The present invention will be more clearly understood from the description of the preferred embodiments as set forth below with reference to the accompanying drawings, wherein:
Before describing in detail the preferred embodiments of the present invention, a partition forming method, a partition formation and problems caused in the process of the partition formation of a conventional plasma display panel will be explained with reference to
In
As shown in
Next, the program proceeds to step ST2. From a mixture in which the abrasive material and the partition cutting powder, which are sent from the working chamber 1, are mixed with each other, big foreign objects such as objects of dry film resist are removed by a foreign object removing portion (mesh) 7. In the foreign object removing portion (mesh) 7, the big foreign objects, which can not pass through the mesh, are periodically collected by a dust collector (not shown) and discarded.
The program further proceeds to step ST10. In step ST10, the mixture, in which the abrasive material and the partition cutting powder are mixed with each other, from which the big foreign objects have been removed by the foreign object removing portion 7, is separated into large particles and small particles by the air current type cyclone 3.
Small particles, which have been separated by the air current type cyclone 3, are collected by the dust collector 6 in step ST6. The program further proceeds to step ST7, and the partition cutting powder and the abrasive material are discarded.
On the other hand, the large particles, which have been separated by the air current type cyclone 3, are supplied to the abrasive material recovery tank 4 in step ST3. The program further proceeds to step ST4, and the large particles are returned to the abrasive material supplying portion 5 and reused as abrasive material. New abrasive material is replenished to the abrasive material supplying portion 5 from the outside.
In step ST5, from the abrasive material sent from the abrasive material supplying portion 5, foreign objects are removed by the foreign object removing portion 8. After that, the program is returned to step ST1 and the abrasive material is injected from the nozzle 2 in the working chamber 1, so that partitions of a predetermined shape can be formed on the substrate.
In this connection, in step ST8, the foreign objects, which have been removed by the foreign object removing portion 8, are periodically collected by a dust collector and discarded as the abrasive material which can not be reused.
As explained before referring to
However, in this air current type classifier, particles can not be sufficiently dispersed. Therefore, the partition cutting powder or the abrasive material and partition cutting powder are coagulated and the partition cutting powder is mixed into the abrasive material which has already been classified. Accordingly, there is a possibility that the sampler rate is lowered and the partitions are damaged. Therefore, in the conventional plasma display panel partition forming device (blasting device), for example, a no-load running test is periodically performed, that is, a no-load running test is performed each time a predetermined number of works are processed so as to prevent an increase in the partition cutting powder. Therefore, an operation rate of the device is lowered.
Further, for example, when a cutting point is changed in order to suppress an increase in the partition cutting powder, a recovery rate of the abrasive material is lowered. Further, in order to perform sandblasting on a highly fine panel which has been recently produced, it is indispensable to reduce a particle size of the abrasive material. However, for the reasons described above, it is not easy to change the abrasive material.
Referring to the accompanying drawings, an embodiment of the method of forming partitions of a plasma display panel of the present invention will be described in detail below. Further, an embodiment of the device for forming the partitions of the plasma display panel of the present invention will be described in detail below.
In
As shown in
Next, the program proceeds to step ST2. Big foreign objects such as dry film resist are removed from a mixture of the abrasive material and the partition cutting powder, which were sent from the working chamber 1, by the foreign object removing portion 7. In this case, in the foreign object removing portion 7, the big foreign objects, which can not pass through the mesh, are periodically collected by a dust collector (not shown) and discarded.
Then, the program proceeds to step ST10. The mixture of the abrasive material and the partition cutting powder, from which the big foreign objects have been removed by the foreign object removing portion 7, is separated into large and small particles by the air current type cyclone 3.
Small particles, which have been separated by the air current type cyclone 3, are collected by the dust collector (6) in step ST6. The program further proceeds to step ST7. The partition cutting powder and the abrasive material are discarded. In this case, no solid contents exist in the small particles separated by the air current type cyclone 3.
On the other hand, large particles separated by the air current type cyclone 3 are dispersed in the liquid in the dispersion tank 10 in step ST21. In this case, the specific gravity of the abrasive material and the partition cutting powder is relatively high. Therefore, the abrasive material and the partition cutting powder are always agitated by agitator blades 16 driven by the motor 11. In this connection, the agitator includes: a dispersing tank 10; a motor 11; and agitating blades 16. Examples of the liquid in the dispersing tank 10 are an organic solvent such as ethanol, water, and water and a dispersing agent.
A mixed solution, in which large particles are agitated in the dispersing tank 10, is supplied to the hydro-cyclone 13 by the liquid feed pump 12 and subjected to wet classification in step ST22.
Rough powder, which has been classified by the wet classification by the hydro-cyclone 13, is dried by the continuous drying furnace 14. Then, the program proceeds to step ST3 and the rough powder is supplied to the abrasive material recovery tank 4. The program further proceeds to step ST4 and the rough powder is returned to the abrasive material supplying portion 5 and reused as the abrasive material. In this case, new abrasive material is replenished to the abrasive material supplying portion 5 from the outside.
In step ST5, from the abrasive material sent from the abrasive material supplying portion 5, foreign objects are removed by the foreign object removing portion 8. After that, the program is returned to step ST1 and the abrasive material is injected from the nozzle 2 in the working chamber 1 so that partitions of a predetermined shape can be formed on the substrate.
In this connection, the foreign objects removed by the foreign object removing portion 8 are periodically collected by a dust collector in step ST8 and then discarded as the abrasive material, which can not be reused, in step ST9.
Fine powder, which has been classified by the wet classification by the hydro-cyclone 13, is separated into the liquid and the solid components (partition cutting powder) by the centrifugal dehydrator 15 in step 24. Then, the liquid is returned to the dispersing tank 10 and the solid components are discarded.
In the present embodiment, a series of processing is continuously performed. In this case, a series of processing includes: processing in which the abrasive material and the partition cutting powder after a process of sandblasting are dispersed in liquid; processing in which the abrasive material and the partition cutting powder after a process of sandblasting, which are dispersed in liquid, are subjected to wet classification; and processing in which rough powder, which has been classified by wet classification, is dried in a continuous drying furnace so that the abrasive material can be reused. Due to the foregoing, dispersion and classification of the abrasive material and the partition cutting powder can be subjected to in-line processing with high accuracy. Further, it is possible to enhance a recovery efficiency of the abrasion material. It is also possible to enhance an operation rate of the device.
In the embodiment described above, large particles, which have been separated by the air current type cyclone 3, are dispersed and agitated in the liquid in the dispersing tank 10 and classified by the wet classification by the hydro-cyclone 13. However, the characteristic of the present invention is to disperse the abrasive material and the partition cutting powder after the completion of sandblasting. Therefore, for example, the air current type cyclone 3 may not be necessarily provided.
As described above in detail, according to the present invention, when the wet type classifier (hydro-cyclone) is used, it is possible to enhance the degree of dispersion of the partition cutting powder and the abrasive material. Further, the dispersion can be also enhanced by a shearing force generated by the hydro-cyclone. Therefore, the classification accuracy can be more enhanced. Further, the abrasive material used for the plasma display panel partition forming device can be easily changed.
The present invention can be widely applied to a plasma display panel partition forming device in which partitions of various shapes of the plasma display panel are formed by the method of sandblasting.
Many different embodiments of the present invention may be constructed without departing from the scope of the present invention, and it should be understood that the present invention is not limited to the specific embodiments described in this specification, except as defined in the appended claims.
Number | Date | Country | Kind |
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2006-194771 | Jul 2006 | JP | national |