Processing apparatus for plate glass having a conductive layer

Abstract

To provide a plate-shaped glass processing device for collecting a conductive layer which hardly includes glass debris, efficiently and safely, using dissolution liquid for dissolving glass.SOLUTION: There is provided a plate shaped glass processing device for processing a plate-shaped glass in which a conductive layer 14 is adhered through a low melting point glass 16, the plate shaped glass processing device comprises, at least, injection means, transport means and collection means. The injection means injects dissolution liquid capable of dissolving the low melting point glass 16 from an upper side to the plate shaped glass, in a processing chamber, the transport means transports the plate shaped glass by a transport roller so that the conductive layer 14 is an upper side, through the processing chamber, the collection means collects the conductive layer 14 from which the plate shaped glass is peeled. The injection means causes a liquid flow of the dissolution liquid on a top surface of the plate shaped glass, and injects the dissolution liquid so as to have a component in the horizontal direction, in the plate shaped glass processing device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flat glass processing apparatus configured to melt low-melting point glass for a plurality of flat glass plates, each having a conductive layer and low-melting point glass on a portion of the glass surface. [Background technology]

[0002] For example, the rear window of an automobile contains a heating wire in addition to the glass. This heating wire is made from conductive paste. After the rear window is produced, the sintered conductive layer is bonded to the rear window via the exuded low-melting-point glass.

[0003] This conductive layer is known to contain recyclable materials such as silver and its alloys.

[0004] In order to recycle these materials, there has been a method of recovering the conductive layer by colliding a fluid containing fine particles with the rear glass (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-80461 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above method generates glass fragments and produces a conductive layer containing the glass fragments, making it difficult to recover a good quality conductive layer.

[0007] Therefore, an object of the present invention is to provide a plate glass processing device that can efficiently and safely recover a conductive layer that is less likely to contain glass fragments using a dissolving liquid that dissolves glass. [Means for solving the problem]

[0008] The plate-shaped glass processing apparatus according to the present invention is used for a continuously conveyed glass plate having a conductive layer adhering to a part of the surface of the glass plate via a low-melting glass. This plate-shaped glass is, for example, a rear glass used in an automobile. The conductive layer contains recyclable substances such as silver and its alloys. However, the content rates of these substances vary depending on the performance of the heating wire. This processing apparatus processes the rear glass so as to peel off and recover the conductive layer.

[0009] This recovery apparatus includes at least injection means, conveyance means, and recovery means.

[0010] Since the dissolution liquid used in the injection means is a liquid that may have an adverse effect on the human body, such as containing hydrofluoric acid, it is processed inside the chamber. Note that the dissolution liquid is not limited to hydrofluoric acid.

[0011] The processing chamber is a device configured to be surrounded by a cover and not to come into contact with the outside air. Since this device can block the outside and process a gas containing a dissolution liquid for dissolving glass and a chemical atmosphere, these liquids and gases do not leak outside the processing chamber and can be used safely.

[0012] The processing chamber has an injection device that mainly injects a dissolution liquid for dissolving the low-melting glass. The dissolution liquid is injected into the rear glass from at least a plurality of locations above.

[0013] Furthermore, this injection device injects the dissolution liquid so as to have a horizontal component. Since the dissolution liquid having a horizontal component reacts with the low-melting glass in the longitudinal portion of the conductive layer and the low-melting glass, the low-melting glass can be easily dissolved.

[0014] In addition, since the plurality of injection devices perform injection in the same direction, a liquid flow is generated on the upper surface of the rear glass. This liquid flow serves as a force to scrape the low-melting-point glass along the upper surface of the rear glass. Therefore, the generated liquid flow promotes the melting of the low-melting-point glass and also acts as a force to peel off the conductive layer, enabling the efficient peeling of the conductive layer.

[0015] Since the dissolving liquid hardly contacts the main surface of the rear glass on the side of the conveying roller described later, sludge precipitation can be suppressed when melting the glass as compared with the method of reacting the entire rear glass.

[0016] The conveying means conveys the rear glass via the above-described processing chamber. For example, conveying rollers arranged continuously and linearly are used. The rear glass is placed on the conveying rollers such that the side having the conductive layer faces upward. By using such conveying means, a plurality of rear glasses can be efficiently processed.

[0017] When this conveying means is operated, since the dissolving liquid is less likely to contact the main surface of the rear glass on the side of the conveying roller, the amount of sludge generated when melting the glass can be suppressed as compared with the method of reacting the entire rear glass.

[0018] The recovery means for the conductive layer is a method for recovering the conductive layer peeled off from the rear glass in the processing chamber. For example, a net-like structure is used for recovery to mainly separate the conductive layer and the dissolving liquid.

[0019] Depending on the content rate of the above-described substances contained in the conductive layer, the specific gravity of the conductive layer with respect to the dissolving liquid changes. Therefore, if there is a conductive layer that precipitates in the dissolving liquid, there is also a conductive layer that floats in the dissolving liquid. Thus, by adopting the method of filtering off the conductive layer as described above, the conductive layer can be easily recovered regardless of its specific gravity.

[0020] After processing a certain number of sheets, the operation of taking out the conductive layer deposited on the net-like structure is periodically performed, and the conductive layer can be recovered.

[0021] After the series of steps described above has been completed, the rear glass can be removed from the processing chamber. Since the removed rear glass has almost no conductive layer, it is in a state that is easy to recycle.

[0022] Furthermore, it is desirable that the injector in the injection means reciprocate in a specific direction, which generates a liquid flow in both the conductive layer and the longitudinal portion of the low-melting-point glass, thereby enabling more efficient melting of the low-melting-point glass.

[0023] In addition, the recovery means is preferably a plurality of acid-resistant filters provided at the location where the dissolution liquid flows in. These filters are arranged so that the mesh size of the filters becomes finer from upstream to downstream.

[0024] By installing multiple filters at the point where the dissolving solution flows in, the surface area for filtering out the conductive layer is increased, reducing the frequency of replacement of the recovery means and enabling more efficient recovery of the conductive layer. Furthermore, since the dissolving solution is an acidic solution such as hydrofluoric acid, filters made of acid-resistant resin or the like can be used for a long period of time and reduce operating costs. [Effects of the Invention]

[0025] According to the present invention, a plate glass processing apparatus can be provided that can efficiently and safely recover a conductive layer that is less likely to contain glass fragments using a dissolving liquid that dissolves glass. [Brief explanation of the drawings]

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0027] An embodiment of a sheet glass processing apparatus according to the present invention will be described below with reference to the drawings. As shown in Fig. 1(A), a conductive layer and low-melting-point glass 12 are used as a heating wire on a rear window 10 of a vehicle. The rear window 10 also has a black portion 18. Although the rear window 10 is originally curved, it is shown in the drawing as being flat.

[0028] As shown in FIG. 1(B), the conductive layer 14 is adhered to the rear glass 10 via low-melting-point glass 16. The conductive layer 14 contains materials such as silver and its alloys. These materials are useful resources and can be recycled. However, the content of these materials contained in the rear glass varies depending on the performance of the heating wire.

[0029] To remove the conductive layer 14, a method is employed in which the low-melting-point glass 16 that bonds the conductive layer 14 to the rear glass 10 is dissolved using a dissolving solution containing, for example, hydrofluoric acid.

[0030] 2 and 3 show a schematic configuration of the sheet glass processing apparatus. The sheet glass processing apparatus is composed of, for example, an input section 22, multiple processing chambers, a cleaning section 34, and an output section 36. The multiple processing chambers are further composed of a pre-processing chamber 24, a first processing chamber 26, a second processing chamber 28, a third processing chamber 30, and a fourth processing chamber 32. In addition, transport rollers 20 are installed between the input section 22 and the output section 36, allowing the rear glass 10 to be transported continuously. Note that the number of processing chambers is not limited to the above, and the transport means is not limited to the above as long as it is capable of transporting the rear glass 10.

[0031] The loading section 22 is configured to be able to receive the rear glass 10 that is loaded manually by an operator or automatically by a robot or the like. The rear glass 10 is transported with the conductive layer and the low-melting-point glass 12 on top, and is transported in a state where it is curved toward the transport rollers 20.

[0032] The pre-processing chamber 24 is configured to receive the rear glass 10 transported from the loading section 22 into the next processing chamber and thereafter. Each of the first to fourth processing chambers has a plurality of spray devices 40 that spray a dissolving solution containing hydrofluoric acid onto the rear glass 10 to dissolve the low-melting-point glass 16. This dissolving solution mainly dissolves the low-melting-point glass 16 and peels the conductive layer 14 from the rear glass 10. Each processing chamber is operated in the same manner, but the concentration of the dissolving solution and the pressure of the spray devices 40 may be changed as appropriate for each chamber.

[0033] A plurality of spraying devices 40 are provided in the transport direction and in the direction perpendicular to the transport direction. When spraying the dissolving liquid, the spraying devices 40 in the processing chamber spray the liquid so that it has a horizontal component, generating a liquid flow in the dissolving liquid.

[0034] When multiple injectors 40 are sprayed in the same direction, for example, as shown in Figure 4, the injectors 40 operate to the right in the drawing, causing the dissolving liquid 44 to flow in the same direction. This dissolving liquid 44 generates a large amount of fast liquid flow, which generates a force that scrapes the low-melting-point glass 16.

[0035] Furthermore, since the dissolving liquid 44 contains hydrofluoric acid that dissolves the low-melting-point glass 16, this, together with the liquid flow, promotes the peeling of the conductive layer 14.

[0036] For a more detailed explanation, Fig. 5 is used. Fig. 5 is an enlarged view of a portion of the rear glass 10 from which the conductive layer 14 is peeled. Fig. 5(A) is a view showing the state before the peeling method is performed. The conductive layer 14 is adhered to the rear glass 10 via low-melting point glass 16.

[0037] After the peeling means is started, the dissolving liquid 44 flows and dissolves the low-melting-point glass 16. Since the conductive layer 14 is flexible, it moves with the flow of the liquid as the low-melting-point glass 16 begins to melt, as shown in FIG.

[0038] That is, the conductive layer can be efficiently recovered by causing the liquid flow of the dissolving liquid 44 to collide with the longitudinal portions of the conductive layer and the low-melting-point glass 12. The spray direction is not limited to the example direction as long as it has a horizontal component.

[0039] Furthermore, when the rear glass 10 is sprayed in the processing chamber, the dissolving liquid 44 is less likely to flow onto the rear glass 10 on the side of the transport roller 20. Because the dissolving liquid 44 is less likely to act on that part of the rear glass, less sludge is deposited on the entire rear glass 10. This eliminates the need to separate the sludge during recovery, making it easier to recover the conductive layer.

[0040] Another embodiment of the injection means is a method in which the injection device 40 reciprocates in a specific direction to generate liquid flows from both the conductive layer and the longitudinal portion of the low-melting-point glass 12 .

[0041] As shown in FIG. 6, the injection device 40 operates in the left direction shown in the figure, and the dissolution liquid 44 flows in the same direction. By generating the liquid flow of the dissolution liquid 44 in the same manner as described above, the peeling of the conductive layer 14 is promoted. By repeating the reciprocating operation as shown in FIGS. 4 and 6, a force can be applied to the low melting point glass 16 from a different direction. For example, when the rear glass 10 is conveyed so that the directions of the conductive layer and the low melting point glass 12 and the conveying direction are the same, the injection device 40 is reciprocated in a direction orthogonal to the conveying direction.

[0042] In this way, by the reciprocating operation of the injection device 40, dissolution can be promoted from both the longitudinal portions of the conductive layer and the low melting point glass 12.

[0043] When performing the above series of injection means, there is a cover from the pretreatment chamber 24 to the cleaning unit 34, the dissolution liquid 44 is recovered without leakage, and the gas in the chamber is processed via the gas collecting pipe 38. Therefore, the plate glass processing device is hermetically and watertightly closed as a whole. The dissolution liquid containing hydrofluoric acid does not flow out to the outside, and the gas containing fluorine ions does not scatter.

[0044] After the injection means, the plate glass processing device washes away the remaining dissolution liquid 44 on the rear glass 10 in the process of the cleaning unit 34 (see FIGS. 2 and 3).

[0045] The rear glass 10 that has completed all the processes is carried out at the carry-out unit 36. At the carry-out unit 36, it is carried out by manual work by an operator or automatic work by a robot or the like.

[0046] The carried-out rear glass 10 hardly contains the conductive layer 14 and is in a state where it is easy to recycle.

[0047] The recovery means of the conductive layer 14 will be described below. As shown in FIGS. 4 and 6, the plate-shaped glass processing apparatus has a net-like structure 42 as a recovery means below the carry-in roller 20. When the dissolving solution 44 mainly containing the conductive layer 14 flows downward according to gravity, the conductive layer 14 is mainly filtered by this net-like structure 42, and the dissolving solution 44 can flow through.

[0048] Since the performance of the heating wire depends on the content rate of silver, its alloy, etc. contained in the conductive layer 14, the content rate of these substances differs for each product of the rear glass. The specific gravity of the conductive layer with respect to the dissolving solution changes. Therefore, there is a conductive layer that precipitates in the dissolving solution and a conductive layer that floats in the dissolving solution. Therefore, by adopting the method of filtering out the conductive layer 14 as described above, the conductive layer can be easily recovered regardless of its specific gravity.

[0049] When a certain number of sheets are processed, the conductive layer 14 mainly accumulates on the net-like structure 42, and thus the conductive layer 14 is recovered.

[0050] Furthermore, as shown in FIG. 7, it is desirable that the above-described recovery means is provided with a plurality of acid-resistant filters 46 having different filter mesh coarseness. When a plurality of filters 46 are provided at the location where the dissolving solution flows in, the surface area for filtering out the conductive layer 14 becomes large, and the conductive layer 14 can be recovered more efficiently. Also, since the dissolving solution 44 is an acidic solution containing hydrofluoric acid, as long as it is a filter made of an acid-resistant resin or the like, it can be used for a long time and the operation cost can be reduced.

[0051] As shown in FIG. 7, the plurality of filters 46 provided at the location where the dissolving solution flows in are arranged such that the filter mesh coarseness becomes coarser to finer from the upstream to the downstream. When the dissolving solution 44 passes through these filters, the conductive layer 14 with a large size accumulates on the filter 46 with a coarse filter mesh. On the filter 46 with a fine mesh, the conductive layer 14 with a relatively small size accumulates.

[0052] The above-described embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above-described embodiments. Furthermore, the scope of the present invention is intended to include all modifications that are equivalent to the claims and fall within their scope. [Explanation of symbols]

[0053] 10-Rear window 12-Conductive layer and low-melting glass 14-Conductive layer 16-Low Melting Point Glass 18-Black part 20-Transport roller 22-Loading area 24-Pretreatment Chamber 26—First processing chamber 28—Second processing chamber 30—Third processing chamber 32-Fourth processing chamber 34-Cleaning section 36-Export Section 38-Air collection pipe 40-Injector 42-Reticulated structure 44-Solution solution 46-Filter

Claims

1. A plate-shaped glass processing apparatus for processing a plate-shaped glass with a conductive layer attached thereto through a low-melting glass having a softening point in the range of 300°C or higher and 500°C or lower, comprising: a processing chamber having at least injection means for injecting a melting solution capable of melting the low-melting glass onto the plate-shaped glass with a conductive layer from above; conveying means for conveying the plate-shaped glass with a conductive layer through the processing chamber such that the portion with the conductive layer is on the upper side; and recovery means configured to recover the conductive layer peeled off from the plate-shaped glass with a conductive layer. The injection means generates a liquid flow of the melting solution on the upper surface of the plate-shaped glass with a conductive layer and injects the melting solution so as to have a horizontal component. The plate-shaped glass processing apparatus is characterized by this.

2. The recovery means is a plurality of acid-resistant filters provided at a location where the melting solution flows in, and the filters are arranged such that the coarseness of the filter mesh becomes finer from upstream to downstream. The plate-shaped glass processing apparatus according to claim 1 is characterized by this.

3. The plate-shaped glass processing apparatus according to claim 1 or 2, wherein the injection means has an injection device that reciprocates perpendicular to the conveying direction.

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