JP5877124B2 - Cutting method of glass strip - Google Patents

Description

  The present invention relates to a method for cutting strip glass (glass ribbon).

  The cutting of the plate glass (glass plate) is usually performed using a cutter. When mechanical stress is applied to the scribe line on the glass surface formed by the cutter, the plate glass is divided along the scribe line.

  A method of cutting a sheet glass using laser light has also been proposed. In this method, a method of extending the initial crack on the surface of the sheet glass by laser light irradiation and refrigerant injection is employed. When a coolant is sprayed onto a region heated by laser light irradiation and rapidly cooled, tensile stress is generated in the region. When this tensile stress is generated near the tip of the crack, the crack extends. When the surface of the glass sheet is scanned in the direction in which the crack is to be extended in this order, the area to be irradiated with the laser light (irradiated area) and the area to which the coolant is blown (cooled area) are scribed on the glass sheet. Is formed. Thereafter, mechanical stress is applied to the scribe line in the same manner as described above, and the plate glass is divided along the scribe line. Advantages of the cutting method using laser light include that even a very thin glass can be cut without any problem, and that the smoothness of the cut surface of the glass is excellent.

  It has been proposed to apply cutting using a laser beam to a sheet glass production line. The cutting performed on the production line is sometimes referred to as “online cutting” to distinguish it from the cutting of the glass sheet taken out of the manufacturing line (cutting outside the manufacturing line is called “offline cutting”). In on-line cutting, a strip-shaped glass that is formed into a predetermined thickness in a forming apparatus and flows on a production line is a cutting target. The band-shaped glass is unloaded from a forming apparatus (for example, a float bath), and while being transported on the production line, a scribe line is formed in the width direction at a predetermined position, and further cut along the scribe line on the downstream side. . By carrying out this division in conjunction with cutting off both thick side end regions (so-called ears), a plate-like glass (glass plate) having a predetermined size is sampled from the central region.

  The apparatus disclosed in Patent Document 1 includes a carriage (head) that moves along a linear slide member that is attached so as to cross the belt-shaped glass conveyance path. This head irradiates the strip glass with laser light while traversing the strip glass, and continuously supplies the coolant to the region irradiated with the laser light. Thus, a scribe line is formed along the width direction of the strip glass. In online cutting using a laser beam, the initial crack is usually formed only in the vicinity of the edge in the side edge region of the strip glass.

Special table 2010-526014 gazette

  According to the study by the present inventors, when an initial crack is provided only in the vicinity of the edge, and the initial crack is to be extended to the central region, the crack extends from a desired position in a direction deviating from the desired direction. It may be formed at a deviated position. If the deviation width of the position becomes too large, it may be impossible to extend the crack. According to the study by the present inventors, this phenomenon is likely to be caused by the fact that stress remains in the vicinity of the edge.

  In view of the above, an object of the present invention is to improve a method for cutting a strip glass using a laser beam.

The present invention
A strip-shaped glass unloaded from the molding apparatus and transported in a predetermined transport direction, sandwiching the product-plate thickness region having a predetermined thickness and the product-plate thickness region, from the product-plate thickness region A crack forming step of forming an initial crack using a cutter in a strip-shaped glass including the first thick region and the second thick region formed into a thick wall;
A crack extension step of forming a scribe line by extending the initial crack in a width direction perpendicular to the transport direction by supplying a laser beam and a refrigerant to the belt-shaped glass;
A glass cutting step for cutting the strip glass along the scribe line,
In the crack forming step, a method for cutting a strip glass, which forms the initial crack having one end in the product plate thickness region,
I will provide a.

  According to the present invention, the initial crack extends from the product plate thickness region to form a scribe line. The product thickness region is thinner than the thick region (first thick region and second thick region) and the residual stress is difficult to concentrate, so cracks extending from the product thickness region deviate from the desired direction. hard. Therefore, it becomes easy to form a scribe line at a position where it should be originally formed.

It is a top view of the strip glass for demonstrating embodiment of this invention. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. FIG. 4 is a partially enlarged view near the head of FIG. 3. It is a top view of the strip glass which shows the area | region where a crack expand | extends. It is a figure for showing an example of a parting process. It is a figure for showing an example of a cutting-off process. It is a figure which shows an example of the crack formed when the initial crack extended | stretched when the initial crack was formed only in the 1st thick area | region. It is a figure which shows another example of the crack formed when the initial crack extended | stretched when the initial crack was formed only in the 1st thick area | region. It is a figure which shows an example of the crack formed when the initial crack extended | stretched when the initial crack from a 1st thick area to a product plate | board thickness area | region was formed. It is a figure which shows an example of the crack formed when the initial stage crack extended when the terminal crack was not formed in the 2nd thick region. It is a figure which shows an example of the crack formed when the initial crack extended | stretched when the termination | terminus crack was formed in the 2nd thick region. In Experiment 1, it is a figure which shows a mode that an initial stage crack expand | extends.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a state in which a strip glass (glass ribbon) 10 carried out from a glass forming apparatus and conveyed in a horizontal direction is observed from above. The strip glass 10 is formed to a predetermined thickness in a glass forming apparatus (not shown; for example, float bath) installed on the upstream side in the transport direction 40 (upstream side of the region shown in FIG. 1). Are transported at a constant speed. The belt-shaped glass 10 is transported by a transport roller 21 that supports the belt-shaped glass 10 from below. In addition, when the strip | belt-shaped glass 10 is thin, it is preferable to make the pitch of the conveyance roller 21 fine. Further, a conveyance belt may be used instead of the conveyance roller 21.

  The II-II sectional view of FIG. 1 is shown as FIG. As shown in FIG. 1 and FIG. 2, the strip-shaped glass 10 includes a strip-shaped product plate thickness region 1 and a product plate thickness region 1, and a first thick region formed thicker than the product plate thickness region 1. 2a and the second thick region 2b.

  The product plate thickness region 1 has a predetermined thickness T, and a glass plate as a product is sampled from a part of the product plate thickness region 1. Considering that the standard of the thickness of the glass plate as a product is minute but an allowable range is set, and that the thickness is stable at the center in the width direction 41 of the glass strip 10, In the present specification, the “predetermined thickness T” refers to a thickness at which the ratio T / Tc to the central thickness Tc in the width direction 41 of the strip glass 10 is within a predetermined range. In addition, when the thickness of the strip glass 10 varies in the transport direction 40, the average value of the thickness in the transport direction 40 at each point is adopted as the thickness at each point in the width direction 41 of the strip glass 10. I decided to. T / Tc is specifically 0.7 to 1.3, preferably 0.9 to 1.1. In FIG. 2, for convenience of explanation, the boundary between the product plate thickness region 1 and the first thick region 2a is represented as a first boundary 5a. Similarly, a boundary between the product plate thickness region 1 and the second thick region 2b is represented as a second boundary 5b.

  A scribe line 11 is formed on the belt-like glass 10 by a scribe line forming head (hereinafter simply referred to as “head”) 51 that traverses the glass strip 10. The scribe line 11 is formed so as to extend in parallel to the width direction 41 orthogonal to the transport direction 40 and to maintain a predetermined interval in the transport direction 40. In addition, scribe lines 15 a and 15 b are formed on the belt-like glass 10 so as to extend parallel to the transport direction 40 by the heads 53 a and 53 b installed above the glass strip 10. The scribe lines 15a and 15b are formed at positions closer to the center of the strip glass 10 than the boundaries 5a and 5b. The order of forming the scribe line 11 and the scribe lines 15a and 15b is not particularly limited.

  The strip glass 10 is divided in the scribe line 11 by a first dividing device arranged on the downstream side in the conveying direction 40 (a dividing step). Moreover, the strip glass 10 is divided | segmented in the scribe lines 15a and 15b by the 2nd parting apparatus arrange | positioned in the downstream of the conveyance direction 40 (cut-off process). There is no restriction | limiting in particular in the order of implementation of a parting process and a cutting-off process. However, a region (scribe line 11 is formed between the first edge 3a (the edge on the first thick region 2a side extending in the transport direction 40) and the initial end of the initial crack 61 (details of the initial crack 61 will be described later). In the case where there is a region that is not present, it is preferable that the cutting step is performed after the cutting-off step.

  In order to form the scribe line 11 parallel to the width direction 41 of the glass strip 10, the head 51 runs obliquely with respect to the width direction 41. The oblique traveling direction 42 and the width direction 41 of the head 51 form an angle θ that is determined depending on the conveyance speed of the belt-like glass 10 and the traveling speed of the head 51. The head 51 travels at a constant speed by being guided by a guide (not shown) that crosses the upper portion of the glass strip 10 in parallel with the oblique traveling direction 42. For convenience, the line on which the head 51 travels is shown in FIG.

  1 along the head travel line 50 is shown in FIG. 3, and a partially enlarged view of FIG. 3 is shown in FIG. The head 51 includes an optical system 70 for condensing laser light on the strip glass 10 and an injection nozzle 80 for locally cooling the strip glass 10 by ejecting a coolant. The head 51 further includes a cutter 19 that is a crack forming device that forms the initial crack 61 in the belt-like glass 10.

  The cutter 19 is typically a wheel cutter, but there is no particular limitation on the type thereof as long as it can form a stretchable crack in the strip glass 10. Another example of the cutter 19 is a point cutter. The cutter 19 plays a role of forming the initial crack 61 that is the starting point of the scribe line 11 in the strip glass 10.

  When the initial crack 61 is formed, the cutter 19 is pressed against the surface of the strip glass 10 by a cutter pressing device (not shown). Since the support member 22 supports the strip glass 10 at a position along the head travel line 50, a reaction force is applied from the cutter 19 to the strip glass 10 by this pressing. However, this pressure is released after the initial crack 61 is formed, and as a result, the cutter 19 is typically not in contact with the strip glass 10 as shown in FIG.

  In the present embodiment, an initial crack 61 is formed that extends from the first thick region 2 a to the product plate thickness region 1 and ends in the product plate thickness region 1. The length of the initial crack 61 to be formed is not particularly limited, but in order to facilitate the extension of the initial crack 61, for example, 15 mm or more is appropriate, and preferably 20 mm or more. Moreover, the length of the part extended in the product plate | board thickness area | region 1 among the initial stage cracks 61 is 200 mm or less, for example, Preferably it is 150 mm or less.

  The extension of the initial crack 61 for forming the scribe line 11 is performed by the laser beam 17 and the refrigerant 18 supplied from the head 51. In other words, if heating by the laser beam 17 and rapid cooling by the refrigerant 18 are successively applied to the end of the crack, a tensile stress is generated on the glass surface in the vicinity of the crack, and the crack extends due to this tensile stress. The head 51 advances on the head travel line 50 (to the left in the illustrated form) while extending the crack.

  As shown in FIG. 5, as the head 51 travels, the belt-like glass 10 is irradiated with the laser light 17 via the optical system 70, and the coolant 18 is supplied from the injection nozzle 80. The region 28 proceeds on the head travel line 50 in this order. In other words, these regions travel on the head travel line 50 while the cooled region 28 follows the irradiated region 27. The head 51 moves the laser beam condensing device (optical system 70) that forms the irradiated region 27 and the cooling device 80 that forms the cooled region 28 while maintaining the relative positional relationship between the devices. Take a role.

Returning to FIG. 4, the laser light irradiation system and the refrigerant supply system will be briefly described. However, these systems can be used without any particular limitation. The laser beam 17 is condensed from the laser beam generator 71 to the irradiated region 27 of the strip glass 10 via the laser beam expanding device 72 and the condensing device (optical system 70) in the head 51. The optical system 70 includes mirrors and other optical elements 73, 74, and 75. As the laser beam 17, a CO ₂ laser, a YAG laser, or the like can be used. The refrigerant 18 is supplied from a refrigerant supply device (not shown) to the area to be cooled 28 via an injection nozzle 80 provided in the head 51. For example, air, nitrogen, helium, or water may be used as the refrigerant.

  In the present embodiment, the cutter 19 is pressed again onto the surface of the strip glass 10 while the head 51 passes over the second thick region 2b. As a result, the end crack 12 is formed in the second thick region 2b. In the present embodiment, the extension of the crack 62 by the laser beam 17 and the refrigerant 18 is performed until at least the crack 62 reaches the thick region 2 b, and the terminal crack 12 is formed so as to be continuous with the extended crack 62. As shown in FIG. 1, the initial crack 61, the crack 62 formed by extending the initial crack 61, and the terminal crack 12 constitute a scribe line 11.

  The band-shaped glass 10 on which the scribe line 11 is formed is divided along the scribe line 11 on the downstream side in the transport direction 40. As shown in FIGS. 6A and 6B, when the scribe line 11 of the strip glass 10 approaches, the moving roller 25 lifts the strip glass 10 in the thickness direction. Cracks constituting the scribe line 11 are elongated by the stress generated by the weight of the raised glass strip 10 and the glass strip 10 is cleaved. More specifically, the moving roller 25 as a glass cutting device lifts the glass strip 10 so that the displacement amount of the portion in contact with the moving roller 25 is maximized, and advances the cutting along the scribe line 11. As shown in FIG. 6C, after the division is completed, the moving roller 25 is pulled down to prepare for the next division.

  The moving roller 25 moves upward while supporting the back surface of the glass strip 10 on both the upstream side (left side in the figure) and the downstream side (right side in the figure) across the scribe line 11 so that stress is applied to the scribe line 11. Is lifted up (FIG. 6B). As the moving roller 25 subsequently descends, the downstream end 10e of the strip-shaped glass 10 once moved upward returns to the lower side (FIG. 6C).

  In this embodiment, the cutting at the scribe line 11 is caused to proceed by the stress generated by its own weight. However, when the moving roller 25 is raised, the strip glass 10 is moved upstream or downstream in the conveying direction 40 of the moving roller 25. The cutting may be advanced by pressing the surface from above. If it does in this way, even if it is a case where the thin and light strip glass 10 is parted, it is easy to ensure the stress required for parting.

  Returning to FIG. 1, the heads 53 a and 53 b are provided with the same members as the head 51, and after forming an initial crack with a cutter, the laser beam and the coolant are sequentially supplied to the belt-like glass 10 and the scribe lines 15 a and 53 b are supplied. 15b is formed. However, the heads 53 a and 53 b are fixed at predetermined positions on the strip glass 10. For this reason, the heads 53a and 53b move along the length direction of the strip glass 10 along the length direction of the strip glass 10 with the movement of the strip glass 10 in the transport direction 40. 15a and 15b are formed. The scribe lines 15a and 15b are formed and sampled on lines 45a and 45b (hereinafter referred to as “longitudinal belts”) that pass through the irradiated region irradiated with the laser light 17 and extend in parallel with the transport direction 40. And a region to be cut off.

  The first thick region 2a and the second thick region 2b of the strip glass 10 are cut off on the downstream side in the transport direction (FIGS. 7A and 7B). In the cut-off process in the present embodiment, a part of the product plate thickness region 1 is cut off together with the first thick region 2a and the second thick region 2b so that the entire initial crack 61 is removed. In this embodiment, it is because the end surface formed of the initial crack 61 does not remain in the glass plate sampled as a product.

  As shown in FIG. 7B, the division along the length direction can also be performed by lifting the glass strip 10 on both the left and right sides of the drawing across the scribe lines 15a and 15b. In the illustrated form, the glass strip 10 is lifted so that the amount of displacement at the part where the support members 29a and 29b are in contact is maximized, and stress is applied to the scribe lines 15a and 15b.

  Hereinafter, the effects of the present embodiment will be described with reference to FIGS.

  When the initial crack 61 is formed only in the first thick region 2a, the initial crack 61 does not extend in the width direction 41 due to the residual stress in the first thick region 2a and deviates from the passing line 50p through which the head 51 passes. A crack 62 may be formed. Although this deviation is alleviated in the product plate thickness region 1, it may not be completely eliminated at the intersection with the longitudinal belt 45a (FIG. 8). In this case, the cut surface to be formed along the width direction 41 in the glass plate to be sampled is distorted in the vicinity of the longitudinal belt 45a. In addition, when the residual stress in the first thick region 2a is particularly large, the initial crack 61 may extend in a direction greatly deviating from the width direction 41, and the tip of the crack 62 may reach a position greatly deviating from the passage line 50p. . The laser beam and the tensile stress derived from the refrigerant do not sufficiently reach the position greatly deviating from the passing line 50p. Therefore, in this case, the extension of the initial crack 61 is interrupted in the first thick region 2a (FIG. 9). On the other hand, in this embodiment, an initial crack 61 having one end in the product plate thickness region 1 is formed. The residual stress in the product plate thickness region 1 is smaller than the residual stress in the first thick region 2a. Therefore, it is possible to prevent the initial crack 61 from extending in a direction deviating from the width direction 41 (FIG. 10).

  By the way, when forming the starting end of the initial crack 61 in the product plate thickness region 1 of the strip glass 10, in order to apply a pressing force (impact) to the position where the starting end is to be formed, when the strip glass 10 is thin, An unintended crack centering on the starting edge may occur. If a crack occurs, the glass strip 10 may not be divided stably. From such a situation, in the crack formation process in the present embodiment, the initial crack 61 that reaches the product plate thickness region 1 from the first thick region 2a and ends in the product plate thickness region 1 is formed as described above. The occurrence of cracks.

  Moreover, in this embodiment, the initial crack 61 which has a start end in the product plate | board thickness area | region 1 side rather than the 1st edge 3a extended along the conveyance direction 40 of the strip glass 10 is formed. When the inside of the product plate thickness region 1 is the starting end, the initial crack 61 can be formed more stably than when the first edge 3a is the starting end.

  Further, when the residual stress in the second thick region 2b is large, even if the initial crack 61 can be extended so that the crack 62 crosses the product plate thickness region 1, the second thick region 2b The crack 62 may deviate from the passing line 50p (FIG. 11). If the deviation becomes too large, the crack extension may be interrupted. In consideration of this, in the present embodiment, the terminal crack 12 that is continuous with the scribe line (crack 62) formed in the crack extending step and extends in the width direction 41 in the second thick region 2b is irradiated with laser light and refrigerant. It is supposed to form prior to the supply (terminal crack formation step; FIG. 12). In addition, it is desirable to form the termination | terminus crack 12 which has an end in the 2nd edge 3b extended adjacent to the 2nd thick region 2b along the conveyance direction 40 of the strip glass 10. As shown in FIG. In the present embodiment, the initial crack 61 and the terminal crack 12 are not included in the glass plate to be sampled as a product, and the end surfaces of the glass plate are all formed by extending the cracks by the laser beam and the refrigerant. Therefore, the glass plate excellent in the smoothness of the end face can be obtained. In addition, from the viewpoint of stably dividing the glass strip 10, it is preferable to form the terminal crack 12 even when the cutting-off process is performed prior to the cutting process. Further, the end crack 12 may be formed simultaneously with the laser beam irradiation or the coolant supply, or may be formed after the laser beam irradiation and the coolant supply.

  In addition, the thickness of the strip glass 10 is not particularly limited, but is, for example, 0.1 mm to 5 mm. In particular, in the case of a thickness of 0.1 mm to 1.1 mm, the difference in thickness between the product plate thickness region 1 and the first thick region 2a tends to be large, and thus the effect of applying the present invention. Also grows.

  Hereinafter, an experiment conducted for confirming a phenomenon in which the crack does not extend when the initial crack 61 greatly deviates from the passing line 50p will be described with reference to FIG.

(Experiment 1)
As the plate glass 110, a soda lime glass plate having a thickness of 0.4 mm, a short side length of 100 mm, and a long side length of 200 mm, expressed in mass% and having the following components was prepared.

SiO ₂ : 71.9%
Al ₂ O ₃ : 1.7%
MgO: 4.0%
CaO: 8.0%
Na ₂ O: 13.5%
K ₂ O: 0.9%

  The plate glass 110 was fixed to the transfer table 190 so that the direction along the long side of the plate glass 110 coincided with the transfer direction 142 of the transfer table 190.

  An initial crack 161 was formed in the sheet glass 110 while the transfer table 190 was stationary. Specifically, an initial crack 161 having a length of 10 mm is formed starting from a position 50 mm away from one short side 110a of the glass sheet 110 in the direction of the other short side 110b and extending toward the short side 110b. did. The initial crack 161 was formed using a sintered diamond cutter wheel (outer diameter φ2.5 mm, thickness 1.0 mm, inner diameter φ1.1 mm, blade edge angle 135 degrees).

  Next, while moving the transfer table 190, the plate glass 110 was irradiated with laser light, and water (refrigerant) was further injected. Specifically, first, the irradiated region 127 and the cooled region 128 are initially set at a position ahead of the short side 110a in the transport direction 142, and the major axis of the initial crack 161 and the major axis of the irradiated region 127 are the same. Then, the position of the transfer table 190 was initially set so that the distance Δx between the two long axes was 0 μm. Next, the laser beam condensing device and the cooling device were adjusted so that the irradiated region 127 had a length of 22 mm and a width of 1 mm, and the cooled region 128 was in contact with one end of the irradiated region 127 in the length direction. (FIG. 13A). Next, while maintaining the positions of the irradiated region 127 and the cooled region 128 fixed, the conveying table 190 is moved 180 mm / min in the conveying direction 142 until these positions become downstream of the conveying direction 142 of the short side 110b. It was moved at a speed of s (FIGS. 13B and 13C).

In Experiment 1, 50 W laser light output from a CO ₂ laser oscillator (ULC-100 manufactured by UNIVERSAL LASER SYSTEMS) was refracted and reflected using two axicon lenses, a cylindrical lens, and a mirror to irradiate the irradiated region 127. It was set. Moreover, the to-be-cooled area | region 128 was set by injecting the water of the injection amount 5.0ml / min from a nozzle (Everloy minimist 04-10-13).

  Next, the same experiment was repeated by changing the initial setting position of the transfer table 190 in increments of 50 μm so that Δx increases in increments of 50 μm.

  When Δx was 0 μm to 150 μm, the initial crack 161 was elongated and the crack 162 was formed. However, when Δx was 200 μm or more, the initial crack 161 did not expand.

(Experiment 2)
The experiment similar to Experiment 1 was performed by changing the thickness of the plate glass 110 to 0.7 mm. In Experiment 2, when Δx was 0 μm to 150 μm, the initial crack 161 was elongated. When Δx is 200 μm, the initial crack 161 may or may not expand. When Δx was 250 μm or more, the initial crack 161 did not expand.

(Experiment 3)
The thickness of the plate glass 110 is set to 0.33 mm, the length of the initial crack 161 is set to 20 mm, the transfer speed of the transfer table 190 is set to 300 mm / s, the output of the CO ₂ laser oscillator is set to 60 W, and the irradiation region 127 is irradiated. An experiment similar to the experiment 1 was performed except that the length was changed to 30 mm. In Experiment 3, when Δx was 0 μm to 500 μm, the initial crack 161 was elongated. When Δx is 550 μm, the initial crack 161 may or may not expand. When Δx was 600 μm or more, the initial crack 161 did not expand.

(Experiment 4)
The experiment similar to the experiment 3 was performed by changing the thickness of the plate glass 110 to 0.7 mm. In Experiment 4, when Δx was 0 μm to 500 μm, the initial crack 161 was elongated. When Δx was 550 μm or more, the initial crack 161 did not expand.

(Experiment 5)
In Experiment 5, an initial crack 161 having a length of 10 mm extending from the one point on the short side 110a to the short side 110b was formed. Otherwise, the same experiment as Experiment 1 was performed. In Experiment 5, when Δx was 0 to 1000 μm, the initial crack 161 was elongated.

  Comparing Experiment 1 and Experiment 5, in Experiment 1, the phenomenon in which the extension of the initial crack 161 did not start due to the misalignment between the axis of the initial crack 161 and the axis of the irradiated region 127 was more likely to occur. For this reason, in the present embodiment in which the initial crack 61 is formed at the center side of the first edge 3a of the strip glass 10, the extension of the initial crack 61 starts due to the positional deviation between the initial crack 61 and the irradiated region 27. It is understood that a phenomenon that is not performed easily occurs. In consideration of this, it can be said that in the present embodiment, it is preferable to adopt a configuration in which the laser beam is easily irradiated by overlapping the initial crack 61. Moreover, it can be said that it is preferable to employ a configuration in which it is easy to maintain the state in which the cooled region 28 is in contact with one end in the length direction of the irradiated region 27 so as to easily secure the stress necessary for elongation. From this point of view, the cutter 19 and the laser beam are condensed so that the initial crack 61 is formed in the linear region (passing line 50p) crossing the belt-like glass 10, the laser beam is irradiated, and the refrigerant is injected. The configuration of forming the scribe line 11 by moving the head 51 having the optical system and the injection nozzle 80 for injecting the refrigerant along the linear region (passage line 50p) on one surface of the belt-like glass 10 is as follows. This is effective in the embodiment.

1 Product Thickness Region 2a (of Strip Glass) First Thick Region 2b (of Strip Glass) Second Thick Region 3a (of Strip Glass) First Edge 3b (of Strip Glass) Second Edge 5a First boundary 5b Second boundary 10 Strip glass 10e Downstream end 11 of strip glass Scribing line 12 Termination crack 15a, 15b Scribing line 17 Laser beam 18 Refrigerant 19 Cutter 21 Transport rollers 22, 29a, 29b Support member 25 Moving roller 27, 127 Irradiated area 28, 128 Cooled area 40 (Strip glass) Transport direction 41 (Strip glass) Width direction 42 Skew travel direction 45a, 45b Longitudinal belt 50 Head travel line 50p Passing lines 51, 53a, 53b Head 61 161 Initial crack 62, 162 Crack 70 Optical system 71 Laser light generator 72 Laser beam expansion device 73, 74, 75 Optical element 80 Injection nozzle (cooling device)
110a, 110b Short side 142 (conveying table) conveying direction

Claims (9)

A strip-shaped glass unloaded from the molding apparatus and transported in a predetermined transport direction, sandwiching the product-plate thickness region having a predetermined thickness and the product-plate thickness region, from the product-plate thickness region A crack forming step of forming an initial crack using a cutter in a strip-shaped glass including the first thick region and the second thick region formed into a thick wall;
A crack extension step of forming a scribe line by extending the initial crack in a width direction perpendicular to the transport direction by supplying a laser beam and a refrigerant to the belt-shaped glass;
A glass cutting step for cutting the strip glass along the scribe line,
In the crack forming step, forming the initial crack having one end in the product plate thickness region ,
A terminal crack forming step of forming a terminal crack continuous with the scribe line formed in the crack extension step and extending in the width direction in the second thick region by using a cutter;
In the terminal crack forming step, the terminal glass is cut by forming the terminal crack having one end at an edge extending adjacent to the second thick region along the transport direction of the belt-shaped glass. Further comprising a step of cutting off the first thick region and the second thick region;
2. The strip-shaped glass according to claim 1, wherein in the cutting step, a part of the product plate thickness region is cut off together with the first thick region and the second thick region so that the entire initial crack is removed. Cutting method. A strip-shaped glass unloaded from the molding apparatus and transported in a predetermined transport direction, sandwiching the product-plate thickness region having a predetermined thickness and the product-plate thickness region, from the product-plate thickness region A crack forming step of forming an initial crack using a cutter in a strip-shaped glass including the first thick region and the second thick region formed into a thick wall;
A crack extension step of forming a scribe line by extending the initial crack in a width direction perpendicular to the transport direction by supplying a laser beam and a refrigerant to the belt-shaped glass;
A glass cutting step for cutting the strip glass along the scribe line,
In the crack forming step, forming the initial crack having one end in the product plate thickness region,
Further comprising a step of cutting off the first thick region and the second thick region;
A strip glass cutting method, wherein the cutting step is performed after the cutting step. 4. The strip-shaped glass according to claim 3, wherein in the cutting step, a part of the product plate thickness region is cut off together with the first thick region and the second thick region so that the entire initial crack is removed. Cutting method. In the crack formation process, it leads from the first thick region in the product thickness region, to form the initial crack with a termination in the product thickness region, according to any one of claims 1-4 A method for cutting strip glass. In the crack formation process to form the initial cracks than edge extends adjacent along said conveying direction on said first thick-walled region of the ribbon having a starting end to the product thickness region side Claim 5 The cutting method of the strip glass described in 2. The strip glass cutting method according to any one of claims 1 to 6 , wherein in the crack forming step, the initial crack in which a length of a portion extending in the product plate thickness region is 200 mm or less is formed. In the crack formation process, a length forming the initial crack is 15mm or more, the cutting method of glass ribbon according to any one of claims 1-7.   The cutter, the condensing system for condensing the laser light, and the refrigerant so that the initial crack is formed in a linear region crossing the belt-like glass, the laser light is irradiated, and the refrigerant is ejected. The scribe line forming head having an injection nozzle for injecting the liquid is moved along the linear region on one surface of the belt-like glass to form the scribe line. The cutting method of the strip glass described in 2.

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