Sealant removing apparatus using laser and selant removing method using laser

Abstract

Provided are a sealant removing apparatus using a laser and a sealant removing method using a laser that can prevent deformation of a back sheet layer by controlling the angle of a laser beam. The sealant removing apparatus using a laser comprises: a stage module that mounts a waste solar panel; and a laser module that radiates a laser beam directed in one direction to a sealant attached to a surface of a glass plate of the waste solar panel, wherein the laser module obliquely radiates the laser beam onto the glass plate to reduce the laser beam transmitted through the glass plate and to a back sheet layer attached to the glass plate.

Description

Laser-based sealant removal device and laser-based sealant removal method

[0001] The present invention relates to a device and method for removing sealant attached to a waste solar panel, and more specifically, to a laser-based sealant removal device and laser-based sealant removal method that can cleanly remove sealant using a laser and protect a backsheet layer by adjusting the angle of the laser light.

[0002] Solar panels are typically constructed using a multilayer structure. For example, a solar panel may be constructed using a laminated structure consisting of a protective glass plate, a backsheet layer (a type of film layer bonded to the solar cells sealed with encapsulant), and a backsheet. These solar panels are further protected by a metal frame around the edges.

[0003] While this structure is useful for extending the lifespan of solar cells and modularizing the device, it also increases the complexity of the solar panel disposal process. Specifically, the solar panel disposal process involves several steps to disassemble the panel into its components, and these steps are crucial for component recycling.

[0004] For example, waste solar panels can be disassembled through processes such as dismantling the metal frame and separating the glass plate from the backsheet layer. Among these processes, the process of using a scraper to peel the backsheet layer attached to the glass plate is particularly important (e.g., Republic of Korea Patent Publication No. 10-2021-0094258).

[0005] However, during the peeling process, when the scraper cuts the cut surface, the pressure of the scraper is transmitted to the glass plate. If the surface of the glass plate is uneven due to sealant (adhesive applied to seal the gap between the frame and the glass plate, etc.) or foreign substances attached to it, problems such as the glass plate being broken due to the pressure may occur.

[0006] In particular, sealant is difficult to process because it is bonded between the frame and the glass plate, and even if it is processed as a separate process, it is difficult to completely scrape it off due to the material (it is not easy to remove because it is made of adhesive) and location (it is arranged in a narrow and long manner, such as at the edge of the glass plate where the frame was), which is a problem when disposing of solar panels.

[0007] Meanwhile, the present invention was researched and developed with the support of the Korean government to solve these problems.

[0008] [National Research and Development Project 1 that supported this invention]

[0009] [Project ID] 2022003170

[0010] [Assignment Number] 2022003170007

[0011] [Ministry Name] Ministry of Environment

[0012] [Name of Project Management (Specialist) Institution] Korea Environmental Industry & Technology Institute

[0013] [Research Project Name] Green Innovation Enterprise Growth Support Program (Commercialization)

[0014] [Research Project Name] Development of Solar Waste Panel Resource Recycling Process Technology and Commercialization

[0015] [Contribution rate] 1 / 2

[0016] [Name of the project performing organization] Wonkwang SNT Co., Ltd.

[0017] Research Period: April 1, 2022 - December 31, 2024

[0018] [National Research and Development Project 2 that supported this invention]

[0019] [Project ID] 2050000175

[0020] [Assignment Number] RS-2022-KE002108

[0021] [Ministry Name] Ministry of Environment

[0022] [Name of Project Management (Specialist) Institution] Korea Environmental Industry & Technology Institute

[0023] [Research Project Name] Green Innovation Enterprise Growth Support Program (Research and Development)

[0024] [Research Project Name] Development of a Module-Level Power Evaluation Device (MLPE) for Solar Power Generation Systems to Improve Solar Waste Circulation

[0025] [Contribution rate] 1 / 2

[0026] [Name of the project performing organization] Wonkwang SNT Co., Ltd.

[0027] Research Period: April 1, 2022 - December 31, 2024

[0028] <Reference prior art literature>

[0029] (Patent Document 1) Republic of Korea Patent Publication No. 10-2021-0094258, (July 29, 2021)

[0030] The technical problem of the present invention is to solve such problems, and to provide a sealant removal device that can effectively remove sealant attached to waste solar panels when processing waste solar panels, and to provide a laser-based sealant removal device that significantly increases the sealant removal effect by using a laser. In addition, the present invention provides a laser-based sealant removal device that can protect a backsheet layer by reducing the amount of laser light transmitted through a glass plate by adjusting the angle of the laser light. In addition, a method for removing sealant using a laser is also provided.

[0031] The technical problems of the present invention are not limited to the problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0032] A sealant removal device using a laser according to the present invention comprises: a stage module for mounting a waste solar panel; and a laser module for irradiating a laser light directed in one direction onto a sealant attached to a glass plate surface of the waste solar panel, wherein the laser module irradiates the laser light obliquely with respect to the glass plate, thereby reducing the laser light transmitted through the glass plate to a backsheet layer attached to the glass plate.

[0033] The incident angle of the laser light can be formed to be greater than the critical irradiation angle, which is an acute angle with respect to the normal line of the glass plate.

[0034] The above critical angle may be an angle at which the light reflectance of the glass plate for a specific polarization has a minimum value.

[0035] The stage module may further include an incident angle control unit that adjusts the incident angle of the laser light by varying the angle of the light emission unit of the laser module.

[0036] The method may further include an aiming module that adjusts the position of the laser module with respect to the stage module to aim the laser light toward the edge of the glass plate on which the sealant is applied.

[0037] The laser module may further include a focus control unit that focuses the laser light and creates a focus of the laser light above the surface of the glass plate.

[0038] The device may further include a transport module that moves at least one of the laser module and the stage module to move the laser light parallel to the surface of the glass plate relative to the glass plate.

[0039] The above-mentioned solar panel may further include a cooling module that sprays a coolant onto the back sheet layer bonded to the glass plate.

[0040] The sealant removal device of the present invention comprises a stage module for settling a waste solar panel with a backsheet layer and a glass plate attached thereto so that the front surface of the glass plate is exposed; and a laser module for irradiating a laser light onto a sealant attached to the front surface of the glass plate, but irradiating the laser light obliquely so as to form an acute angle with the front surface, so that the front surface of the glass plate formed on the opposite side of the backsheet layer can be uniformly treated while the backsheet layer and the glass plate are attached thereto.

[0041] The above sealant is formed along the edge of the front surface of the glass plate, and the laser module can be moved by the transport module so that the irradiation point of the laser light overlaps the edge.

[0042] The method for removing sealant using a laser according to the present invention comprises the steps of (a) arranging a waste solar panel with a backsheet layer and a glass plate attached thereto so that the front surface of the glass plate is exposed; and (b) obliquely irradiating the sealant attached to the front surface of the glass plate with the laser light so as to form an acute angle with the front surface and burning and removing the sealant, thereby enabling the front surface of the glass plate formed on the opposite side of the backsheet layer to be uniformly treated while the backsheet layer and the glass plate are attached thereto.

[0043] In the above step (b), the incident angle of the laser light is adjusted to be greater than the critical irradiation angle, which is an acute angle with respect to the normal line of the glass plate, so that the amount of laser light transmitted through the glass plate to the back sheet layer can be reduced.

[0044] According to the present invention, the surface of a glass plate can be treated very uniformly before the peeling process during the dismantling of waste solar panels. This method removes only the sealant attached to the entire surface of the glass plate while the glass plate and backsheet layer of the waste solar panel are bonded. Specifically, by burning away the sealant and other foreign substances with a laser, the surface of the glass plate is treated very cleanly and uniformly. Therefore, the problem of glass breakage due to unevenness in the glass plate during subsequent processes can be effectively resolved. In particular, by adjusting the optical path of the laser beam, the amount of laser light transmitted through the glass plate is reduced, and the effect of the laser beam on the bonded backsheet layer is reduced, effectively protecting the backsheet layer. Therefore, the backsheet layer can be easily dismantled and recycled during subsequent processes. Furthermore, by burning away the sealant with a laser, the amount of residue is reduced and the process is simplified.

[0045] FIG. 1 is a perspective view of a sealant removal device using a laser according to one embodiment of the present invention.

[0046] Fig. 2 is a cross-sectional drawing of the state before the sealant removal device of Fig. 1 is installed on a waste solar panel, with respect to the stage module.

[0047] Figure 3 is an operating diagram for explaining the incident angle of laser light.

[0048] Figure 4 is a graph showing changes in optical transmittance and reflectance with respect to the incident angle of laser light.

[0049] Fig. 5 is an operational diagram illustrating a process of mounting a waste solar panel on the sealant removal device of Fig. 1 and removing the sealant.

[0050] Fig. 6 is an operational diagram showing the movement method of the laser irradiation position during the sealant removal process of Fig. 5.

[0051] Figure 7 is an operational diagram illustrating a sealant removal process of a sealant removal device according to another embodiment of the present invention.

[0052] The advantages and features of the present invention, as well as the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the claims. Like reference numerals designate like elements throughout the specification.

[0053] Hereinafter, with reference to FIGS. 1 to 7, a sealant removal device using a laser and a sealant removal method using a laser according to the present invention will be described in detail. First, with reference to FIGS. 1 to 6, one embodiment of the sealant removal device of the present invention will be described in detail, and then, based on the description, another embodiment of the sealant removal device of the present invention will be described in detail with reference to FIG. 7. The method will be described based on the description of the device and the contents of the device.

[0054] FIG. 1 is a perspective view of a sealant removal device using a laser according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view of the state of the sealant removal device of FIG. 1 before installation of a waste solar panel on a stage module.

[0055] Referring to FIGS. 1 and 2, a sealant removal device (1) using a laser according to the present invention (hereinafter, a sealant removal device) includes a stage module (100) on which a waste solar panel (A) is mounted, and a laser module (200) arranged adjacent to the stage module (100). The laser module (200) irradiates a surface of a glass plate (A1) of the waste solar panel (A) with a laser light directed in one direction (see L in FIG. 3) to burn and remove the sealant (B) attached to the glass plate (A1).

[0056] At this time, the laser light is not irradiated perpendicularly to the glass plate (A1), but is irradiated obliquely to the glass plate (A1) by forming an incident angle of a constant size (see Fig. 3). Since the reflectance (e.g., which can be calculated from the Fresnel equation) and transmittance of light change as a function of the incident angle (the angle with respect to the normal to the glass plate) at the boundary of the medium (e.g., between air and the glass plate), the amount of light transmitted into the glass plate (A1) can be reduced by controlling the incident angle of the laser light. Accordingly, the effects due to the transmitted light (such as heating due to the transmitted light) can be reduced, thereby protecting the backsheet layer (A2).

[0057] Accordingly, the present invention can protect the backsheet layer (A2) bonded to the glass plate (A1) without substantial deformation while treating the surface of the glass plate (A1) with laser light, even without using an additional structure (e.g., cooling equipment) to protect the backsheet layer (A2). However, since it is also possible to add and use other structures, such as a cooling module, as needed (another embodiment of the present invention), it is not necessary to understand that such a configuration is excluded.

[0058] The sealant removal device (1) of the present invention is configured as follows. The sealant removal device (1) includes a stage module (100) for mounting a waste solar panel (A), and a laser module (200) for irradiating a laser light (see L of FIG. 3) directed in one direction to a sealant (B) attached to a surface of a glass plate (A1) of the waste solar panel (A), wherein the laser module (200) irradiates the laser light obliquely with respect to the glass plate (A1), thereby reducing the laser light transmitted to the back sheet layer attached to the glass plate (A1) by penetrating the glass plate (A1).

[0059] In one embodiment of the present invention, the sealant removal device (1) can be formed so that the incident angle of the laser light (see α in FIG. 3) is greater than the critical irradiation angle (see α0 in FIG. 4) which is an acute angle with respect to the normal line (meaning a line perpendicular to the surface) of the glass plate (A1), and the critical irradiation angle is the light reflectance of the glass plate (A1) for a specific polarization (e.g., R in FIG. 4). p) can be formed at an angle having a minimum value. Therefore, within the incident range of the laser light, the effect of increasing the light reflectance and decreasing the transmittance as the angle increases can be prominent.

[0060] In addition, the sealant removal device (1) may further include an incident angle control unit (203) that adjusts the incident angle of the laser light by varying the angle of the laser module (200) with respect to the stage module (100). Accordingly, the incident angle can be varied.

[0061] In addition, the device may further include a targeting module (210) that adjusts the position of the laser module (200) with respect to the stage module (100) to aim the laser light toward the edge of the glass plate (A1) on which the sealant (B) is applied, and a transfer module (300) that moves at least one of the laser module (200) and the stage module (100) to move the laser light parallel to the surface of the glass plate (A1) with respect to the glass plate (A1). Accordingly, after adjusting the position of the laser light, the sealant (B) can be removed more accurately and conveniently by moving the laser light.

[0062] Hereinafter, the configuration and operational effects of the present invention will be described in more detail based on one embodiment of the present invention.

[0063] First, the structural aspects of the sealant removal device (1) are described, and then the effect of the incident angle of the laser light is described in more detail.

[0064] Referring to FIGS. 1 and 2, the stage module (100) may be formed as a structure having a hollow interior and a flat surface. The stage module (100) may be configured to accommodate a waste solar panel (A), and thus may be modified in various ways within such a configuration. Therefore, the drawings are merely exemplary. For example, the stage module (100) may be configured to include a movable frame (110) formed by connecting square bars or the like to surround the waste solar panel (A). The movable frame (110) may have an accommodation space therein, and the accommodation space may be formed to be open to expose the front (the side with the glass plate) and the back (the side with the back sheet layer) of the waste solar panel (A), excluding the side surfaces. In this example, the stage module (100) can support the waste solar panel (A) by using a plurality of catches (112) that protrude from the movable frame (110) and are caught on the waste solar panel (A) (see Fig. 2 - the dotted line is the position where the waste solar panel is installed).

[0065] The stage module (100) can be modified into various shapes capable of mounting a waste solar panel (A), and thus its shape need not be limited to the drawing. The arrangement of the stage module (100) need not be limited to the horizontal direction as shown in the drawing, and vertical arrangement, etc., are also possible. In the present invention, the stage module (100) can be arranged so that the waste solar panel (A) is at the irradiation point, taking into account that the laser module (200) irradiates the laser light obliquely.

[0066] A brief description of the waste solar panel (A) is as follows. The waste solar panel (A) may have a glass plate (A1) formed on the front and a back sheet layer (A2) formed on the back. The front of the glass plate (A1) is exposed, and the back is bonded to the back sheet layer (A2). The waste solar panel (A) is mounted on the stage module (100) so as to be within the irradiation range of the laser light. In the case where the laser module (200) is positioned above the stage module (100) as in the present embodiment, the waste solar panel (A) may be mounted on the stage module (100) so that the front surface where the glass plate (A1) is positioned faces upward.

[0067] The waste solar panel (A) is formed in a layered structure in which a glass plate (A1) and a back sheet layer (A2) are laminated (see enlarged views of FIGS. 1 and 2). The back sheet layer (A2) may be a type of film layer in which a solar cell sealed with an encapsulant and a back sheet are bonded, and is bonded to the glass plate (A1). The back sheet layer (A2) may be peeled from the glass plate (A1) in a subsequent peeling process, and the present invention may be used to uniformly treat the surface of the glass plate (A1) located opposite the back sheet layer (A2) before the peeling process (i.e., the front surface of the glass plate). That is, the sealant (B) and / or other foreign substances attached to the surface of the glass plate (A1) can be removed by the present invention.

[0068] The waste solar panel (A) of the present invention may have a metal frame (not shown) that was connected to protect the side (edge ​​portion) disassembled, and thus the sealant (B) applied between the glass plate (A1) and the metal frame (not shown) may remain along the edge of the surface of the glass plate (A1). The sealant (B) is made of a viscous resin or the like, and needs to be removed because it is fixed to the surface of the glass plate (A1) in a hardened state, making the surface uneven.

[0069] The laser module (200) irradiates a laser light (see L in FIG. 3) directed in one direction to the sealant (B) attached to the surface of the glass plate (A1) of the waste solar panel (A). When the laser light hits the sealant (B), the sealant (B) is burned and removed, so that no residue remains and the sealant (B) is processed quickly compared to a removal method such as scraping it off. The laser module (200) irradiates the laser light obliquely to the glass plate (A1) so as to have a constant angle of incidence (see α in FIG. 3) with respect to the normal direction of the glass plate (A1).

[0070] It is known that when light is incident from one medium to another (e.g., incident from air to a glass plate), the reflectance (e.g., which can be calculated from the Fresnel equation) and the transmittance at the interface of the media vary as a function of the incident angle. Therefore, by controlling the incident angle of the laser light, the amount of light transmitted into the glass plate (A1) can be effectively reduced. The present invention has the feature of reducing the laser light transmitted to the back sheet layer (A2) attached to the glass plate (A1) by transmitting the laser light obliquely to the glass plate (A1) through the glass plate (A1). This will be described in detail later.

[0071] The laser module (200) is positioned adjacent to the stage module (100) as illustrated in FIGS. 1 and 2, and is positioned so as to be able to irradiate laser light toward the glass plate (A1) of the waste solar panel (A). To adjust the angle of the laser light, the laser module (200) may be positioned outside the waste solar panel (A). In the case where the glass plate (A1) faces upward as in the present embodiment, the laser module (200) is positioned above the waste solar panel (A). The laser module (200) has a light output portion (201) formed at the end through which laser light is emitted, and the light output portion (201) may face the glass plate (A1). The light output portion (201) may be arranged to be inclined with respect to the stage module (100) as illustrated.

[0072] The laser module (200) includes a oscillation unit (not shown) that generates laser light, etc., and the output can be adjusted through appropriate control. The shape and structure of the laser module (200) can be modified within the limit of being able to irradiate laser light, so the drawing is an example. However, since the laser module (200) must irradiate laser light obliquely with respect to the glass plate (A1), the light output unit (201) can be arranged at a certain angle with respect to the stage module (100).

[0073] The laser module (200) may include an incident angle control unit (203) that adjusts the incident angle of the laser light on the glass plate (A1) by varying the angle of the light output unit (201) with respect to the stage module (100). The incident angle control unit (203) may be formed, for example, with a structure that adjusts the orientation by rotating the light output unit (201) about a center of rotation. The incident angle control unit (203) may also be formed to have two or more intersecting rotation axes and to adjust different orientations with respect to two or more intersecting rotation centers (see the enlarged view of FIG. 1).

[0074] The azimuth adjustment of the incident angle control unit (203) can be formed automatically or manually. For example, the incident angle control unit (203) can be formed by forming the light output unit (201) in a nozzle shape and rotatably connecting it to the rotation center, etc. The incident angle control unit (203) is only briefly illustrated in the drawing, as there is no need to be any particular restrictions on the structure or shape as long as the angle adjustment of the light output unit (201) is possible.

[0075] If necessary, if the light irradiation angle of the laser module (200) is formed appropriately, it is possible to fix the incident angle and remove the sealant (B), so in such a case, the incident angle control unit (203) may not be formed.

[0076] In this embodiment, the laser module (200) can be combined with an aiming module (210). The aiming module (210) can adjust the position of the laser module (200) with respect to the stage module (100) to aim the laser light irradiated by the laser module (200) toward the edge of the glass plate (A1) on which the sealant (B) is applied.

[0077] In particular, since the laser module (200) in this embodiment includes an incident angle control unit (203), the laser module (200) can be adjusted so that laser light is irradiated obliquely onto the surface of the glass plate (A1) by simultaneously utilizing angle control using the incident angle control unit (203) and position control using the aiming module (210).

[0078] For example, the aiming module (210) may be formed with a structure including a two-axis linear guide or the like that can move the laser module (200) in at least two mutually perpendicular axes, thereby making it possible to freely adjust the position of the laser module (200) at least on a plane parallel to the surface of the waste solar panel (A) (see FIG. 1). The operating range of the aiming module (210) may be extended to the outside of the waste solar panel (A).

[0079] However, this is just one example, and the aiming module (210) need not be limited to that, and the aiming module (210) can be formed by utilizing various types of structures that can change position (e.g., a three-axis linear guide, a robot arm with joints, etc.). The aiming module (210) also need not be limited to the drawing, as it can be transformed into various forms that can change the irradiation position of the laser light by adjusting the position of the laser module (200).

[0080] The sealant removal device (1) may include a transport module (300). The transport module (300) moves at least one of the laser module (200) and the stage module (100) to move the laser light irradiated by the laser module (200) parallel to the surface of the glass plate (A1) of the waste solar panel (A) with respect to the glass plate (A1) (see the operating diagram of FIG. 6). Accordingly, after setting the irradiation position and angle of the laser light using the aiming module (210) and the incident angle control unit (203), the sealant (B), etc., which are attached in a straight line, can be automatically removed while moving the laser light parallel to the glass plate (A1) with the transport module (300).

[0081] The transport module (300) may be formed, for example, in a structure that moves the stage module (100). For example, as in the present embodiment, the stage module (100) may include a movable frame (110), and the transport module (300) may be configured to move the movable frame (110). For example, the transport module (300) may be formed in a form that includes a drive roller (see 310 in FIG. 2) that contacts the movable frame (110) to move the movable frame (110) in a longitudinal direction, and a motor (see 320 in FIG. 2) that transmits power to the drive roller (310) to rotate it.

[0082] For example, the movable frame (110) is slidably connected to a guide bar (111) arranged in the longitudinal direction of the waste solar panel (A), so that when the driving roller (310) rotates, it can move in parallel in the forward and reverse directions along the guide bar (111). In this way, the irradiation position of the laser light can be automatically changed by the way the stage module (100) moves.

[0083] However, it is not necessary to be limited to that, and it is entirely possible to move the laser module (200) instead of the stage module (100), or to move the stage module (100) and the laser module (200) simultaneously (in opposite directions). In such cases, the shape of the transport module can be changed in a corresponding manner. The transport module (300) can also be transformed into various shapes, and therefore is not limited to the drawing.

[0084] The sealant removal device (1) uses this structure to secure a waste solar panel (A) to a stage module (100), and uses a laser module (200) to irradiate laser light obliquely to the glass plate (A1) of the waste solar panel (A) to remove the sealant (B) (and other foreign substances, etc.). In particular, by controlling the incident angle of the laser light, the transmitted light can be reduced, thereby preventing deformation of the back sheet layer. Hereinafter, the effects of the incident angle of the laser light will be described in detail with reference to FIGS. 3 and 4.

[0085] Figure 3 is an operating diagram for explaining the incident angle of laser light, and Figure 4 is a graph showing changes in light transmittance and reflectance with respect to the incident angle of laser light.

[0086] Referring to Fig. 3, laser light (L) is irradiated obliquely from a laser module (200) to a glass plate (A1). At this time, the incident angle (α) of the laser light (L) is measured with respect to the normal direction (perpendicular to the surface) of the glass plate (A1) and is formed as an acute angle as illustrated. Due to the obliquely irradiated laser light (L), reflected light (La) and transmitted light (Lb) are generated at corresponding angles on the surface of the glass plate (A1) (the reflected light can change its angle with respect to the incident angle according to the law of reflection, and the transmitted light can change its angle with respect to the incident angle according to Snell's law), and some of them can be transmitted into the glass plate (A1).

[0087] The laser light (L) may come into contact with the sealant (B), but may be incident on the surface of the glass plate (A1) after the sealant (B) is removed. This situation must be carefully considered, especially since the sealant (B) is removed very quickly by the high-power laser light (L). If a large portion of the incident laser light (L) penetrates the glass plate (A1) and directly reaches the backsheet layer (A2), there is a possibility that thermal deformation will occur in the backsheet layer (A2).

[0088] The present invention effectively reduces the amount of light transmitted by the laser light (L) through the glass plate (A1) by forming the incident angle (α) of the laser light (L) to be greater than the critical irradiation angle (see α0 in Fig. 4), which is an acute angle with respect to the normal line of the glass plate (A1). The critical irradiation angle can be formed specifically according to the following principle.

[0089] Light is an electromagnetic wave, so it propagates in the form of alternating oscillations of electric and magnetic fields, and can be expressed as a combination of two polarizations distinguished by the plane of vibration. For example, the plane of vibration of the electric field can be expressed as a combination of polarization perpendicular to the plane of incidence (which may be the plane perpendicular to the glass plate in Figure 3, the plane on which the laser light is placed) (typically s-polarization) and parallel to the plane of incidence (typically p-polarization). When each polarization is incident on the boundary between two media (e.g., air and glass), the reflectivity and transmittance change depending on the refractive index and the angle of incidence of the media.

[0090] Since the sum of reflectance and transmittance is 1 by conservation of energy, the transmittance of each polarization is 1-reflectance [i.e. transmittance of s-polarization (T s )=1-R s , transmittance of p-polarized light (T p )=1-R p ]. Therefore, as the reflectance increases, the transmittance decreases correspondingly. According to the Fresnel equation, the reflectance (R) of each polarization s , R p ) can be expressed as a function of the angle of incidence of light and the refractive index of the medium as follows.

[0091]

[0092] [Mathematical Formula 1]

[0093]

[0094] [Equation 2]

[0095]

[0096]

[0097] In the above equation, R s is the reflectance of s-polarized light, R p is the reflectance of p-polarized light, n1 is the refractive index of the first medium, n2 is the refractive index of the second medium, and θ i represents the angle of incidence of light. The angle of incidence θ in the formula iis substantially the same as the incident angle (α) of the laser light (L) in the situation of Fig. 3. Therefore, if the change in refractive index and reflectance with respect to the incident angle (α) of light incident from air (first medium, refractive index n1 = 1) to glass (second medium, refractive index n2 = 1.5) is graphed, it can be represented as in Fig. 4.

[0098] Figure 4 is a graph showing the change in refractive index (reflectance) and transmittance (transmittance) according to the Fresnel equation for a situation where light is incident from air to glass. The graph shows that as the incident angle (α) increases, the reflectance (R) generally increases. s , R p ) increases and the angle of incidence increases, the reflectance increases more rapidly. Transmittance (T s =1-R s , T p =1-R p ) decreases inversely as the incident angle (α) increases. Therefore, in order to increase the reflectivity of the laser light (and therefore reduce the transmittance), it is advantageous to form the incident angle (α) large.

[0099] Reflectance and transmittance are the ratios of the amplitudes of the reflected and transmitted waves (e.g., the amplitude of the electric field) to the incident wave, respectively. Since the energy of electromagnetic waves is proportional to the amplitude, ultimately, the higher the reflectance, the more reflected light energy increases and the less transmitted light energy decreases. Therefore, increasing the light reflectance can reduce the energy of the laser light (L) transmitted to the glass plate (A1).

[0100] However, as shown in Fig. 4, the reflectance of p-polarized light (R p) has a characteristic of decreasing until it reaches a specific angle (α0) and having an extreme value where the reflectance is zero at that angle. Therefore, in order to increase the reflectance of both polarized lights simultaneously, it is highly desirable to form the incident angle (α) larger than that angle. In other words, the angle at which the reflectance of p-polarized light has a minimum value is set as the critical angle (α0), and the incident angle (α) is formed at an angle larger than the critical angle to effectively increase the light reflectance (R s , R p ) can be increased.

[0101] Therefore, the critical angle (α0) is the light reflectance (R) of the glass plate for a specific polarization (p polarization). p ) can be set to an angle at which the p-polarized light has a minimum value, and the reflectivity of the p-polarized light at that angle can be zero. This angle is also known as Brewster's angle, and since the p-polarized light at that angle is substantially not reflected and can be transmitted entirely through the glass plate (A1), it is highly desirable to form the incident angle (α) of the laser light (L) at an angle greater than the critical irradiation angle (α0) (which may be the same angle as Brewster's angle). For example, the critical irradiation angle (α0) calculated for a typical glass plate (A1) with a refractive index of 1.5 by this principle can be approximately 56 degrees.

[0102] In addition, since geometrical aiming may become difficult when the incident angle (α) is close to 90 degrees, for example, the incident angle (α) of the laser light (L) may be set to an upper limit that is larger than the critical irradiation angle (α0) but smaller than 90 degrees, and the critical irradiation angle (α0) may be set to a lower limit, so that the angle may be formed between the critical irradiation angle (α0) and the upper limit. In this way, by setting the critical irradiation angle (α0) of the laser light (L) and controlling the incident angle (α) of the laser light (L) to an angle larger than the critical irradiation angle (α0), the laser light (L) transmitted through the glass plate (A1) can be very effectively reduced.

[0103] The incident angle (α) of the laser light (L) can be adjusted by the incident angle control unit (203) described above. Therefore, the laser light can be emitted by adjusting the incident angle (α) to any angle greater than the critical irradiation angle (α0) described above. Of course, in the case where the emission angle of the laser module (200) is fixed without the incident angle control unit (203) described above, the angle of the light emission unit (201) can be adjusted in advance so that the incident angle (α) of the laser light (L) is greater than the critical irradiation angle (α0). In this way, by irradiating the laser light (L) obliquely to the surface of the glass plate (A1), the amount of light transmitted through the glass plate is reduced without using any other additional structure (e.g., cooling equipment, etc.), thereby protecting the backsheet layer (A2), and the sealant (B) on the surface of the glass plate (A1) can be cleanly removed with the laser light.

[0104] Hereinafter, the sealant removal process will be described in more detail with reference to FIGS. 5 and 6.

[0105] Fig. 5 is an operational diagram illustrating a process of mounting a waste solar panel on the sealant removal device of Fig. 1 and removing the sealant, and Fig. 6 is an operational diagram illustrating a method of moving a laser irradiation position during the sealant removal process of Fig. 5.

[0106] In the above-described manner, the present invention can effectively reduce the laser light (L) transmitted to the back sheet layer (A2) by burning and removing the sealant (B) on the surface of the glass plate (A1) by irradiating the laser light (L) obliquely to the glass plate (A1) as shown in Fig. 5. The incident angle (α) of the illustrated laser light is an acute angle that is larger than the critical irradiation angle (α0) described above. By forming the incident angle (α) at ​​an appropriate angle between the critical irradiation angle (α0) and 90 degrees, the reflected light (La) can be increased and the transmitted light (Lb) can be effectively reduced.

[0107] For example, while the laser light (L) is irradiated, the backsheet layer (A2) can be maintained below a temperature (e.g., the melting point of the resin forming the backsheet layer) at which deformation of the backsheet layer (A2) substantially occurs due to the reduction effect of the transmitted light (Lb). In this way, by controlling the incident angle (α) of the laser light (L), the amount of light transmitted through the glass plate (A1) can be effectively reduced, and deformation of the backsheet layer (A2) caused by the laser light (L) can be substantially eliminated.

[0108] Accordingly, there is no problem in removing the sealant (B) for a relatively long period of time while moving the laser light (L) parallel to the glass plate (A1), as illustrated in Fig. 6. That is, since the deformation of the actual back sheet layer (A2) can be prevented by controlling the incident angle (α) of the laser light (L), the sealant (B) or other foreign substances attached to the edge and / or other points on the surface of the glass plate (A1) can be removed with the laser light (L) while preserving the back sheet layer (A2).

[0109] The laser light (L) can be moved parallel along the glass plate (A1), for example, by moving the stage module (100) with the transport module (300). After the waste solar panel (A) is placed on the stage module (100), the laser module (200) is aimed, and the laser light (L) is irradiated to start the sealant (B) removal process as shown in FIG. 5, the transport module (300) is operated as shown in FIG. 6 to move the stage module (100) to one side, while continuously changing the irradiation position of the laser light (L). In this way, by moving the laser light (L) parallelly with the transport module (300), the sealant (B) attached to the glass plate (A1) can be removed very effectively.

[0110] In addition, the sealant removal device (1) can also be controlled to reduce the amount of laser light (L) transmitted through the glass plate (A1) by adjusting the focus of the laser light (L). For example, the sealant removal device (1) can include a focus control unit (202) that is arranged in the laser module (200) and focuses the laser light (L) to create a focus of the laser light (L) above the surface of the glass plate (A1). Although briefly illustrated, for example, the focus control unit (202) can be formed as an optical system that can focus the laser light (L) and change the position of the focus, and within that limit, it is also possible to precisely control the position of the focus so that it is formed on the sealant (B) by implementing it in an appropriate form. The focus control unit (202) can be arranged at the end of the light output unit (201) of the laser module (200).

[0111] In this way, the sealant (B) and other foreign substances on the surface of the glass plate (A1) can be burned and removed very effectively with the laser light (L), and at the same time, by controlling the incident angle (α), the amount of light transmitted through the glass plate (A1) can be reduced, thereby preventing deformation of the backsheet layer (A2). Therefore, not only can the surface of the glass plate (A1) be treated cleanly, but the recycling of the backsheet layer (A2) can also be very effective.

[0112] Hereinafter, a sealant removal device according to another embodiment of the present invention will be described in detail with reference to FIG. 7. To ensure a concise and clear explanation, the differences from the aforementioned embodiment will be emphasized, and any explanations of other aspects will be replaced by the aforementioned description.

[0113] Figure 7 is an operational diagram illustrating a sealant removal process of a sealant removal device according to another embodiment of the present invention.

[0114] Referring to Fig. 7, a sealant removal device (1-1) using a laser according to another embodiment of the present invention is formed so that the temperature of the back sheet layer (A2) can be controlled by a cooling module (400). The cooling module (400) can be formed in a form that sprays a coolant (C) onto the back sheet layer (A2) bonded to the glass plate (A1) of the waste solar panel (A).

[0115] The cooling module (400) may include, for example, a nozzle (401) structure capable of spraying a coolant. The coolant may be formed of a fluid sprayed through the nozzle (401), and the fluid may be a liquid and / or a gas, and the gas may include various types of air at room temperature and / or cooled air.

[0116] Although not shown, the cooling module (400) may also be provided with a pipe structure (not shown) that supplies coolant sprayed through a nozzle (401). For example, the coolant may be supplied to the cooling module (400) by an external pressurizing device (pump, etc.). The coolant may be one or more fluids that may be used selectively and in combination, and such fluids may include fluids at room temperature or cooled to a temperature lower than room temperature. Accordingly, the type and / or temperature and / or spray amount of the coolant sprayed through the cooling module (400) may be adjusted (although not shown, this may be adjusted by a valve formed in the pipe or cooling module, etc.) to further lower the temperature of the backsheet layer (A2). Since the cooling module (400) can be modified in various ways in such a form, the detailed structure is omitted in the drawing.

[0117] Preferably, the cooling module (400) may be arranged to face the backsheet layer (A2) of the waste solar panel (A) so that the nozzle (401) faces the backsheet layer (A2). The cooling module (400) may be arranged to spray the coolant (C) toward the backsheet layer (A2) opposite the irradiation point where the laser light (L) is irradiated. This arrangement may be advantageous in spraying the coolant at the irradiation point of the laser light to intensively cool the area around the temperature rise point.

[0118] The cooling module (400) can be coupled to the position control module (410). The position control module (410) can adjust the coolant injection position of the cooling module (400) to any position of the back sheet layer (A2). For example, the position control module (410) can be formed in a shape corresponding to the aforementioned aiming module (210) and can be formed with a structure including a two-axis linear guide or the like that can move the cooling module (400) in at least two directions perpendicular to each other like the aiming module (210). Therefore, the cooling module (400) can freely change its position at least on a plane parallel to the surface of the waste solar panel (A).

[0119] However, since this is also just one example, the position control module (410) does not need to be limited to that, and another type of position control module (410) can be formed by utilizing various types of structures that can change position (e.g., 3-axis linear guide, robot arm with joints, etc.). The position control module (410) does not need to be limited to the drawing, as it can be transformed into various types that can change the coolant injection position by adjusting the position of the cooling module (400).

[0120] As illustrated by this cooling module (400), the injection position can be adjusted, and the coolant (C) can be injected to the backsheet layer (A2) corresponding to the irradiation point where the laser light (L) is irradiated, thereby sufficiently lowering the temperature of the backsheet layer (A2). For example, in cases where the incident angle (α) of the laser light (L) needs to be relatively small, it is also possible to install this cooling module (400) to offset the influence of the transmitted light (Lb).

[0121] During the removal of the sealant (B), the stage module (100) can be moved as described above to change the position of the laser light (L). For example, by fixing the laser module (200) and the cooling module (400) and moving only the stage module (100) in parallel (see FIG. 6), the irradiation position of the laser light on the waste solar panel (A) and the spraying position of the coolant can be changed simultaneously, so that the process can proceed conveniently. It is also entirely possible to configure the sealant removal device (1-1) in a form that includes the cooling module (400) in this manner.

[0122] The sealant removal device (1) of the present invention also has the following features in one aspect. The sealant removal device (1) is applied to the flattening process of the front surface of the glass plate before peeling off the back sheet layer (A2) of the waste solar panel (A), and thus is performed in a state where the back sheet layer (A2) and the glass plate (A1) are bonded. That is, the sealant removal device (1) includes a stage module (100) that places a waste solar panel (A) (e.g., one in which only the metal frame and junction box described above have been dismantled) with a backsheet layer (A2) and a glass plate (A1) attached thereto so that the front surface of the glass plate (A1) is exposed, and a laser module (200) that irradiates a laser light onto a sealant (B) attached to the front surface of the glass plate (A1) at an angle so as to form an acute angle with the front surface, so that the front surface of the glass plate (A1) formed on the opposite side of the backsheet layer (A2) can be uniformly processed while the backsheet layer (A2) and the glass plate (A1) are attached thereto.

[0123] At this time, the sealant (B) is formed along the edge of the front surface of the glass plate (A1), and the laser module (200) can be moved by the transport module (400) so that the laser light irradiation point overlaps the edge. This configuration can be confirmed from the embodiments described above, and this configuration is also not excluded from the technical concept of the present invention.

[0124] The angle of the laser beam can be defined as either the angle relative to the front surface (the surface to which the sealant is attached) of the glass plate (A1) or the angle relative to a normal line perpendicular to the front surface. Since the front surface of the glass plate is perpendicular to the normal line, when the laser beam is irradiated between them, the laser beam can form an acute angle with both the front surface and the normal line. This means that the laser beam forms an acute angle with the front surface, and this is illustrated in Fig. 3. For details, please refer to the above description.

[0125] Hereinafter, a sealant removal method using a laser according to the present invention will be described in detail. Since the sealant removal method of the present invention can be substantially performed using the sealant removal device (1) described above, any details that can be understood based on the above description will be omitted for illustrative purposes. The sealant removal method may include the following steps.

[0126] First, a waste solar panel (A) with a backsheet layer (A2) and a glass plate (A1) attached is placed so that the front surface of the glass plate (A1) is exposed [step (a)]. This step is illustrated in FIGS. 1 and 2, so details refer to the above description.

[0127] Thereafter, the sealant (B) attached to the front surface of the glass plate (A1) is irradiated with laser light obliquely at an acute angle to the front surface, thereby burning and removing the sealant [step (b)]. This step is illustrated in FIGS. 3 to 6 , so for details, refer to the above-described description. In this manner, the front surface of the glass plate (A1) formed on the opposite side of the back sheet layer (A2) while the back sheet layer (A2) and the glass plate (A1) are attached can be uniformly treated. In addition, the amount of light transmitted into the back sheet layer can be reduced, thereby protecting the back sheet layer.

[0128] At this time, in the above step (b), by adjusting the incident angle (α) of the laser light to be greater than the critical irradiation angle, which is an acute angle with respect to the normal to the glass plate (A1), the amount of laser light transmitted through the glass plate (A1) to the back sheet layer (A2) can be reduced. Therefore, as described above, by adjusting the angle of the laser light, the back sheet layer can be prevented from overheating and deformation. This is illustrated in FIGS. 3 and 4, etc., so refer to the above description for details. In this way, while uniformly processing the entire surface of the glass plate with a laser, the back sheet layer attached to the opposite side is protected from deformation, and the back sheet layer can be separated and recycled through a subsequent process, such as by peeling the back sheet layer.

[0129] Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

[0130] [Explanation of symbols]

[0131] 1: Laser-assisted sealant removal device

[0132] 100: Stage module 110: Movable frame

[0133] 111: Guide bar 112: Hook

[0134] 200: Laser module 201: Light output unit

[0135] 202: Focus control unit 203: Incident angle control unit

[0136] 210: Aiming module 300: Transport module

[0137] 310: Drive roller 320: Motor

[0138] 400: Cooling module 401: Nozzle

[0139] 410: Position control module A: Waste solar panel

[0140] A1: Glass plate A2: Back sheet layer

[0141] B: Sealant L: Laser light

[0142] La: reflected light Lb: transmitted light

[0143] C: Coolant α: Incidence angle

[0144] α0: critical angle

[0145] The present invention allows for a uniform treatment of the glass surface prior to the peeling process during the disassembly of waste solar panels, facilitating subsequent processes. In particular, the laser burns away sealant and other foreign substances, eliminating residue and ensuring a clean, streamlined process. Furthermore, it prevents deformation of the backsheet layer, making it highly advantageous for recycling. Therefore, the present invention has significant industrial applicability.

Claims

1. A stage module for mounting waste solar panels; and Including a laser module that irradiates a laser light directed in one direction to a sealant attached to the glass surface of the above-mentioned waste solar panel, The above laser module is a sealant removal device that uses a laser to irradiate the laser light obliquely to the glass plate, thereby reducing the laser light transmitted through the glass plate to the back sheet layer attached to the glass plate.

2. In paragraph 1, A sealant removal device using a laser in which the incident angle of the laser light is formed larger than the critical irradiation angle, which is an acute angle with respect to the normal line of the glass plate.

3. In paragraph 2, The above critical irradiation angle is an angle at which the light reflectance of the glass plate for a specific polarization has a minimum value. A sealant removal device using a laser.

4. In paragraph 1, A sealant removal device using a laser, further comprising an incident angle control unit that adjusts the incident angle of the laser light by varying the angle of the light emission unit of the laser module with respect to the stage module.

5. In paragraph 1, A sealant removal device using a laser, further comprising an aiming module that adjusts the position of the laser module with respect to the stage module to aim the laser light toward the edge of the glass plate on which the sealant is applied.

6. In paragraph 5, A sealant removal device using a laser, further comprising a focus control unit disposed in the laser module and focusing the laser light to create a focus of the laser light above the surface of the glass plate.

7. In paragraph 5, A sealant removal device using a laser, further comprising a transport module that moves at least one of the laser module and the stage module to move the laser light parallel to the surface of the glass plate.

8. In paragraph 1, A sealant removal device using a laser further comprising a cooling module that sprays a coolant onto the back sheet layer bonded to the glass plate of the above-mentioned waste solar panel.

9. A stage module for mounting a waste solar panel with a backsheet layer and a glass plate attached so that the front surface of the glass plate is exposed; and Including a laser module that irradiates laser light to the sealant attached to the front surface of the glass plate, and irradiates the laser light obliquely so as to form an acute angle with the front surface. A sealant removal device using a laser that evenly processes the front surface of the glass plate formed on the opposite side of the back sheet layer while the back sheet layer and the glass plate are attached.

10. In paragraph 9, A sealant removal device using a laser, wherein the sealant is formed along the edge of the front surface of the glass plate, and the laser module is moved by a transport module so that the irradiation point of the laser light overlaps the edge. 11.(a) A step of arranging a waste solar panel with a back sheet layer and a glass plate attached so that the front surface of the glass plate is exposed; and (b) including a step of irradiating the laser light obliquely to the sealant attached to the front surface of the glass plate so as to form an acute angle with the front surface and burning and removing the sealant. A sealant removal method using a laser to uniformly process the front surface of the glass plate formed on the opposite side of the back sheet layer while the back sheet layer and the glass plate are attached.

12. In paragraph 11, A method for removing sealant using a laser, wherein in the step (b), the angle of incidence of the laser light is adjusted to be greater than the critical irradiation angle, which is an acute angle with respect to the normal line of the glass plate, thereby reducing the amount of laser light transmitted through the glass plate to the back sheet layer.

Images