveable cold zone fluid bearing surface(s) during processing of a glass article.
A strengthened glass article comprising:
- a first major surface;
- a second major surface opposite the first major surface and separated from the first major surface by a thickness t;
- an interior region located between the first and second major surfaces;
- and
- an outer edge surface extending between and surrounding the first and second major surfaces such that the outer edge surface defines a perimeter of the article;
- wherein the article is thermally tempered such that at the first major surface is under compressive stress;
- the strengthened glass article comprising a glass material having a low temperature linear CTE, expressed in 1/° C., of αSCTE, a high temperature linear CTE, expressed in 1/° C., of αLCTE, an elastic modulus, expressed in GPa, of E, a strain temperature, expressed in units of ° C., of Tstrain, and a softening temperature, expressed in units of ° C., of Tsoft;
- the compressive stress of the first major surface is less than 600 MPa and greater than
- P
- 1
-
- (
- h
- )
- *
- t
- (
- P
- 2
-
- (
- h
- )
- *
- t
- )
- ·
- E
- ·
- [
- T
- strain
- ·
- α
- CTE
- s
- +
- α
- CTE
- L
- ·
- (
- T
- soft
- -
- T
- strain
- )
- ]
- ;
- in units of MPa;
- wherein P1 is given by
- 910.2
- -
- 259.2
- ·
- exp
-
- (
- -
- h
- 0.143
- )
- ;
- P2 is given by
- 2.53
- +
- 23.65
- (
- 1
- +
- (
- h
- 0.00738
- )
- 1.58
- )
- ;
- and h is greater than or equal to 0.020;
- wherein at least the first major surface is a curved surface other than a portion of a cylindrical surface and other than a portion of a toroidal surface.
Dependencies are inferred from the claim text.