JP7022329B2 - Sheet glass manufacturing method and manufacturing equipment - Google Patents

Description

The present invention relates to a plate glass manufacturing method including an end face grinding step of grinding an end face of a plate glass and an end face polishing step of polishing the end face of the plate glass after grinding, and a plate glass manufacturing apparatus capable of executing both steps. ..

As is well known, since cracks remain on the end face (cut surface) of the plate glass that has undergone the cutting process using the scribe wheel, the plate glass may be cracked or glass powder may be generated from the end surface in the subsequent process. It causes the problem. In order to avoid such a problem, in the plate glass manufacturing process, it is customary to perform an end face grinding process for grinding the end face of the plate glass and an end face polishing step for polishing the end face of the plate glass after grinding (). See Patent Document 1).

As an example of the embodiment in which both of the above steps are performed, the following aspects can be mentioned. That is, in order to execute the end face grinding process, a grinding wheel having a groove capable of grinding the end face of the plate glass formed on the outer peripheral portion is used. Then, by grinding while pressing the grinding wheel against the end face of the plate glass, the shape of the end face is processed so as to follow the shape of the groove. As a result, the end face is ground and the ridgeline of the end face is chamfered to form a round or flat chamfered surface. Further, in order to execute the end face polishing step, a plurality of polishing grindstones having grooves formed on the outer peripheral portion capable of polishing the end face of the plate glass are used. Then, by polishing while sequentially pressing a plurality of polishing grindstones against the end face of the plate glass after grinding, the end face including the chamfered surface is finished.

Special Table 2014-518169 Gazette

By the way, when the end face grinding step and the end face polishing step are executed under the above aspect, cracks are generated every time the polishing grindstone is pressed against the end face of the plate glass after grinding, and as a result, after the end face polishing step. In some cases, the quality of the end face of the grindstone was deteriorated. When the quality of the end face is deteriorated, glass powder is likely to be generated from the end face, which may cause wiring defects when the flat glass is used as a glass substrate of an electronic device. The present invention made in view of such circumstances has a technical problem of improving the quality of the end face by suppressing cracks remaining on the end face as much as possible.

The present invention, which was devised to solve the above problems, is a method for manufacturing a plate glass including an end face polishing step for grinding the end face of the plate glass and an end face polishing step for polishing the end face of the plate glass after grinding. The end face polishing step is the first polishing step of polishing while pressing the first polishing grindstone against the end face of the plate glass with the first pressing force, and the second pressing force against the end face of the plate glass after polishing with the first polishing grindstone. It includes a second polishing step of polishing while pressing a second polishing grindstone, and is characterized in that the second pressing pressure is smaller than the first pressing pressure.

In the end face polishing step in this method, the first polishing step of polishing while pressing the first polishing grindstone against the end face of the plate glass after grinding with the first pressing pressure is executed. Further, under a second pressing pressure smaller than the first pressing pressure, a second polishing step of polishing while pressing the second polishing grindstone against the end face after polishing with the first polishing grindstone is executed. According to this end face polishing step, it is possible to suppress cracks generated on the end face in the second polishing step by the amount that the second pressing force is smaller than the first pressing force. As a result, cracks remaining on the end face of the obtained flat glass can be suppressed as much as possible, and the quality of the end face can be improved.

In the above method, it is preferable that the lockwell hardness HRM of the binder for fixing the abrasive grains of the second polishing wheel is HRM or less of the lockwell hardness HRM of the binder for fixing the abrasive grains of the first polishing wheel.

By doing so, cracks generated on the end face in the second polishing step can be further suppressed, which is further advantageous in improving the quality of the end face of the flat glass.

In the above method, it is preferable to use a phenol resin, a polyurethane resin or a polyimide resin as a binder of the first polishing grindstone and a polyurethane resin or an epoxy resin as a binder of the second polishing grindstone.

By doing so, the lockwell hardness HRM of the binder of the second polishing wheel can be made equal to or less than the rockwell hardness HRM of the binder of the first polishing wheel, which is more advantageous in enhancing the above-mentioned actions and effects. Become.

Further, the present invention, which was devised to solve the above problems, is a plate glass manufacturing apparatus provided with a grinding wheel for grinding the end face of the plate glass and a polishing grindstone for polishing the end surface of the plate glass after grinding. As the polishing grindstone, the first polishing grindstone that polishes while being pressed against the end face of the plate glass with the first pressing pressure, and the first polishing grindstone that is pressed against the end face of the plate glass after polishing with the first polishing grindstone with the second pressing pressure. It has a second polishing grindstone that grinds in the state of being polished, and is characterized in that the second pressing force is smaller than the first pressing force.

According to this apparatus, it is possible to obtain the same action / effect as the above-mentioned action / effect in the above description of the method for manufacturing a flat glass.

According to the present invention, cracks remaining on the end face can be suppressed as much as possible, and the quality of the end face can be improved.

It is a top view which shows the manufacturing method and manufacturing apparatus of the flat glass which concerns on embodiment of this invention.

Hereinafter, a method for manufacturing a flat glass and a manufacturing apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the plate glass manufacturing apparatus 1 (hereinafter, simply referred to as manufacturing apparatus 1) according to the present embodiment is used to execute the plate glass manufacturing method according to the present embodiment. The manufacturing apparatus 1 includes a grinding wheel 2 that grinds the end face Ga of the plate glass G, a first polishing grindstone 3 that first grinds the end face Ga of the plate glass G after grinding, and a second polishing grindstone 4 that grinds the end face Ga later. ing. Here, in the present embodiment, a manufacturing apparatus 1 for performing grinding and polishing on both end faces Ga and Ga extending in the X direction of a rectangular flat glass G in a flat position will be given as an example.

The flat glass G is molded by a known molding method such as a float method, an overflow down draw method, and a slot down draw method, and is cut into a predetermined size. The thickness of the plate glass G is preferably 0.1 mm to 1.4 mm, more preferably 0.2 mm to 0.7 mm, and most preferably 0.2 mm to 0.5 mm. The flat glass G is preferably a glass substrate used for flat panel displays, touch panels, solar cells, organic EL lighting, and the like. Flat panel displays on which a glass substrate is used include, for example, liquid crystal displays and organic EL displays.

In order to process both end surfaces Ga and Ga of the plate glass G, the grinding wheel 2, the first polishing wheel 3 and the second polishing wheel 4 are arranged so as to be paired with the plate glass G interposed therebetween. Each pair of the grinding wheel 2, the first polishing wheel 3, and the second polishing wheel 4 is in the X direction in synchronization with the plate glass G fixed on the surface plate (not shown) provided in the manufacturing apparatus 1. Processing is performed while moving in the T direction parallel to. Grooves (not shown) for processing the end face Ga are formed on the outer peripheral portions (rotating peripheral portions) of these grindstones 2, 3 and 4 in a plurality of upper and lower stages. The end face Ga is processed by pressing one of the plurality of stages of grooves against the end face Ga. Further, the rotation directions of these grindstones 2, 3 and 4 may be clockwise (in a plan view) or counterclockwise when viewed from the Z direction.

The grinding wheel 2 is a grindstone for forming a cross-sectional shape of the end face Ga (a shape of a cross section orthogonal to the X direction), and the end face Ga is machined under a state where the position in the Y direction is fixed. On the other hand, the first polishing grindstone 3 and the second polishing grindstone 4 are grindstones for finishing the end face Ga after grinding, and are pressed against the end face Ga with a constant pressing force. The end face Ga is processed under the bottom. The grinding wheel 2 may grind the end face Ga in a state of being pressed against the end face Ga with a constant pressing force.

Here, comparing the first pressing force F1 for pressing the first polishing wheel 3 against the end surface Ga and the second pressing force F2 for pressing the second polishing wheel 4 against the end surface Ga, the second pressing force F2 is higher. It's getting smaller. The "pushing pressure" referred to here is a force that acts in parallel with the Y direction and whose unit is represented by [N]. From the viewpoint of further suppressing cracks generated in the end face Ga, the second pressing force F2 is preferably 0.8 times or less, more preferably 0.6 times or less the first pressing force F1. Further, from the viewpoint of ensuring the amount of polishing by the second polishing grindstone 4, the second pressing pressure F2 is preferably 0.1 times or more, more preferably 0.2 times or more the first pressing pressure F1. preferable.

The first pressing force F1 is preferably 30N to 100N, more preferably 40N to 80N. The second pressing force F2 is preferably 3N to 80N, more preferably 5N to 40N, and most preferably 10N to 30N.

The grinding wheel 2 is preferably a metal bond grindstone in which a metal bond (metal bond) is used as the bond for the abrasive grains. The metal used as the binder is preferably one selected from iron, copper, cobalt, nickel, tungsten and the like, or one selected from two or more and mixed, and particularly preferably one containing iron. The abrasive grains bonded to the grinding wheel 2 are preferably diamond abrasive grains, and the particle size is preferably # 300 to 600.

The first polishing grindstone 3 and the second polishing grindstone 4 are preferably resin bond grindstones in which a resin binder (resin bond) is used as the binder for the abrasive grains. It is preferable to use a thermosetting resin as the resin binder. As a specific example, a phenol resin, an epoxy resin, a polyimide resin, a polyurethane resin or the like can be adopted as the resin binder. The abrasive grains bonded to the first polishing wheel 3 and the second polishing wheel 4 include diamond particles, aluminum oxide particles, silicon carbide particles, cubic boron nitride particles, metal oxide particles, metal carbide particles, and metal nitride particles. Etc. can be used. The particle size of the abrasive grains is preferably # 100 to 3000, and more preferably # 200 to 1000.

Here, in order to further suppress cracks generated in the end face Ga in the second polishing step, the lockwell hardness HRM of the binder of the second polishing wheel 4 is equal to or less than the rockwell hardness HRM of the binder of the first polishing wheel 3. It has become. When trying to satisfy the relationship of the Rockwell hardness HRM, as an example, any one of a phenol resin, a polyurethane resin, and a polyimide resin is adopted as a binder of the first polishing grindstone 3, and the second polishing grindstone 4 is used. Either a polyurethane resin or an epoxy resin may be used as the binder.

The lockwell hardness HRM of the binder of the first polishing wheel 3 is preferably 50 to 130. Further, the lockwell hardness HRM of the binder of the second polishing wheel 4 is preferably 50 to 110. Here, the lockwell hardness HRM of the binder means the rockwell hardness HRM of the binder alone without containing a filler or the like.

Hereinafter, a method for manufacturing a flat glass using the above-mentioned manufacturing apparatus 1 will be described.

In this method for manufacturing a flat glass, first, the flat glass G is carried to a position where a surface plate is installed by a transport means (for example, a belt conveyor or the like) (not shown), and then the flat glass G is fixed on the surface plate. This flat glass G is a glass that has already undergone a cutting step, and each of both end faces Ga and Ga is a cut surface formed by the cutting step.

Next, an end face grinding step of grinding the end face Ga of the plate glass G and an end face polishing step of polishing the end face Ga of the plate glass G after grinding are executed.

In the end face grinding step, the end face Ga of the plate glass G, which is the cut surface, is ground by the grinding wheel 2. As a result, the cross-sectional shape of the end face Ga is formed. In the end face polishing step, the first polishing step of polishing while pressing the first polishing grindstone 3 against the end face Ga of the plate glass G after grinding with the first pressing force F1, and the plate glass G after polishing with the first polishing grindstone 3. The second polishing step of polishing while pressing the second polishing grindstone 4 against the end surface Ga of the second pressing pressure F2 is executed. As a result, finishing processing is performed to reduce the surface roughness of the end face Ga. When the processing of the entire length of the end face Ga by the grinding wheel 2, the first polishing wheel 3, and the second polishing wheel 4 is completed, the end face grinding step and the end face polishing step are completed. The quality of the end face Ga after the end face polishing step can be evaluated by, for example, the magnitude of the surface roughness Ra.

When the end face grinding step and the end face polishing step are completed, the plate glass G on the surface plate that has been ground and polished on the end face Ga is released from fixing, and then the plate glass G is again removed from the position where the surface plate is installed by the transport means. Carry it out and send it to the downstream process. In the downstream process, for example, the end face Gb orthogonal to the end face Ga is subjected to grinding and polishing in the same manner as in the above-mentioned end face grinding step and end face polishing step. After that, the plate glass G is subjected to a cleaning treatment.

Hereinafter, the method for manufacturing the flat glass and the main actions / effects of the manufacturing apparatus 1 will be described.

According to the above-mentioned method for manufacturing flat glass and manufacturing apparatus 1, it is possible to suppress cracks generated in the end face Ga in the second polishing step by the amount that the second pressing force F2 is smaller than the first pressing force F1. Will be. As a result, cracks remaining on the end face Ga of the obtained flat glass G can be suppressed as much as possible, and the quality of the end face Ga can be improved.

Here, the method and apparatus for manufacturing a flat glass according to the present invention are not limited to the embodiments and configurations described in the above embodiments. For example, in addition to the first polishing wheel 3 and the second polishing wheel 4, a new polishing wheel may be introduced. With this new polishing grindstone (third polishing grindstone), the end face Ga may be polished after the end face Ga is ground by the grinding wheel 2 and before the end face Ga is polished by the first polishing grindstone 3. .. In this case, the third pressing force for pressing the third polishing wheel against the end face Ga may be smaller or larger than the first pressing force F1. This is because the cracks generated in the end face Ga in the polishing process with the third polishing grindstone can be almost removed in the first and second polishing steps, and the influence on the quality of the end face Ga is small.

Further, in the above embodiment, only a pair of grinding wheels 2 is used, but the present invention is not limited to this. The grinding process may be performed using two or more pairs of grinding wheels 2.

Further, in the above embodiment, each pair of the grinding wheel 2, the first polishing wheel 3, and the second polishing wheel 4 performs processing of both end surfaces Ga and Ga in a synchronized state, but the present invention is not limited to this. The grinding wheel 2, the first polishing wheel 3, and the second polishing wheel 4 may be processed only on one end surface Ga without forming a pair. In this case, a plurality of grinding wheels 2 may be used. Further, each pair of the grinding wheel 2, the first polishing wheel 3, and the second polishing wheel 4 may be processed on one end face Ga and then on the other end face Ga without synchronization. good.

1 Plate glass manufacturing equipment 2 Grinding grindstone 3 First polishing grindstone 4 Second polishing grindstone F1 First pressing pressure F2 Second pressing pressure G Plate glass Ga End face of plate glass

Claims (3)

A method for manufacturing a plate glass, which includes an end face grinding step of grinding the end face of the plate glass with a grinding wheel and an end face polishing step of polishing the end face of the plate glass after grinding.
The end face polishing step is a first polishing step of polishing while pressing the first polishing grindstone against the end face of the plate glass with the first pressing pressure, and the end face of the plate glass after polishing with the first polishing grindstone. Including the second polishing step of polishing while pressing the second polishing grindstone with the second pressing pressure,
The grinding wheel, the first polishing wheel, and the second polishing wheel are arranged side by side in the direction along the end face of the plate glass.
The magnitude of the second pressing force is set to 0.8 to 0.1 times the magnitude of the first pressing force.
A method for producing a flat glass, wherein the lockwell hardness HRM of the binder for fixing the abrasive grains of the second polishing wheel is set to be equal to or less than the lockwell hardness HRM of the binder for fixing the abrasive grains of the first polishing wheel. .. The plate glass according to claim 1, wherein a phenol resin, a polyurethane resin or a polyimide resin is used as a binder for the first polishing grindstone, and a polyurethane resin or an epoxy resin is used as a binder for the second polishing grindstone. Production method. It is a plate glass manufacturing apparatus provided with a grinding wheel for grinding the end face of the plate glass and a polishing wheel for polishing the end surface of the plate glass after grinding.
As the polishing grindstone, a first polishing grindstone that polishes while being pressed against the end face of the plate glass with the first pressing pressure, and a second pressing against the end face of the plate glass after polishing with the first polishing grindstone. It has a second polishing grindstone that grinds in a pressure-pressed state,
The grinding wheel, the first polishing wheel, and the second polishing wheel are arranged side by side in the direction along the end face of the plate glass.
The magnitude of the second pressing force is 0.8 to 0.1 times the magnitude of the first pressing force.
A plate glass manufacturing apparatus characterized in that the lockwell hardness HRM of the binder for fixing the abrasive grains of the second polishing wheel is equal to or less than the lockwell hardness HRM of the binder for fixing the abrasive grains of the first polishing wheel. ..

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