JP4350298B2 - Drying equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drying apparatus for drying a coating film provided on a substrate, and more particularly to a drying apparatus capable of drying without deteriorating the properties of the coating film.
[0002]
[Prior art]
Conventionally, when ribs are formed on a PDP back plate, a rib paste material is uniformly applied to a thickness of 250 to 300 μm on a glass substrate having a surface on which electrodes and the like are formed, and then a solvent contained in the paste is removed. Evaporate in the dryer. In this case, first, drying is performed at about 150 to 180 ° C. during the constant rate drying period in the drying apparatus, and drying is performed at 220 to 250 ° C. during the reduction rate drying period. In any drying period, hot air having a wind speed of about 1 m / s is supplied perpendicularly or parallel to the surface of the coating film, and the generated solvent vapor is removed from the vicinity of the coating film surface.
[0003]
[Problems to be solved by the invention]
In the above drying method, the solvent vapor generated on the coating film surface during the constant rate drying period is returned to the coating film surface again by the flow of the supply air, so that stagnation occurs on the coating film surface. It was uneven. Moreover, since the solvent stays forever, the drying efficiency does not increase. If the air supply speed of hot air is increased in order to prevent these problems, there is a drawback that a wind pattern is generated on the surface of the coating film.
[0004]
The present invention has been made in consideration of such points, and an object thereof is to provide a drying apparatus that can reliably dry a coating film without deteriorating the properties of the coating film provided on the substrate. And
[0005]
[Means for Solving the Problems]
The present invention is a drying furnace partitioned into a first drying zone and a second drying zone in order from the upstream side of the substrate on which the substrate on which the coating film is formed travels inside. A preheating unit provided on the inlet side of the drying furnace and having a hot plate for placing and heating the substrate, a first drying mechanism provided in the first drying zone, and provided in the second drying zone A drying apparatus including a second drying mechanism.
[0006]
According to this invention, the base material in which the coating film was formed is mounted on the hot plate of a preheating part, and is heated directly. Next, in the first drying zone, constant rate drying of the coating film formed above the heater on the substrate is performed by the first drying mechanism. Thereafter, the base material is sent to the second drying zone, and the coating film on the surface is further dried by the second drying mechanism, and reduction drying is performed. Thus, since the base material is directly heated by the hot plate in advance and then enters the first drying zone, constant rate drying in the first drying zone can be performed quickly.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a drying apparatus according to the present invention.
[0008]
As shown in FIG. 1, a drying apparatus, for example, an infrared drying apparatus 10 includes a first drying zone 10 a and a second drying order in order from the upstream side of the glass substrate 15 in which the substrate 15 travels. A drying furnace 11 partitioned into a drying zone 10b by a partition wall 10c; an infrared heater 16 disposed in parallel with the base material 15 above the base material 15 in the first drying zone 10a of the drying furnace 11; An air supply device 18 and an exhaust device 19 disposed in the drying zone 10 a and above the infrared heater 16 are provided. In this case, the base material 15 travels on the transport roller 12 in the drying furnace 11.
[0009]
In FIG. 1, as the base material 15, a glass base material for a PDP back plate in which a rib paste material is previously applied to a single wafer glass base material having electrodes and a coating film is formed on the surface is conceivable.
[0010]
The air supply device 18 is provided on the downstream side of the base material 15 in the traveling direction L, and supplies air heated to an appropriate temperature in advance. The exhaust device 19 is provided on the upstream side in the running direction L of the base material 15, and an air flow parallel to the infrared heater 16 is formed above the infrared heater 16 by the air supply device 18 and the exhaust device 19.
[0011]
The air supply device 18 may be provided on the upstream side in the traveling direction L of the base material 15, and the exhaust device 19 may be provided on the downstream side in the traveling direction L of the base material 15.
[0012]
Further, an additional air supply device 20 and an additional exhaust device 21 are respectively provided below the base material 15 supported by the transport roller 12 in the first drying zone 11a. The additional air supply device 20 is provided on the downstream side in the running direction L of the base material 15, and the additional exhaust device 21 is provided on the upstream side in the running direction L of the base material 15, and the additional air supply device 20 and the additional exhaust device 21 are provided. Thus, an air flow parallel to the base material 15 is formed below the base material 15.
[0013]
Further, as shown in FIG. 1, the drying furnace 11 is provided with a preheating part 30 on the inlet side via a base material inlet 11a and on the outlet side thereof with an unloader part 25 via a base material outlet 11b. . Furthermore, in the 1st drying zone 10a and the 2nd drying zone 10b of the drying furnace 11, many conveyance rollers 12 which convey the base material 15 as mentioned above are provided.
In FIG. 11, the preheating unit 30 includes an enclosure 30 a and a hot plate 31 that is stored in the enclosure 30 a and directly heats the substrate 11. Further, an exhaust mechanism 32 is provided on the upper portion of the enclosure 30a.
[0014]
Furthermore, as shown in FIG. 1, in the second drying zone 10 b of the drying furnace 11, a hot air blowing device 26 is provided above the base material 15, and an exhaust device 27 is provided below the base material 15. Yes.
[0015]
In FIG. 1, a first drying mechanism is configured by the infrared heater 16, the air supply device 18, the exhaust device 19, the additional air supply device 20, and the additional exhaust device 21 installed in the first drying zone 10 a. Moreover, the 2nd drying mechanism is comprised by the hot air spraying apparatus 26 and the exhaust apparatus 27 which were installed in the 2nd drying zone 10b.
[0016]
Next, the operation of the present embodiment having such a configuration will be described. First, a rib paste material is applied to the glass substrate 15 having electrodes by printing or coating, and the substrate 15 having a coating film (250 to 300 μm) formed on the surface is produced. Next, the base material 15 on which the coating film is formed is placed on the hot plate 31 of the preheating unit 30 and directly heated at a temperature of about 60 to 100 ° C. for a certain time (1 to 5 minutes). Thereafter, the base material 15 enters the drying furnace 11 through the base material inlet 11a by a conveying means such as a walking beam, and travels in the first drying zone 10a of the drying furnace 11 at a constant speed by the carry-in roller 12. Thereafter, the base material 15 is fed into the second drying zone 10b of the drying furnace 11, and then discharged outward from the second drying zone 10b through the base material outlet 11b.
[0017]
During this time, when the substrate 15 is heated in the preheating unit 30, the solvent evaporates from the surface of the coating film provided on the substrate 15, and the evaporated solvent is removed from the exhaust mechanism 32. By discharging the solvent from the exhaust mechanism 32 in this way, the drying efficiency of the coating film can be increased. Thereafter, the substrate 15 is heated by radiant heat from the infrared heater 16 in the first drying zone 10a, and the solvent is further evaporated and removed from the surface of the coating film provided on the substrate 15. The solvent removed from the base material 15 rises and reaches above the infrared heater 16.
[0018]
At this time, since an air flow parallel to the infrared heater 16 is formed by the air supply device 18 and the exhaust device 19 above the infrared heater 16, the evaporated solvent that has reached the upper side of the infrared heater 16 is the infrared heater 16. Is carried to the exhaust device 19 by an air flow parallel to the exhaust gas, and discharged from the exhaust device 19 to the outside.
[0019]
Further, an air flow parallel to the base material 15 is formed below the base material 15 by the additional air supply device 20 and the additional exhaust device 21 also below the base material 15. For this reason, the air flow in the first drying zone 10 a of the drying furnace 11 is stabilized, and the air flow above the infrared heater 16 passes through the side of the infrared heater 16 or the side of the base material 15 and below the base material 15. There is no flow.
[0020]
As described above, in the first drying zone 10a, the air flow does not directly hit the surface of the base material 15, so that the coating surface of the base material 15 is roughened or dried from the coating surface. There is no flash, and constant rate drying of the coating film of the base material 15 can be performed with high accuracy in the first drying zone 10a. Moreover, since the base material 15 is preheated in advance by the preheating unit 30 before entering the first drying zone 10a, constant rate drying of the coating film of the base material 15 in the first drying zone 10a can be performed quickly. .
[0021]
Next, the base material 15 is subjected to the reduction rate drying of the coating film of the base material 15 by the hot air blown from the hot air blowing device 26 in the second drying zone 10b, and the hot air subjected to the reduction rate drying is then exhausted. The air is exhausted from the device 27. Since the coating film of the base material 15 is previously dried and solidified to some extent in the first drying zone 10a, the coating film surface is roughened even if hot air is blown onto the mold film of the base material 15 in the second drying zone 10b. However, the coating film of the base material 15 can be quickly dried by the hot air blown by the hot air blowing device 26.
[0022]
The constant rate drying in the first drying zone 10a is performed at a temperature of 150 ° C. to 180 ° C., while the decreasing rate drying in the second drying zone 10b is performed at 220 ° C. to 250 ° C.
[0023]
As described above, according to the present embodiment, since the base material 15 is heated in the preheating unit 30 in advance, the constant rate drying of the coating film is performed on the base material 15 in the first drying zone 10a. The constant rate drying of the coating film in the 1 drying zone 10a can be performed rapidly. Further, since an air flow is formed above the infrared heater 16 by the air supply device 18 and the exhaust device 19 in the first drying zone 10a, the air flow thus formed does not directly hit the surface of the base material 15. For this reason, the coating film surface provided in the base material 15 is not roughened, and the coating film surface is not peeled by drying from the coating film surface, thereby preventing the adhesion of the coating film from being deteriorated. In this way, it is possible to prevent the properties of the coating film provided on the base material 15 from being deteriorated. Further, since the air flow over the infrared heater 16 flows in parallel with the infrared heater 16, the air flow does not hit the infrared heater 16, and the temperature of the infrared heater 16 does not decrease. Furthermore, since the additional air supply device 20 and the additional exhaust device 21 can form an air flow parallel to the base material 15 below the base material 15, the balance of the air flow in the drying furnace 11 can be stabilized. Therefore, the air flow that directly hits the base material 15 can be eliminated more reliably. The base material 15 that has been subjected to constant rate drying on the coating film in the first drying zone 10a is then subjected to reduced rate drying with hot air blown from the hot air blowing device 26 in the second drying zone 10b.
[0024]
In the above embodiment, an example in which the hot air blowing device 26 is installed in the second drying zone 10b has been shown. However, the present invention is not limited to this, and an infrared heater is installed in the second drying zone 10b as in the first drying zone 10a. May be.
[0025]
【The invention's effect】
As described above, according to the present invention, the base material is directly heated in advance by the hot plate of the preheating unit and then enters the first drying zone. Therefore, constant rate drying by the first drying mechanism in the first drying zone. Can be performed quickly. Thereafter, the base material can be rapidly dried at a reduced rate by the second drying mechanism with respect to the coating film which has been dried at a constant rate and solidified in the second drying zone.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a drying apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Infrared dryer 10a 1st drying zone 10b 2nd drying zone 11 Drying furnace 12 Conveyance roller 15 Base material 16 Infrared heater 18 Air supply device 19 Exhaust device 20 Additional air supply device 21 Additional exhaust device 26 Hot air spraying device 27 Exhaust device 30 Preheating part 30a Enclosure 31 Hot plate 32 Exhaust mechanism

Claims (2)

The substrate on which the coating film is formed travels inside, and a drying furnace partitioned into a first drying zone and a second drying zone in order from the upstream side of the substrate on which the interior travels,
A preheating unit provided on the inlet side of the drying furnace, having a hot plate for placing and heating the substrate;
A first drying mechanism provided in the first drying zone;
A second drying mechanism provided in the second drying zone ,
The preheating part is provided separately from the drying furnace on the inlet side of the drying furnace, has an enclosure for storing the hot plate, and an exhaust mechanism is provided on the upper part of the enclosure.
The first drying mechanism includes an infrared heater disposed substantially parallel to the substrate above the substrate in the first drying zone;
An air supply device for supplying air and an exhaust device for exhausting air disposed above the infrared heater in the first drying zone;
An air flow parallel to the infrared heater is formed above the infrared heater by the air supply device and the exhaust device,
An air supply device is provided on the downstream side in the running direction of the base material, and an exhaust device is provided on the upstream side in the running direction of the base material.
The second drying mechanism comprises a hot air blowing device that blows hot air against the substrate . An additional air supply device and an additional exhaust device are provided below the base material in the first drying zone, and an air flow parallel to the base material is formed below the base material by the additional air supply device and the additional exhaust device. The drying apparatus according to claim 1 .

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