JP2006175526A - Blast method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blast device, adapted to circulating and reusing abrasive, favorably preventing coarse foreign matter from entering the abrasive injected to a workpiece and lengthening the cleaning period. <P>SOLUTION: In this blast working device, granular powder abrasive stored in a storage tank 15 is sent to a working device 12 to perform blast working, the injected abrasive and the cut material to be ground are sent to a wind force classifier 14 by negative pressure, and the abrasive is separated and returned to the storage tank. An ultrasonic screen 25 including a net-like body having such scale division to permit the abrasive to pass and inhibit coarse foreign matter from passing is disposed in a circulating passage for the abrasive, thereby separating coarse foreign matter without clogging over a long period of time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blasting method and apparatus for spraying and grinding a fine powdery abrasive on a workpiece at high speed, and more particularly to a blasting method and apparatus configured to circulate and reuse the abrasive.

  In the step of forming ribs (barriers) on the back plate of a plasma display panel (hereinafter referred to as PDP), first, as shown in FIG. 2 (a), glass paste 3 is applied to the surface of glass substrate 1 provided with electrodes 2 on the surface. Is applied to a certain thickness, a photosensitive resin film 4 is attached to the surface, a mask with a predetermined pattern is placed on the surface, exposed, developed, and a glass paste as shown in FIG. An intermediate product (hereinafter referred to as a workpiece) 5 in which the exposed resin film 4 is left only in a region to be left as a rib 3 is manufactured, and thereafter, a fine powdery abrasive is applied from the injection device 12 to the workpiece 5. As shown in FIG. 2C, blasting is performed to grind and remove a portion of the glass paste that is not protected by the resin film 4, and the rib 3a is formed from the remaining glass paste. It has been rope.

  In an apparatus for performing this blasting process, generally, the abrasive is circulated and reused to reduce running costs. That is, the conventional blasting apparatus is provided in a blasting chamber 10 as shown in FIG. 3, and is a blast gun that blows a fine powdery abrasive onto the workpiece 5 by compressed air from a compressed air supply pipe 11. A processing apparatus 12, an abrasive material after injection, an exhaust path 13 for moving the object to be ground removed from the workpiece by negative pressure, and an abrasive material contained in the airflow sent through the exhaust path 13 A wind classifier 14 that separates and drops using wind power, a storage tank 15 that stores the abrasive that has been separated and dropped by the wind classifier 14, and is connected to the storage tank 15 to supply the abrasive. It has a supply device 16, a supply path 17 for transporting abrasives from the supply device 16 to the processing device 12, and a suction blower that exhausts the blast chamber 10 through the air classification device 14. A dust collector 18 that collects dust such as an object to be ground contained in the airflow from the apparatus 14 is provided, and the abrasive and the object to be ground from the blast chamber 10 are turned into an airflow by the suction force of the dust collector 18. It is put on and supplied to the wind classifier 14 via the exhaust path 13, and the wind classifier 14 separates the normal abrasive from the air flow accompanied by the ground material to be ground or the crushed abrasive, and stored below. On the other hand, dust such as an object to be ground or a crushed abrasive is sent to the dust collector 18 in a state of being placed in an air current and collected by the dust collector 18. The grinding material collected in the storage tank 15 is weighed by the supply device 16 so as to be a predetermined supply amount, rides on the air flow generated by the suction force by the processing device 12 and passes through the supply path 17 to the processing device 12. Supplied and reused for blasting.

  However, in the blast processing apparatus of this configuration, although only normal abrasives are separated and reused by the air classifier 14, the abrasives collected in the storage tank 15 are more than the abrasives. Large coarse particles such as agglomerated workpieces (glass paste powder) (abrasives may be mixed therein), the resin film remaining on the surface of the workpiece 5 may be peeled off or torn When this is sprayed on the workpiece 5 at a high speed, the rib 3a to be formed on the workpiece 5 may be damaged. The ribs 3a formed on the back plate of the PDP are usually very small with a height of about 150 to 200 μm and a gap between the ribs of about 100 μm, and this is formed over the entire area of the back plate. If there is a defect in the rib 3a even at a location, the back plate cannot be used, and such a defect in the rib must be avoided.

Therefore, in order to remove coarse foreign matters, it is known to provide a foreign matter separating / classifying device 19 for removing coarse foreign matters in the exhaust path 13 and the supply path 17 as shown in FIG. One example is described in Patent Document 1. In the foreign matter separating / classifying apparatus described in Patent Document 1, a mesh body is provided at the upper part of a main body to which an air flow accompanied by an abrasive and foreign matters is sent, and an upward air flow is generated in the main body. At the same time, the mesh body is allowed to pass upward, but the coarse foreign matter is blocked from passing by the mesh body and dropped downward by its own weight.
JP-A-9-193019

  However, even if the structure is such that coarse foreign matter blocked from passing by the mesh body is dropped downward as in the foreign matter separation and classification device shown in Patent Document 1, the mesh body is clogged during use, and in particular, the exhaust path 13 In the foreign matter separating / classifying apparatus arranged in the above, clogging progresses quickly, and there is a problem that it is necessary to frequently clean and replace the mesh. For example, the exhaust path 13 of the blast processing apparatus is provided with a foreign matter separating / classifying device having a 200-350 mesh network having a size of 500 mm × 500 mm in length and width, and the flow rate of the abrasive circulating in the system is 5-20 kg. When the continuous operation was performed at a rate of 10 minutes / minute, it was necessary to clean the mesh at 10 to 20 h / time. In addition, even if a foreign matter separating / classifying device provided with a mesh is provided in each of the exhaust passage 13 and the supply passage 17, there is a problem that coarse foreign matters cannot be removed reliably and rib defects cannot be prevented sufficiently. .

  The present invention has been made in view of such a situation, and in a blasting apparatus configured to circulate and reuse abrasives, a sieve having a mesh body is provided in a circulating path of the abrasives to remove coarse foreign substances from the abrasives. Provided is a blasting apparatus that can be removed more reliably than before and can prevent clogging of the mesh for a long period of time, and a blasting method using the blasting apparatus. This is the issue.

  As a result of studies to solve the above problems, the present inventors have found the following matters. In other words, in the conventional foreign matter separation / classification device provided in the exhaust path and supply path of the blast processing device, it is included in the airflow flowing in the path rather than being trapped by the coarse foreign matter being caught by the mesh. The object to be ground (sized to be able to pass through the mesh body) adheres to the mesh body and grows up to cause clogging, but when the mesh body is vibrated ultrasonically, the object to be ground Can be prevented from adhering to the mesh body and growing on the mesh body, and the coarse foreign matter stopped by the mesh body is pushed by the subsequent abrasive while it adheres to the mesh body and forcibly passes through the mesh. However, when the mesh body is ultrasonically vibrated, coarse foreign matter does not adhere to the mesh body, and for this reason, it is almost impossible that the mesh body is pushed by the subsequent abrasive and forcibly passes through the mesh body. It found no.

  The present invention has been made based on such knowledge, a storage tank for storing a fine powdery abrasive, a supply device for supplying an abrasive connected to the storage tank, and an abrasive from the supply device. A supply path for transporting, a processing device comprising a blast gun for injecting abrasive material transported from the supply path onto the workpiece, and an exhaust for moving the abrasive material and workpiece to be ground sprayed from the processing apparatus by negative pressure A path, a grinding material transported from the exhaust path, and a workpiece to be classified, a classifier connected to send the abrasive to the storage tank, and a classifier connected to the classifier to collect the classified dust In the blast processing apparatus provided with a dust collecting device, the abrasive is in a circulation path of the abrasive that returns from the storage tank to the storage tank through the supply device, supply path, processing device, exhaust path, and classification device. Passed That it is obtained by a structure that coarse foreign matter provided an ultrasonic sieve having a mesh of opening the eye that does not pass.

  Here, the installation position of the ultrasonic sieve is arbitrary as long as it is within the circulation path of the abrasive, and in one form, it can be in the path from the classification device to the supply device. Moreover, in another form, the inside of the said exhaust path or the said supply path can be mentioned.

  Furthermore, the ultrasonic sieve provided in the circulation path is not limited to being provided in one place, and may be provided in at least two places of the route from the classifier to the supply device, the exhaust route, and the supply route.

  When the ultrasonic sieve is installed at one place in the circulation path of the abrasive, not only when providing only one ultrasonic sieve, but also providing ultrasonic sieves on a plurality of paths arranged in parallel with each other, A configuration in which a plurality of routes are switched and used, or a configuration in which a plurality of routes are used simultaneously may be employed. If it is set as the structure which switches and uses a some path | route, the operation | work of cleaning of an ultrasonic sieve or the replacement | exchange of a mesh body can be performed, without stopping the driving | operation of a blast processing apparatus. In addition, when a plurality of paths are used at the same time, a small ultrasonic sieve can be used.

  The ultrasonic sieve is not limited to a configuration in which only the ultrasonic vibration is applied to the mesh body, but may be a configuration in which an ultrasonic vibration and a normal vibration are applied, which causes further clogging. Can be difficult.

  As a classification device provided in the above-described blast processing device, an air classification device can be exemplified as a typical one.

  The blasting method of the present invention is characterized by blasting using the above-described blasting apparatus. Here, the workpiece to be subjected to blasting can be any material that requires blasting, but the present invention can be a plasma display panel member such as a back plate of a plasma display panel. It is preferable because the effect of application is great.

  The blasting apparatus of the present invention can separate coarse foreign matter from the abrasive by providing an ultrasonic sieve provided with an open mesh that does not allow coarse foreign matter to pass through the circulation path of the abrasive. At this time, since the mesh body of the ultrasonic sieve is ultrasonically vibrated, there is no growth of foreign matter such as a fine object to be ground on the mesh body, and there is no coarse foreign matter that is prevented from passing through. It does not adhere to the mesh body, and therefore, clogging does not occur for a long period of time, and it is difficult for coarse foreign matter to be pushed by the subsequent abrasive and pass through the mesh body. Thus, it is possible to reliably capture coarse foreign matter, avoid troubles due to coarse foreign matter in blasting, increase the period of cleaning and replacing the screen of the ultrasonic sieve, and operate continuously for a long period of time. Can be obtained.

  Here, by adopting a configuration in which not only ultrasonic vibration but also normal vibration is applied to the mesh of the ultrasonic sieve, coarse foreign matters that have been prevented from passing through can be moved to an appropriate position and collected. Can be operated continuously.

  In the blasting method using the blasting apparatus of the present invention, coarse foreign matters that may be mixed into the abrasive can be removed very well, so troubles due to the blowing of coarse foreign matters can be avoided. When applied to blasting of a plasma display panel member such as a back plate of a plasma display panel, damage that may be caused by spraying coarse foreign matter, such as rib defects, can be prevented, and the product yield can be greatly improved.

  FIG. 1 is a schematic configuration diagram showing a blasting apparatus according to a preferred embodiment of the present invention. The same or similar parts as those of the conventional blasting apparatus shown in FIG. . The blasting apparatus shown in FIG. 1 is used to form ribs on the back plate of a plasma display panel (PDP). The blasting apparatus is provided in a blast chamber 10 and is finely divided by compressed air from a compressed air supply pipe 11. A processing device 12 composed of a blast gun for injecting a shaped abrasive material onto the workpiece 5, and the injected abrasive material and foreign matter such as the object to be ground removed from the workpiece on an air flow generated by negative pressure An exhaust path 13 to be moved, an air classifier 14 configured to classify the abrasive and foreign matter sent through the exhaust path 13 using wind force, and send the abrasive material downward using its own weight, and the wind force An ultrasonic sieve 25 that is disposed under the classifier 14 and allows the abrasives separated by the wind classifier 14 and falling by its own weight to pass therethrough but allows coarse particles to be trapped, and passes through the ultrasonic sieve 25. A storage tank 15 for storing the abrasive that has fallen in this way, a supply device 16 connected to the storage tank 15 for measuring and supplying the abrasive at a predetermined flow rate, and the abrasive from the supply device 16 in the blast chamber 10 And a suction passage for applying a negative pressure to the blast chamber 10 through the air classifier 14, and dust such as an object to be ground contained in the airflow from the air classifier 14. A dust collector 18 to be collected is provided.

  The ultrasonic sieve 25 provided between the air classifier 14 and the storage tank 15 is capable of allowing abrasives falling by its own weight to pass therethrough, but does not allow coarse foreign matters to pass through. A vibrator 27 for ultrasonically vibrating the mesh body 26, an ultrasonic oscillator 28, and the like are provided. As this ultrasonic sieve 25, what is described in the patent 3509863 gazette can be used, for example. As described above, the openings (openings) of the mesh-like body 26 are determined so that abrasives can pass through but coarse particles are not allowed to pass through. When using the one having a diameter of 60 μm, a wire mesh of 250 mesh and an opening (aperture) of 63 μm is used.

  Next, the blasting operation by the blasting apparatus having the above configuration will be described. As shown in FIG. 2, this blasting apparatus performs a blasting process on a workpiece 5 having a structure in which a resin film 4 after exposure is left only in a region to be left as a rib of the glass paste 3. The portion of the glass paste not protected by 4 is ground and removed to form the rib rib 3a. In FIG. 1, a workpiece 5 is continuously conveyed in a blast chamber 10, and a processing device 12 compresses a fine powdery abrasive from the compressed air supply pipe 11 to the workpiece 5. Sprayed at high speed with air to perform blasting. The abrasive is sent from the storage tank 15 to the supply device 16, measured by the supply device 16 so as to have a predetermined flow rate, rides on the air flow generated by the suction force of the processing device 12, and passes through the supply path 17. 12 is supplied.

  The abrasive used for blasting in the blast chamber 10 and foreign matter such as the workpiece to be ground from the workpiece 5 by blasting ride on the air flow generated by the negative pressure due to the suction force of the dust collecting device 18 and blast chamber. 10 through the exhaust path 13 to the wind classifier 14, and the wind classifier 14 separates normal abrasives and foreign matter. That is, normal abrasives are separated from the airflow and fall downward, and foreign matter such as an object to be ground and crushed abrasives are sucked together with the airflow by the dust collector 18 and collected by the dust collector 18. The abrasive that has been separated and dropped by the air classifier 14 is returned to the storage tank 15 through the ultrasonic sieve 25.

  By the way, when the normal abrasive is separated from the air flow by the air classifier 14, the object to be ground (glass paste powder) is aggregated (the abrasive may be mixed therein), the work 5 Coarse foreign matters such as those from which the resin film remaining on the surface is peeled off or torn off are separated from the air flow, although they are extremely small, and may be mixed with normal abrasives and fall downward. However, these coarse foreign matters cannot pass through the mesh 26 of the ultrasonic sieve 25 and are captured on the mesh 26. Here, in the ultrasonic sieve 25, since the mesh body 26 is ultrasonically vibrated, the abrasive material that can pass through does not cause a bridging phenomenon on the mesh body 26 and cannot pass through, so that the mesh material 26 can pass through very quickly. It is possible to pass through the reticulate body 26 and to pass the abrasive that simply falls by its own weight without any trouble. The coarse foreign matter that has been prevented from passing through is in a state of dancing on the mesh body 26 due to the ultrasonic vibration of the mesh body 26, so that clogging does not occur. Even if a fine object to be ground falls, it does not pass through the mesh body 26 and adhere to the mesh body 26 or grow at the adhered position. Thus, continuous operation is possible without clogging over a long period of time. Further, as described above, the coarse foreign matter that is prevented from passing through by the mesh body 26 is in a state where the mesh body 26 is dancing on the top, and therefore hardly adheres to the mesh body 26, and therefore, the subsequent grinding. There is no need to forcibly pass through the net 26 by being pushed by the material. In addition, since the abrasive falls by its own weight, the speed is lower than when it is transported by an air current. Therefore, even if it hits the coarse foreign matter on the mesh body 26, the force pushing the coarse foreign matter is small. The net 26 does not pass through even from a point. Thus, the ultrasonic sieve 25 can very surely capture coarse foreign matter, and the storage material 15 is returned to the storage tank 15 and is reused.

  As described above, in this blasting apparatus, since coarse foreign matter is hardly mixed in the abrasive returned to the storage tank 15, coarse foreign matter is not removed when blasting is performed using the abrasive in the storage tank 15. Since the workpiece 5 is not sprayed, the rib 3a (see FIG. 2) formed on the workpiece 5 is hardly lost due to coarse foreign matter. Thus, the product yield can be significantly improved when rib processing is performed on the back plate of the PDP. Furthermore, since almost no coarse foreign matter is mixed in the storage tank 15, the coarse foreign matter is not sent to the supply device 16 and clogs the supply device 16, reducing machine stoppage due to clogging, maintenance for removing foreign matter, and the like. it can.

  In the embodiment described above, an ultrasonic sieve is used as the ultrasonic sieve 25. However, a frequency (for example, 20 to 60 Hz) as used in a normal vibration sieve is used for this ultrasonic sieve. )), And the captured coarse foreign matter may be moved to an appropriate location.

  In the above-described embodiment, the ultrasonic sieve 25 is provided between the wind classifier 14 and the storage tank 15, but the position where the ultrasonic sieve 25 is attached is not limited to this position, and the supply device from the storage tank 15 is provided. 16, the supply path 17, the processing apparatus 12, the exhaust path 13, and the air classifier 14, and can be provided at an arbitrary position in the circulating path of the abrasive that returns to the storage tank 15. As shown, an ultrasonic sieve can be arranged in the exhaust path 13 and the supply path 17. Further, the ultrasonic sieves 25 and 30 are not limited to being provided at one place in the circulation path, and the ultrasonic sieves 25 and 30 may be provided at a plurality of places. By providing ultrasonic sieves at a plurality of locations, it is possible to prevent further mixing of coarse foreign matters. Furthermore, the present invention is not limited to the case where only the ultrasonic sieves 25 and 30 are provided in the circulation path of the abrasive material, and an ultrasonic sieve and a conventionally used sieve (for example, foreign matter separation shown in Patent Document 1). -A classification device may be used in combination.

  Furthermore, in the above-described embodiment, the air classifier 14 is connected to the storage tank 15 by one path, and the ultrasonic sieve 25 is provided in the one path. However, instead of this structure, the air classifier 14 and the storage tank 15 are connected by a plurality of paths arranged in parallel, and an ultrasonic sieve 25 is provided in each path, and a plurality of paths are switched and used, or a plurality of paths are used simultaneously. It is good also as a structure. If it is set as the structure which switches and uses a some path | route, the operation | work of cleaning of the ultrasonic sieve 25 and the replacement | exchange of a mesh body can be performed, without stopping the driving | operation of a blast processing apparatus. Further, when a plurality of paths are used at the same time, a small ultrasonic sieve can be used. The same applies to the case where an ultrasonic sieve is provided in the exhaust path 13 and the supply path 17.

[Example 1]
In the blasting apparatus having the configuration shown in FIG. 1, as the ultrasonic sieve 25, an ultrasonic sieve “ULTRASONICS” manufactured by Rei Sangyo Co., Ltd. (specifications of the mesh body 26: diameter 600 mm, 250 mesh, opening 63 μm) Was provided. In addition, a foreign matter separating / classifying device having a structure as shown in Patent Document 1 is provided in the exhaust passage 13 (specifications of the mesh body: size 500 mm × 500 mm, 250 mesh, opening 63 μm), and the supply passage 17 is provided with Patent Document 1. And a foreign matter separation / classification device (network specification: diameter 200 mm, 250 mesh, aperture 63 μm) having the structure shown in FIG. Using the blasting apparatus having this structure, rib processing was performed on the back plate of the PDP. The abrasive was circulated for about 160 hours at a circulating rate of 10 kg / min and a frequency (ultrasonic frequency) of the ultrasonic sieve 25 of 36 kHz. During this time, the ultrasonic sieve 25 was not clogged. The foreign matter separation / classification device provided in the exhaust passage 13 was clogged, and therefore cleaning was performed about every 10 to 15 hours. After the operation, the amount of foreign matter trapped by the ultrasonic sieve 25 was measured and found to be about 10 g (the total amount of abrasive that passed through the ultrasonic sieve 25 was about 100 tons). In the blasting using the ultrasonic sieve 25, the product yield increased by about 8% as compared with the case where the ultrasonic sieve 25 was not used (the foreign substance separation / classification device of the exhaust path 13 and the supply path 17 was used). As a result, it is possible to more reliably capture the coarse foreign matter by the ultrasonic sieve 25, and to significantly improve the product yield by catching a very small amount of the coarse foreign matter of only 10 g with respect to 100 tons of the abrasive. Was confirmed.

[Comparative Example 1]
In the blasting apparatus used in Example 1 described above, the blasting apparatus was operated under the same conditions as in Example 1 with no ultrasonic vibration applied to the mesh body 26 of the ultrasonic sieve 25 and stopped. After about an hour of operation, the abrasive material was clogged on the mesh body 26, and the operation became impossible. Therefore, it was confirmed that the passing amount (processing amount) of the abrasive can be dramatically increased by applying ultrasonic vibration to the mesh body.

[Example 2]
In the blasting apparatus used in the first embodiment described above, an ultrasonic sieve having the same specifications as the ultrasonic sieve 25 used in the first embodiment is provided in place of the foreign matter separating / classifying apparatus provided in the exhaust passage 13. The processing apparatus was operated for about 160 hours under the same conditions as in Example 1. After the operation, when the mesh body of the ultrasonic sieve provided in the exhaust passage 13 was visually inspected, no clogging was observed. Thus, it was confirmed that clogging is less likely to occur even if an ultrasonic sieve is provided in the exhaust path 13 through which a large amount of the object to be ground flows. In this case as well, the product yield was as high as in Example 1.

  As described in the above embodiments, the blasting apparatus of the present invention is suitable for blasting for rib processing of the back plate of the PDP, but is not limited to this, and the coarseness to the grinding material It can be used for any blasting in which foreign matter is not desirable.

  The preferred embodiments and examples of the present invention have been described above, but the present invention is not limited to these embodiments and examples, and can be appropriately changed within the scope of the claims. Needless to say.

1 is a schematic configuration diagram of a blasting apparatus according to a preferred embodiment of the present invention. (A), (b), (c) is schematic sectional drawing explaining the process of forming a rib in the backplate of PDP Schematic configuration diagram of a conventional blasting machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Electrode 3 Glass paste 3a Rib 4 Photosensitive resin film 5 Work piece 10 Blasting chamber 11 Compressed air supply pipe 12 Processing apparatus 13 Exhaust path 14 Air classification apparatus 15 Storage tank 16 Supply apparatus 17 Supply path 18 Dust collector 19 Foreign substance separation / classification device 25 Ultrasonic sieve 26 Net body 27 Vibrator 28 Ultrasonic generator 30 Ultrasonic sieve

Claims (10)

  Storage tank for storing fine powdery abrasive, supply device for supplying abrasive connected to the storage tank, supply path for transporting abrasive from the supply device, and transported from the supply path A processing device comprising a blast gun for injecting abrasive material onto the workpiece, an exhaust path for moving the abrasive material and workpiece to be ground by negative pressure, and an abrasive material transported from the exhaust path, In a blasting apparatus equipped with a classifier connected to classify a workpiece and send an abrasive to the storage tank, and a dust collector connected to the classifier and collecting dust after classification, A mesh of open mesh that allows abrasives to pass through but does not allow coarse foreign substances to pass through the circulation path of the abrasives that returns from the storage tank to the storage tank via the supply device, supply route, processing device, exhaust route, and classification device. The Blasting apparatus is characterized by providing an ultrasonic sieve was e.   The blasting apparatus according to claim 1, wherein the ultrasonic sieve is disposed in a path from the classifier to a supply device.   The blasting apparatus according to claim 1, wherein the ultrasonic sieve is provided in the exhaust path.   The blasting apparatus according to claim 1, wherein the ultrasonic sieve is provided in the supply path.   The blasting apparatus according to claim 1, wherein the ultrasonic sieve is provided in at least two places of a path from the classifier to the supply apparatus, the exhaust path, and the supply path.   The blasting apparatus according to any one of claims 1 to 5, wherein the ultrasonic sieve is provided in each of a plurality of paths arranged in parallel to each other.   The blasting apparatus according to any one of claims 1 to 6, wherein the ultrasonic sieve is an ultrasonic sieve using both ultrasonic vibration and normal vibration.   The blasting apparatus according to any one of claims 1 to 7, wherein the classification device is an air classification device.   A blasting method comprising performing blasting using the blasting apparatus according to any one of claims 1 to 8.   10. The blasting method according to claim 9, wherein the workpiece to be blasted is a plasma display panel member.

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