METHOD FOR WINDING A GLASS RIBBON, APPARATUS THEREFOR, AND THE GLASS ROLL PRODUCED THEREBY

Abstract

A method for winding up a glass ribbon is provided, in which, prior to winding up the glass ribbon, the two surfaces of the glass ribbon are each initially treated with a water-containing medium and subsequently dried so as to produce a defined content of water molecules on the two surfaces, by achieving a saturation of the surfaces of the glass ribbon with water, without bringing about an excess of water molecules. A glass roll is produced in which the electrostatic charge of the glass surface is reduced and, as a result, any undesired excess adherence of the glass surface to an interleaf material is prevented and, in this way, glass breakage, in particular during winding up and/or unwinding of the glass roll, can be markedly reduced.

Claims

1. A method for winding up a glass ribbon, comprising: treating two surfaces of the glass ribbon with a water-containing medium; drying the water-containing medium in order to produce a defined content of water molecules on the two surfaces by achieving, in each case, a saturation of the two surfaces with water, without an excess of water molecules being obtained; and winding up the glass ribbon.

2. The method according to claim 1, wherein the step of treating the two surfaces with the water-containing medium does not comprise dipping the glass ribbon in the water-containing medium.

3. The method according to claim 1, wherein the step of treating the two surfaces with the water-containing medium comprises spraying the two surfaces with the water-containing medium.

4. The method according to claim 1, wherein the step of treating the two surfaces with the water-containing medium comprises vaporizing the water-containing medium onto the two surfaces.

5. The method according to claim 1, wherein the step of treating the two surfaces with the water-containing medium comprises applying the water-containing medium as a liquid.

6. The method according to claim 1, wherein the step of treating the two surfaces with the water-containing medium comprises applying the water-containing medium as a gas.

7. The method according to claim 1, wherein the step of drying the water-containing medium comprises delivering dried air to the two surfaces.

8. The method according to claim 7, further comprising preheating the dried air before delivering the dried air to the two surfaces.

9. The method according to claim 1, wherein the step of drying the water-containing medium comprises heating the two surfaces to a temperature below 150° C. and above 100° C.

10. The method according to claim 1, wherein the step of winding up the glass ribbon further comprises winding up the glass ribbon together with an interleaf material.

11. The method according to claim 10, wherein the interleaf material is a material selected from the group consisting of a polymeric material, resin material, paper material, and nonwoven material.

12. The method according to claim 10, wherein the interleaf material is a polymeric material comprising a polymer selected from the group consisting of ionomers, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polypropylene, polyester, polyamide, nylon, polycarbonate, polystyrene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylate copolymer, polyimide, and cellophane.

13. The method according to claim 1, wherein the step of winding up the glass ribbon further comprises adjusting an air humidity to a range between 50% and 80% at 20° C.

14. The method according to claim 1, wherein the step of winding up the glass ribbon further comprises deionizing at least one of ambient air, the glass ribbon, an interleaf material, and combinations thereof.

15. The method according to claim 1, wherein the glass ribbon has a thickness of 50 μm.

16. The method according to claim 1, wherein the glass ribbon comprises a glass selected from the group consisting of lithium aluminum silicate glass, soda-lime silicate glass, borosilicate glass, aluminosilicate glass, and glass ceramic.

17. The method according to claim 1, wherein the glass ribbon comprises lithium aluminum silicate glass comprising (in wt %): TABLE-US-00007 Si.sub.2 55-69, Al.sub.2O.sub.3 19-25, Li.sub.2O 3-5, Total Na.sub.2O + K.sub.2O  0-30, Total MgO + CaO + SrO + BaO 0-5, ZnO 0-4, Ti.sub.2 0-5, Zr.sub.2 0-3, Total Ti.sub.2 + Zr.sub.2 + Sn.sub.2 2-6, P.sub.2O.sub.5 0-8, F 0-1, and B.sub.2O.sub.3 0-2.

18. The method according to claim 17, wherein the lithium aluminum silicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-1 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

19. The method according to claim 1, wherein the glass ribbon comprises soda-lime silicate glass comprising (in wt %): TABLE-US-00008 Si.sub.2 40-80, Al.sub.2O.sub.3 0-6, B.sub.2O.sub.3 0-5, Total Li.sub.2O + Na.sub.2O + K.sub.2O  5-30, Total MgO + CaO + SrO + BaO + ZnO  5-30, Total Ti.sub.2 + Zr.sub.2 0-7, and P.sub.2O.sub.5 0-2.

20. The method according to claim 19, wherein the soda-lime silicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-15 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

21. The method according to claim 1, wherein the glass ribbon comprises borosilicate glass comprising (in wt %): TABLE-US-00009 Si.sub.2 60-85,  Al.sub.2O.sub.3 1-10, B.sub.2O.sub.3 5-20, Total Li.sub.2O + Na.sub.2O + K.sub.2O 2-16, Total MgO + CaO + SrO + BaO + ZnO 0-15, Total Ti.sub.2 + Zr.sub.2 0-5, and P.sub.2O.sub.5 0-2. 

22. The method according to claim 21, wherein the borosilicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-15 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

23. The method according to claim 1, wherein the glass ribbon comprises alkali aluminosilicate glass comprising (in wt %): TABLE-US-00010 Si.sub.2 40-75,  Al.sub.2O.sub.3 10-30,  B.sub.2O.sub.3 0-20, Total Li.sub.2O + Na.sub.2O + K.sub.2O 4-30, Total MgO + CaO + SrO + BaO + ZnO 0-15, Total Ti.sub.2 + Zr.sub.2 0-15, and P.sub.2O.sub.5 0-10.

24. The method according to claim 23, wherein the alkali aluminosilicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-15 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

25. The method according to claim 1, wherein the glass ribbon comprises alkali-free aluminosilicate glass comprising (in wt %): TABLE-US-00011 Si.sub.2 50-75,  Al.sub.2O.sub.3 7-25, B.sub.2O.sub.3 0-20, Total Li.sub.2O + Na.sub.2O + K.sub.2O  0-0.1, Total MgO + CaO + SrO + BaO + ZnO 5-25, Total Ti.sub.2 + Zr.sub.2 0-10, and P.sub.2O.sub.5 0-5. 

26. The method according to claim 25, wherein the alkali-free aluminosilicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-15 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

27. The method according to claim 1, wherein the glass ribbon comprises low-alkali aluminosilicate glass comprising (in wt %): TABLE-US-00012 Si.sub.2 50-75,  Al.sub.2O.sub.3 7-25, B.sub.2O.sub.3 0-20, Total Li.sub.2O + Na.sub.2O + K.sub.2O 0-4,  Total MgO + CaO + SrO + BaO + ZnO 5-25, Total Ti.sub.2 + Zr.sub.2 0-10, and P.sub.2O.sub.5 0-5. 

28. The method according to claim 27, wherein the low-alkali aluminosilicate glass further comprises at least one of: coloring oxides selected from the group consisting of Nd.sub.2O.sub.3, Fe.sub.2O.sub.3, CoO, NiO, V.sub.2O.sub.5, Mn.sub.2, CuO, Ce.sub.2, and Cr.sub.2O.sub.3; rare earth oxides in contents of 0-15 wt %; and refining agents in contents of 0-2 wt %, the refining agents being selected from the group consisting of such as As.sub.2O.sub.3, SB.sub.2O.sub.3, Sn.sub.2, SO.sub.3, Cl, F, and Ce.sub.2.

29. The method according to claim 1, further comprising attaining an electrostatic charge of the glass ribbon in the range of 0 to 1 kV during the treating and drying steps.

30. An apparatus for winding up a glass ribbon, comprising: a treating device configured to treat two surfaces of the glass ribbon with a water-containing medium by spraying or vaporizing the two surfaces with the water-containing medium; and a drying device configured to dry the two surfaces of the glass ribbon with retention of a defined content of water molecules on the two surfaces by achieving, for each of them, a saturation of the two surfaces with water, without obtaining an excess of water molecules.

31. A glass comprising two surfaces each have a defined content of water molecules on the surfaces, wherein, in each case, a saturation of the surfaces with water exists, without any excess of water molecules being present.

32. The glass according to claim 31, wherein the glass is selected from the group consisting of a glass ribbon, a thin glass ribbon, and a glass sheet.

33. A glass roll comprising a glass ribbon according to claim 31 wound up together with a polymeric interleaf material, wherein the glass ribbon has an electrostatic charge in a range of 0 to 1 kV.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The invention will be further illustrated below on the basis of drawings, which are not intended to limit the present invention.

[0056] FIG. 1 is a schematic illustration of an exemplary embodiment of an apparatus for implementing the method according to the invention, wherein a thin glass ribbon is treated in accordance with the invention and then wound up together with an interleaf material onto a roll;

[0057] FIG. 2 a schematic illustration of an exemplary embodiment of another apparatus for implementing the method according to the invention;

[0058] FIG. 3 a perspective view of an exemplary embodiment of the present invention in the form of a glass roll in a wound-up state; and

[0059] FIG. 4 a plan view onto the glass roll of FIG. 3.

DETAILED DESCRIPTION

[0060] The various elements illustrated in the drawing are only representative and are not necessarily drawn to scale. Certain portions thereof may be exaggerated, whereas others may be minimized. The drawings are intended to illustrate exemplary embodiments of the disclosure that can be understood and implemented in a suitable manner by the person skilled in the art, without limiting the invention. In the figures, identical components and elements are referenced with identical reference numbers and symbols.

[0061] FIG. 1 shows a schematic illustration of an embodiment of an apparatus for implementing the method according to the invention, wherein the glass ribbon 10, made of thin glass, is initially treated in accordance with the method according to the invention and subsequently wound up onto a roll 30 together with an interleaf material 20. First of all, the glass ribbon 10 is prepared. The method according to the invention can directly follow after production of the thin glass, for example, that is, after the forming method. The thin glass can be produced by any method, such as, for example, an overflow, fusion, redraw, or float method.

[0062] In the first step of the method according to the invention, after the thin glass has been prepared in the form of a glass ribbon, the two surfaces of the glass ribbon 10 are treated with a water-containing medium. This can be conducted, for example, by means of vaporizers 15.1 and 15.2, which deposit water vapor on the two surfaces of the glass ribbon 10. In the process, one or a plurality of layers of water molecules are formed on the two surfaces of the glass ribbon. In the subsequent drying step, a portion of the water molecules is removed once again by drying. This can be conducted, for example, by means of two drying apparatuses 25.1 and 25.sub.2 A possibility for drying the surfaces of the glass ribbon is, for example, to blow dry air onto the glass surfaces. Another possibility for carrying out the drying is to heat the glass surfaces, albeit preferably below 150° C. so as to carry out a controlled vaporization of the undesired water content. As a result of the treatment with a water-containing medium and the subsequent drying, a continuous water film is obtained on each surface of the glass ribbon 10, so that, preferably, only one layer of water molecules is present on each of the surfaces. Any exceeding or falling short of the defined water content on the surfaces has a detrimental effect on the properties of the glass ribbon, in particular on the electrostatic charge and stress crack corrosion thereof, so that a markedly higher glass breakage is obtained. Only when a defined water content exists on the surface of the glass ribbon 10 can the advantageous properties according to the invention be obtained.

[0063] The defined water content can be determined by just a few tests on the surface of the glass ribbon with the chosen glass composition by the person skilled in the art. The water film then lies in the range according to the invention when a saturation of the glass surface just exists and no excess quantities of water are present. In order to demonstrate that a water film is indeed present on the surface of the glass ribbon in the form of a continuous layer of water molecules, the surface conductivity can be measured, for example.

[0064] After the method according to the invention has been carried out, the resulting thin glass 10 is wound onto a roll 30. To this end, the interleaf material 20, which is composed of polyethylene foam, for example, is provided. The thickness of the interleaf material 20 generally lies in the range of 10 to 2000 μm. As shown in FIG. 1, the interleaf material 20 can be applied onto the surface of the glass ribbon 10 by means of a roll 35, with the roll 35 rotating in the direction of the arrow. Obviously, other possibilities of feeding the interleaf material 20 and applying it onto the surface of the glass ribbon are known to the person skilled in the art.

[0065] Once the interleaf material 20 is situated in the correct position on the surface of the glass ribbon 10, the glass ribbon 10 and the interleaf material 20 are wound up together onto the roll 30, which rotates in the direction of the given arrow. In this way, any direct contact of the glass surfaces with each other is prevented, so that the wound-up thin glass is appropriately protected.

[0066] The diameter of the roll 30 increases as more glass ribbon 10 is wound up together with the interleaf material 20.

[0067] According to a preferred embodiment of the present invention, the interleaf material 20 can be wound up already one or more times onto the roll 30 (not shown), before the winding up of the glass ribbon 10 onto the roll 30 begins. According to another preferred embodiment, the interleaf material can also be wound up one or more times on the roll at the end of the winding operation in order to protect the roll against any unintentional contact or minor impacts.

[0068] FIG. 2 shows a schematic illustration of an exemplary embodiment of another apparatus for implementing the method according to the invention. First of all, the glass ribbon 10 is prepared. The method according to the invention can also be carried out, for example, during production of the thin glass, that is, during the forming process. In the example shown, the glass ribbon 10 is drawn downward from the glass melt 5 into the drawing shaft 18. Therefore, during production, the method according to the invention is carried out in the apparatus according to the invention at the two reactive surfaces of the glass ribbon 10 directly in the drawing shaft 18. For example, it is possible, first of all, also for a deionization of the air to occur, followed by treatment with a water-containing medium and drying (not illustrated), in order to obtain the appropriate moisture in the form of a monolayer of water molecules. Preferably, the drawing shaft 18 is vertical in this case, this being illustrated by the drawing shaft components 22.1 and 22.2 other geometries are possible.

[0069] The treatment with a water-containing medium can be conducted, for example, by delivering moist air or steam. This can be supplied, for example, from above, from below, or in the middle of the drawing shaft 18 (not shown). Situated in the drawing shaft are preferably heating devices (not shown), so that heating is accomplished directly during the drawing down of the glass ribbon 10, and then the temperature is once again lowered until it reaches room temperature. For creation of the layer of water molecules, it should be noted that the temperature lies preferably below 150° C. after application of the water-containing medium so as to obtain the desired saturation of the surface of the glass ribbon. More preferably, the two glass surfaces are subjected simultaneously to the method according to the invention. For further conveyance of the glass ribbon 10, it is possible to provide appropriate devices, such as, for example, the rolls 35.1 and 35.2

[0070] FIG. 3 is a perspective view and illustrates a wound-up glass roll 30 according to a preferred embodiment of the present invention. The glass roll 30 is formed by winding up the glass ribbon 10 around a roll core 40 in a roll, with an interleaf material 20 being situated on the surface of the glass ribbon. Obviously, it is also possible to omit, if appropriate, the roll core 40. It can be taken out of the roll 30 after winding up the glass roll 30, so as, for example, to reduce the weight of the entire glass roll 30.

[0071] The glass ribbon 10, which is wound up, is a thin glass and has a thickness in the range of ≦300 μm, for example. The glass composition can be chosen at will by the person skilled in the art. An exemplary glass is a borosilicate glass.

[0072] FIG. 4 shows a plan view onto the glass roll 30 of FIG. 3. The interleaf material 20 is situated on the top surface of the glass ribbon 10 and is wound up together with the glass ribbon 10 onto the reel core 40 of the glass roll 30.

[0073] FIGS. 1 to 4 illustrate possible embodiments only by way of example. They are not to be understood as being limiting, but rather merely represent examples of possible embodiments. Other possibilities of implementation are conceivable.

[0074] The present invention will be described below on the basis of an exemplary embodiment, which is not intended to limit the present invention.

Exemplary Embodiment

[0075] A glass ribbon was produced in the usual way. The prepared thin glass ribbon had a thickness of 50 μm. The thin glass ribbon was first of all wetted by use of a water vaporizer. Subsequently, the wetted surface of the glass ribbon was dried in the air.

[0076] The electrostatic charge prior to wetting and drying of the glass ribbon was: 15 kV. After the method according to the invention was carried out, the electrostatic charge was: 0.3 kV.

[0077] After the method according the invention was carried out, the glass breakage was markedly reduced. This was ascertained by optical inspection in comparison to an identical glass roll that, however, had not been subjected to the method according to the invention.

[0078] The present invention therefore relates to a method in which a glass roll is produced, in which the electrostatic charge of the glass surface is reduced and, as a result, any undesired excess adherence of the glass surface to an interleaf material is prevented and, in consequence, glass breakage can be markedly reduced, in particular during winding up and/or unwinding of the glass roll.