Method for opening an insulating glass unit

Abstract

The invention relates to a method for opening an insulating glass unit (11), comprising at least two glass panes (20a; 20b) spaced apart from one another; a spacer (21) which is arranged between the two glass panes (20a; 20b) and runs around at the edges of the two glass panes and which is adhesively bonded to the two glass panes (20a; 20b), and a secondary seal (23) which runs around at the outer side of the spacer (21), wherein the spacer (21) and the two glass panes (20a; 20b) enclose a gas volume (24), wherein the radiation (13) of at least one flash lamp device (12; 32) is applied to the surfaces of the two glass panes (20a; 20b) at least in a surface edge region in which the spacer (21) and the secondary seal (23) are arranged.

Description

[0001] Method for opening an insulating glass unit

[0002] Description

[0003] The invention relates to a method by which the glass panes of insulating glass units can be separated from one another, thus disassembling the insulating glass units into their individual components, allowing the individual components of the insulating glass units to be sorted and recycled. Such a process of disassembling an insulating glass unit is also referred to as opening an insulating glass unit.

[0004] In building construction, glazing is often achieved using so-called insulating glass units. An insulating glass unit comprises at least two spaced-apart panes of glass, the distance between which is fixed by a spacer positioned between the panes and running along their edges. The spacer, often made of stainless steel, an aluminum alloy, or plastic, is bonded to the panes, creating an adhesive layer between the spacer and the glass.

[0005] It is also known to inject a thermoplastic material as a spacer between the circumferential edges of two glass panes. In such an embodiment of a spacer, the spacer itself encompasses the two adhesive layers, or the adhesive layers and the spacer merge seamlessly into one another. Such spacers are also referred to as "thermoplastic spacers" or, in short, "TPS".

[0006] The spacer with adhesive layers in an insulating glass unit is also referred to as the primary seal because it ensures that any gas trapped between the glass panes and the spacer cannot escape. Furthermore, a secondary seal around the outside of the spacer provides mechanical stability. This secondary seal can, for example, consist of a polymer compound. Insulating glass units of this type improve the energy efficiency of buildings.

[0007] Insulating glass units are also known as multiple-pane insulating glass, thermal insulation glazing, or insulating glazing, and are abbreviated as "IGU" in technical literature, derived from the English term "Insulated Glass Unit." Currently, insulating glass units installed in buildings are increasingly being removed due to age or building demolition, resulting in these units as waste. Recycling insulating glass units is complex but worthwhile. The raw materials they contain, especially the glass, can be reused. Glass components from old insulating glass units can, for example, be used as a pure additive in a glass melt during the production of new float glass, or the glass panes themselves can be reused. When recycling insulating glass units, they are typically mechanically shredded, and the individual materials are then sorted using various separation methods.However, this results in a very high level of effort and no separation of materials by type.

[0008] The website https: / / www.morleyglass.co.uk / morley-glass-igu-recycling-scheme-breaks-1000-energy-years-savings-mark / describes a solution for recycling insulating glass units in which the units are first mechanically shredded, producing a mixture of glass, aluminum, and polymer fragments. This mixture is then melted. However, this process does not yield a pure glass melt. JP 2004230313 A2 therefore proposes further coarse sorting of the shredded mixture using a blower. However, this process also fails to produce a pure separation of the components.

[0009] The webpage “https: / / doi.org / 10.1007 / s40940-024-00276-x”, which features an article by Martien Teich et al. entitled “Reuse and remanufacturing of insulated glass units”, suggests either disassembling the insulating glass units manually, which is very time-consuming, or using a commercial cutting process. Finally, the webpage “https: / / gpd.fi / wp-content / uploads / 2022 / 09 / GPD2022_Graham_Dodd_Glass-Sustainability_Reversing-the-Supply-Chain_Recovery-of-IGU-Components.pdf” features an article entitled “Reversing the Supply Chain: Recovery of IGU Components”, which proposes using mechanical grinding or cutting tools attached to a robotic arm to open an insulating glass unit.

[0010] The established separation methods for dismantling insulating glass units described above are very complex and therefore expensive. This makes recycling partially uneconomical. Furthermore, separating the glass panes from insulating glass units, for example using mechanical cutting with a cutting blade, often results in damage to the glass. Removing adhesive residue, spacer fragments, and / or secondary sealant residue adhering to the glass panes is also a complex process.

[0011] JP 2008-155197 A and JP 2019-055363 A describe devices and methods for opening multiple-pane insulating glass units. A laser beam is guided precisely along the sealant inside the insulating glass unit via an optical system, scanning only in one direction parallel to the longitudinal extent of the space between the panes. This targeted laser irradiation reduces the adhesive force of the sealant, making it easier to separate the glass panes. This allows for a material-friendly separation of the multiple-pane glass. However, a disadvantage is that laser sources, precise optics, scanner systems, and safety equipment are significantly more complex than simple mechanical separation methods. Furthermore, the laser must be focused very precisely on the sealing zone between the panes and kept within this focus area.Furthermore, the process window is defined by the laser exposure time and controlled by the line width and traverse speed. This necessitates a complex, vibration-free transport system (in the millimeter range) for the windows, some of which weigh over 100 kg. Differences in glass thickness, coatings, spacer position, or sealing material can alter the energy input and require precise process control. If the laser energy is set too high or incorrectly focused, thermal stresses, microcracks, or localized melting points can occur in the glass.

[0012] This can lead to the destruction of glass panes, especially with coated glass or laminated safety glass. Similarly, incomplete material separation is possible due to faulty laser focusing or an unsuitable scan pattern. This can result in contamination remaining on the glass or even breakage due to faulty separation, making further processing (of the same type) difficult or even impossible.

[0013] The invention is therefore based on the technical problem of creating a method for opening an insulating glass unit that overcomes the disadvantages of the prior art. In particular, the method according to the invention should make it possible to open and thus disassemble an insulating glass unit in such a way that the glass panes remain undamaged. Furthermore, the method according to the invention should also produce glass panes that are free of macroscopic residues of the adhesive layers and fragments of the spacers. The solution to the technical problem is achieved by objects with the features of claim 1. Further advantageous embodiments of the invention are described in the dependent claims.

[0014] The inventive method for opening an insulating glass unit, comprising at least two spaced-apart glass panes; a spacer arranged between the two glass panes and circumferentially around the edges of the two glass panes, which is bonded to the two glass panes by means of two adhesive layers, and a secondary seal circumferentially around the outside of the spacer, wherein the spacer and the two glass panes enclose a gas volume, is characterized in that the surfaces of the two glass panes are exposed to the radiation of at least one flash lamp device, at least in a surface edge region in which the spacer, the two adhesive layers and the secondary seal are arranged.It should be noted that the spacer and the two adhesive layers can also be made of a thermoplastic material in which the spacer and the two adhesive layers merge seamlessly. As previously mentioned, such spacers are also referred to as "thermoplastic spacers" or abbreviated as "TPS".

[0015] By subjecting at least one surface edge area of ​​the glass panes to the radiation from a flash lamp device, the adhesive layers between the glass panes and the spacer undergo a modification such that their adhesive properties are significantly reduced. Surprisingly, it has also been shown that, according to the invention, subjecting the glass panes to the radiation from a flash lamp device not only alters the adhesive layers between the spacer and the glass panes, but also modifies the secondary seal around the outside of the spacer in such a way that, after subjecting both sides of an insulating glass unit to the radiation from a flash lamp device according to the invention, the glass panes can be removed from the spacer with only minimal force.The radiation from such a flash lamp device presumably causes thermal and / or chemical degradation reactions at the interface between the glass panes and the adhesive layers, as well as at the interface between the glass panes and the secondary sealant. Using the method according to the invention, insulating glass units can thus be opened or disassembled in such a way that undamaged glass panes result from this process. Surprisingly, it has also been found that, after disassembly of an insulating glass unit according to the invention, residues of the adhesive layers and the secondary sealant adhering to the glass panes can be removed with known solvents. Such a solvent can, for example, comprise ethanol and / or isopropanol, with which the glass panes can be wiped. Alternatively, the residues adhering to the glass panes can also be washed off using a glass washing machine known from the prior art.Such cleaning processes are already established in the manufacture and recycling of glass panes, so that the inventive method can be integrated into existing plants for the manufacture or recycling of glass panes and insulating glass units with minimal effort.

[0016] The inventive method thus produces not only undamaged glass panes, but also macroscopically pure glass panes, which can then be sorted and fed into a recycling process or reused. The inventive solution reduces the technical effort and is therefore considerably more process-stable and less expensive compared to known laser-based methods, and also does not require the high-precision control technology necessary for known laser methods.

[0017] A key element for carrying out the method according to the invention is the at least one flash lamp assembly. This typically comprises a lamp unit in the form of one or more longitudinally extending, tubular discharge lamps and a beam shaping system using appropriately adapted reflectors, including cooling. The radiation exits through a highly transparent window glass, which protects the lamp unit and the reflector assembly from environmental influences. Such flash lamp assemblies are known.

[0018] For the method according to the invention, a flash lamp device is to be used in which the radiation is in a wavelength range of 250 nm to 1000 nm, the duration of the flashes of the flash lamp device is in a range of 1 ms to 10 ms and the energy densities of the flashes of the flash lamp device are in a range of 1 J / cm² 2 up to 50 J / cm 2The parameters can be adjusted. For example, the flashes can be repeated at a frequency in the Hz range. The precise values ​​for the aforementioned parameters, as well as the number of flashes per unit area and the flash frequency required for a specific task, can be determined with minimal effort through laboratory tests. In a preferred embodiment, only one flash per unit area is used.

[0019] In the method according to the invention, a flash lamp device can be used which comprises one or more flash lamp modules. If a flash lamp device comprises several flash lamp modules, the individual flash lamp modules can preferably be controlled separately in one embodiment.

[0020] As previously explained, the application of radiation from a flash lamp device to an insulating glass unit according to the invention causes a chemical reaction within the adhesive layers and within the secondary seal surrounding the outer surface of the spacer, which can be accompanied by gas evolution. Such gas evolution and / or the heating of the insulating glass unit as a result of the flashing light can, in turn, increase the pressure of the gas volume injected between the glass panes. In the worst case, this can lead to the glass panes shattering.

[0021] In a further embodiment of the invention, at least one recess is provided in the secondary seal and the spacer before the surfaces of the two glass panes are exposed to the radiation from the flash lamp device, such that the volume of gas enclosed by the two glass panes and the spacer can escape through the recess. Such a recess can be provided, for example, by drilling into the secondary seal and the spacer. The volume of gas enclosed between the glass panes can then be extracted through the recess by means of a pump device, for example, before and / or during exposure to the radiation from a flash lamp device.This approach reduces the pressure between the two panes of glass in an insulating glass unit, thus preventing the panes from shattering when exposed to the radiation of a flash lamp device. Alternatively, two or more recesses can be incorporated into the spacer and the secondary seal, so that when suction is drawn through at least one recess, a gas flow is created in the space between the two panes, which can also contribute to cooling the glass panes.

[0022] As previously described, the inventive method requires that at least the edge regions of both glass panes be exposed to the radiation of at least one flash lamp device. This can be achieved, for example, by first exposing the surface of one glass pane of an insulating glass unit to the radiation of the flash lamp device, then rotating the insulating glass unit, and then, in a second process step, exposing the surface of the other glass pane to the radiation of the flash lamp device.

[0023] Alternatively, an insulating glass unit can be positioned between a first flash lamp unit and a second flash lamp unit, with the surfaces of both glass panes of the insulating glass unit being simultaneously exposed to the radiation from the first flash lamp unit and the second flash lamp unit, respectively. The flashes from the first flash lamp unit and the flashes from the second flash lamp unit can be generated synchronously or with a time offset.

[0024] Furthermore, the inventive application of radiation from at least one flash lamp device to the surfaces of the two glass panes of an insulating glass unit can be carried out using a stationary process or a dynamic process.

[0025] The present invention is explained in more detail below with reference to exemplary embodiments. The figures show:

[0026] Fig. 1 a, 1 b shows a schematic representation of a device with which the method according to the invention can be carried out;

[0027] Fig. 2a a schematic sectional view of an edge region of a

[0028] Insulating glass unit; Fig. 2b a schematic sectional view of the edge area of ​​an insulating glass unit from Fig. 2a with a recess in the spacer and the secondary seal;

[0029] Fig. 3a, 3b shows a schematic representation of an alternative device with which the method according to the invention can be carried out.

[0030] Fig. 4a, 4b shows a schematic representation of another alternative device with which the method according to the invention can be carried out.

[0031] Figures 1a and 1b show a first device 10 with which the method according to the invention can be carried out. Figure 1a shows a schematic side view and Figure 1b a schematic top view. The device 10 is intended to make it possible to open an insulating glass unit 11 and thus disassemble it into its individual parts without damaging the glass panes of the insulating glass unit 11. The device 10 also includes a flash lamp device 12, which generates radiation 13 in the form of light flashes. The radiation is in a wavelength range of 250 nm to 1000 nm, the duration of the light flashes of the flash lamp device 12 is in a range of 1 ms to 10 ms, and the energy densities of the light flashes of the flash lamp device are in a range of 1 J / cm². 2 up to 50 J / cm 2 set.

[0032] The flash lamp device 12 comprises three flash lamp modules: a first flash lamp module 12a, a second flash lamp module 12b, and a third flash lamp module 12c. The flash lamp modules 12a, 12b, and 12c can be controlled separately by means of a control device (not shown in Figures 1a and 1b). According to the invention, at least the edge regions of the two glass panes of the insulating glass unit 11 are to be illuminated by the radiation 13 of the flash lamp device 12.

[0033] A section of an edge of the insulating glass unit 11 is shown schematically in section in Fig. 2a to illustrate the basic structure of an insulating glass unit. The insulating glass unit 11 comprises a first glass pane 20a and a second glass pane 20b, which are spaced apart by a spacer 21. The spacer 21 extends around the edges of both glass panes 20a and 20b. The spacer 21 is further bonded to the first glass pane 20a by means of a first adhesive layer 22a and to the second glass pane 20b by means of a second adhesive layer 22b. A secondary seal 23 is also formed around the outer surface of the spacer 21. A primary seal, comprising the spacer 21 and the two adhesive layers 22a and 22b, ensures that a gas volume 24 enclosed between the two glass panes 20a and 20b cannot escape from this space.The insulating glass unit 11 according to FIGS. 1a and 1b is designed in the shape of a rectangle and thus has a first short side 14a, a second short side 14b, a first long side 15a and a second long side 15b. The method according to the invention can also be applied to insulating glass units in which the glass panes have a shape other than a rectangle.

[0034] Fig. 2b shows a schematic sectional view of the edge region already depicted in Fig. 2a, in which, however, a recess 25 has been drilled into the secondary seal 23 and the spacer 21, through which the gas volume 24 can escape before and / or during the insulating glass unit 11 is exposed to the radiation 13 of the flash lamp device 12. The gas volume 24 can also be extracted from the space between the two glass panes through the recess 25 by means of a pump device.

[0035] According to the invention, at least a circumferential edge region of the two glass panes 20a and 20b is exposed to the radiation of the flash lamp device 12 in order to modify the two adhesive layers 22a and 22b as well as the secondary sealant 23 in such a way that their adhesive strength is reduced with respect to the first glass pane 20a and the second glass pane 20b. For this purpose, the insulating glass unit 11 is moved in the direction of the horizontal arrow from Fig. 1a under the flash lamp device 12 and thus initially exposes the first glass pane 20a in a circumferential edge region to the radiation of the flash lamp device 12. This can be carried out, for example, as follows: When the first short side 14a of the insulating glass unit is below the flash lamp device 12, or...Once the insulating glass unit 11 reaches the radiation range of the flash lamp device 12, all three flash lamp modules 12a, 12b, and 12c are switched on, thus subjecting an edge region of the first short side 14a of the insulating glass unit 11 to calibration flashes. For this purpose, the insulating glass unit 11 can be stopped under the flash lamp device 12 or, alternatively, move continuously beneath it. These two process variants also apply to the flashing events of the flash lamp device 12 described below. If the insulating glass unit 11 continues to move and the edge region of the first short side 14 of the insulating glass unit 11 leaves the radiation range of the flash lamp device 12, the flash lamp module 12 is switched off, so that only an edge region of the first long side 15a and an edge region of the second long side 15b are subjected to the radiation 13 of the flash lamp modules 12a and 12c, respectively.However, with each flash of light from the first flash lamp module 12a and the third flash lamp module 12b, only a partial edge area of ​​the long sides 15a and 15b, respectively, is illuminated. Therefore, the insulating unit can be moved forward in such a way that the radiation areas of successive flashes either abut each other or at least partially overlap. This procedure can also be applied in the embodiments described below whenever an edge area of ​​a glass pane to be irradiated cannot be completely covered by the radiation area of ​​a flash from a flash lamp device.

[0036] When the insulating glass unit 11 finally reaches the radiation area of ​​the flash lamp device 12 with an edge area of ​​the second short side 14b, the flash lamp module 12b is switched on again, so that the entire edge area of ​​the second short side 14b is exposed to the radiation of the flash lamp device 12.

[0037] After such a first pass, the entire perimeter of the first glass pane 20a, encompassing the entire interface between the first adhesive layer 22a and the secondary sealant 23, is exposed to the radiation 13 of the flash lamp device 12. This modifies the first adhesive layer 22a and the secondary sealant 23, reducing their adhesive strength to such an extent that the first glass pane 20a is either already detached from the spacer 21 or can be removed from the spacer 21 with minimal force. Due to the modification of the adhesive layer 22a and the secondary sealant 23 according to the invention, any residues of these layers adhering to the glass pane 20a can be removed using established cleaning processes. For example, these residues can be wiped off with a solution containing ethanol and / or isopropanol or washed off using a known glass washing machine.

[0038] After removing the first glass pane 20a, the remaining portion of the insulating glass unit 11 is turned over, and in a second pass, the second glass pane 20b is exposed to the radiation 13 of the flash lamp device 12 in the same way as the first glass pane 20a in the first pass. Alternatively, after the first pass, the first glass pane 20a is not yet detached from the spacer 21, but the entire insulating glass unit is turned over, the second glass pane 20b is exposed to the radiation 13 of the flash lamp device 12, and only then are the first glass pane 20a and the second glass pane 20b detached from the spacer 21.

[0039] Using the method according to the invention, insulating glass units can thus be disassembled in such a way that macroscopically pure and undamaged glass panes result from this process.

[0040] The execution of the method according to the invention using the device 10 from the Fig.

[0041] 1 a and 1 b have so far been described as follows: the flash lamp device 12 is fixedly arranged and the insulating glass unit 11 is moved underneath it.

[0042] Alternatively, the insulating glass unit 11 can be fixedly arranged and the flash lamp device 12 can perform a movement above the insulating glass unit 11 in order to impart the radiation 13 of the flash lamp device 12 to the surfaces of the insulating glass unit 11.

[0043] An alternative embodiment of the device 10 from FIGS. 1a and 1b comprises a second flash lamp assembly, which is designed in the same way as the flash lamp assembly 12 and is arranged opposite the flash lamp assembly 12. In such a device, the insulating glass unit 11 can then be passed between the two flash lamp assemblies and both glass panes 20a and 20b can be exposed to the radiation from the flash lamp assemblies in a single pass.

[0044] Figures 3a and 3b show an alternative device 30 with which the method according to the invention can also be carried out. Figure 3a shows a schematic side view and Figure 3b a schematic top view of the device 30. The device 30 comprises an annular flash lamp assembly 32, which is intended to assist in opening or disassembling an insulating glass unit 11, as already known from Figures 1a and 1b. For this purpose, the flash lamp assembly 32 and the insulating glass unit 11 are arranged opposite each other, and the flash lamp assembly 32 is designed such that its radiation area completely covers the circumferential edge region of a glass pane of the insulating glass unit 11, which, according to the invention, is to be illuminated with calibration flashes.This embodiment is therefore a stationary process in which the insulating glass unit 11 and the exposure device 32 do not move relative to each other while a glass pane of the insulating glass unit 11 is being irradiated. After a glass pane has been completely irradiated, it is either removed from the spacer, the remaining part of the insulating glass unit 11 is turned over, and then the second glass pane is irradiated with flashes of light, or the already irradiated glass pane remains in the assembly of the insulating glass unit 11, which is then turned over, and the second glass pane is subsequently irradiated with flashes of light, so that the insulating glass unit 11 is only opened after the second glass pane has been irradiated.

[0045] An alternative device to device 30 can comprise a second flash lamp arrangement configured identically to flash lamp arrangement 32, wherein the two flash lamp arrangements are positioned opposite each other and the insulating glass unit 11 is arranged between them. By means of such a device, both glass panes of an insulating glass unit can be simultaneously subjected to flashes of light in a stationary process according to the invention.

[0046] Figures 4a and 4b show a further alternative device 40 with which the method according to the invention can also be carried out. Figure 4a shows a schematic side view and Figure 4b a schematic top view of the device 40. The device 40 comprises a flash lamp assembly, which in turn includes a first flash lamp unit 42a and a second flash lamp unit 42b. With the aid of these, it should be possible to disassemble an insulating glass unit 11, already known from Figures 1a and 1b, without damaging the two glass panes. The first flash lamp unit 42a has a length or radiation area with which a radiation-impacted edge area of ​​the first short side 14a or the second short side 14b of the insulating glass unit 11 is completely covered. The second flash lamp unit 42b has a length or radiation area of ​​42a.A radiation field is created that completely covers an edge area of ​​the first long side 15a or the second long side 15b of the insulating glass unit 11 that is to be illuminated. The horizontal arrow in Fig. 4a again illustrates the direction of movement of the insulating glass unit 11. The second flash lamp module 42b is designed to be movable in the directions of the vertical double arrow in Fig. 4b. In the device 40, the insulating glass unit 11 is first moved under the second flash lamp module 42b, and the second flash lamp module 42 is positioned over the edge area of ​​the first long side 15a or the second long side 15b that is to be illuminated, and then this edge area is illuminated with the radiation from the second flash lamp module 42b.The second flash lamp unit is then positioned over the edge area of ​​the opposite long side to be illuminated, and this edge area is illuminated with the radiation from the second flash lamp unit 42b. The insulating glass unit 11 is then moved and positioned with its first short side 14a under the first flash lamp unit 42a, and the edge area of ​​the first short side 14a is illuminated with the radiation from the first flash lamp unit 42a. Following this, the second short side 14a is positioned under the first flash lamp unit 42a, and the edge area of ​​the second short side 14a is illuminated with the radiation from the first flash lamp unit 42a. This completes the illumination of the entire annular edge area of ​​the first glass pane of the insulating glass unit 11 with flashing light radiation. The insulating glass unit 11 is then turned over, and the same process steps are repeated for the second glass pane.

[0047] In an alternative embodiment of the device 40, both the first flash lamp unit 42a and the second flash lamp unit 42b are designed to be movable, so that the insulating glass unit is not moved, but rather both flash lamp units are positioned according to the surface area to be treated. It is also possible that the radiation fields of the first flash lamp unit 42a and / or the second flash lamp unit 42b do not completely cover the length of the edge areas to be treated, so that the length of each edge area is gradually irradiated in sections with the radiation from the associated flash lamp unit.

[0048] Another method using a device according to Figs. 4a and 4b consists in the two flash lamp units 42a and 42b being fixedly arranged, and the insulating glass unit 11 being moved in such a way that a surface area of ​​the insulating glass unit 11 to be irradiated is moved into the radiation area of ​​one of the two flash lamp units.

[0049] Another alternative embodiment of the device 40 comprises a second flash lamp assembly, so that both glass panes of the insulating glass unit 11 can be treated simultaneously. Finally, another alternative embodiment of a device for carrying out the method according to the invention is described, which comprises one flash lamp assembly or two opposing flash lamp assemblies, wherein, for example, an insulating glass unit is positioned by means of a robot in front of one flash lamp assembly or between the two flash lamp assemblies, so that irradiation of the sealed edge of the insulating glass unit is made possible. This embodiment has the advantage that such an arrangement can be used for different glass formats.

Claims

Patent claims 1. Method for opening an insulating glass unit (11) comprising at least two spaced-apart glass panes (20a; 20b); a spacer (21) arranged between the two glass panes (20a; 20b) and circumferentially extending around the edges of the two glass panes, which is bonded to the two glass panes (20a; 20b) and a secondary seal (23) circumferentially extending around the outside of the spacer (21), wherein the spacer (21) and the two glass panes (20a; 20b) enclose a gas volume (24), characterized in that the surfaces of the two glass panes (20a; 20b) are exposed to the radiation (13) of at least one flash lamp device (12; 32) at least in a surface edge region in which the spacer (21) and the secondary seal (23) are arranged.

2. Method according to claim 1, characterized in that a flash lamp device (12; 32) with radiation (13) in the wavelength range of 250 nm to 1000 nm is used.

3. Method according to claim 1 or 2, characterized in that the duration of the flashes of the flash lamp device (12; 32) is set in a range from 1 ms to 10 ms.

4. Method according to one of the preceding claims, characterized in that the energy densities of the flashes of the flash lamp device (12; 32) are in a range of 1 J / cm² 2 up to 50 J / cm 2 be hired.

5. A method according to any one of the preceding claims, characterized in that, prior to the application of the radiation (13) from the flash lamp device (12) to the surfaces of the two glass panes (20a; 20b), at least one recess (25) is provided in the secondary seal (23) and the spacer (21) such that the gas volume (24) enclosed by the two glass panes (20a; 20b) and the spacer (21) can escape through the recess (25).

6. A method according to claim 5, characterized in that the recess (25) is provided in the secondary seal (23) and the spacer (21) by means of a drilling process.

7. Method according to claim 5 or 6, characterized in that the gas volume (24) is extracted by means of a pumping device before and / or during the application of the radiation (13) of the flash lamp device (12) to the surfaces of the two glass panes (20a; 20b).

8. Method according to one of claims 1 to 7, characterized in that in a first process step the surface of a glass pane (20a) is exposed to the radiation (13) of the flash lamp device (12), then the insulating glass unit (11) is rotated and then in a second process step the surface of the other glass pane (20b) is exposed to the radiation (13) of the flash lamp device (12).

9. Method according to one of claims 1 to 7, characterized in that the insulating glass unit (11) is arranged between a first flash lamp device and a second flash lamp device, wherein the surfaces of both glass panes (20a; 20b) are simultaneously exposed to the radiation of the first flash lamp device or the second flash lamp device.

10. Method according to claim 9, characterized in that the flashes of the first flash lamp device and the flashes of the second flash lamp device are generated synchronously with each other or with a time offset from each other.

11. Method according to one of the preceding claims, characterized in that the application of radiation (13) from the at least one flash lamp device (12) to the surfaces of the two glass panes (20a; 20b) is carried out by means of a stationary process or a dynamic process.

12. Method according to one of the preceding claims, characterized in that the glass panes (20a; 20b) are cleaned after exposure to the radiation (13) of the flash lamp device (12) and after opening the insulating glass unit (11) by means of a solution comprising ethanol and / or isopropanol or are washed by means of a glass washing machine.

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