Method and apparatus for forming locally thin glass and foldable plate-like glass articles manufactured therewith

Abstract

There is provided a method for producing a foldable glass article (1) having a strip-shaped section (3) with a reduced average thickness compared to adjacent sections (5, 7) such that the stiffness of the strip-shaped section (3) is reduced due to the reduction of the average thickness so that the glass article (1) can be folded around the strip-shaped section (3) without breaking, the method comprises, in a thermoforming step, forming the glass (10) of the glass sheet (2) by dispensing the softened glass such that the glass thickness decreases along the strip-shaped section (3).

Description

Technical Field

[0001] This invention generally relates to the manufacture of glass sheets. Specifically, this invention relates to the production of glass sheets having one or more sections with reduced thickness to facilitate glass bending. Background Technology

[0002] Foldable electronic displays utilize front covers or carriers that are flexible enough to allow for tight bending. However, providing electronic displays with covers or carriers that are both foldable and durable has proven challenging. Currently, structured metal panels are frequently used as back panels to flexibly support displays. Tuned folding forces are provided through localized structuring. Typically, such back panels are made of stainless steel or titanium with a thickness of approximately 0.15 mm. However, a drawback of metal carriers is their susceptibility to fatigue due to the material's ductility.

[0003] Glass is an alternative material for flexible displays, offering considerable strength, especially when chemically strengthened. However, glass is brittle and generally unsuitable for bending. For current foldable devices, ultra-thin glass (UTG) has become the standard solution for display cover glass. Its flexibility and foldability are key to foldable applications. Nevertheless, a drawback of UTG is its extremely thin thickness, resulting in lower resistance to sharp impacts or scratches. To achieve higher impact resistance, the glass must be thicker, negatively impacting its flexibility. However, bendable glass sheets can be achieved by structuring strip areas to reduce their stiffness. Therefore, cover glass with hinge structures or thinned folding areas has increasingly attracted manufacturers' interest. These cover glasses have thicker glass in the main display area and structured or thinned folding areas to achieve the desired flexibility.

[0004] Therefore, various methods were tried. One feasible method is to introduce an arrangement of holes. However, this method requires a multi-step process, such as using a laser to outline the hole contours and then etching.

[0005] Next-generation foldable displays go beyond single-fold designs, integrating multi-fold functionality for larger screens. Popular solutions include so-called S-type, G-type, and book-style foldable displays. S-type and G-type folding variants are characterized by having two folding zones with different bending radii. The S-type variant is particularly noteworthy because, compared to previous foldable devices, this design also places a foldable cover glass on the unprotected outer side of the device when folded. In this case, at least one folding zone will be exposed to the outside of the device in a particularly vulnerable state, as the glass is under tensile stress when folded. Furthermore, for these foldable displays, locally structured glass may not be the optimal solution as a cover glass due to the finely structured hinge areas and the potential optical defects associated with these areas. Therefore, locally thinned glass may be a viable solution.

[0006] To date, locally thinned glass has primarily been manufactured by etching a pre-formed glass substrate of uniform thickness. Various etching techniques are used to thin the folded regions. These methods may include, or a combination of, the following steps: locally applying an etching solution to the folded region (e.g., by applying an etching paste or solution, masking the folded region, etc.); immersing only the folded region in the etching solution; locally processing the folded region (laser or mechanical processing) and then etching; or applying the etching solution while subjecting it to localized heating to increase the etching rate only in the target area; and other methods. What all these methods have in common is that they are all secondary processes that require selective post-processing of the uniformly thick bare glass substrate, which is not only technically challenging but also time-consuming and costly.

[0007] US 2021 / 0107829 A1 discloses a method in which laser ablation is used to thin glass. The ablation process can be performed in the hot state of the glass strip. However, laser ablation requires high beam energy and typically results in a narrow groove-like structure defined by the beam profile. To obtain a wider stiffness reduction region, multiple parallel grooves are introduced.

[0008] Therefore, one object of the present invention is to facilitate the manufacture of foldable glass sheets (particularly glass sheets that can be used as carriers for flexible electronic displays). This object is achieved through the independent claims. Advantageous improvements are defined in the corresponding dependent claims. Summary of the Invention

[0009] Therefore, a method for producing a foldable glass article is provided, the glass article having strip segments with a reduced average thickness compared to adjacent segments, such that the stiffness of the strip segments is reduced due to the reduction in average thickness. Thus, the glass sheet can be folded around the strip segments without breaking. The method includes forming the glass sheet by dispensing softened glass, such that the glass thickness decreases along the strip segments, in a thermoforming step. The foldable glass article disclosed herein is understood to be a glass article that can be bent at strip segments such that the angle between adjacent segments changes from 0° to at least 90°, preferably at least 120°. When fully folded, it obtains a booklet-like shape, wherein adjacent segments are opposite each other at an angle of 180°, close to 180°, or even greater than 180°, for example, if opposite edges are in contact with each other in the folded state.

[0010] This method is based on the principle that the structuring of glass articles is achieved through thermoforming rather than subtractive forming methods such as ablation or hole cutting. In particular, the method according to this disclosure can be used to dispense glass without removing it from the glass sheet.

[0011] An apparatus for performing the method disclosed herein to produce glass articles thus has a device for dispensing glass in a softened or molten state to form a glass sheet having strip segments with a reduced average thickness compared to adjacent segments, thereby reducing the stiffness of the strip segments and enabling the glass sheet to be folded around the strip segments without breaking.

[0012] Dispensing or redispensing glass in a thermoforming process using the methods or apparatus described herein typically results in locally thinned sections of a glass article forming a specific shape. Specifically, a foldable sheet-like glass article can be obtained having two opposing sides and a circumferential edge, and a strip segment with a reduced average thickness compared to adjacent segments, such that the stiffness of the strip segment is reduced due to the decrease in average thickness, allowing the glass sheet to fold around the strip segment without breaking. The strip segment extends laterally along the sides and terminates at both ends by the circumferential edge. The surface profile of at least one of the sides and / or the thickness profile within the strip segment is continuously curved, wherein the central surface of the strip segment is concave and curved, and wherein the curvature of this concave surface changes to a convex surface curvature in the direction from the center toward the adjacent segment, such that a central concave curved surface portion is arranged between two convex curved surface portions, wherein the curved surface portion forms a recess. In particular, unlike glass articles that are foldable due to the arrangement of holes, the strip section may have a closed surface, that is, without openings.

[0013] The glass article 1, which can be produced using the methods or apparatus described herein, can be used in foldable consumer electronics products, such as mobile phones, tablets, laptops, and screens (monitor or television screens). Additionally, the foldable glass of the present invention can also be used as the back panel of a corresponding foldable mobile phone. Therefore, according to another aspect of this disclosure, an electronic device is provided, comprising the glass article described herein. In this respect, the glass article can be particularly used as a front cover, substrate, or support for electronic components.

[0014] The invention will now be described in more detail with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 The orifice of the drawing device is shown.

[0016] Figure 2 It shows that it has the following characteristics: Figure 1 The drawing device for the orifice shown.

[0017] Figure 3 It shows that it is available Figure 1 , Figure 2 Glass products produced by the device.

[0018] Figure 4 This is a side view of another embodiment of a glass article.

[0019] Figure 5 An example of an opening for producing glass articles with multiple folded areas is shown.

[0020] Figure 6 An example of a glass product in a folded state is shown.

[0021] Figure 7 An aperture is shown for producing a glass strip with multiple folded areas and oppositely arranged protrusions.

[0022] Figure 8 A section of a glass strip with cutting lines for producing foldable glass articles is shown.

[0023] Figure 9 Another embodiment of the device with a local heating element is shown.

[0024] Figure 10 A variant of a glass article is shown, which has a thickened transition section between the reduced thickness section and the adjacent section.

[0025] Figure 11 and Figure 12 A variant of the orifice equipped with a local heating device is shown.

[0026] Figure 13The components of a float glass drawing apparatus are shown.

[0027] Figure 14 A device for downward drawing is shown, which has various devices for introducing a thinning region transverse to the drawing direction.

[0028] Figure 15 and Figure 16 An embodiment of the overflow trough is shown.

[0029] Figure 17 The method steps for producing locally thinned glass sheets are shown by heating a strip region and drawing the glass sheet in a longitudinal direction perpendicular to the strip region.

[0030] Figure 18 The steps of a method for producing partially thinned glass sheets by redrawing the glass sheet are shown.

[0031] Figure 19 and Figure 20 Examples of glass sheets or glass articles produced by molten glass strips are shown.

[0032] Figure 21 A waterfall-style drop-down device is shown.

[0033] Figure 22 It shows Figure 21 The device shown is shown in top view.

[0034] Figure 23 and Figure 24 An overflow-melting apparatus for combining glass melt flows is shown.

[0035] Figure 25 and Figure 26 A single-sided groove is shown. Figure 23 and Figure 24 Variations of the embodiments.

[0036] Figure 27 A pull-down device with a guide body is shown. Detailed Implementation

[0037] Various devices exist for dispensing glass in a softened or molten state to form glass sheets with strip-shaped segments, each segment having a reduced average thickness compared to adjacent segments. A preferred method for dispensing glass is drawing the glass sheet from a melt or preform. Typically, in preferred embodiments, the method for forming the glass sheet involves drawing a glass sheet from a glass melt into the form of a glass ribbon, wherein the glass is dispensed before the glass ribbon cools and solidifies. Various methods exist for drawing glass ribbons from a melt, with preferred variations being the down-draw method and the overflow-melt method. Figure 1 and Figure 2An example of an apparatus 30 for producing glass sheets 2 in the form of glass strips 20 by a down-drawing method is shown. Without being limited to a particular drawing method, glass dispensing can be achieved by locally reducing or impeding the flow of the molten glass (particularly by extending into the flow of the molten glass) through at least one protrusion. The protrusion locally reduces the flow, thereby reducing the thickness of the resulting glass. Of course, Figure 1 The protrusion 14 shown is merely an example. The shape, width, and height of the protrusion 14 can vary in many ways.

[0038] The apparatus 30 includes an elongated orifice 12 located in a pipe or container 15 through which molten glass 21 flows and is drawn into a glass strip 20. The drawing force can be applied by a drawing roller 13. Figure 1 An example of the aperture 12 is shown in a top view. Typically, and not limited to this specific example, a glass sheet 2 in the form of a glass strip 20 is formed by pulling glass 10 downwards from the slit-like aperture 12. The aperture 12 has at least one protrusion 14 that narrows the width. This protrusion 14, which may be located on one or both sides of the aperture 12, or a corresponding narrowing portion of the aperture, is used to distribute the glass 10 such that the thickness of the glass strip 20 decreases in the strip-shaped section 3 extending downwards from the protrusion 14. A foldable glass article at the strip-shaped section 3 can then be cut from the glass strip, wherein the cutting direction extends laterally (particularly perpendicular to the longitudinal direction of the glass strip 20 or the strip-shaped section 3).

[0039] Figure 3A foldable glass article 1 is shown, which can be produced by cutting a glass strip 20 perpendicular to the drawing direction. The glass article 1 is generally plate-shaped, having two opposing sides 101, 102 and a circumferential edge 104. A strip segment 3, in which the plate-shaped glass article 1 is partially thinned, extends along the surface of the article 1. In particular, the entire strip segment 3 extends on one of the sides 101, such that the strip segment 3 terminates at two opposing segments of the edge 104. In other words, the segment 3 terminates at its ends 33, 34 by the circumferential edge 104. The surface within the strip segment 3 is continuously curved. Furthermore, the surface at the center of the strip segment 3 is concave. The curvature of the concave surface at the center changes to a convex surface curvature in the direction from the center toward the segments 5, 7 adjacent to the strip segment 3. Thus, a central concave curved surface portion 37 of the strip segment 3 is provided between two convex curved surface portions 36, 38. Furthermore, this curved surface portion forms a recess 105, which correspondingly results in local thinning or a reduction in average thickness. The continuously curved surface profile and / or thickness profile of strip segment 3 is achieved by distributing glass during thermoforming. A smooth, circular profile also contributes to high fracture strength. Typically, glass is preferably distributed during thermoforming to create a shallow indentation relative to its width. This benefits fracture strength and, because the surface can be considered quasi-planar, facilitates mounting or depositing other components. This smooth curvature can be achieved if the combined width of the convex curved surface portions 36, 38 of strip segment 3 is at least as large as the width of the concave curved surface portion 37. Similarly... Figure 3 In another alternative or additional embodiment implemented in the example, the width of the recess 105 is at least three times, preferably at least five times, and particularly preferably at least ten times, the depth of the recess 105. In a preferred embodiment, the width of the strip segment 3 can typically be between 5 mm and 50 mm, preferably between 8 mm and 20 mm. The thickness of the glass article 1 described herein is preferably between 50 μm and 1500 μm, preferably between 70 μm and 1000 μm. The typical thickness of glass articles that can be used as back panels for smartphones or tablet displays is in the range of 60 μm to 200 μm. This thickness is referred to as the general thickness or average thickness of the outer side of the strip segment 3 (i.e., within adjacent segments 5, 7).

[0040] The minimum thickness within the strip segment 3, where the thickness decreases, ranges from 15 μm to 150 μm. Of course, these dimensions also depend on the thickness of the glass article 1, i.e., its thickness outside the strip segment 3. Therefore, the given ranges overlap, and the choice of dimensions must always ensure that the average thickness of the strip segment 3 is less than the average thickness of the adjacent segments 5 and 7.

[0041] like Figure 1As shown in the example, because the protrusion 14 is provided only on one side of the aperture 12, the aperture 12 can be asymmetrical. This may result in an asymmetrical profile of the glass article 1, similar to... Figure 3 For example, a recess 105 is formed in one of the sides 101. Figure 3 As shown, the opposing sides 102 can be flat. However, depending on the viscosity of the glass when it is dispensed to form the specific profile disclosed herein, depressions can be formed on the sides 101, 102 of the glass article 1 due to hydrodynamic movement, even if a protrusion is provided only on one side of the orifice. Hydrodynamic movement in molten glass can also cause depressions to form on the opposing sides of the glass. Therefore, according to one embodiment of the glass article 1, the surface profiles and / or thickness profiles within the strip segment 3 of the two sides 101, 102 are continuously curved, such that the sides 101, 102 approach each other toward the center of the strip segment 3. This implementation is, for example... Figure 4 The side view is shown.

[0042] However, if obstructive features such as protrusions in the orifice profile are sufficiently pronounced, an asymmetrical surface profile can be formed, where the concavity on one side is more pronounced than that on the opposite side. This same phenomenon also occurs in… Figure 4 This is achieved in the example shown, where recess 105 is deeper than its relative recess 106. Therefore, according to one embodiment, typically, recess 105 within the strip segment 3 on one side 101 has a greater depth than the recess on the opposite side 102. In another embodiment, which may be advantageous for a particular application, the depths of recesses 105 and 106 may be similar or equal, such that the surface profiles are substantially mirror-symmetrical.

[0043] According to this disclosure and as follows Figure 3 and Figure 4 The glass article 1 exemplarily shown is characterized by a fire-polished surface, thus having a very low surface roughness. Therefore, according to one aspect of this disclosure, a foldable sheet-like glass article 1 is provided, particularly manufactured using the method or apparatus 30 according to this disclosure, wherein the glass article 1 has two opposing sides 101, 102, a circumferential edge 104, and a strip segment 3 with a reduced average thickness compared to adjacent segments 5, 7, such that the stiffness of the strip segment 3 is reduced due to the reduced average thickness, allowing the glass sheet 1 to be folded around the strip segment 3 without breaking. The strip segment 3 extends laterally along the sides 101, 102 and terminates at its two ends 33, 34 by the circumferential edge 104. The average surface roughness of the two sides 101, 102, including the surface of the strip segment 3, is less than 0.5 nm, and / or the two sides 101, 102, including the surface of the strip segment 3, have a fire-polished surface.

[0044] Specifically, for use as a front cover, back panel, or substrate in foldable electronic devices such as foldable displays, chemical strengthening of the glass article 1 is advantageous for its fracture stability. Chemical strengthening generates compressive forces on the sides. However, due to significant differences in the thickness of article 1 at strip segment 3 or between strip segment 3 and adjacent segments 5, 7, expansion differences may occur between strip segment 3 and adjacent segments 5, 7 due to ion exchange, potentially leading to wrinkling. To counteract this, the compressive stress (CS) and / or ion exchange layer depth (DoL) can be adapted to the local thickness of the glass article 1 such that at least one of the parameters CS and DoL of strip segment 3 is lower than that of adjacent segments 5, 7.

[0045] exist Figure 1 and Figure 2 In the example, only a single protrusion 14 is provided in the aperture 12. However, in order to make efficient use of the current strip width, more strip-thinning areas with corresponding protrusions can be produced. This can be used to produce glass articles with more than one folded area or more than one strip segment 3, respectively. Figure 5 Three examples of orifices for producing glass articles 1 are shown, which can be folded at least twice, or each has more than one folded area or strip segment 3.

[0046] Example (a) has an orifice with two protrusions 14 located on the same side 121 of the orifice. A glass article 1 produced from a glass strip drawn from such an orifice can be folded in a book-fold manner, where the outer section folds inward. Example (b) is a variation in which one protrusion is wider than the other. This forms strip-shaped foldable sections 3 of different widths. This is suitable for producing foldable glass articles where the outer sections can be folded inward, so that one section overlaps with the other. This type of folding is commonly referred to as a "G-fold." In example (c), as in the other examples, the protrusions are offset along the orifice 12 but located on opposite sides of the orifice 12. Thus, the recesses created by the protrusions are located on opposite sides of the glass article, making the glass article 1 suitable for an S-fold. Figure 6 The diagram illustrates the corresponding glass articles that can be obtained using these openings in a folded state. Example (a) shows an article that can be obtained using... Figure 5 The book-shaped folded article 1 obtained from the aperture 12 shown in Example (a) is shown. Article 1 includes two laterally spaced strip segments 3 with decreasing average thickness and adjacent segments 5, 7, and 9, wherein segment 7 is located between the strip segments 3. Article 1 can be folded as shown, wherein the outer segments 5 and 9 are folded inward toward each other.

[0047] Example (b) is a "G-shaped fold" article 1 similar to Example (a), however, the dimensions of sections 5, 7, and 9 are designed so that the outer sections 5 and 9 overlap in the folded state. As described above, this article 1 can utilize... Figure 5 The aperture 12 shown in Example (b) is made. Specifically, the strip segment 3 between adjacent segments 7 and 9 can be wider than the other strip segment 3 to provide a larger bending radius, so that segment 9 is folded on top of segment 5.

[0048] A glass article 1 folded into an S-shape is shown in example (c). According to this example, the outer sections 5 and 9 are folded in opposite directions, so that they face the opposite sides 101 and 102 of the central section 7 located between the two strip sections 3. If used... Figure 5 The aperture 12 in example (c) makes it easier to fold the glass article 1 in this way, thereby producing a glass strip with a deeper recess on the opposite side.

[0049] Generally, without limiting themselves to specific examples or drawing methods, these embodiments share the common feature of drawing a glass strip 20 having at least two laterally spaced strip segments 3 with decreasing average thickness, wherein glass articles 1 are produced (particularly cut from the glass strip) such that the glass articles 1 have at least two strip segments 3, wherein at least three segments 5, 7, 9 are foldably connected together by the strip segments 3. Of course, a glass article 1 having at least two strip segments 3 (where at least three segments 5, 7, 9 are foldably connected together by the strip segments 3) may include one or more other strip segments 3 and adjacent segments of substantially uniform thickness.

[0050] Utilize Figure 1 and Figure 5 The aperture 12 shown in the example allows for the production of a single glass article 1 from the glass strip 20 with each horizontal cut. However, glass strips 20 with large widths can be drawn using the down-drawing method and other drawing methods such as overflow-melt drawing. Therefore, in an improved version of the method, a glass strip 20 is produced having a plurality of strip segments 3 with decreasing average thickness, the strip segments 3 being laterally spaced along a direction perpendicular to the drawing direction or perpendicular to the longitudinal direction of the glass strip 20, wherein the glass strip 20 is cut along at least one cutting line 40 (which extends along two strip segments 3 and between the two strip segments 3), and further laterally (preferably perpendicular to the longitudinal direction of the glass strip 20) to obtain a plurality of glass articles 1, each glass article having at least one strip segment 3 with decreasing average thickness.

[0051] Figure 7An embodiment of an aperture for producing a glass strip having multiple folded areas and opposing protrusions is shown to implement the method described above. It can be seen that the aperture 12 has multiple protrusions 14. In this example, the aperture 12 is symmetrical, with opposing protrusions 14 on both sides 120, 121. This arrangement will form symmetrical recesses along the strip segment 3. For example, in order to produce... Figure 6 The glass articles 1 shown each have two strip-shaped thinning sections 3, and glass strips produced by longitudinal cutting through orifices 12 can be made between each second pair of sections 3. The cutting positions are shown by dashed lines. Figure 8 The illustration shows what can be adopted based on Figure 7 The section of glass strip 20 produced by the orifice 12. The vertical cutting line 40 extends along the drawing direction and corresponds to... Figure 7 The dotted lines shown. Cutting line 41 extends laterally, specifically perpendicular to cutting line 40, and can be referred to as a horizontal cutting line. Cutting the glass strip 20 along both lines 40 and 41 yields a plurality of foldable glass articles 1, or at least intermediate articles. Of course, other cutting patterns can also be used. In the example shown, each foldable glass article 1 has two laterally spaced strip segments 3. However, similar to... Figure 3 and Figure 4 For example, glass products with a single strip segment 3 can also be produced.

[0052] Drawing glass articles 2 into the form of glass strips 20 with one or more strip-shaped segments 3 of decreasing average thickness can be challenging because controlling the cooling of such strips can be challenging due to the varying thicknesses, resulting in different cooling rates for the corresponding segments. Thinner segments will cool much faster than thicker segments and may therefore become more rigid, while adjacent segments remain flexible and deformable. Thus, controlling the thickness of each segment is complex, and stress can accumulate in the strip, potentially causing it to break at the cold end of the melting bath or when bent in the horizontal transport direction during the separation of individual sheets. One feasible way to avoid stress buildup and achieve uniform cooling is to apply localized temperature control. For example, localized heaters can be used to match the temperature in one or more thinned strip segments 3 to that of adjacent segments. Therefore, similarly... Figure 2 As shown, a local heating device 25 can be provided to raise the temperature within one or more strip sections 3 so that the temperature therein is adapted to that of adjacent sections 5, 7, wherein the heating device 25 is positioned or arranged such that heating is applied to the respective strip section 3 at a location where the glass of the adjacent sections 5, 7 is still in a softened or formable state, respectively.

[0053] On the other hand, the thickness of the glass strip 20 can also be controlled by localized heating. In other words, the device for dispensing glass in a softened or molten state to produce glass sheet 2 may include a localized heating device, wherein the glass sheet 2 has strip-shaped segments 3 with a reduced average thickness compared to adjacent segments 5, 7. In this regard, not limited to a particular example, in another embodiment, the glass sheet 2 is formed in the form of a glass strip 20 by drawing, wherein the glass 10 is locally heated to a higher temperature along the strip region 16 while still in a softened state compared to adjacent regions of the glass strip 20, so that its viscosity along the region 16 is lower than that in the adjacent regions, wherein the glass thickness along the strip region 16 is reduced due to drawing. As shown, the strip region 16 (i.e., its longitudinal direction) generally extends parallel to the drawing direction or parallel to the longitudinal direction of the glass strip. Figure 9 As shown in the example, a laser beam 251 from laser 250 can be used as a local heating device to perform local heating. Alternatively, other heating devices such as coil heaters can be used. In this example, two laser beams 251 are used to form two laterally spaced strip regions 16 extending along the longitudinal direction of the glass strip 20. Due to the increased temperature within the strip regions 16, the viscosity of the glass is locally reduced. Thus, these regions are drawn thinner compared to the untreated regions. Consequently, strip segments 3 with reduced average thickness are formed along the regions 16. Unlike the example of device 30 shown, heating can also be performed from both sides of the glass, so that the glass is uniformly thinned on either side. Furthermore, heating methods using different heat sources can be combined, for example, combining precise laser heating at a specific location with a wider processing area of ​​a coil heater. For example, this can help to make the transition region of the glass from the thinned region to the thicker region smoother. However, one possible feature of this method is that the glass is allocated to move it out of the heating region 16, thereby forming a thickened transition section with a substantially constant thickness between the strip section 3 and the adjacent sections 5, 7. Figure 10 A variant of the glass article 1 is shown, which has thickened transition sections 50 and 70 between the reduced-thickness strip section 3 and the adjacent sections 5 and 7. The transition sections 50 and 70 may benefit the stability and fracture strength of the glass article 1.

[0054] Preferably, a lateral component of the pulling force can be applied simultaneously with localized heating, for example, via a pulling roller, to stretch the strip transversely to the pulling direction. Therefore, the applied pulling force has a component perpendicular to the pulling direction. For example, the pulling roller 13 can be slightly inclined to the longitudinal direction of the glass strip 20, applying not only a force in the vertical pulling direction but also a lateral component that stretches the glass strip 20, thereby reducing its thickness in the region of lowest viscosity. In this embodiment, the formation of a substantially constant thickness thickened transition section between the strip segment 3 and adjacent segments 5, 7 can be reduced or completely avoided.

[0055] In alternative or additional solutions, secondary heating in or below the forming area can be achieved through locally heated pull-down orifices, which are in the form of straight slits, slits with contractions, or protrusions 12. Figure 11 An orifice 12 with a local heating device 25 (e.g., a coil heater 252) is shown to locally raise the temperature of the glass melt passing through the orifice 12 to a temperature higher than that of the adjacent region of the glass strip 20 to be formed. This is similar to... Figure 9 For example, a strip region 16 is formed in the glass strip 20, which is heated and extends along the longitudinal direction of the glass strip 20.

[0056] Figure 12 It shows Figure 11 A variation of the illustrated embodiment. In this variation, the orifice 12 has at least one similar to Figure 1 The protrusion 14 in the illustrated embodiment. Figure 12 In the embodiments, local heating devices 25 (e.g., coil heaters 252) are disposed in or at the orifice 12 to heat the glass melt passing through the contraction or protrusion 14, respectively, thereby raising its temperature above that of adjacent regions. In the illustrated embodiment, the local heating device 25 is disposed on the side 121 of the orifice 12 with the protrusion 14. Optionally or additionally, the heating device 25 may be disposed on the opposite side 120 of the orifice. In both cases, a strip region 16 with a temperature rise is formed along the glass strip 20. If these local regions at the contraction or protrusion 14 in the orifice 12 are hotter than the rest of the slit, the hotter glass can be drawn thinner than the relatively cooler glass passing through the rest of the orifice 12. Another beneficial effect of the combination of the protrusion 14 and the local heating device 25 is that the faster cooling of the thinning strip section 3 along the glass strip 20 can be at least partially compensated. This also applies to other local heating devices 25, for example, according to Figure 9 Laser 250 in an embodiment.

[0057] So far, a drawing process that can be used for the method described according to this disclosure has been described based on the method of drawing glass strip 20 downward from orifice 12. However, other drawing processes can also be used. Another drawing process is the float glass process. In the float glass process, the molten glass is drawn while floating on a bath of liquid metal. Figure 13 An example of an apparatus 30 for producing glass articles 1, having a float bath 45, is shown, on which glass sheets in the form of glass strips 20 are formed by means of a float process. Furthermore, typically, but not limited to, a specific drawing process, distributing softened glass 10 to reduce the glass thickness along the strip section 3 may also include blowing a gas jet 49 onto the softened glass 10 or the molten glass 21. This embodiment also... Figure 13 This is achieved in the example. A gas nozzle 47 is provided to blow a gas jet 49 onto the glass strip 20, which is still in a molten or softened state. The gas jet 49 causes the glass 10 to shift outward, thereby combining with the movement in the drawing direction as indicated by the arrow to form a strip segment 3 with a reduced average thickness. The gas jet 49 can also be used to locally heat the glass 10. Of course, multiple nozzles 47 can be arranged at intervals to introduce multiple spaced segments 3 into the glass strip 20.

[0058] In the above example, when one or more thinning segments 3 are introduced into the glass strip 20, the longitudinal direction of the strip segments 3 extends along the longitudinal direction of the glass strip 20 or the drawing direction, respectively. However, according to other embodiments, a glass sheet 2 in the form of a glass strip 20 is formed by drawing, wherein a plurality of strip segments 3 with a reduced average thickness compared to adjacent segments 5, 7 are formed in the drawing process, wherein the longitudinal direction of the strip segments 3 extends laterally, preferably perpendicular to the drawing direction.

[0059] This structuring of the glass strip 20 can be achieved, in particular, by at least one of the following: - Change the drawing speed; - Change the temperature so that the strip area extending laterally in the drawing direction has a higher temperature compared to the adjacent areas.

[0060] Figure 14 The apparatus 30 is shown for drawing a glass strip 20 downwards, and includes various devices for producing thinned strip segments 3 oriented transversely to the drawing direction. These devices can be used interchangeably or in combination.

[0061] To change the temperature, the temperature of the drawing groove or orifice can be adjusted by oscillation. For this purpose, as shown, a suitable heating device 25 can be integrated into the container 15 or orifice 12. Similarly, a coil heater 252 or other electric heating elements can be used. Also, as shown, a heating device 25 (e.g., a coil heater 252) can be positioned below the orifice 12, which has a sufficiently fast response time to produce a narrow and well-defined temperature rise zone. Furthermore, thermal energy can be deposited on the glass strip 20 by a confined radiation source such as a laser 250 (whose laser beam 251 can scan in a direction transverse to the drawing direction) to form a temperature-rising strip segment. Due to the temperature rise in this region, the glass is softer than the glass in the middle region, causing the temperature-rising region to expand under the applied drawing force, thereby reducing its thickness and resulting in a strip segment 3 with reduced thickness.

[0062] Another additional or optional possibility is to control and alternate the stretching speed or stretching force. For this purpose, the speed of the stretching roller 13 can be changed in an oscillating manner, or a roller 13 with a non-circular (e.g., elliptical) shape and / or an eccentrically arranged axis of rotation can be used. In the example shown, the stretching roller 13 is elliptical and has an eccentric axis of rotation to achieve oscillation of the stretching speed and / or stretching force.

[0063] As described above, various drawing principles can be employed to implement the methods described herein. Examples have been shown so far for drawing downwards and floating to produce glass strips 20 with one or more strip segments 3 having reduced thickness.

[0064] Similar to the use of a pull-down orifice 12 with an adjusted profile, the shape of the overflow-melt supply channel can also be adapted to change the flow of molten glass at different locations, thereby obtaining the desired thickness distribution. Figure 15 The cross-section of the overflow-melting tank 18 in operation is shown. Figure 16 A top view of the trough 18 is shown. Molten glass 21 is continuously fed into the channel 19 of the trough 18, causing it to overflow and flow down its sidewalls 180, 182. According to one embodiment, a glass sheet 2 in the form of a glass ribbon 20 is formed by overflow-melting from the trough 18, which has a protrusion 14 on at least one side (particularly at least one of its sidewalls 180, 182), consistent with the implementation in the illustrated example. Alternatively, protrusions may be provided on one or both sides of the top of the channel to slow the glass flow. In this example, the protrusions are provided on two opposing sidewalls 180, 182. However, protrusions 14 may also be provided only on one of the sidewalls 180, 182, thereby achieving a similar effect to using only one side (e.g., as shown in the example). Figure 1As shown, the orifice 12 with its protrusion is pulled downwards. Therefore, this design can be used to achieve, for example... Figure 3 , 4 The thinned section 3 with an asymmetrical profile is schematically shown in the diagram. Depending on the band width and the design of the final application, multiple similar sections may exist. Figure 8 An example is the thinning section 3 formed by providing multiple protrusions 14 on the groove 18.

[0065] As an alternative to or supplement to the above embodiments, a convenient method is glass re-stretching, which is also a stretching process. The process steps according to one embodiment based on re-stretching are as follows: Figure 17 As shown. Specifically, a glass sheet 2, preferably having a uniform thickness, is provided. This glass sheet can be locally heated along a strip region 16, causing the glass in the strip region 16 to soften, and wherein the glass sheet 2 is subsequently drawn in a direction transverse to the strip region 16, thereby expanding the strip region 16 and reducing the glass thickness within the strip region 16. Thus, a strip segment 3 with a reduced average thickness is produced. Heating can be achieved by a suitable local heating device 25, particularly as already discussed... Figure 9 and 14 As described in the embodiments. Preferably, the glass of the glass sheet 2 is in a cold state or at least in a rigid state, such that only the glass within the strip region 16 is softened. In a variant of this embodiment, the glass sheet 2 is already in a hot state, or even soft, wherein the glass in the strip region 16 is further heated and softened, resulting in a relatively low viscosity compared to adjacent regions. Figure 17 Image (a) shows a glass sheet 2 and a local heating element 25 disposed on top of one of its sides 101. A strip region 16 below the local heating element 25 is heated until the glass softens. When the local temperature is close to or above the softening point, the viscosity of the region to be thinned is much lower. Therefore, when a force is applied transversely to the longitudinal direction of the strip region 16, these regions will deform / elongate more significantly compared to the unheated regions. The applied force... Figure 17 In (a), arrows are used to indicate this. Generally, since the total volume of the glass is constant, a larger thickness difference between the thinning section 3 and the adjacent sections 5 and 7 will always result in a wider thinning section 3. Figure 17 Figure (b) shows the drawn glass sheet 2. The heated region 16 is widened and thinned, thus forming a strip segment 3 with a smaller average thickness relative to the adjacent segments 5 and 7.

[0066] When the target is the same thickness difference, if the initial thickness of the glass is large, the increase in width due to drawing is usually relatively small. Furthermore, some shrinkage typically occurs at the edge of the thinning / drawing section 3. Therefore, it is advantageous to cut the processed glass sheet to a certain size to obtain the glass article 1. However, in some cases, it may also be advantageous to recess the thinned area from the main edge to protect the thinned section 3.

[0067] When the initial thickness is relatively large, a secondary re-stretching process can be performed along the direction of strip segment 3 to further reduce the thickness of the entire glass sheet to the desired size. Here, preforms with pre-formed thin and thick regions can be drawn to the target thickness. Typically, the thickness of different regions will be reduced at the same rate through this process. Therefore, the initial thickness profile should be carefully designed to achieve the desired final thickness profile. This step can be used not only through processes such as... Figure 17 The glass articles obtained by the process described above are also applicable to all variations of methods for producing partially thinned glass sheets, such as the down-drawing method or the overflow melting method. Therefore, typically, according to one embodiment, a glass sheet 2 having strip segments 3 with reduced average thickness is provided and heated, causing the glass 10 of the glass sheet 2 to soften, and wherein the glass sheet 2 is drawn in a direction along the longitudinal direction of the strip segments 3 to reduce the thickness of the glass sheet 2. Figure 18 The process of re-drawing a locally thinned glass sheet is illustrated. Preferably, as shown in FIG. (a), a local heating device 25 is used to heat the strip region 16. This region extends laterally (particularly perpendicular to the longitudinal direction of the strip segment 3). Simultaneously, as indicated by the arrow, a pulling force is applied in the direction along the strip segment 3. This results in the re-drawing of the heated region, causing it to expand along the drawing direction while reducing its thickness. Figure 18 Figure (b) shows a redrawn glass article 2 with a smaller thickness and a longer length compared to the original glass sheet 2.

[0068] In another alternative or additional embodiment, the glass sheet 2 having strip segments 3 with reduced average thickness can be treated with an etching medium. This will uniformly reduce the thickness of the glass sheet. Thus, by etching the glass sheet 2, the average thickness of the strip segments 3 is further reduced. Similar effects can be achieved using other glass removal methods (e.g., grinding). Therefore, generally, without being limited to a particular type of process, a glass sheet 2 having strip segments 3 with reduced average thickness is provided, wherein by uniformly removing glass from at least one side 101, 102 of the glass sheet 2, the thickness D of the glass sheet 2 (i.e., the thickness of segments 5, 7 adjacent to the strip segment 3) and the minimum thickness D at the strip segment 3 are increased. min The ratio. For illustrative purposes, in Figure 18 Figure (a) shows the thickness D and the minimum thickness D. min .

[0069] Etching (particularly etching for reducing the thickness of the glass article 1) typically also results in specific surface qualities. In particular, a very uniform surface quality can be achieved compared to glass substrates having folded regions formed by laser structuring and etching. Thus, according to another aspect of this disclosure, a foldable plate-shaped glass article 1 is provided, particularly a glass article 1 produced using the method or apparatus 30 according to this disclosure, wherein the glass article 1 has two opposing sides 101, 102, a circumferential edge 104, and a strip segment 3 with a reduced average thickness compared to adjacent segments 5, 7, such that the stiffness of the strip segment 3 is reduced due to the reduction in average thickness, thereby enabling the glass article 1 to be folded around the strip segment 3 without breaking, the strip segment 3 extending laterally along the sides 101, 102 and terminating at its two ends 33, 34 by the circumferential edge 104, the combined surface roughness of the two sides 101, 102, including the surface of the strip segment 3, is greater than 90%.

[0070] So far, the presented embodiments have all been based on distributing glass away from the area to be thinned. However, additional glass can also be supplied to a segment adjacent to the thinning segment 3. Thus, instead of diverting or obstructing the melt flow to create the thinning segment, the adjacent segment can be thickened by distributing (in particular, adding melt flow). Obviously, this can also produce glass articles with strip segments 3 having a reduced average thickness. Accordingly, in another embodiment, a method is provided comprising: merging and melting glass melt flows or softened glass strips of different widths to form a glass ribbon, arranging the glass strips or glass melt flows in the glass ribbon such that at least one strip segment 3 with a reduced average thickness is produced.

[0071] Figure 19 and Figure 20 Examples of glass sheets 2 or glass articles 1 produced therefrom (e.g., simply by cutting the glass sheet 2 to a specified size) according to the foregoing method embodiments are shown. In both cases, the glass sheet 27 is typically fused together with narrower glass strips 29, thereby maintaining gaps 22 bridged by the glass sheet 27 between the glass strips 29. Due to this gap, strip sections 3 with reduced thickness are formed compared to sections 5, 7, 9 having the combined thickness of the molten glass elements 27, 29. Figure 19 In the variant, a single strip segment 3 is formed between glass strips 5 and 7, while Figure 20 An embodiment with three spaced-apart glass strips 29 is shown to form two strip segments 3, thereby creating two folded regions between them. The glass elements 27 and glass strips 29 can be melted, for example, after reheating to soften the glass. However, this glass distribution method can also be achieved by combining glass melt strips or glass melt streams separately.

[0072] In another embodiment, the glass sheet 27 and the glass strip 29 are combined by gluing or, more generally, by a method other than melting in a softened state, i.e., by fixing them together at a temperature below the softening temperature. Therefore, generally not limited to a specific method of fixing glass components together, a method for producing a foldable glass article 1 is envisioned, wherein the glass article 1 has a strip segment 3 with a reduced average thickness compared to adjacent segments 5, 7, such that the stiffness of the strip segment 3 is reduced due to the reduced average thickness, allowing the glass sheet 1 to fold around the strip segment 3 without breaking, wherein the glass sheet 27 is connected to a narrower glass strip 29 such that the glass strip 29 is laterally spaced and forms a gap 22 therebetween, thereby forming the strip segment 3 with a reduced average thickness along the gap 3. As described above, fixing the glass strip 29 to the glass sheet 27 can be achieved by gluing, and / or at a temperature (e.g., room temperature) where the glass is not softened but in a rigid state.

[0073] In an improved embodiment, the glass body formed by combining glass strips and fixing them to glass sheet 27 can then be stretched to reduce its thickness.

[0074] In one embodiment, the glass ribbon 20 is formed by a waterfall-style pull-down process. This apparatus, as well as other apparatus discussed herein, may have a device for combining melt flows of varying widths to produce a glass ribbon 20 having at least one strip segment 3 with a reduced average thickness. Figure 21 The diagram shows an apparatus 30 for producing glass articles 1 using the waterfall-style drop method. A top view of this apparatus is shown below. Figure 22 As shown. Without being limited to the specific example shown, the apparatus 30 may include a container 15 containing molten glass 21, the container 15 having a slit 52 through which the molten glass flows out as a melt stream 23 and is guided on a lip 54, wherein preferably the melt stream 23 extends over the entire width of the glass strip 20 to be formed, and wherein a second container 16 having a second molten glass 21 is provided, wherein the molten glass is released from the second container 16 through laterally spaced slits 52 and guided on a lip 54, wherein the lip 54 of the second container 16 is arranged such that the molten glass stream 24 released from the lip 54 falls onto the molten glass stream 23 on the lip 54 of the first container 15 and merges or melts together with the melt stream 23. The merged melt stream is released from the lip 54 of the first container 15, thereby forming a glass strip 20 drawn by a pair of drawing rollers 13.

[0075] There is a gap 22 between the glass melt flow 24 from the second container 16, which causes a thinned strip section 3 to be formed in the longitudinal direction of the glass strip 20.

[0076] Optionally or additionally, the waterfall drop device may also have the same features as the reference. Figure 1 and Figure 2 The aforementioned pull-down device is similar to a device used for distributing molten glass. This means that, in addition to adding the melt flow 24, or as an alternative, one or more protrusions 14 can be provided at the slit or on the lip to locally reduce the thickness of the melt flow 23.

[0077] The same principle of merging glass melt flows 23 and 24 can also be used in other drawing equipment. Figure 23 and Figure 24 An overflow-melting apparatus for merging glass melt flows 23, 24 is shown. Figure 23 A cross-section of device 30 is shown. Figure 24 A side view of device 30 is shown. Typically, it is not limited to, for example... Figure 23 , 24 The specific settings shown and Figure 25 The variations shown, and similar to the waterfall-style drop device described above, are implemented based on an overflow melting device 30 having at least two stacked troughs, wherein the troughs are configured to release glass melt flows of different widths, which merge to form a glass ribbon having strip-shaped sections of decreasing average thickness formed by gaps between two laterally spaced glass melt flows. In the example shown, the upper trough 185 releases two melt flows 24, which are laterally spaced apart on each side. For example, the upper edge of the trough 185 may have, for example, a... Figure 24 The protrusion 14 shown divides the overflowing molten glass 21 into laterally spaced molten glass flows 24. The lower trough 18 generates a downward-flowing molten glass flow 23 at its sidewalls 180, 182, which has a greater width that defines the width of the glass strip 20 to be produced. All molten glass flows 23, 24 merge at the lower end of the lower trough 18 to form the glass strip 20. Due to the gaps between the molten glass flows 24, the thickness of the glass strip 20 is locally reduced, thereby forming strip segments 3 with reduced average thickness. Several variations of the illustrated example are possible. Instead of a single upper trough 185, a series of troughs can be provided to generate laterally spaced molten glass flows 24. Furthermore, the positions of the troughs 18, 185 can be interchanged, such that the lower trough releases laterally spaced molten glass flows 24 with reduced width and gaps between them. Additionally, at least one of the troughs can be asymmetrical, such that a molten glass flow is released only on one side. The opposite configuration is also possible, in which the lower slot can have a protrusion (e.g., as shown in the image). Figure 15 and 16 (Example in the text) The upper groove applies a uniform wide band on top of the separated or locally thinned lower band.

[0078] Figure 25A variant with two single-sided grooves 18, 185 is shown. Such an asymmetrical arrangement can be used to produce glass articles with asymmetrical thickness profiles, for example, as... Figure 3 or Figure 4 As shown. In this embodiment, the glass melt flows 23 and 24 are released only to one side of the tanks 18 and 185, and flow only along one sidewall 182 of the lower tank. Similarly, several variations are possible. For example, in... Figure 24 In one embodiment, a protrusion 14 may be provided at the upper edge of one of the tanks 18 and 185 to produce laterally spaced and narrowed glass melt flows 24, thereby achieving at least one strip segment 3 with reduced average thickness. Optionally, a rotating cylinder 56 may be provided below the lower end of the lower tank to guide the combined glass melt flows 23 and 24, such as... Figure 26 As shown in the variant.

[0079] In another embodiment, multiple glass streams are combined into a single strip, or glass is dispensed by merging glass melt streams, including producing glass sheets in the form of glass strips via an up-draw process. Glass laminates can be produced where a first strip is drawn through a Fourcault orifice while a second glass stream is injected into a reservoir at the top of the same Fourcault orifice and subsequently drawn upwards together with the first strip. A glass strip 20 and glass articles 1 cut from it, having strip segments 3, can be produced by using two or fewer second glass streams on the thicker portions of the glass strip. Typically, the up-draw process is not well-suited for producing very thin glass. However, such processes can be combined with redrawing processes, for example, in conjunction with... Figure 18 The description is as follows. Furthermore, the pull-up process and equipment can be used with a Focke orifice provided with a protrusion 14, i.e., the orifice is shaped as... Figure 1 and Figure 5 Therefore, in one embodiment, an apparatus 30 is provided, including a pull-up device having a Focke orifice having at least one protrusion 14, for producing a glass strip 20 having strip segments 3 with reduced average thickness.

[0080] A variant of the pull-down method and apparatus utilizes a guide protruding downward from the orifice. This variant can also be used in the methods and apparatus according to this disclosure. Figure 27A schematic example of device 30 is shown, which includes a pull-down device with a guide 58. Without being limited to the specific example shown, one embodiment of this variant is based on the following steps: providing a first glass melt flow 23 through an orifice 12, the first glass melt flow 23 flowing downward along a guide 58 disposed within and projecting downward from the orifice 12; and providing a second glass melt flow 24, the second glass melt flow 24 being narrower than the first glass melt flow 23, and laterally spaced apart by a certain gap between the second glass melt flows 24; wherein the first glass melt flow 23 and the second glass melt flow 24 merge on the guide 58, wherein the merged glass melt flows 23, 24 are peeled off from the guide 58 at the lower end of the guide 58 and drawn into a glass strip 20, wherein the gap 22 between the second glass melt flows forms a strip segment 3 on the glass strip 20 with a reduced average thickness relative to adjacent segments. Preferably, as shown, the glass melt flows 23 and 24 merge below the orifice 12 on the guide body 58. In the cross-sectional view, only one of the second glass melt flows 24 is visible. However, the side view shows a similar configuration of the glass melt flow with gap 22, for example, as... Figure 22 As shown. Figure 27 The arrangement of the equipment is asymmetrical because the second molten glass stream is supplied only to one side of the guide 58. However, the molten glass stream 24 can also be supplied from both sides. Furthermore, the second molten glass stream 24 is supplied by a separate container 16. However, the molten glass streams 23 and 24 can also be supplied by a single container 15 via suitable pipes.

[0081] List of reference numerals 1. Glassware 2.27 glass slides 3 strip sections Sections 5, 7, and 9 adjacent to strip segment 3 10 Glass 12-hole opening 13. Drawing rollers 14. Protrusion Containers 15 and 17 16 Heated strip areas 18, 185 Overflow-Melting Tank 19 channels 20 glass ribbons 21. Glass melt 22 gap 23, 24 Glass molten flow 25 Local heating devices 29 Glass strips 30 Equipment for producing glass products 1 The ends of strip sections 33 and 34 The convex curved surface portion of section 36 and 38 37. The concave curved surface portion of section 3 40 Vertical cutting lines 42 Horizontal cutting line 45 float glass bath 47 Nozzles 49 Gas jet 50, 70 transition sections 52 Slits 54. Lips 56 tubes 58 Guide Body Side view of 101, 102 1 Circumferential edge of 104 1 105, 106 dents 120, 121, 12 (side view) 250 laser 251 laser beams 252 Coil heater.

Claims

1. A method for producing a foldable glass article (1) having a strip segment (3) with a reduced average thickness compared to adjacent segments (5, 7), such that the stiffness of the strip segment (3) is reduced due to the reduction in average thickness, thereby enabling the glass sheet (1) to be folded around the strip segment (3) without breaking, the method comprising: In the thermoforming step, the glass sheet (2) is formed into glass (10) by distributing softened glass so that the glass thickness decreases along the strip section (3).

2. The method according to claim 1, wherein, Dispensing glass without removing glass (10) from the glass sheet (2).

3. The method according to claim 1, wherein the method comprises forming a glass sheet in the form of a glass ribbon (20) from the glass melt (21), wherein, The glass (10) is dispensed before the glass (10) in the glass strip (20) is cooled and solidified.

4. The method according to claim 1, wherein, The glass (10) is dispensed by a protrusion (14) that locally slows down the flow of the glass melt (21) and extends into the flow of the glass melt (21).

5. The method according to claim 4, wherein, A glass sheet (2) in the form of a glass strip (20) is formed by pulling the glass (10) downward from a slit-like opening (12), the opening (12) having a protrusion (14) that narrows the width.

6. The method according to claim 4, wherein, A glass sheet (2) in the form of a glass ribbon (20) is formed by overflow-melting from a groove (18) having a protrusion (14) on at least one side.

7. The method according to claim 1, wherein, A glass ribbon (20) is formed having a plurality of strip segments (3) with decreasing average thickness, the plurality of strip segments being laterally spaced apart in a direction perpendicular to the longitudinal direction of the glass ribbon (20), wherein the glass ribbon (20) is cut along at least one cutting line extending between two strip segments (3) and further cut in a direction perpendicular to the longitudinal direction of the glass ribbon (20) to obtain a plurality of glass articles (1), each glass article having at least one strip segment (3) with decreasing average thickness.

8. The method according to claim 1, wherein, A glass sheet (2) is formed by drawing into the form of a glass strip (20), wherein the glass (10) is locally heated along a strip region (16) while still in a softened state to a higher temperature than that of an adjacent region of the glass strip (20), so that the viscosity along the region (16) is lower than that in the adjacent region, wherein the strip region (16) extends parallel to the drawing direction, and wherein a drawing force having a component perpendicular to the drawing direction is applied, such that the glass thickness along the strip region (16) is reduced by drawing.

9. The method according to claim 1, wherein, A glass sheet (2) is provided, preferably having a uniform thickness, and the glass sheet is locally heated along a strip region (16) to soften the glass (10) in the strip region (16), wherein the glass sheet (2) is drawn in a direction transverse to the strip region (16) to expand the strip region (16) and reduce the glass thickness in the strip region (16).

10. The method according to claim 1, wherein, A glass sheet (2) having a strip section (3) with a reduced average thickness is provided and heated, such that the glass (10) of the glass sheet (2) softens, and wherein the glass sheet (2) is drawn in a direction along the longitudinal direction of the strip section (3) to reduce the thickness of the glass sheet (2).

11. The method according to claim 1, wherein, A glass sheet (2) is formed in the form of a glass strip (20) by drawing, wherein a plurality of strip segments (3) with a reduced average thickness compared to adjacent segments (5, 7) are formed in the drawing process, wherein the longitudinal direction of the strip segments (3) extends laterally, preferably perpendicular to the drawing direction.

12. The method according to the preceding claim, wherein, Forming multiple strip segments with decreasing average thickness (3) includes at least one of the following steps: - Change the drawing speed; - Change the temperature so that the temperature of the strip area extending laterally in the drawing direction is increased compared to the adjacent areas.

13. The method according to claim 1, wherein, Distributing softened glass to reduce the glass thickness along the strip segment (3) includes at least one of the following features: - Combine and melt glass melt flows (23, 24) or softened glass strips (27, 29) of different widths to form a glass ribbon (20), in which glass strips (27, 29) or glass melt flows (23, 24) are arranged to produce at least one strip segment (3) with reduced average thickness. - The gas jet (49) is blown onto the softened glass (10) or the glass melt (21).

14. The method according to claim 1, wherein, The average thickness of the strip segment (3) is further reduced by etching the glass sheet (2).

15. The method according to claim 1, wherein, By uniformly removing glass from at least one side (101, 102) of the glass sheet (2), the ratio of the thickness D of the glass sheet (2) to the minimum thickness Dmin at the strip segment (3) is increased.

16. The method according to claim 1, wherein, A glass strip (20) is drawn, the glass strip (20) having at least two laterally spaced strip segments (3) with decreasing average thickness, wherein a glass article (1) is cut from the glass strip (20) such that the glass article (1) has at least two strip segments (3), wherein at least three segments (5, 7, 9) are foldably connected together by the strip segments (3).

17. An apparatus (30) for performing the method according to any one of the preceding claims to produce a glass article (1), the apparatus (30) having means for dispensing glass in a softened or molten state to form a glass sheet having strip segments (3) with a reduced average thickness compared to adjacent segments (5, 7), thereby reducing the stiffness of the strip segments (3) and enabling the glass sheet (1) to be folded around the strip segments (3) without breaking.

18. The device (30) according to the preceding claim, wherein, The device for dispensing glass in a softened or molten state includes at least one of the following: - A protrusion (14) located in the orifice (12) for pulling the glass strip (20). - Local heating device (25).

19. A foldable sheet-like glass article (1), particularly capable of being produced using the method or apparatus (30) according to any one of the preceding claims, the glass article (1) having two opposing sides (101, 102) and a circumferential edge (104) and a strip segment (3) with a reduced average thickness compared to adjacent segments (5, 7), such that the stiffness of the strip segment (3) is reduced due to the reduction in average thickness, thereby allowing the glass sheet (1) to be folded around the strip segment (3) without breaking, the strip segment (3) extending laterally along the sides (101, 102) and terminating at its two ends (33, 34) by the circumferential edge (104), wherein, At least one of the side surfaces (101, 102) has a surface profile and / or a thickness profile within the strip segment (3) that is continuously curved, wherein the surface at the center of the strip segment (3) is concave and curved, and wherein the curvature of the concave surface changes to a convex surface curvature in the direction from the center toward the adjacent segments (5, 7), such that a centrally located concave curved surface portion (37) is arranged between two convex curved surface portions (36, 38), the curved surface portions forming recesses (104, 105).

20. The plate-shaped glass article (1) according to the preceding claim, comprising at least one of the following features: - The combined width of the convex curved surface portions (36, 38) of the strip section (3) is at least as large as the width of the concave curved surface portion (37); - The width of the recess (105) is at least three times, preferably at least five times, greater than the depth of the recess (105); - The glass article (1) includes a thickened transition section (50, 70) located between the strip section (3) and the adjacent sections (5, 7) of constant thickness.

21. The plate-shaped glass article (1) according to claim 19, wherein, The surface profiles of the two sides (101, 102) and / or the thickness profile within the strip segment (3) are continuously curved such that the sides (101, 102) approach each other toward the center of the strip segment (3).

22. The plate-shaped glass article (1) according to the preceding claim, wherein, The recess in the strip section (3) on one of the sides (101) has a greater depth than the recess on the opposite side (102).

23. The plate-shaped glass article according to claim 19, having at least one of the following characteristics: - The average surface roughness of the two sides (101, 102), including the surface of the strip section (3), is less than 0.5 nm; - The two sides (101, 102), including the surface of the strip section (3), have fire-polished surfaces; - The surface roughness uniformity of the combined surface of the two sides (101, 102), including the surface of the strip section (3), is greater than 90%.

24. The plate-shaped glass article (1) according to claim 19, wherein, The glass product (1) has undergone chemical strengthening treatment.

25. The plate-shaped glass article (1) according to the preceding claim, wherein, Compared to the adjacent segments (5, 7), at least one of the parameters compressive stress (CS) and ion exchange layer depth (DoL) in the strip segment (3) is lower.

26. An electronic device comprising the glass article (1) according to claim 19.

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