METHOD FOR CUTTING A LAMINATED ULTRA-THIN GLASS LAYER

Abstract

A method and a device for cutting a laminate including at least one glass layer with a thickness less than or equal to 0.3 mm and including at least one polymeric layer are disclosed. The method includes generating a surface scratch on a first surface of the glass layer, wherein the scratch, starting from a lateral edge, extends along a cutting line. The method further includes moving a first laser beam, starting from the scratch, across the first surface along the cutting line. The method also includes cooling the glass layer along the cutting line, wherein the glass layer breaks along the cutting line The polymeric layer is severed by moving a second laser beam along the cutting line. The device includes means for cutting the laminate according to the disclosed method.

Claims

1.-15. (canceled)

16. A method for cutting a laminate, comprising: (a) providing a laminate including at least one glass layer with a thickness less than or equal to 0.3 mm, wherein the laminate further includes at least one polymeric layer; (b) generating a surface scratch on a first surface of each of the at least one glass layer, wherein the scratch, starting from a lateral edge, extends along a cutting line; (c) moving a first laser beam, starting from the scratch, across the first surface along the cutting line; (d) cooling the at least one glass layer along the cutting line, wherein the at least one glass layer breaks along the cutting line; and (e) severing the at least one polymeric layer by moving a second laser beam along the cutting line.

17. The method according to claim 16, wherein the first laser beam has a wavelength of 1 m to 20 m.

18. The method according to claim 16, wherein the first laser beam has a wavelength of 5 m to 15 m.

19. The method according to claim 16, wherein the first laser beam is generated by a CO.sub.2 laser.

20. The method according to claim 19, wherein the first laser beam is generated in continuous wave operation.

21. The method according to claim 16, wherein the first laser beam and the second laser beam are generated by the same laser and irradiate the laminate from opposite directions.

22. The method according to claim 16, wherein the at least one glass layer includes a first glass layer and a second glass layer, wherein the first glass layer is bonded to the second glass layer via the at least one polymeric layer, wherein the process steps (b), (c) and (d) are applied on a first surface of the first glass layer facing away from the at least one polymeric layer, wherein the process steps (b), (c) and (d) are applied on a first surface of the second glass layer facing away from the at least one polymeric layer, wherein the polymeric layer is irradiated with the second laser beam through the first glass layer or through the second glass layer, and wherein the second laser beam has a wavelength of 300 nm to 1200 nm.

23. The method according to claim 22, wherein the second laser beam is generated by a doped YAG laser.

24. The method according to claim 23, wherein the doped YAG laser is an Nd:YAG laser.

25. The method according to claim 23, wherein the second laser beam is operated with pulses in the picosecond range.

26. The method according to claim 16, wherein the scratch has a length of 0.5 mm to 50 mm.

27. The method according to claim 16, wherein the scratch has a length of 1 mm to 20 mm.

28. The method according to claim 16, wherein the scratch has a length of 2 mm to 10 mm.

29. The method according to claim 16, wherein the scratch is mechanically generated.

30. The method according claim 16, wherein the scratch is generated by means of laser radiation.

31. The method according claim 30, wherein the laser radiation has a wavelength of 300 nm to 1200 nm and power of 0.5 W to 3 W.

32. The method according to claim 16, wherein the first laser beam is moved at a speed of 1 m/min to 30 m/min across the first surface.

33. The method according to claim 32, wherein the first laser beam and the second laser beam are moved at the same speed.

34. The method according to claim 16, wherein the first laser beam is moved at a speed of 5 m/min to 20 m/min across the first surface.

35. The method according to claim 16, wherein the cooling of the glass layer is done by impingement with a gaseous and/or liquid coolant along the cutting line.

36. The method according to claim 35, wherein the impingement with a gaseous and/or liquid coolant is by means of a nozzle.

37. The method according to claim 16, wherein the cooling of the glass layer is done by impingement with an air/water mixture.

38. The method according to claim 16, wherein the laminate is unrolled from a roll immediately before cutting.

39. A device for cutting a laminate including at least one glass layer and at least one polymeric layer, comprising: means for generating a surface scratch on a first surface of the at least one glass layer of the laminate, wherein the at least one glass layer has a thickness less than or equal to 0.3 mm; means for generating and moving a first laser beam, which is configured to be moved, starting from the scratch, along a cutting line across the first surface; means for cooling the glass layer along the cutting line; and means for generating and moving a second laser beam, which is configured to sever the polymeric layer of the laminate along the cutting line.

40. The device according to claim 39, further comprising a roll holder, into which a roll provided with the laminate can be inserted.

41. A method of using a laminate; comprising: cutting a laminate with the method according to claim 16; and installing the cut laminate in a thin-film solar cell or active glazing with switchable properties.

42. The method of using a laminate according to claim 41, wherein the switchable properties are electrically switchable.

43. The method of using a laminate according to claim 41, wherein installing the cut laminate includes providing an electrochromic element, an PDLC element (polymer dispersed liquid crystal), an electroluminescent element, an organic light emitting diode (OLED), or an SPD element (suspended particle device).

Description

[0048] The invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are schematic representations and not to scale. The drawings in no way restrict the invention. They depict:

[0049] FIG. 1 a perspective view of an ultrathin glass laminate during the method according to the invention,

[0050] FIG. 2 a cross-section through the laminate along the cutting line L,

[0051] FIG. 3 a cross-section through another embodiment of the laminate, and

[0052] FIG. 4 an exemplary embodiment of the method according to the invention with reference to a flowchart.

[0053] FIG. 1 depicts a schematic representation of the method according to the invention. A laminate 10 with an ultrathin glass layer and a polymeric layer has been provided on a roll 8 and partially unrolled from the roll 8. The method according to the invention is applied to cut off a portion of the laminate 10 by means of a cut perpendicular to the unrolling direction.

[0054] In the first process step, a surface scratch 2 is introduced into the first surface of the glass layer facing away from the polymeric layer. The means 9 for introducing the scratch 2 is, for example, a diamond tool, whereby the movement and the pressure exerted can be regulated by a controller 11. Alternatively, the means 9 can also be, for example, an Nd:YAG laser with pulses in the picosecond range (for example, pulse length of 10 ps and pulse repetition frequency of 400 k Hz) and power of 1 W. The scratch 2 has, for example, a depth of 0.03 mm and a length of 5 mm and extends, starting from a lateral edge of the glass layer 1, along the desired cutting line L. The scratch 2 results in a concentration of stresses and defines the desired cutting line L, along which it extends over its length of 5 mm, as a predetermined breaking point.

[0055] Then, a first laser beam 3 is moved, starting from the scratch 2, along the cutting line L. The laser beam 3 is the beam of a CO.sub.2 laser in continuous wave operation with a wavelength of 10.6 m and power of 50 W. The laser beam 3 is focused with an elongated beam profile on the glass surface by means of a cylindrical lens (not shown). On the glass surface, the profile has, for example, a length of 30 mm and a width of 500 m. The beam profile is aligned along the cutting line L; the long axis of the beam profile thus lies on the cutting line L. The laser beam 3 is effectively absorbed by the glass layer 1, by means of which the glass layer is heated along the cutting line L.

[0056] A nozzle 4 is moved behind the laser beam 3 along the cutting line L. The laser beam 3 and nozzle 4 move at the same speed. The glass layer is impinged on by means of the nozzle 4 with a coolant, for example, an air/water mixture. The rapid cooling of the heated glass layer results in thermal stresses, which result in the breaking of the glass layer 1 along the cutting line L.

[0057] The arrows depicted in the figure indicate the direction of movement.

[0058] A second laser beam 6 is focused on the thermoplastic layer 5 from the opposite direction. The second laser beam 6 is moved at the same speed v as the first laser beam 3 and the nozzle 4. The second and the first laser beam (3, 6) move, in particular, simultaneously such that the laser foci are situated in roughly the same position on the cutting line L. The laser beam 6 severs the thermoplastic layer 5. In a preferred embodiment, the laser beams 3 and 6 are generated by the same laser. However, it is also possible for the two beams 3, 6 to each be provided with its own laser.

[0059] As has been found, the breaking of the ultrathin glass takes place automatically due to the thermal stresses. Consequently, it is possible to dispense with active breaking through exertion of pressure. Therefore, the method according to the invention is suitable for industrial mass production where the glass layer is typically unrolled from a roll 8 and processed directly. Moreover, the process yields smooth cut edges without disruptive damage such as microcracks. The laminate 10 with the glass layer and the thermoplastic layer can be separated in one step by the method according to the invention, which is very advantageous from a production technology standpoint.

[0060] FIG. 2 depicts a cross-section through the laminate 10 during the method of FIG. 1. The laminate 10 comprises the glass layer 1, of which the second surface II is bonded to the polymeric, thermoplastic layer 5. The surface of the glass layer 1 facing away from the polymeric layer 5, on which surface the generation of the scratch, the irradiation with the first laser beam 3, and the impingement with the coolant take place, is referred to, in the context of the invention, as the first surface I. The glass layer 1 has a thickness of, for example, 100 m. The thermoplastic layer 5 is made, for example, of a 100-m-thick film made of ETFE.

[0061] The laser beam 3 and the nozzle 4 are successively moved at the speed v along the cutting line L. The second laser beam 6 is moved simultaneously at the same speed v.

[0062] FIG. 3 depicts a cross-section through another laminate. In this case, a first glass layer 1 is bonded to a second glass layer 7 via a polymeric layer 5. The surfaces II, III of the glass layers 1, 7 facing the polymeric layer 5 are, in the context of the invention, referred to as second surfaces. The surfaces I, IV facing away from the polymeric layer 5 are referred to as first surfaces. The polymeric layer 5 is again, for example, a thermoplastic film made of ETFE with a thickness of 100 m.

[0063] The glass cutting method according to the invention with the surface scratch 2, the laser beam 3, and der nozzle 4 is executed simultaneously on the first surfaces I, IV of the glass layers 1, 7, by which means the glass layers are severed along a common cutting line L. A laser beam 6 is focused through the first glass layer 1 on the thermoplastic layer 5 and is moved at the same speed v as the other laser beams 3 and the nozzle 4 along the cutting line L. The laser beam 6 has, for example, a wavelength of 532 nm and is generated by a frequency doubled Nd:YAG laser. Light in the visible range, is not substantially absorbed by the glass layer 1 such that the laser beam 6 strikes the thermoplastic layer 5 largely unimpeded. The Nd:YAG laser is operated, for example, with pulses in the picosecond range (for example, pulse length of 10 ps and pulse repetition frequency of 400 k Hz) and has power of 1 W.

[0064] In the schematic representation, the second laser beam 6 is arranged behind the first two laser beams 3 and the nozzles 4 in the direction of movement. Thus, the cutting of the glass layers 1, 7 is done first, with the severing of the laminate temporally offset. The second laser beam 6 can, however, also be aimed at the position on the cutting line L on which the first laser beams 3, 6 are situated. Then, the cutting of the glass layers 1, 7 and the severing of the polymeric layer 5 are done simultaneously.

[0065] The laminate with the glass layers 1, 7 and the thermoplastic layer 5 can be separated in one step by the method according to the invention, which is very advantageous from a production technology standpoint.

[0066] FIG. 4 depicts an exemplary embodiment of the method according to the invention for cutting laminated, ultrathin glass layers.

LIST OF REFERENCE CHARACTERS

[0067] (10) laminate [0068] (1) (first) glass layer [0069] (2) surface scratch [0070] (3) laser radiation for cutting the glass layer 1 [0071] (4) nozzle for cooling the glass layer 1 [0072] (5) polymeric layer [0073] (6) laser radiation for severing the polymeric layer 5 [0074] (7) second glass layer [0075] (8) roll [0076] (9) means for generating the surface scratch 2 [0077] (11) controller of the means 9 [0078] L cutting line [0079] I first surface of the glass layer 1 [0080] II second surface of the glass layer 1 [0081] III first surface of the second glass layer 7 [0082] IV second surface of the second glass layer 7