Cassette and chemical strengthening system comprising the same

Abstract

Provided is a cassette and a chemical strengthening system including the same. One embodiment of a chemical strengthening system includes a strengthening section that performs chemical strengthening of a glass sheet, a heating section that performs post-heating of the glass sheet, and a cassette that mounts the glass sheet and is movable between the strengthening section and the heating section. The cassette includes a lower end support rod that supports a lower end of the glass sheet, the lower end support rod being rotatable about a rotation axis that does not move within the cassette.

Description

Technical Field

[0001] The present invention relates to a box (i.e., a glass plate mounting box) and a chemical strengthening system including the same. Background Technology

[0002] The strength of glass can be increased through a chemical strengthening process. For example, if a glass plate is immersed in a potassium nitrate (KNO3) solution in a strengthening bath, the sodium ions (Na+) on the surface of the glass plate will increase. + ) by potassium ions (K + The ion exchange reaction replaces the surface layer of the glass, thus creating a compressive stress layer on the glass surface. This strengthens the surface density of the glass, thereby inhibiting the growth of microcracks and increasing the flexural strength of the glass.

[0003] To strengthen multiple glass plates at once, a cassette capable of holding multiple plates can be used. That is, multiple glass plates can be placed in the cassette, and both the glass plates and the cassette can be immersed in a potassium nitrate solution within a strengthening tank. After the chemical strengthening process, a post-heating treatment can be performed while the glass plates are still in the cassette. At this time, ion-exchange salts may remain at the contact area between the glass plate and the cassette, and these residual salts may solidify, potentially leading to poor appearance quality of the glass plates. Furthermore, due to the difference in thermal expansion coefficients between the glass and the salt, interfacial stress will form when the residual salt solidifies, which may cause the glass plate to deform. This poor appearance quality is more likely to occur when the glass plate is thin. Summary of the Invention

[0004] Various embodiments are intended to provide a cassette (i.e., a glass plate mounting cassette) that can prevent or reduce poor appearance quality of glass plates, and a chemical strengthening system including the cassette.

[0005] One embodiment of the chemical strengthening system includes: a strengthening section for performing chemical strengthening of a glass plate; a heating section for performing post-heat treatment of the glass plate; and a housing for mounting the glass plate and movable between the strengthening section and the heating section. The housing includes a lower end support rod supporting the lower end of the glass plate, and the lower end support rod is rotatable about a rotation axis that is stationary within the housing.

[0006] The chemical strengthening system may further include: a motor, which rotates and drives the lower support rod.

[0007] The chemical strengthening system may further include: a discharge section overlapping the heating section; and a mesh component located between the heating section and the discharge section. During the post-heat treatment, the cassette may be positioned on the mesh component.

[0008] The lower support rod can contact the mesh component, and the box can move on the mesh component when the lower support rod rotates.

[0009] The rotation axis of the lower support rod can be perpendicular to the direction of movement of the box.

[0010] The chemical enhancement system may further include a motor that drives the cartridge to move linearly along the grid component. The lower support rod is rotatable during the movement of the cartridge.

[0011] During the post-heat treatment, the lower support rod is rotatable, and the salt remaining on the glass plate can flow to the discharge section through the lower support rod and the mesh component.

[0012] The box may include three or more of the lower end support rods.

[0013] The lower support rod may include a support groove formed concentrically with respect to the axis of rotation, and the glass plate may be configured such that the lower end is located in the support groove.

[0014] The box may also include a frame, and the lower support rod may include a shaft inserted into a slot in the frame and a support slot at the lower end of the glass plate.

[0015] The box may also include upper support rods that are combined with the frame to hold the upper part of the glass plate at both ends.

[0016] The box may also include a middle support rod that is combined with the frame to hold the middle portion of the glass plate at both ends.

[0017] The chemical strengthening can be performed at a temperature of 360°C to 370°C, and the post-heat treatment can be performed at a temperature of 330°C to 370°C.

[0018] One embodiment of the case includes a frame and a lower support rod coupled to the frame and supporting the lower end of a glass plate. The lower support rod is rotatable about a rotation axis that does not move within the case.

[0019] The frame may include a pair of opposing support plates, and the lower support rod may include a shaft inserted into a groove in the support plate and a support groove formed concentrically with respect to the axis of rotation.

[0020] The box may include three or more of the lower end support rods.

[0021] The spacing between the lower support rods can be less than the radius of the lower support rods.

[0022] The box may also include a pair of upper support rods that are attached to the frame and hold the upper part of the glass plate at both ends.

[0023] The box may also include a pair of intermediate support rods that are attached to the frame and hold the middle portion of the glass plate at both ends.

[0024] The frame may include a slot or slit that allows for changing the engagement position of the upper support rod.

[0025] (Invention Effects)

[0026] According to various embodiments, residual salts can be removed without chemical treatment during post-heat treatment following the chemical strengthening process of the glass plate. This prevents or improves poor appearance quality of the glass plate caused by the solidification of residual salts. Furthermore, according to the embodiments, beneficial effects can be observed throughout the specification. Attached Figure Description

[0027] Figure 1 and Figure 2 This is a schematic diagram illustrating a chemical enhancement system according to an embodiment.

[0028] Figure 3 It is used in Figure 1 and Figure 2 The diagram shown illustrates the concept of residual salt removal in a chemical fortification system.

[0029] Figure 4 This is a perspective view showing a glass plate mounting box according to an embodiment.

[0030] Figure 5 and Figure 6 This is a schematic diagram illustrating a chemical enhancement system according to an embodiment.

[0031] Figure 7 It is used in Figure 5 and Figure 6 The diagram shown illustrates the concept of residual salt removal in a chemical fortification system.

[0032] Figure 8 This is a diagram illustrating a tempered glass manufacturing process according to an embodiment.

[0033] Figure 9 The image shows a box with a non-rotating lower support rod and a glass plate used for chemical strengthening and post-heat treatment.

[0034] Figure 10 The image shows a box with a rotating lower support rod and its use for chemical strengthening and post-heat treatment.

[0035] Figure 11The diagram schematically illustrates the lower end of a glass plate undergoing chemical strengthening and post-heat treatment using a non-rotating cassette with a lower end support rod, and the lower end of a glass plate undergoing chemical strengthening and post-heat treatment using a rotating cassette with a lower end support rod.

[0036] Symbol explanation:

[0037] 10: Reinforcing section; 20: Heating section; 30: Discharge section; 40: Mesh component; 50: Box; 51: Frame; 52: Lower support rod; 521: Shaft; 522: Support groove; 53: Upper support rod; 531: Shaft; 532: Retaining groove; 54: Middle support rod; 541: Shaft; 542: Retaining groove; 60: Motor; G: Glass plate. Detailed Implementation

[0038] The various embodiments are described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement them.

[0039] For ease of explanation, the size and thickness of each component shown in the figure are arbitrarily depicted.

[0040] When a layer, membrane, region, plate, or other component is located on or above other components, this includes not only cases where it is directly located on other components, but also cases where other components are included in between. Conversely, when a component is directly located on other components, it means that no other components are present in between.

[0041] In the specification, if a certain part includes a certain component, it means that other components may also be included unless there is a contrary statement.

[0042] In the specification, connection does not only refer to the situation where two or more constituent elements are directly connected, but also to the situation where two or more constituent elements are indirectly connected through other constituent elements. In addition to the situation where they are physically connected or electrically connected, it also includes the situation where parts that are referred to by different names according to their location or function but are actually a whole are connected to each other.

[0043] In the accompanying drawings, the symbols “x”, “y”, and “z” are used to indicate directions. Here, “x” represents a first direction, “y” represents a second direction perpendicular to the first direction, and “z” represents a third direction perpendicular to both the first and second directions. The first direction x, the second direction y, and the third direction z can correspond to the horizontal, vertical, and thickness directions of the display device, respectively.

[0044] Unless otherwise specified in the specification, “overlap” refers to overlap on a planar diagram and overlap in a third direction z.

[0045] Figure 1 and Figure 2This is a schematic diagram illustrating a chemical strengthening system according to one embodiment. Figure 3 It is used in Figure 1 and Figure 2 The diagram shown illustrates the concept of residual salt removal in a chemical fortification system. Figure 1 and Figure 2 These can be respectively represented by the front view and the plan view of the chemically enhanced system.

[0046] Reference Figure 1 and Figure 2 The chemical strengthening system may include a strengthening section 10, a heating section 20, and a discharge section 30. The chemical strengthening system may include a mesh member 40 located between the heating section 20 and the discharge section 30. The chemical strengthening system may include a glass plate mounting box 50 (hereinafter simply referred to as the box) configured to move between the strengthening section 10 and the heating section 20, and may include a motor 60 for rotating a lower end support rod 52 of the box 50.

[0047] A glass plate G may be mounted in the housing 50. The glass plate G may have a thickness of about 50 μm or less, for example, a thickness of about 20 μm to about 50 μm. The glass plate G may have a Young's modulus of about 100 GPa or less at room temperature, for example, a Young's modulus of about 65 GPa to about 75 GPa. Figure 1 The glass plate G mounted on the box 50 is shown, while Figure 2 Not shown in the image.

[0048] The strengthening section 10 may include a strengthening tank 11 and a solution containing a molten salt for ion exchange located therein. The molten salt may contain potassium nitrate. In the strengthening section 10, the glass plate G can be chemically strengthened by ion exchange. Chemical strengthening using ion exchange is a method of replacing the alkali ions of the glass plate G with other alkali ions to form a compressive stress layer on the surface of the glass plate G. For example, if the glass plate G is immersed in the molten salt of the strengthening section 10, the sodium ions (Na+) of the glass plate G will be replaced by other alkali ions. + ) can be replaced by sodium ions with ionic radii smaller than those of sodium ions (Na) + Large potassium ions (K) + ).

[0049] The heating element 20 may be located on the strengthening element 10. The heating element 20 may include a cavity 21 and a heater 22 and a temperature controller 23 located inside and outside the cavity 21, respectively. The heating element 20 may include a door 24 for inserting or removing the cartridge 50 into the cavity 21. The door 24 may be located on the front or back of the chemical strengthening system. The heating element 20 may be used in post-heat treatment after chemical strengthening of the glass plate G. The heating element 20 may also be used in preheat treatment before chemical strengthening of the glass plate G.

[0050] After chemical strengthening, salt may remain on the glass plate G mounted in the cassette 50, which is transferred to the heating section 20. This residual salt can flow to the discharge section 30. To facilitate the discharge of residual salt, a mesh member 40 can be disposed between the heating section 20 and the discharge section 30. The cassette 50 can be placed on the mesh member 40, and the residual salt can flow to the discharge section 30 through the holes in the mesh member 40. The mesh member 40 can overlap with the discharge section 30, and the discharge section 30 can be configured not to overlap with the strengthening section 10. In order to place the cassette 50 on the mesh member 40 after chemical strengthening, the cassette 50 can be moved in a third direction z and then in a first direction x.

[0051] The box 50 can be inserted into the heating section 20 through the door 24 and discharged out of the heating section 20. The box 50 can be transferred between the reinforcing section 10 and the heating section 20 by a transfer member (not shown). The box 50 can hold multiple glass plates G. Inside the box 50, the glass plates G can be configured such that their circumferential surfaces are parallel to a third direction z. The box 50 may include a lower end support rod 52 supporting the glass plates G at its lower part. The box 50 can be formed of materials such as metal, metal alloys (e.g., stainless steel), or plastic (e.g., PVC).

[0052] Shaft 521 of lower support rod 52 (refer to) Figure 4 It can be rotatably connected to the support plate 511 (see reference). Figure 4 For the rotation of the lower support rod 52, the lower support rod 52 can be connected to a motor 60. In other words, the motor 60 can drive the lower support rod 52 to rotate about a rotation axis. The motor 60 can be located outside the housing 50 and can be mechanically connected to the lower support rod 52 (especially the shaft 521 of the lower support rod 52) via a power transmission component. Multiple lower support rods 52 can be rotatably driven by one motor 60, and the motor 60 can also be provided individually or connected to each lower support rod 52. For example, the motor 60 can be connected to the shaft 521 of each lower support rod 52.

[0053] Figure 3 The relationship between the lower end support rod 52 of the box 50 and the glass plate G and grid component 40 is shown. (Refer to...) Figure 3The lower support rod 52 supports the glass plate G, and the lower end of the glass plate G abuts against the lower support rod 52. During post-heat treatment in the heating section 20 after chemical strengthening, residual salt can flow to the lower end of the glass plate G by gravity. This residual salt can solidify at the high temperature of the post-heat treatment process; however, if the residual salt solidifies on the surface of the glass plate G or at the contact point between the glass plate G and the housing 50, it may cause poor appearance quality such as wrinkles or dents on the glass plate G. In particular, if the glass plate G is an ultra-thin glass plate (e.g., less than 50 μm, less than 30 μm, or less than 20 μm), the possibility of poor appearance quality due to reduced rigidity of the glass plate G may increase.

[0054] As in the embodiment, as the lower support rod 52 at the lower end of the supporting glass plate G rotates, residual salt will not condense at the lower end of the glass plate G or accumulate at the contact portion between the glass plate G and the lower support rod 52, and can flow downward along the lower support rod 52. That is, as the lower support rod 52 rotates, the surface area of ​​the residual salt in contact with the lower support rod 52 increases, and the residual salt can be removed from the glass plate G through the draining effect caused by the contact with the lower support rod 52. The residual salt flowing downward along the lower support rod 52 can fall into the discharge portion 30 through the mesh member 40.

[0055] Although the glass plate G can be stably supported by only two lower support rods 52, the housing 50 may include three or more lower support rods 52 to increase the contact area between the lower end of the glass plate G and the lower support rods 52 (i.e., to increase the number of contact points between the glass plate G and the lower support rods 52). Increasing the number of lower support rods 52 increases the contact points through which residual salt at the lower end of the glass plate G can flow downwards, thus further improving the residual salt removal effect. To obtain uniform contact points across the entire lower end of the glass plate G, the lower support rods 52 can be arranged at equal intervals. To accommodate more lower support rods 52, the interval between the lower support rods 52 may, for example, be smaller than the radius of the lower support rods 52.

[0056] The lower support rod 52 can contact the mesh member 40. As the lower support rod 52 rotates, the box 50 can move in the second direction y. Even if the lower support rod 52 rotates, if the box 50 is fixed, residual salt may accumulate at the contact portion between the lower support rod 52 and the mesh member 40. If the box 50 moves, the contact portion between the lower support rod 52 and the mesh member 40 moves, thus facilitating the discharge of residual salt. The width of the mesh member 40 is limited in the second direction y, which is the direction of movement of the box 50. Therefore, for example, the lower support rod 52 can rotate clockwise until the box 50 moves from a first location to a second location on the mesh member 40, and if the box 50 reaches the second location, the lower support rod 52 can rotate counterclockwise until the box 50 moves to the first location on the mesh member 40. That is, the lower support rod 52 can operate to rotate in both clockwise and counterclockwise directions, allowing the box 50 to move back and forth on the mesh member 40 along the second direction y.

[0057] The direction of movement of the box 50 on the mesh component 40 as the lower support rod 52 rotates can vary depending on the configuration of the box 50. For example, if the box 50 is configured such that the axis 521 of the lower support rod 52 is parallel to the second direction y, then the box 50 can move along the first direction x when the lower support rod 52 rotates.

[0058] On the other hand, the lower support rod 52 may not contact the mesh component 40, or even if it does, it can fix the box 50 so that it does not move in the second direction y. Alternatively, a portion of the lower support rod 52 may rotate clockwise and a portion may rotate counterclockwise.

[0059] Figure 4 This is a perspective view showing a glass plate mounting box according to an embodiment.

[0060] Reference Figure 4 The structure of the box 50 is described in more detail below. The box 50 may include a frame 51, a lower support rod 52, an upper support rod 53, and a middle support rod 54. The lower support rod 52, the upper support rod 53, and the middle support rod 54 may be combined with the frame 51.

[0061] The frame 51 may include a pair of opposing support plates 511 and a connecting rod 512 connecting the pair of support plates 511. The frame 51 may be generally hexahedral in shape. The support plates 511 may be generally quadrilateral. An opening 513 may be formed in the support plate 511 to allow smooth flow of fluid for chemical strengthening into and out of the frame 51. A slit 514 may be formed in the support plate 511 to allow horizontal movement and fixation of the upper support rod 53 and / or the middle support rod 54. A groove 515 may be formed in the support plate 511 to allow vertical movement and fixation of the upper support rod 53 and / or the middle support rod 54.

[0062] Two or more lower support rods 52 may be provided, but as previously stated, three or more are advantageous for improving residual salt removal. The lower support rod 52 may include a shaft 521 inserted into a groove 516 of the housing 51 and a support groove 522. The lower end of the glass plate G may be located in the support groove 522. The shaft 521 may be configured to rotate. As the shaft 521 rotates, the lower support rod 52 may rotate about a rotation axis, and the support groove 522 may also rotate. Even when the lower support rod 52 rotates, its position within the housing 51 remains unchanged because the shaft 521 is inserted into the groove 516. When the lower support rod 52 rotates, the shaft 521 may be located within the same groove 516, and the position of the rotation axis of the lower support rod 52 does not move or change within the housing 50.

[0063] Shaft 521 can be connected to the aforementioned motor 60 and rotated by the drive of motor 60. Shaft 521 can be directly or indirectly connected to the rotation shaft of motor 60 located outside the housing 50. A small motor can be installed inside the lower support rod 52, thereby also causing the lower support rod 52 to rotate about a rotation axis parallel to the extension direction of the lower support rod 52. Support groove 522 can be formed concentrically with respect to the rotation axis of the lower support rod 52. The two sides or one side of the support groove 522 can be approximately disk-shaped. The lower end of the glass plate G can be located in the support groove 522.

[0064] Although not shown, the frame 51 or the lower support rod 52 may include a fixing component that can prevent rotation of the lower support rod 52. For example, before chemical strengthening, when the glass plate G is mounted on the cassette 50 or when the cassette 50 is moved while the glass plate G is mounted, if the lower support rod 52 rotates, the glass plate G may break. Therefore, the rotation of the lower support rod 52 can be temporarily restricted by the fixing component.

[0065] A pair of upper support rods 53 may be provided. Each upper support rod 53 may include a shaft 531 that inserts into a slot 515 or slit 514 of the frame 51, and a holding groove 532. The holding groove 532 may be formed concentrically with respect to the central axis of the upper support rod 53. One or both sides of the holding groove 532 may be generally disk-shaped. The pair of upper support rods 53 may be configured and fixed parallel to the frame 51, and the holding groove 532 may hold the two ends of the generally upper portion of the glass plate G.

[0066] The intermediate support rods 54 may also be provided as a pair. Each intermediate support rod 54 may include a shaft 541 inserted into a slot 515 or slit 514 of the frame 51 and a retaining groove 542. The retaining groove 542 may be formed concentrically with respect to the central axis of the intermediate support rod 54. The two sides or one side of the retaining groove 542 may be generally disk-shaped. A pair of intermediate support rods 54 may be arranged parallel to and fixed to the frame 51, and the retaining groove 542 may retain the two ends of the generally intermediate portion of the glass plate G.

[0067] The intermediate support rod 54 may have substantially the same structure as the upper support rod 53. The number of retaining grooves 532 in the upper support rod 53 and the number of retaining grooves 542 in the intermediate support rod 54 may correspond to the number of glass plates G that the case 50 can hold. The position and spacing of the upper support rod 53 and the intermediate support rod 54 may be adjusted according to the size of the glass plates G held to provide optimal retention. For this purpose, the support plate 511 of the frame 51 may include a plurality of grooves 515 and / or slits 514 capable of fixing the shaft 531 of the upper support rod 53 and the shaft 541 of the intermediate support rod 54.

[0068] Figure 5 and Figure 6 This is a schematic diagram illustrating a chemical strengthening system according to one embodiment. Figure 7 It is used in Figure 5 and Figure 6 The diagram shown illustrates the concept of residual salt removal in a chemical fortification system. Figure 5 and Figure 6 These can be respectively represented by the front view and the plan view of the chemically enhanced system.

[0069] for Figures 5 to 7 The embodiments shown are described primarily to highlight their differences from the embodiments described above.

[0070] Reference Figure 5 and Figure 6 The chemical enhancement system may include a strengthening section 10, a heating section 20, and a discharge section 30. The chemical enhancement system may include a mesh member 40 located between the heating section 20 and the discharge section 30. The chemical enhancement system may include a movable housing 50 configured between the strengthening section 10 and the heating section 20. The housing 50 can be inserted into the heating section 20 through a door 24 located on the side of the heating section 20 and can be discharged to the outside of the heating section 20.

[0071] The chemical enhancement system may include a motor 60 for moving a cartridge 50 along a second direction y. The motor 60 may be located outside the cartridge 50 and may be mechanically connected to the cartridge 50 via a known power transmission component (e.g., to the frame of the cartridge 50). Figure 5 and Figure 6(Connection not shown in the diagram). The motor 60 and the power transmission component can push or pull the box 50 so that the box 50 moves linearly along the second direction y between a first location and a second location on the grid component 40.

[0072] The lower support rod 52 of the housing 50 is configured to be rotatable. Unlike the previous embodiment, the lower support rod 52 is not rotated by the motor 60 itself, but is rotatable when the housing 50 moves.

[0073] Reference Figure 7 The lower support rod 52 can contact the mesh component 40. Therefore, if the box 50 moves along the second direction y via the drive of the motor 60, the lower support rod 52 can rotate around its axis of rotation, like a car wheel. As the lower support rod 52 rotates, residual salt will not condense at the lower end of the glass plate G or accumulate at the contact point between the glass plate G and the lower support rod 52, but will flow downwards along the lower support rod 52. That is, as the lower support rod 52 rotates, the surface area of ​​the residual salt in contact with it increases, and the residual salt can be removed through the discharge effect caused by the contact with the lower support rod 52.

[0074] The lower support rod 52 can be configured such that the rotation axis is perpendicular to the direction of movement of the housing 50, so that the lower support rod 52 can rotate as the housing 50 moves. Figure 7 As shown, when the housing 50 moves along the second direction y, the axis of the lower support rod 52 can be parallel to the first direction x. If the housing 50 moves along the first direction x, the axis of the lower support rod 52 can be parallel to the second direction y.

[0075] Figure 8 This is a diagram illustrating the manufacturing process of a reinforced glass plate according to an embodiment.

[0076] Reference Figure 8 This describes the process of manufacturing a tempered glass sheet. A healing step S10 can be performed on the glass sheet G, which has been prepared through processes such as cutting, chamfering, and grinding, to remove surface contaminants.

[0077] After the curing step S10, the chemical strengthening step S20 (hereinafter referred to as the chemical strengthening step) of the glass plate G can be performed. The glass plate G can be placed into the strengthening section 10 of the chemical strengthening system according to an embodiment while mounted on the box 50. As mentioned above, the chemical strengthening step S20 forms a compressive stress layer on the surface of the glass plate G by ion exchange. The chemical strengthening step S20 can be performed at a temperature of about 350°C to about 400°C, but preferably at a temperature of about 360°C to about 370°C. When the strengthening temperature is above 370°C, it may be difficult to control the strengthening time and the depth of layer (DOL). When the strengthening temperature is below 360°C, it may be difficult to ensure the compressive stress (CS) and the depth of layer on the target surface.

[0078] Following the chemical strengthening step S20, a post-heat treatment step S30 can be performed to heat-treat the glass plate G. The glass plate G can be transferred from the strengthening section 10 to the heating section 20 while mounted on the box 50, and can be placed on the mesh member 40 located between the heating section 20 and the discharge section 30. The post-heat treatment step S30 is preferably performed at a temperature of approximately 330°C to approximately 370°C. When the post-heat treatment temperature is above 370°C, surface compressive stress loss may occur. When the post-heat treatment temperature is below 330°C, problems may arise with ion exchange salt residue and solidification.

[0079] In the post-heat treatment step S30, the surface compressive stress of the glass plate G may increase a second time. Furthermore, the ion exchange salts remaining in the glass plate G and the housing 50 can flow to the discharge section 30 through the mesh member 40. To improve the removal capacity of residual salts, as mentioned above, as the lower end support rod 52 of the housing 50 supporting the lower end of the glass plate G is rotated directly / indirectly by the motor 60, the surface area of ​​the residual salts in contact with the lower end support rod 52 can be increased, and the discharge effect can be improved. This can improve or prevent the generation of interfacial stress caused by the solidification of residual salts and the occurrence of poor appearance quality (e.g., bending, sagging, dents, etc. of the glass plate G). With the removal of salts at the contact portion between the glass plate G and the lower end support rod 52, the glass plate G can be prevented from breaking due to the difference in thermal expansion coefficients between the glass and the salt.

[0080] According to one embodiment, since residual salt can be removed without chemical treatment in the post-heat treatment step S30, environmental pollution can be reduced when removing salt after chemical strengthening. Furthermore, the temperature and time of the post-heat treatment can be reduced, thereby improving the reduction of surface compressive stress and rigidity after the post-heat treatment.

[0081] On the other hand, a preheating step can be performed before the chemical strengthening step S20. The preheating step can be performed in the heating section 20. In the preheating step, for the surface of the preheated glass plate G, the surface compressive stress can increase in the chemical strengthening step S20 due to the difference between the preheating temperature and the strengthening temperature, as well as surface ion exchange.

[0082] After the post-heat treatment step S30, a cooling step (hereinafter referred to as the cooling step) S40 can be performed on the glass plate G. The cooling step S40 can be performed after the glass plate G is removed from the case 50, but it can also be performed while the glass plate G is mounted on the case 50.

[0083] After the cooling step S40, the step S50 of washing and drying the glass plate G can be performed.

[0084] Figure 9 The images show a box with a non-rotating lower support rod and a glass plate used for chemical strengthening and post-heat treatment. Figure 10 The image shows a box with a rotating lower support rod and its use for chemical strengthening and post-heat treatment.

[0085] Reference Figure 9 The image shows a glass plate (right image) that has been chemically strengthened and subsequently heat-treated, mounted in a typical cassette (left image) with the lower support rod of the cassette not rotating. Salt solidification is confirmed at the lower end of the glass plate, and dents are present.

[0086] Reference Figure 10 The image shows an embodiment of a glass plate mounted on a lower support rod of a cassette (left image) and subjected to chemical strengthening and post-heat treatment. The glass plate is shown in the right image. [The image is] confirmed to be related to... Figure 9 The glass plate shown exhibits a significant improvement in salt solidification and dents at the lower end compared to the previous glass plate.

[0087] Figure 11 The diagram schematically illustrates the lower end of a glass plate undergoing chemical strengthening and post-heat treatment using a non-rotating cassette with a lower end support rod, and the lower end of a glass plate undergoing chemical strengthening and post-heat treatment using a rotating cassette with a lower end support rod.

[0088] Reference Figure 11 Glass plates subjected to post-heat treatment using a cassette with a non-rotating lower support rod (left image) may develop defects such as warping or dents at the contact point with the lower support rod due to salt buildup from residual salt, as indicated by the dashed circle. In contrast, glass plates subjected to post-heat treatment while the lower support rod is rotated (right image) effectively remove residual salt, thus preventing or improving defects in the glass plate.

[0089] The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art using the basic concepts of the present invention as defined in the claims also fall within the scope of the present invention.

Claims

1. A chemical fortification system, comprising: The strengthening department performs chemical strengthening of glass plates; The heating section performs the post-heat treatment of the glass plate; A box, housing the glass plate, and movable between the reinforcing section and the heating section; and The motor is connected to the box. The box includes a lower end support rod that supports the lower end of the glass plate. The lower support rod is rotatable about a rotation axis that does not move within the box. The lower end support rod supporting the lower end of the glass plate is directly or indirectly driven to rotate by the motor.

2. The chemical enhancement system according to claim 1, further comprising: The discharge section overlaps with the heating section; as well as A mesh component is located between the heating section and the discharge section. During the post-heat treatment, the box is located on the mesh component.

3. The chemical enhancement system according to claim 2, wherein, The lower support rod contacts the mesh component, and the box moves on the mesh component when the lower support rod rotates.

4. The chemical enhancement system according to claim 3, wherein, The rotation axis of the lower support rod is perpendicular to the direction of movement of the box.

5. The chemical enhancement system according to claim 2, further comprising: An electric motor drives the box to move linearly along the mesh component. As the box moves, the lower support rod rotates.

6. The chemical enhancement system according to claim 2, wherein, During the post-heat treatment, the lower support rod rotates, and the salt remaining on the glass plate flows through the lower support rod and the mesh component to the discharge section.

7. The chemical enhancement system according to claim 1, wherein, The box includes three or more of the lower end support rods.

8. The chemical enhancement system according to claim 1, wherein, The lower end support rod includes a support groove formed concentrically with respect to the axis of rotation, and the glass plate is configured such that the lower end is located in the support groove.

9. The chemical enhancement system according to claim 1, wherein, The box also includes a frame. The lower support rod includes a shaft inserted into a groove in the frame and a support groove at the lower end of the glass plate.

10. The chemical enhancement system according to claim 9, wherein, The box also includes upper support rods that are combined with the frame to hold the upper part of the glass plate at both ends.

11. The chemical enhancement system according to claim 9, wherein, The box also includes a middle support rod that is combined with the frame to hold the middle portion of the glass plate at both ends.

12. The chemical enhancement system according to claim 1, wherein, The chemical strengthening is performed at a temperature of 360°C to 370°C, and the post-heat treatment is performed at a temperature of 330°C to 370°C.

Images