阅读说明：本技术 用于减少因硫化镍基夹杂物引起的玻璃破坏的方法和系统 (Method and system for reducing glass damage due to nickel sulfide based inclusions ) 是由 阿列克谢·克拉斯诺夫 格雷戈里·高德特 胡学群 于 2019-03-07 设计创作，主要内容包括：本发明提供了一种用于减少因夹杂物诸如硫化镍基夹杂物引起的钢化后玻璃破坏的方法和/或系统。在热钢化过程的冷却期的至少一部分期间,将附加能量引导至所述玻璃中的夹杂物诸如硫化镍基夹杂物处。所述玻璃可以是钠钙硅基浮法玻璃。所述附加能量可以为例如来自至少一个光源的可见光和/或红外(IR)光的形式,所述光被引导至所述硫化镍基夹杂物。(The present invention provides a method and/or system for reducing post-tempering glass damage caused by inclusions, such as nickel sulfide-based inclusions. Additional energy is directed at inclusions, such as nickel sulfide based inclusions, in the glass during at least a portion of a cooling period of a thermal tempering process. The glass may be soda-lime-silica-based float glass. The additional energy may be in the form of, for example, visible and/or Infrared (IR) light from at least one light source, which is directed to the nickel sulfide-based inclusions.)

1. A method of thermally tempering glass to reduce glass breakage due to nickel sulfide based inclusions, the method comprising:

thermally tempering glass comprising a base glass composition, the base glass composition comprising:

wherein the thermal tempering comprises heating the glass to at least a softening temperature via a temperature of at least 580 ℃ and then rapidly cooling the glass via forced cold air; and

during at least a portion of the rapid cooling, additional energy is directed at least nickel sulfide-based inclusions in the glass to slow cooling of the inclusions relative to another region of the glass, thereby allowing the nickel sulfide-based inclusions to safely transform from the high temperature alpha-phase to the beta-phase.

2. The method of claim 1, wherein the additional energy is directed from at least one light source through at least one window in a tempering chamber where the glass is thermally tempered to at least the nickel sulfide-based inclusions in the glass.

3. The method of claim 2, wherein the at least one window comprises a quartz window.

4. The method of any preceding claim, further comprising concentrating the additional energy on a region of the glass containing at least the nickel sulfide-based inclusions.

5. A method according to any preceding claim, wherein the additional energy comprises at least one wavelength in the range 300nm-1100 nm.

6. The method of claim 5, wherein the additional energy comprises at least one wavelength in the range of 380nm-700 nm.

7. A method according to any preceding claim, wherein the additional energy comprises a plurality of wavelengths in the range 300nm-1100 nm.

8. The method of any preceding claim, wherein the additional energy is directed at least at the inclusions during at least a substantial portion of the rapid cooling process.

9. The method of any preceding claim, wherein the amount of additional energy provided is sufficient to: (i) preventing at least one nickel sulfide-based inclusion in the glass from being trapped in the alpha-phase of a final glass product, and (ii) allowing the nickel sulfide-based inclusion in the alpha-phase to relax to a relatively harmless beta-phase within 24 hours after the application of the forced cooling air is terminated, such that the inclusion in the final glass product is in the beta-phase.

10. The method of any preceding claim, wherein the additional energy is directed to the entire or substantially the entire size of the glass.

11. The method of claim 10, wherein the dimension is a width of the glass as viewed from above.

12. The method of any preceding claim, wherein when the additional energy is directed to the glass, the location of nickel sulfide-based inclusions is unknown and/or whether nickel sulfide-based inclusions are present in the glass to which the additional energy is directed is unknown.

13. The method of any preceding claim, wherein the additional energy is directed only to regions of the glass where nickel sulfide based inclusions are believed to be present.

14. A method of making a thermally tempered glass, the method comprising:

thermally tempering glass comprising a base glass composition, the base glass composition comprising:

wherein the thermal tempering comprises heating the glass to at least a softening temperature via a temperature of at least 580 ℃ and then rapidly cooling the glass in a rapid cooling process; and

directing additional energy to at least nickel sulfide-based inclusions in the glass during at least a portion of the rapid cooling of the glass to slow cooling of the nickel sulfide-based inclusions to allow the nickel sulfide-based inclusions to safely transition from a high temperature alpha-phase to a beta-phase.

15. The method of claim 14, wherein the additional energy is directed from at least one light source through at least one window in a tempering chamber where the glass is thermally tempered to at least the nickel sulfide-based inclusions in the glass.

16. The method of claim 15, wherein the at least one window comprises a quartz window.

17. The method of any of claims 14-16, further comprising concentrating the additional energy on at least a region of the glass containing the nickel sulfide-based inclusions.

18. The method of any one of claims 14 to 17, wherein the additional energy comprises at least one wavelength in the range of 300nm-1100 nm.

19. The method of any one of claims 14 to 18, wherein the additional energy is directed at the inclusions during at least a majority of the rapid cooling process.

20. The method of any one of claims 14 to 19, wherein the amount of additional energy provided is sufficient to: (i) preventing at least one nickel sulfide-based inclusion in the glass from being trapped in the alpha-phase of a final glass product, and (ii) allowing the nickel sulfide-based inclusion in the alpha-phase to relax to a relatively harmless beta-phase within 24 hours after the application of the forced cooling air is terminated, such that the inclusion in the final glass product is in the beta-phase.

21. The method of any one of claims 14 to 20, wherein the additional energy is directed over the entire or substantially the entire dimension of the glass.

22. The method of claim 21, wherein the dimension is a width of the glass viewed from above.

23. The method of any of claims 14 to 22, wherein when the additional energy is directed to the glass, the location of nickel sulfide-based inclusions is unknown and/or whether nickel sulfide-based inclusions are present in the glass to which the additional energy is directed is unknown.

24. The method of any of claims 14-23, wherein the additional energy is directed only to regions of the glass where nickel sulfide based inclusions are believed to be present.

25. A system for thermally tempering glass to reduce glass breakage due to nickel sulfide based inclusions, the system comprising:

a chamber configured for thermally tempering glass comprising a base glass composition comprising:

at least one heat source configured to heat the glass in the chamber to at least a softening temperature via a temperature of at least 580 ℃,

at least one cooling orifice configured for rapid cooling of the glass via forced cool air; and

at least one processor configured to control at least one energy source to direct additional energy to at least nickel sulfide-based inclusions in the glass during at least a portion of the rapid cooling to slow cooling of the inclusions relative to another region of the glass to allow the nickel sulfide-based inclusions to safely transition from a high temperature alpha-phase to a beta-phase.

26. The system of claim 25, wherein the additional energy is directed from the at least one energy source through at least one window in the chamber to at least the nickel sulfide-based inclusions in the glass.

27. The system of claim 26, wherein the at least one window comprises a quartz window.

28. The system of any one of claims 25 to 27, wherein the additional energy comprises at least one wavelength in the range of 300nm-1100 nm.

29. The system of any one of claims 25 to 28, wherein the at least one processor is configured to cause the additional energy to be directed at least at the inclusions during at least a majority of the rapid cooling.

30. The system of any one of claims 25 to 29, wherein the at least one energy source and/or processor is configured to provide the additional energy in an amount sufficient to: (i) preventing at least one nickel sulfide-based inclusion in the glass from being trapped in the alpha-phase of a final glass product, and (ii) allowing the nickel sulfide-based inclusion in the alpha-phase to relax to a relatively harmless beta-phase within 24 hours after the application of the forced cooling air is terminated, such that the inclusion in the final glass product is in the beta-phase.

31. The system of any one of claims 25 to 30, wherein the at least one energy source and/or processor is configured to direct the additional energy over the entire size or substantially the entire size of the glass.

32. The system of claim 31, wherein the dimension is a width of the glass as viewed from above.

33. A system for treating glass to reduce glass breakage due to nickel sulfide based inclusions, the system comprising:

a chamber configured to heat glass comprising a base glass composition comprising:

at least one heat source configured to heat the glass in the chamber to at least a softening temperature via a temperature of at least 580 ℃,

at least one cooling orifice configured to cool the glass; and

at least one processor configured to control at least one energy source to direct additional energy to the glass during at least a portion of the cooling so as to slow cooling of inclusions relative to another region of the glass to allow the inclusions to safely transition from a first phase to a second phase.

34. The system of claim 33, wherein the additional energy is directed from the at least one energy source through at least one window in the chamber to at least the inclusions in the glass.

35. The system of any one of claims 33 to 34, wherein the additional energy comprises at least one wavelength in the range of 300nm-1100 nm.

36. The system according to any one of claims 33 to 35, wherein the at least one processor is configured to cause the additional energy to be directed to the glass during at least a majority of the rapid cooling.

Background

Methods of making float glass are known in the art. See, for example, U.S. patent nos. 3,954,432, 3,083,551, 3,220,816, 7,743,630, 8,677,782, 9,016,094 and 5,214,008, the disclosures of all of which are hereby incorporated by reference in their entirety. Generally, in a float glass production line, the batch materials are heated in a furnace or melter to form a glass melt. The glass melt is poured into a bath of molten material, such as tin (tin bath), and then continuously cooled to form a float glass ribbon. The float glass ribbon is then sent to an annealing lehr for further processing and then cut to form solid glass articles, such as flat glass sheets. For float glass, the glass batch typically comprises soda ash, calcium oxide, and silica to form a soda-lime-silica-based flat glass.

Float glass is widely used in windows for commercial and residential buildings, glass furniture, shower doors and automotive windshields. For many products, float glass must be heat tempered (heated to at least 580 ℃ C. and then rapidly cooled) to ensure safety in the event of breakage. Impurities in the raw materials, sulfur in the additives, and/or contaminants from the float process occasionally and unpredictably form undesirable chemical compounds (e.g., inclusions) during glass formation, which are undesirable defects in the glass. For example, nickel is known to spontaneously combine with sulfur to form nickel sulfide inclusions or nickel sulfide (with any suitable stoichiometry, such as NiS) based inclusions.

Although nickel sulfide inclusions are generally harmless in annealed glass (e.g., made via a float process without any additional heat treatment, such as thermal tempering), they are known to cause spontaneous breakage of thermally tempered glass. In addition, nickel sulfide inclusions/defects in thermally tempered glass have resulted in long term catastrophic glass failure in the installed product.

Various methods have been used to detect NiS inclusions and other similar sized microdefects (e.g., 40-150 micron sized defects) on-line. U.S. patent No. 7,511,807, incorporated herein by reference, for example, directs light onto glass and looks for light scattering in order to detect inclusions.

It will be appreciated that there is a need in the art to reduce this glass breakage.

Disclosure of Invention

Exemplary embodiments of the present invention are directed to a method and/or system for reducing post-tempering glass damage due to inclusions, such as nickel sulfide-based inclusions. The methods and/or systems herein may be used in conjunction with glass, such as soda-lime-silica-based float glass, in which such inclusions are prone to occur. In certain exemplary embodiments of the invention, additional energy is directed at inclusions, such as nickel sulfide-based inclusions, in the glass during at least a portion of the cooling period of the thermal tempering process. The additional energy may be in the form of, for example, visible and/or Infrared (IR) light from at least one light source, which is directed to the nickel sulfide-based inclusions. In certain exemplary embodiments, the additional energy may be directed at the inclusions through a window (e.g., a quartz window) disposed in a wall of the tempering chamber, such that the light source may optionally be located outside of the tempering chamber. It has been found that the additional energy directed at the inclusions during at least a portion of the cooling portion of the hot patenting process reduces the chance of inclusions being trapped in the alpha-phase and allows the inclusions to relax to their relatively harmless beta-phase.

In one exemplary embodiment of the present invention, there is provided a method of thermally tempering glass to reduce glass breakage due to nickel sulfide-based inclusions, the method comprising: thermally tempering glass comprising a base glass composition, the base glass composition comprising: 67% -75% of SiO₂10% -20% of Na₂O, 5-15% of CaO and 0-7% of Al₂O₃And 0-7% of K₂And during at least a portion of the rapid cooling, directing additional energy at the nickel sulfide-based inclusions in the glass to slow the cooling of the inclusions relative to another region of the glass, thereby allowing the nickel sulfide-based inclusions to safely transition from the α -phase, at an elevated temperature, to the β -phase.

In one exemplary embodiment of the present invention, a system for thermally tempering glass to reduce glass breakage due to nickel sulfide-based inclusions is provided, the system comprising: a chamber configured to thermally temper glass; at least one heat source (e.g., an IR source) configured to heat the glass in the chamber to at least a softening temperature via a temperature of at least 580 ℃; at least one cooling orifice (e.g., one or more cooling jets) configured for rapid cooling of the glass via forced cooling air; and at least one processor configured to control the at least one energy source to direct additional energy at the nickel sulfide-based inclusions in the glass during at least a portion of the rapid cooling to slow cooling of the inclusions relative to another region of the glass to allow the nickel sulfide-based inclusions to safely transition from the high temperature alpha-phase to the beta-phase.

A system for treating glass to reduce glass breakage due to nickel sulfide based inclusions, the system comprising: a chamber configured to heat glass comprising a base glass composition, the base glass composition comprising: 67% -75% of SiO₂10% -20% of Na₂O, 5-15% of CaO and 0-7% of Al₂O₃And 0-7% of K₂O; at least one heat source configured to heat the glass in the chamber to at least a softening temperature via a temperature of at least 580 ℃; at least one cooling orifice configured to cool glass; and at least one processor configured to control the at least one energy source to direct additional energy to the glass during at least a portion of the cooling so as to slow cooling of the inclusions relative to another region of the glass to allow safe transition of the inclusions from the first phase to the second phase.

Drawings

FIG. 1 is a graph of temperature (deg.C) versus time (seconds) illustrating a method according to an exemplary embodiment of the present invention in which additional energy is directed at inclusions in the glass during at least a portion of the cooling portion of the thermal tempering process.

Fig. 2 is a schematic view of a tempering system/apparatus for reducing glass breakage due to inclusions, such as nickel sulfide-based inclusions, that may utilize the process shown in fig. 1, according to an exemplary embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention are directed to a method and/or system for reducing post-tempering glass breakage caused by inclusions such as nickel sulfide-based inclusions (e.g., nickel sulfide inclusions and/or other micro-defects having a size of about 30 μm to 200 μm, more preferably about 40 μm to 150 μm). The methods and/or systems herein may be used in conjunction with glass, such as soda-lime-silica-based float glass, in which such inclusions are prone to occur. In certain exemplary embodiments of the invention, additional energy is directed at inclusions, such as nickel sulfide-based inclusions, in the glass during at least a portion of the cooling period of the thermal tempering process. The additional energy may be in the form of, for example, visible and/or Infrared (IR) light from at least one light source, which is directed to the nickel sulfide-based inclusions. In certain exemplary embodiments, the additional energy may be directed at the inclusions through a window (e.g., a quartz window) disposed in a wall of the tempering chamber, such that the light source may optionally be located outside of the tempering chamber. The chamber may be a furnace, oven, or the like, and at least one heat source (e.g., an IR source) may be located in the chamber to heat the glass for tempering as discussed herein. It has been found that the additional energy directed at the inclusions during at least a portion of the cooling portion of the hot patenting process reduces the chance of inclusions being trapped in the alpha-phase and allows the inclusions to relax to their relatively harmless beta-phase.

Nickel sulfide exists in different phases at different temperatures. For example, the two specific phases of NiS are known as the alpha-phase and the beta-phase. At temperatures below 715 ° F (379 ℃), the nickel sulfide is relatively stable in the β -phase. Above this temperature, it is stable in the alpha-phase. Thus, any NiS inclusions may be in the alpha-phase when making glass in a high temperature furnace. In a typical annealed glass, the slow cooling process provided by the lehr allows sufficient time for the NiS to transition from its alpha-phase to its relatively harmless beta-phase as the glass cools.

However, for safety purposes, glass (e.g., soda-lime-silica-based float glass) is typically Heat Treated (HT), such as heat tempered. A typical thermal tempering process involves heating the glass using a temperature of at least 580 ℃ (e.g., about 580 ℃ to 640 ℃, more preferably about 580 ℃ to 620 ℃) and then rapidly cooling the glass via forced cold air. During rapid/rapid cooling processes used to make thermally strengthened and tempered glass, nickel sulfide-based inclusions typically do not have sufficient time to complete the phase transformation from the troublesome alpha-phase to the relatively harmless beta-phase (which is a relatively slow process). Thus, nickel sulfide inclusions are often trapped in the glass as a high temperature alpha-phase, for example, in thermally tempered glass. However, once the glass cools beyond the transformation temperature, the nickel sulfide inclusions attempt to re-enter the lower energy beta-phase. This process can take months to years for trapped inclusions. This may have no effect on the glass, if not for the purpose of changing the NiS from the α -phase to the β -phase, its volume may increase by, for example, 2% to 4%. This expansion may create localized tensile stresses that may cause the glass to break. Thus, nickel sulfide-based inclusions trapped in the heat-treated (e.g., heat tempered) glass in their alpha-phase are problematic and may lead to subsequent destruction of the glass.

Nickel sulfide is a compound having various forms. The most common form of nickel sulfide is Ni₇S₆、NiS、NiS_1.03、Ni₃S₂And Ni₃S₂+ Ni. When observed under an electron microscope, Ni₇S₆NiS and NiS_1.03Is golden yellow and has a rough surface similar to a golf ball. These three types are non-magnetic and have been found to cause damage to the tempered glass, as discussed above.

In certain exemplary embodiments, a soda-lime-silica-based glass comprises a base glass portion comprising, in weight percent: 67% -75% of SiO₂10% -20% of Na₂O, 5-15% of CaO and 0-7% of Al₂O3, 0-7% MgO and 0-7% K₂And O. Optionally, the colorant portion of the glass may also contain one or more colorants, such as iron, selenium, cobalt, erbium, and the like. Alternatively, the glass may be a different type of glass, such as borosilicate glass, aluminosilicate glass, or the like.

An exemplary soda-lime-silica base glass according to certain embodiments of the present invention, which may be made via a float process or other suitable process, includes the following base constituents on a weight percent basis:

table 1: exemplary base glass

Other minor ingredients, including various refining aids such as salt cake, crystal water, etc., may also be included in the base glass. In certain embodiments, for example, the glasses herein can be made from the batch raw materials silica sand, soda ash, dolomite, limestone, and using salt cake (SO)₃) As a refining agent. In some cases, reducing agents and oxidizing agents may also be used. In certain instances, the soda-lime-silica based glasses herein may comprise about 10% -15% by weight Na₂O and CaO in an amount of about 6% to about 12%. In addition to the base glass materials discussed above, the glass batch materials and/or the final glass may also include a colorant portion that includes materials such as iron, erbium, cobalt, selenium, and the like in suitable amounts to color and/or absorb the glass in a desired manner. In certain exemplary embodiments of the invention, the total iron content in the glass may be about 0.05% to 1.2%, more preferably about 0.3% to 0.8%. For certain clear, high transmission glasses, the total iron can be about 0.005% to 0.025%. The total amount of iron present in the glass and hence in the colorant portion thereof is referred to herein as Fe, according to standard practice₂O₃And (4) showing. However, this does not mean that all of the iron is actually Fe₂O₃In the form of (1). Likewise, even though all of the ferrous iron in the glass may not be in the form of FeO, the amount of ferrous iron is reported herein as FeO.

For example, when glass is manufactured via the float process, glass batch raw materials (e.g., silica sand, soda ash, dolomite, limestone, colorants, etc.) are provided to and heated in a furnace or furnace to form a glass melt. The glass melt is poured into a bath of molten material, such as tin (tin bath), where the glass is formed and continuously cooled to form a float glass ribbon. The float glass ribbon travels to an annealing lehr for slow cooling. Optionally, the lateral edge portions of the glass sheet may be trimmed under high temperature conditions prior to entering the annealing lehr. The glass sheet typically reaches the beginning of the lehr at a temperature of at least about 540 c, more preferably at least about 580 c, with a possible range of temperatures being about 540 c (or 580 c) to 800 c. During annealing, the temperature of the glass ribbon is slowly cooled from the annealing point (e.g., about 538 ℃ to 560 ℃) to a strain point of about 495 ℃ to 560 ℃, which may be referred to as the annealing range. While these temperature ranges are preferred for annealing, different temperatures may be used in some cases. During annealing, the continuous glass sheet may be supported by rollers or gases. After annealing, the continuous glass sheet proceeds to further processing, such as one or more of cutting, additional cooling, coating, and the like. A system for detecting inclusions (e.g., nickel sulfide-based inclusions) in glass may be provided on the float line or after the float line. Inclusions can be detected, for example, via thermal imaging, wavelength analysis, naked eye analysis, imaging analysis, and/or light scattering analysis, for example. Such annealed glass may be used as is (e.g., in a window or other suitable application), or may be subsequently heat treated (e.g., heat tempered) for safety applications. In certain exemplary embodiments, the additional energy directed to the glass discussed herein may be directed indiscriminately to the entire glass or substantially the entire glass when we are unaware of the exact location of any possible nickel sulfide-based inclusions or even the presence or absence of any such inclusions in the glass. However, in other exemplary embodiments, when the presence and location of nickel sulfide-based inclusions are known, the additional energy may be directed only to locations in the glass where nickel sulfide-based inclusions are known to be present.

FIG. 1 is a graph of temperature (deg.C) versus time (seconds) illustrating a method according to an exemplary embodiment of the present invention in which additional energy is directed at inclusions in the glass during at least a portion of the cooling portion of the thermal tempering process; and fig. 2 is a schematic view of a tempering system/apparatus for reducing glass breakage due to inclusions, such as nickel sulfide-based inclusions, that may utilize the process shown in fig. 1, according to an exemplary embodiment of the present invention.

The thermal tempering process includes heating the glass to a softening temperature using a temperature of at least 580 ℃ (e.g., about 580 ℃ to 640 ℃, more preferably about 585 ℃ to 625 ℃), and then rapidly cooling the glass via forced cold air, as shown in fig. 1. The glass is heated for about 0.5 to 10 minutes, more preferably about 1 to 8 minutes. The glass is then rapidly cooled via forced cold air from a nozzle or the like, and the temperature of the glass is lowered (see, for example, fig. 1). However, the temperature drop is steep as shown by the solid line in fig. 1, and generally nickel sulfide-based inclusions in the glass do not have enough time to complete the phase transition from the troublesome alpha-phase to the relatively harmless beta-phase (which is a relatively slow process). Thus, nickel sulfide inclusions are often trapped in the glass as a high temperature alpha-phase, for example, in thermally tempered glass.

Referring to fig. 1-2, this problem is addressed by directing additional energy at inclusions, such as nickel sulfide-based inclusions, in the glass during at least a portion of the cooling period of the thermal tempering process in order to slow the cooling process of the inclusions (see, e.g., the dashed line in fig. 1). The heating profile, cooling, and additional energy may be controlled by at least one processor configured to control it, such as in the manner shown in fig. 1 or otherwise described herein. In certain example embodiments of the invention, the additional energy is not directed at the entire glass, but only at the region of the glass having inclusions (e.g., nickel sulfide-based inclusions), so as not to significantly interfere with the tempering process of the remainder of the glass, and to slow the cooling process of the inclusions relative to the cooling of the glass body to be tempered. However, in alternative exemplary embodiments of the present invention, additional energy may be applied to the entire glass substrate. The additional energy may be in the form of, for example, visible and/or Infrared (IR) light from at least one light source, which is directed to the nickel sulfide-based inclusions. The light source may be a laser, a high intensity light source, or the like, and in certain exemplary embodiments, additional energy may be concentrated on the area containing the inclusions. In certain exemplary embodiments of the invention, the additional energy may include at least one wavelength in the range of about 300nm to 1100nm, more preferably about 380nm to 700 nm. The additional energy may be a single wavelength or only a few wavelengths, or may be a combination of various wavelengths within a specified wavelength range.

In certain exemplary embodiments, the additional energy may be directed at the inclusions through one or more windows (e.g., at least one quartz window) disposed in the walls of the tempering chamber, such that the light source may optionally be located outside of the tempering chamber. In an exemplary embodiment of the present invention, a window through which additional energy is directed may be provided in a side wall and/or ceiling of the tempering chamber. It has been found that the additional energy directed at the inclusions during at least a portion of the cooling portion of the hot patenting process slows the cooling process of the nickel sulfide based inclusions and thus reduces the chances of inclusions being trapped in the alpha-phase and thus allows the inclusions to relax to their relatively harmless beta-phase. The amount of additional energy provided is sufficient to: (i) preventing at least one nickel sulfide-based inclusion in the glass from being trapped in the alpha-phase, and (ii) allowing the nickel sulfide-based inclusion in the alpha-phase to relax to a relatively harmless beta-phase within 24 hours after the application of the forced cooling air is terminated, such that the inclusion in the final glass product is in the beta-phase.

In one exemplary embodiment, as shown in fig. 1, the additional energy is applied from a point in time near the beginning of the cooling period, and may continue until a point in time just before, at, or after the end of the tempering of the glass. As a result, the glass sheet is tempered and the nickel sulfide based inclusions are safely transformed from their high temperature alpha-phase to a relatively harmless beta-phase.

Accordingly, in one exemplary embodiment of the present invention, there is provided a method of thermally tempering glass to reduce glass breakage due to nickel sulfide-based inclusions, the method comprising: thermally tempering glass comprising a base glass composition, the base glass composition comprising: 67% -75% of SiO₂10% -20% of Na₂O, 5-15% of CaO and 0-7% of Al₂O₃And 0-7% of K₂O, wherein the thermal tempering comprises heating the glass to at least a softening temperature via a temperature of at least 580 ℃ and then rapidly cooling the glass via forced cool air, and directing additional energy to at least nickel sulfide based inclusions in the glass during at least a portion of the rapid cooling to slow the cooling of the inclusions relative to another region of the glass to allow the nickel sulfide based inclusions to transform from a high temperature of α -The phase was safely converted to the β -phase.

In the method of the preceding paragraph, additional energy may be directed from at least one light source through at least one window in a tempering chamber to nickel sulfide-based inclusions in the glass, where the glass is thermally tempered. The at least one window may comprise at least one quartz window.

In the method of any of the two preceding paragraphs, it may be provided that the additional energy is concentrated on at least the region of the glass containing nickel sulfide-based inclusions.

In the method of any one of the preceding three paragraphs, the additional energy may comprise at least one wavelength in the range 300nm-1100nm, more preferably 380nm-700 nm. The additional energy may comprise a plurality of wavelengths within said range.

In the method of any of the preceding four paragraphs, additional energy may be directed at the inclusions during at least a substantial portion of the rapid cooling process.

In the method of any of the preceding five paragraphs, the amount of additional energy provided may be sufficient to: (i) preventing at least one nickel sulfide-based inclusion in the glass from being trapped in the alpha-phase, and (ii) allowing the nickel sulfide-based inclusion in the alpha-phase to relax to a relatively harmless beta-phase within 24 hours after the application of the forced cooling air is terminated, such that the inclusion in the final glass product is in the beta-phase.

In the method of any of the preceding six paragraphs, (a) the additional energy may be directed indiscriminately over the entire size or substantially the entire size of the glass (e.g., over at least 80% of the glass size), such as when the location of nickel sulfide inclusions is unknown and/or when it is unknown whether nickel sulfide based inclusions are still present in the glass; or (b) the additional energy may be directed only to locations in the glass where the presence of nickel sulfide-based inclusions is known to be present, such as in embodiments and/or situations where the presence and location of nickel sulfide-based inclusions is known.

In one exemplary embodiment of the present invention, a method for thermally tempering glass to reduce nickel sulfide based inclusion initiation is providedA glass breaking system for a glass comprising: a chamber configured for thermally tempering glass comprising a base glass composition comprising: 67% -75% of SiO₂10% -20% of Na₂O, 5-15% of CaO and 0-7% of Al₂O₃And 0-7% of K₂The system includes a chamber, at least one energy source (e.g., an IR source) configured to heat glass in the chamber to at least a softening temperature via a temperature of at least 580 ℃, at least one cooling orifice (e.g., one or more cooling jets) configured for rapid cooling of the glass via forced cool air, and at least one processor configured to control the at least one energy source to direct additional energy at nickel sulfide-based inclusions in the glass during at least a portion of the rapid cooling so as to slow cooling of the inclusions relative to another region of the glass, thereby allowing the nickel sulfide-based inclusions to safely transition from an α -phase at an elevated temperature to a β -phase.

Numerous other features, modifications and improvements will become apparent to those skilled in the art once the above disclosure is given. Accordingly, such features, modifications and improvements are considered part of this invention, the scope of which is defined by the following claims.