DELAYSING EQUIPMENT AND METHOD FOR DELAYSING GLASS SHEETS, PREFERABLY LAMINATED GLASS SHEETS

Description

[0001] The present invention relates to a decoating method for edge decoating of glass panels, preferably laminated glass panels, and to a use of a decoating device therefor.

[0002] Flat glass refers to any glass in the form of panes or sheets, regardless of the manufacturing process used. In order to provide flat glass sheets with filtering, mirroring, heating or other functions, a wide variety of single- or multi-layer functional coatings are applied to the flat glass sheets. The functions can be, for example, heat insulation, sun protection, or heating. The individual functional layers are usually metallic layers. For example, they are low-emission layers or electrical heating layers. One or more dielectric (functional) layers, e.g. made of an oxide such as aluminum oxide, can be arranged between the individual metallic functional layers of a functional coating.

[0003] The individual functional layers are preferably applied to flat glass blanks of maximum commercially available size (6,100 mm x 3,250 mm). From these extensively coated flat glass blanks, individual panes are then cut as required, which are then further processed into functional units. These functional units can be, for example, insulating glass units, with the edges of the individual panes being bonded using spacers, for example. Edge bonding adhesives are used for this edge bonding, but these adhesives are designed exclusively for direct bonding to glass surfaces and not to the functional layers. The flat glass blanks must therefore be stripped in the bonding area, with the stripping width being, for example, approximately 10 mm. Without stripping, reliable adhesion of the edge bonding adhesive cannot be guaranteed. This process is called edge stripping.

[0004] The edge decoating takes place along the edges of the glass sheets and / or along subsequent cutting, scoring or separating lines, along which the flat glass sheets are divided into individual glass sheets after decoating.

[0005] Typically, the functional coating is a single functional layer or a layer structure with multiple functional layers with a total thickness of < 2 µm. The layer structure is usually obtained through deposition processes.

[0006] For example, in the case of glass sheets that have already been cut to their final dimensions, edge decoating is carried out along the glass sheet edges in a single decoating width. For raw glass sheets, decoating is carried out on both sides next to the later cutting, scoring, or separating line in double the decoating width. Here, too, however, with appropriate glass sheet dimensions and the quality of the glass sheet edges, decoating can be carried out along the glass sheet edges in a single decoating width. In the area of ​​the later cutting, scoring, or separating lines, the decoating marks created are thus twice as wide as in the area of ​​the glass sheet edges. A disadvantage of edge decoating, however, is that passing over the sharp edges with decoating tools can cause severe and asymmetrical wear.

[0007] In this field, the functional layers are removed by mechanical means such as grinding tools or sandblasting. However, it can also be done with gas burners.

[0008] From DE 41 18 241 C2, which forms the basis for the preamble of claim 1, it is known, for example, to use grinding devices for decoating. In this process, the coating is ground off the raw glass sheet along the cutting lines T. The cut is then made in the longitudinal center of the resulting decoating track. The cutting contour formed by the cutting lines is delimited by edge and zero cuts R, which are spaced from the outer edges of the raw flat glass sheets.

[0009] From DE 34 03 682 a method and a device are known in which decoating and cutting processes are combined, with decoating being carried out using gas burners.

[0010] The German utility model DE 20 2013 104 834 U1 relates to a table for processing non-metallic, transparent materials by laser radiation, in particular for removing metallic coatings, for example low-emission coatings, and other coatings from glass.

[0011] EP 1 864 950 A1, WO 2016 / 096435 A1, and DE 10 2007 015 767 A1 also disclose the stripping of glass substrates (flat glass, solar cells) using a laser. The material to be removed in each case is the functional layer.

[0012] Furthermore, for some time now, there have been types of glass in which the functional coating, or even just the uncoated glass surface (in the case of glass panels without a functional coating), is protected by a removable protective film (TPF = temporary protective film) or a polymer protective layer (e.g., EasyPro®< from St. Gobain) to protect it from potential mechanical damage. The polymer protective layer is applied, for example, by spraying and is not removable, but firmly bonded to the respective surface. However, it burns off easily and residue-free during tempering in the furnace.

[0013] For further processing of the glass panels, e.g., insulating glass production, the protective film or polymer protective layer must, of course, be removed, analogous to the functional layers, at least at the edge areas. The removal of the protective film or polymer protective layer is currently done mechanically using a grinding tool, particularly a grinding wheel. If the glass panel has a functional coating, the protective film or polymer protective layer and the functional coating are ground off in a single operation.

[0014] However, this is not without its problems. Mechanically sanding off the polymer protective layer generates a great deal of dust, which then contaminates the system, damages components, and can also pose a health hazard. When sanding off the protective film at higher feed speeds, it curls up, creating long strips that then clog the extraction system or partially remain on the glass. Furthermore, the feed speed for both applications is significantly (approximately 5-10 times) slower than for pure edge removal, i.e., the removal of the functional layers.

[0015] In a process offered by Macotec, the protective film is first cut with a double-blade knife and then removed by suction. In a second step, the functional layers are removed. The functional layer(s) are removed mechanically by sanding.

[0016] US 2013 / 0140291 A1 discloses a device for cutting glass panes. The device comprises a laser beam generating device and a cutting device with a cutting wheel. To cut the glass pane, grooves are first created in the surface of the glass pane using the laser beam generating device. The glass is then cut using the cutting wheel.

[0017] WO 2016 / 096435 A1 discloses that a functional coating is removed using a decoating tool that generates a laser beam. The decoating tool can also be a grinding wheel or another suitable tool. Furthermore, WO 2016 / 096435 A1 discloses that the device can comprise a cutting tool with a cutting wheel or a diamond needle or a laser. The cutting tool cuts or scores the glass sheet.

[0018] The object of the present invention is therefore to provide an edge stripping method for removing the protective film from glass panels, preferably from laminated glass panels, wherein the stripping should be simple, fast, safe and cost-effective.

[0019] Another object of the invention is the use of a decoating device for carrying out the decoating process.

[0020] These objects are achieved by a decoating method according to claim 1 and the use of a decoating device according to claim 10. Advantageous developments of the invention are characterized in the subsequent subclaims.

[0021] The invention is explained in more detail below using a drawing as an example. The drawings show: Figure 1: Highly simplified and schematic plan view of a cutting and decoating station with a decoating device used according to the invention with a decoated glass sheet. Figure 2: Highly simplified and schematic plan view of a section through a glass sheet with a decoating device used according to the invention arranged above it. Figure 3: Highly simplified and schematic plan view of a glass sheet with foil strip sections before grinding. Figure 4: Highly simplified and schematic plan view of a glass sheet before grinding according to a further variant of the decoating method according to the invention.

[0022] A cutting and decoating station 1 ( Fig. 1 ) preferably has a support table 2 for receiving a glass sheet 3, a first travel bridge 4, a second travel bridge 5, a cutting device 6 and a decoating device 7 used according to the invention.

[0023] The glass panel 3 ( Fig. 2 ) has a first and second glass panel surface 3a;b as well as a surrounding glass panel edge 3c. The glass panel 3 can be, for example, a single glass pane ( Fig. 2 ) or a laminated glass panel made up of several interconnected glass panes. Furthermore, it is preferably a raw glass panel. However, it can also be a cut-to-size glass panel.

[0024] In addition, the glass panel 3 has a superficial functional coating 8 on at least one of its two glass surfaces 3a;b. The functional coating 8 can have one or more individual functional layers. If there are multiple functional layers, this thus constitutes a functional layer laminate. The functional layers modify certain properties of the glass panel 3 or impart certain functions to it. These functions can be, for example, thermal insulation, sun protection, or heating. The individual functional layers are preferably metallic layers, e.g., low-emission layers.

[0025] The functional coating 8 preferably has a thickness of 1 < µm.

[0026] Furthermore, the glass panel 3 has a protective coating 9 in the form of a removable protective film 10 on at least one of its two glass surfaces 3a;b. The protective coating 9 covers the respective glass surface 3a;b on the outside and protects the functional coating 8 arranged underneath or, if no functional coating 8 is present, the uncoated glass surface 3a;b, from mechanical damage. The protective coating 9 thus forms the outer or exterior layer of the glass panel 3.

[0027] In contrast to the functional coating 8, the protective coating 9 is completely removed before the final use of the glass panel 3. It is therefore not permanently present. The protective film 10 is removed. A functional coating 8, on the other hand, is permanently present, at least in some areas.

[0028] The protective film 10 is preferably made of plastic, preferably polyvinyl chloride (PVC), and can be removed from the glass panel surface 3a;b.

[0029] In addition, the protective film 10 preferably has a thickness of 20 to 100 µm.

[0030] The two travel bridges 4; 5 span the support table 2 on the top and / or bottom and can each be moved back and forth over the glass sheet 3 in a first travel direction 11a. Appropriate drive means are provided for this purpose. The first travel direction 11a is parallel to a glass sheet plane or to the two glass sheet surfaces 3a; b.

[0031] The cutting device 6 serves in a manner known per se for cutting or scoring the glass sheet surface(s) 3a;b along predetermined scoring or separating lines 12. If the glass sheet 3 is a single glass pane, only one of the two glass sheet surfaces 3a;b is scored. For this purpose, the cutting device 6 has, in a manner known per se, a cutting head 13 with a scoring tool, preferably a cutting wheel. The cutting head 13 is mounted on the first travel bridge 4 in a manner known per se so that it can be moved in a second travel direction 11b. Appropriate drive means are provided for this purpose. The second travel direction 11b is perpendicular to the first travel direction 11a and likewise parallel to a glass sheet plane or to the two glass sheet surfaces 3a;b. The cutting wheel is freely or drivenly rotatable about a horizontal axis of rotation which is parallel to the glass sheet plane or to the two glass sheet surfaces 3a;b.In addition, the cutting wheel can rotate freely or with a drive around a vertical axis of rotation perpendicular to the glass sheet plane or to the two glass sheet surfaces 3a;b. This allows any desired cutting contours to be created in a conventional manner.

[0032] In a laminated glass sheet, both glass sheet surfaces 3a;b are scored, preferably simultaneously, in a conventional manner. The glass sheet 3 is then scored on both the top and bottom sides, preferably simultaneously. Two cutting heads 13 arranged one above the other are provided for this purpose.

[0033] The decoating device 7 used according to the invention serves to remove the protective coating 9 and the functional coating 8 arranged underneath. For this purpose, it comprises a laser beam generating device 14 for generating a laser beam 15 and a grinding head 16. Furthermore, the decoating device 7 is mounted on the second travel bridge 5 so that it can be moved in the second travel direction 11b. Appropriate drive means are provided for this purpose.

[0034] The laser beam generating device 14 serves to cut the protective film 10, which will be discussed in more detail below. For this purpose, the laser beam generating device 14 generates the laser beam 15 directed onto the glass surface 3a. The laser beam generating device 14 comprises a laser radiation source and associated optics. The laser beam 15 can be pivoted or deflected from a starting position in which it is vertically aligned.

[0035] The laser radiation source preferably generates a laser beam 15 whose wavelength lies in the infrared range. The wavelength of the laser beam 15 is preferably 1 to 19 µm, more preferably 9 to 11 µm.

[0036] In addition, the laser radiation source preferably generates a laser beam 15 whose laser power is < 200 W, preferably < 100 W, and / or ≥ 5 W, preferably ≥ 10 W.

[0037] The grinding head 16 serves to remove the incised protective film 10 and / or to remove the functional coating, which will be discussed in more detail below. For this purpose, the grinding head 16 has, in a conventional manner, at least one grinding tool, preferably at least one grinding wheel 17.

[0038] The grinding wheel 17 is freely rotatable or driven about a horizontal axis of rotation that is parallel to the glass sheet plane or to the two glass sheet surfaces 3a;b. In addition, the grinding wheel 17 is freely rotatable or driven about a vertical axis of rotation that is perpendicular to the glass sheet plane or to the two glass sheet surfaces 3a;b. This allows any desired decoating contours to be created in a conventional manner in combination with the movement of the decoating device 7 along the second travel bridge 5. According to a preferred embodiment, the grinding head 16 has two grinding wheels (not shown) according to DE 196 322 40 A1. In this case, the first grinding wheel has a thickness of a single decoating width and the second grinding wheel has a thickness of twice the decoating width.

[0039] The decoating method according to the invention will now be explained in more detail. In particular, the decoating of a glass panel 3 having a protective film 10 as a protective coating 9 will be explained: For edge decoating, the areas inside the glass panel 3 on both sides and along the later separating or scoring lines 12 are decoated. For this purpose, according to the invention, a film strip 18 of the protective film 10 to be removed is first cut out of the protective film 10 by means of the laser beam 15 and simultaneously divided into individual film strip sections 19 ( Fig. 3 ). The individual foil strip sections 19 remain adhered to the glass panel 3. This means that along the subsequent separating or scoring lines 12 or, as seen in a longitudinal direction of the foil strip 18 to be removed, there are several foil strip sections 19 arranged one behind the other, which are not connected to one another and each adhere to the glass panel 3.

[0040] The film strip 18 and the film strip segments 19 are cut out by introducing burn marks or laser marks 20a;b into the protective film 10. In the area of ​​the laser marks 20a;b, the protective film 10 is completely removed, in particular vaporized or burned. The laser marks 20a;b surround the film strip segments 19. They thus form the outline or contour of the film strip segments 19.

[0041] The movement of the laser beam 15 takes place by means of the optics of the laser beam generating device 14 and by movement of the decoating device 7 along the travel bridge 5 and movement of the travel bridge 5. The optics of the laser generating device 14 is namely able to move the laser beam 15 in an area of ​​e.g. 100 mm x 100 mm (scan field) with the aid of two adjustable mirrors (scan optics).

[0042] After the film strip 18 has been cut out and divided into the individual film strip segments 19, these are ground using the grinding wheel 17 in a conventional manner. At the same time, the functional coating 8 is also ground off. In order to grind the desired contours, the grinding head 13, together with the grinding wheel 17, is moved in a conventional manner in the second travel direction 11b along the second travel bridge 5. Furthermore, the second travel bridge 5 is moved in the first travel direction 11a. The grinding wheel 17 is rotated about its wheel rotation axis and, if necessary, pivoted about its vertical axis.

[0043] After grinding, the glass sheet 3 has decoating marks 21 on the processed glass sheet surface 3a. The decoating marks 21 extend along the subsequent scoring or separating line 12 and on both sides adjacent to it. In particular, the scoring or separating line 12 is located centrally in the decoating mark 21. The glass sheet is thus decoated in twice the decoating width on both sides adjacent to the subsequent scoring or separating line 12.

[0044] Along the glass sheet edges 3c, decoating is preferably carried out in a single decoating width – provided the final dimensions of the glass sheet 3c are appropriate and the quality of the glass sheet edges 3c is sufficient. The same applies to glass sheets 3 cut to final dimensions, where decoating is only carried out along the glass sheet edges 3c, but no longer in the area within the glass sheet edges 3c.

[0045] Because the film strip 18 to be removed has previously been divided into individual film strip sections 19, the protective film 10 does not roll up during grinding, even at higher feed speeds. The individual removed film strip sections 19 can be easily vacuumed away without clogging the suction system or leaving film residue on the glass panel 3. Thus, the decoating method according to the invention ensures fast, clean, and safe decoating.

[0046] In the method described above, laser tracks 20a are generated that are transverse or perpendicular to the longitudinal direction of the film strip 18 to be removed, and laser tracks 20b that are parallel to the longitudinal direction of the film strip 18 to be removed. As a result, the film strip sections 19 are already cut out of the protective film 10 or separated from the remainder of the protective film 10 before grinding. The laser tracks 20a do not have to be perpendicular to the longitudinal direction of the film strip 18 to be removed, but merely oblique to it. The laser tracks 20a;b also do not have to be straight.

[0047] It is also within the scope of the invention that, before the mechanical removal of the film strip 18, only laser tracks 20a are introduced obliquely, in particular transversely or perpendicularly, to the longitudinal direction of the film strip 18 to be removed ( Fig. 4). Oblique thus means that the laser tracks 20a deviate at a certain angle from the longitudinal direction of the film strip 18 to be removed.

[0048] It is only important that the laser tracks 20a are introduced in such a way that the film strip 18 is removed in the form of individual film strip sections 19 separated from one another by the laser tracks 20a.

[0049] Furthermore, it is also possible for the laser tracks 20a;b not to be generated as completely continuous lines, i.e., the protective film 10 is not completely removed in the area of ​​the laser tracks 20a,b, but rather the protective film 10 is merely perforated in the area of ​​the laser tracks 20a;b. During perforation, the protective film 10 is provided with holes at, preferably even, intervals.

[0050] After decoating, the separating or scoring lines 12 are then created by means of the cutting head 13 and then the glass sheet 3 is broken into individual glass sheet cuts along the scoring or separating lines 12 in a manner known per se.

[0051] It is also within the scope of the invention that the cutting device 6 is separated from the decoating device 7, i.e. is arranged in a different station.

[0052] Furthermore, the grinding head 16 and the laser beam generating device 14 can also be decoupled from each other. This means that they can be moved separately and / or attached to different travel bridges.

[0053] In addition, the contours can also be created by moving the decoating device 7 on a stationary bridge and moving the glass sheet during the decoating process. It is only important that the decoating device 7, including the grinding wheel 17 and / or laser beam 15, and the glass sheet 3 execute appropriate relative movements to each other. The same applies to the cutting process.

[0054] Furthermore, it is of course also within the scope of the invention for only a single traversing bridge to be present, and for the cutting device and the decoating device to be arranged on the same traversing bridge. However, the grinding head 16 and the laser beam generating device 14 can also be arranged on different traversing bridges.

[0055] If the glass panels also have a protective film and, if applicable, a functional coating on both glass panel surfaces, the decoating takes place either for both glass panel surfaces simultaneously or one after the other.

Claims

1. A decoating method for the edge decoating of glass sheets (3), the glass sheets (3) having at least on one of their two glass surfaces (3a;b) a protective coating (9) in the form of a peel-off protective film (10), and preferably having a functional coating (8) situated thereunder, the protective film (10) being partially mechanically removed, in particular ground away, for the edge decoating, in the form of at least one film strip (18), characterized in that before the mechanical removal of the film strip (18), laser traces (20a;b) are introduced into the protective film (10), the laser traces (20a;b) being introduced in such a way that the film strip (18) is removed in the form of individual film strip partial pieces (19) separated from one another by the laser traces (20a).

2. The decoating method according to Claim 1, characterized in that the laser traces (20a) are introduced at an angle, preferably perpendicular, to a longitudinal direction of the film strip (18) that is to be removed.

3. The decoating method according to Claim 1 or 2, characterized in that a) the protective film (10) is completely removed, in particular vaporized or burnt, in the region of the laser traces (20a;b), or b) the protective film (10) is perforated in the region of the laser traces (20a;b), using laser radiation.

4. The decoating method according to one of the preceding claims, characterized in that the angular laser traces (20a) are introduced in such a way that they are situated one after the other, seen in the longitudinal direction of the film strip (18) that is to be removed.

5. The decoating method according to one of the preceding claims, characterized by the following method steps: a) cutting the at least one film strip (18) out from the protective film (10), and dividing the film strip (18) into the individual film strip partial pieces (19) using laser radiation, b) mechanical removal, in particular grinding away, of the film strip partial pieces (19).

6. The decoating method according to Claim 5, characterized in that a) the film strip partial pieces (19) are cut out in such a way that they continue to adhere to the glass sheet (3), and / or b) the cutting out of the film strip partial pieces (19) is done by introducing the laser traces (20a;b) into the protective film (10), and the laser traces (20a;b) surround the film strip partial pieces (19).

7. The decoating method according to one of the preceding claims, characterized in that the glass sheet (3) has the functional coating (8) situated under the protective coating (9), and the functional coating (8) is simultaneously also removed during the mechanical removal, in particular during the grinding away, of the film strip partial pieces (19).

8. The decoating method according to one of the preceding claims, characterized in that the removed film strip partial pieces (19) are suctioned away.

9. The decoating method according to one of the preceding claims, characterized in that a) in order to produce the laser traces (20a;b), a laser beam (15) is used having a wavelength in the infrared range, preferably having a wavelength from 1.0 to 12 µm, preferably 9 to 11 µm, and / or b) for the production of the laser traces (20a;b), a laser beam (15) is used having a laser power < 200 W, preferably having a laser power < 100 W, and / or having a laser power of ≥ 5 W, preferably having a laser power of ≥ 10 W.

10. Use of a decoating device (7) for carrying out the method according to one of the preceding claims, the decoating device (7) having a grinding device for grinding away the protective film (10) and a laser beam-producing device (14) for producing a laser beam (15) for removing the protective film (10) in the form of laser traces (20a;b) before the grinding away of the protective film (10).

11. Use according to Claim 10, characterized in that a) the laser beam-producing device (14) has means for producing a laser beam (15) having a wavelength in the infrared range, preferably having a wavelength from 1 to 12 µm, preferably 9 to 11 µm, and / or b) the laser beam-producing device (14) has means for producing a laser beam (15) having a laser power < 200 W, preferably having a laser power < 100 W, and / or having a laser power of ≥ 5 W, preferably having a laser power of ≥ 10 W.