JPH08281176A - Method and apparatus for spraying powder or granule - Google Patents

Abstract

PURPOSE: To provide a method in which a mixture of powder or granules dispersed in a solvent is sprayed uniformly without generating partial blocks of powder or granules and an apparatus for the method. CONSTITUTION: A method in which a mixture of powder or granules dispersed in a solvent is sprayed on an object. The mixture is discharged at a constant flow rate from the tip of a nozzle 11, and ultrasonic oscillation is applied to the mixture through fluid for dispersion at the tip of the nozzle 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for spraying powdery or granular materials such as spacers for maintaining a constant gap between transparent substrates of a liquid crystal display panel. More specifically, it relates to a spraying method and apparatus for uniformly spraying powdery or granular materials.

[0002]

2. Description of the Related Art Conventionally, for example, in a liquid crystal display panel, a pair of transparent substrates are adhered so as to have a constant gap, and the gap is filled with a liquid crystal material. A spacer is interposed between the transparent substrates to keep the gap between the pair of transparent substrates uniform.

As the spacer, fine particles such as a spherical body made of resin having a diameter of about 5 to 15 μm or a cylindrical body made of glass having a diameter of about 5 to 15 μm and a length of about 30 to 50 μm are used. As a method of interposing this spacer, before superimposing the transparent substrates, spacers dispersed in a medium such as a mixed solution of water and alcohol are sprayed from the nozzles on the surfaces of the opposite sides of one transparent substrate by air pressure. The method of laminating and bonding the other transparent substrate is adopted.

[0004]

However, when the spacers are sprayed as described above, variations in the spacer density of the coating material in which the spacers are dispersed in the solvent, the pressure of the air, the state of electrostatic charge (static electricity), etc. As a result, the distribution density of the spacers on the surface of the transparent substrate becomes uneven. That is, a plurality of spacers are partially hardened and scattered. When the distribution density of such spacers becomes uneven,
The light transmittance of the dense parts of the spacers will decrease, and there will be subtle differences in the distance between the transparent substrates of the rough parts of the spacers.
There is a problem that the voltage applied to the liquid crystal layer or the like becomes non-uniform and the display characteristics are deteriorated or display unevenness occurs.

On the other hand, it is possible to increase the alcohol concentration of the solvent in which the spacers are dispersed in order to eliminate the uneven spraying. However, if the alcohol concentration is increased, a high-concentration alcohol gas will be exhausted, resulting in explosion, ignition, etc. However, there is a problem that the risk is high and the handling is inconvenient.

Such a problem is not limited to the spraying of spacers at the time of manufacturing a liquid crystal display panel, and for example, spraying pesticides or in the case of spraying liquid such as instant coffee in a mist to prepare powder. The same occurs when the coating material in which the powdery material or the particulate material is dispersed is uniformly dispersed.

The present invention solves such a problem and uniformly spreads a coating material in which a powder or granular material is dispersed in a solvent, and does not cause partial agglomeration of the powder or granular material. It is an object of the present invention to provide a method and a device for uniformly distributing powder or granules.

[0008]

DISCLOSURE OF THE INVENTION The method for spraying powdery or granular materials of the present invention is a method for spraying powdery or granular materials in which the powdery or granular materials are dispersed in a solvent and uniformly sprayed on an object. The method is characterized in that a coating material in which the powdery or granular material is dispersed in a solvent is discharged from a tip of a nozzle at a constant flow rate, and ultrasonic vibration is applied to the coating material at the tip of the nozzle. And

The ultrasonic vibration is applied to the applied material by spraying the dispersion fluid to which the ultrasonic vibration is applied to the tip of the nozzle. The ultrasonic vibration is applied to the applied material while keeping the discharge amount of the applied material constant. It is preferable because vibration can be applied.

The powdery or granular material spraying apparatus of the present invention comprises a cylinder containing a coating material in which the powdery or granular material is dispersed in a solvent and having a discharge nozzle at its tip, and the cylinder. A drive fluid inlet for discharging the applied material at a constant flow rate, a dispersion fluid outlet provided near the tip of the nozzle of the cylinder, and a dispersion fluid connected to the outlet. It comprises a fluid supply pipe and an ultrasonic vibration applying means for applying ultrasonic vibration to the dispersion fluid provided in a part of the supply pipe.

The ultrasonic vibration applying means comprises a piston provided in a part of the supply pipe, an ultrasonic oscillator connected to the piston, and a drive device for driving the ultrasonic oscillator. It is preferable because ultrasonic vibration can be applied to the dispersion fluid with a simple structure.

[0012]

According to the present invention, ultrasonic vibration is applied to a coating material in which a powdery or granular material is dispersed in a solvent when the coating material is discharged from the tip of the nozzle to the target material. While maintaining the discharge amount of the object constant, the powdery or granular material that has become a lump due to the applied ultrasonic vibration is dispersed and evenly dispersed. As a result, powder or granules are evenly distributed, the gap between both transparent substrates is kept constant in the case of a liquid crystal display panel, etc., and a constant particle size is obtained when forming powder such as coffee powder. The powder of is obtained.

[0013]

The powdery or granular material spraying method and apparatus of the present invention will now be described with reference to the drawings.

FIG. 1 is an explanatory view of one embodiment of the powdery or granular material spraying apparatus of the present invention.

In FIG. 1, reference numeral 1 is a cylinder having a nozzle 11 at its tip, and inside thereof is a powder or granular material such as a spacer for a liquid crystal display panel such as a mixed liquid of water and alcohol. The coating material dispersed in the solvent is sequentially injected from the coating material injection port 12. Also cylinder 1
Is provided on the opposite side of the nozzle 11 from the nozzle 11, and a drive fluid inlet 13 for discharging the coating material at a constant flow rate is provided, and the drive fluid such as air or nitrogen is constant via the flow rate adjusting valve 14. It is designed to flow in at a flow rate. When a constant flow rate of the driving fluid flows into the cylinder 1, the coating material is discharged from the nozzle 11 together with the driving fluid, and a powder or granular material such as spacers is sprayed on the object together with the solvent and the driving fluid.

In the present invention, a dispersion fluid discharge port 21 to which ultrasonic vibration is applied is provided in the vicinity of the tip of the nozzle 11 for spraying the coating material, and the dispersion fluid supply pipe 2 is provided at the discharge port 21. Are connected to each other, and the supply pipe 2 is provided with ultrasonic vibration applying means. That is, the present inventors have made diligent studies in order to prevent the occurrence of display unevenness and the deterioration of display characteristics due to the non-uniformity of the dispersion of spacers that occurs when manufacturing a liquid crystal display panel. It was found that the lumps can be loosened and uniformly sprayed by applying ultrasonic vibration to the.
However, it was found that when ultrasonic vibration was directly applied to the applied material, the flow rate of the applied material could not be kept constant, and there was a case where the applied material was not evenly dispersed due to variations in the applied amount. Therefore, as a result of further intensive studies, ultrasonic vibration was applied to a dispersion fluid separately provided at the tip of a nozzle for spraying the coating material, and ultrasonic waves were applied to the coating material through the dispersion fluid. By applying the vibration, ultrasonic vibration is applied to the coating material while maintaining a constant flow rate of the coating material,
It has been found that a lump of powder or granular material can be loosened to obtain a uniform dispersed state.

In the above-mentioned ultrasonic vibration applying means, for example, a piston 22 for pressurizing and depressurizing is provided in a part of the supply pipe 2, an ultrasonic oscillator 23 is connected to the piston 22, and the ultrasonic oscillator 23 further has the ultrasonic oscillator 23. It is configured by connecting the drive device 24. Therefore, the vibration due to the oscillation of the ultrasonic oscillator 23 is transmitted to the piston 22, and the piston 22 vibrates according to the vibration of the ultrasonic oscillator 23.
As a result, the vibration is transmitted to the dispersion fluid supplied to the supply pipe 2, the dispersion fluid to which the ultrasonic vibration is applied propagates in the supply pipe 2, is discharged from the discharge port 21, and is discharged from the nozzle 11 of the cylinder 1. Ultrasonic vibration is transmitted to the discharged coating material. As a result, even if there are lumps of powder or particles such as spacers, they are dispersed and evenly distributed.

As the dispersion fluid, for example, air or a gas such as nitrogen is used, but in some cases, a liquid such as a mixed solution of alcohol and water may be used.

[0019]

EFFECTS OF THE INVENTION According to the present invention, when a coating material in which a powdery or granular material is dispersed in a solvent is sprayed on an object, the tip of a nozzle for discharging the coating material passes through a dispersion medium. Since the ultrasonic vibration is applied to the applied material, it is possible to loosen a lump such as a powdery substance due to the ultrasonic vibration while maintaining a constant flow rate of the applied material. As a result, it is possible to uniformly disperse the powdery material and the like.

Therefore, if the present invention is used for spraying the spacers of the liquid crystal display panel, the spacers can be easily sprayed uniformly without increasing the alcohol ratio of the solvent, and the gaps between the transparent substrates can be kept uniform. The liquid crystal display panel having excellent display characteristics can be obtained safely and at low cost because the light transmission characteristics are uniform and there is no display unevenness.

Further, in a wide range of fields such as agricultural sector such as pesticide spraying and food sector such as instant coffee powder formation, it is possible to uniformly disperse powders or granules or to form powders with uniform particle size. it can.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an embodiment of a spraying device of the present invention.

[Explanation of symbols]

 1 Cylinder 2 Dispersion Fluid Supply Pipe 11 Nozzle 13 Drive Fluid Inlet 21 Discharge Port 22 Piston 23 Ultrasonic Oscillator 24 Drive Device

Claims (4)

[Claims] 1. A method for spraying a powder or granules, wherein the powder or granules are dispersed in a solvent and uniformly sprayed on an object, wherein the powder or granules are dispersed in a solvent. A method for spraying a powder or granular material, which comprises ejecting a coating material from a tip of a nozzle at a constant flow rate and applying ultrasonic vibration to the coating material at the tip of the nozzle. 2. The spraying method according to claim 1, wherein the ultrasonic vibration is applied to the coating material by spraying a dispersion fluid to which ultrasonic vibration is applied to the tip of the nozzle. 3. A cylinder in which a coating material in which a powdery or granular material is dispersed in a solvent is stored and a nozzle for discharging is provided at the tip, and the coating material provided in the cylinder is discharged at a constant flow rate. An inflow port for the driving fluid, a discharge port for the dispersion fluid provided near the tip of the nozzle of the cylinder, and a supply pipe for the dispersion fluid connected to the discharge port.
A powdery or granular material spraying device comprising ultrasonic vibration applying means provided in a part of the supply pipe for applying ultrasonic vibration to the dispersion fluid. 4. The ultrasonic vibration applying means comprises a piston provided in a part of the supply pipe, an ultrasonic oscillator connected to the piston, and a drive device for driving the ultrasonic oscillator. Item 3. The spraying device according to item 3.