JP2005131637A - Coating apparatus having cleaning mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for performing superior cleaning without causing solvent shock(mainly aggregate or gel, or coating liquid dregs, caused by coating liquid of a cleaning solvent) and free from uneven cleaning when cleaning the inside of pipes of a coating apparatus supplying the coating liquid to a die head by a coating liquid supply pump from a coating liquid storage tank, and the inside of the die head. <P>SOLUTION: This coating apparatus has a cleaning mechanism in which, when cleaning the inside of pipes of the coating apparatus and the inside of the die head, two types or more of the measured amount of solvents are used by sequentially changing from a solvent compatible with the coating liquid to one with high cleaning property, and further drying is performed by gaseous nitrogen or the like for preventing remaining of washing solvent components used for cleaning. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention does not generate a solvent shock when washing the piping of the coating apparatus for supplying the coating liquid from the coating liquid storage tank to the die head by the coating liquid supply pump and the inside of the die head, and there is no cleaning variation. The present invention relates to a coating apparatus having a cleaning mechanism that can perform good cleaning.

  Conventionally, when coating is performed using a coating apparatus, various systems such as gravure coating, roll coating, slide coating, curtain coating, and extrusion coating are used depending on the application. In addition, an extrusion coat, a curtain coat, a slide coat, or the like is used when performing high-speed and relatively stable high-quality coating, and a die head having a slit nozzle is used. However, the slit width of the slit nozzle 41 as shown in FIGS. 3A and 3B is used to make the coating amount uniform in the width direction when the viscosity of the coating liquid changes or when the coating liquid is switched. The complicated structural parts such as a and the manifold 40 are cleaned and adjusted over a long period of time.

  Furthermore, when switching the coating liquid, as shown in FIG. 4, the inner diameter from the coating liquid storage tank 9 to the supply port of the die head 5 is small and a complicated piping path. The pipe used for the piping is a resin pipe, a stainless steel pipe, or a metal pipe whose inner surface is coated with a resin, and further, a coating liquid supply pump 23 or a coating liquid switching valve 10 or A coating liquid filter 8 and the like are connected to the pipe and piped.

  Also, when exchanging the coating liquid or periodically cleaning it, drain the coating liquid and then wash the inside of the pipe with a solvent, or pressurize it with the coating liquid to be used next. The method of extruding and replacing is used. In this case, an appropriate amount of the cleaning solvent or the next coating liquid is discharged depending on the internal volume of the pipe to perform liquid replacement. In addition, a complicated structure or shape portion such as the inside of the die head is manually disassembled and cleaned each time.

  In recent years, with the diversification of coating liquids, it has been particularly demanded to increase the switching time of the coating liquid. However, because of the above, it still takes a long time to switch the coating solution. In particular, it takes a very long time to clean the die head. Furthermore, solvent shock (mainly caused by the coating solvent due to the cleaning solvent) is caused by the mixing of different coating liquids and the compatibility between the coating liquid and the cleaning solvent. Aggregates and gels: coating liquid residue) are generated.

  From the above, there is known a coating head cleaning method having a slit nozzle that can easily and efficiently clean the inside of a coating head (die head) having a slit nozzle (see, for example, Patent Document 1).

  Furthermore, a slit nozzle cleaning method and a cleaning mechanism (see, for example, Patent Document 2) that can completely remove the solidifying coating liquid remaining at the tip of the slit nozzle of the die head without causing a reduction in work efficiency. .) Is also known.

  Also, by moving the pipe inner wall with compressed gas using a pig (PIG: lump of metal) for pipe cleaning, the paint is pushed out, reducing paint loss during pipe cleaning and a small amount of cleaning solvent In addition, there is also known a die coater paint cleaning device (for example, see Patent Document 3) that can be cleaned efficiently in a short time.

  Further, when cleaning the inner wall of the pipe, the inner wall of the paint transfer pipe is cleaned using a paint remover, then treated with an acid, followed by a flushing process and a water replacement process ( For example, see Patent Document 4).

Prior art documents are shown below.
JP-A-7-132267 JP 2003-10767 A JP-A-9-85153 JP-A 63-256163

  In Patent Document 1, when cleaning the inside of the slit head, the cleaning liquid is supplied from the coating liquid supply pipe connected to the coating head into the coating head, and nitrogen gas and argon gas are supplied into the cleaning liquid passing through the coating liquid supply pipe. It is described that by blowing an inert gas or the like, the cleaning liquid flow is bubbled, the stirring effect by the bubbles is increased, and the residual coating liquid adhering to a minute gap or the like can be washed away. However, there is a problem that a solvent shock occurs when a cleaning solution that is not compatible with the coating solution is used.

  Next, in Patent Document 2, the tip of the slit nozzle is sprayed from the injection port of the cleaning nozzle, and the remaining cleaning liquid is dried and removed. Cleaning the inside of the manifold of the pipe or die head or the inside of the slit nozzle, etc. Have difficulty.

  Further, Patent Document 3 describes that the paint is washed by moving the pipe inner wall by the compressed gas. The pipes used for piping as described above are either resin pipes with a coating machine or coating liquid, or metal pipes whose inner surfaces are coated with fluororesin or silicone resin. This causes a problem that the coating surface is damaged or the resin surface is uneven and the coating liquid is more easily adhered. Further, when the slit width of the slit nozzle is narrow, there is a problem that the pig is clogged with the slit portion, which is not suitable for the internal cleaning of the die head.

  In Patent Document 4, when the paint transfer pipe inner wall is washed, first, it is treated with a paint remover, then treated with an acid, then flushed, and the pipe inner wall is washed by water replacement treatment. It is stated that it will be.

  However, depending on the paint, there is a problem that a solvent shock occurs when the compatibility of the solvent used in the paint remover used as the treating agent and the paint to be washed is poor. In addition, there is also a problem that it takes time for drying or the like by water replacement at the end.

  The present invention has been made in view of the above-described conventional problems, and generates a solvent shock due to the coating liquid and the cleaning solvent when cleaning the inner wall of the pipe of the coating apparatus such as a die coater and the inside of the die head. There is provided a coating apparatus having a cleaning mechanism capable of performing a good cleaning without a variation in cleaning in a short time.

The invention described in claim 1
A coating liquid storage tank, a coating liquid supply pump, and a die head are provided, and the coating liquid storage tank and the coating liquid supply pump are connected by a first coating liquid pipe, and the coating liquid supply In the coating apparatus in which the pump and the die head are connected by a second coating liquid pipe,
A coating liquid switching valve is provided on at least one of the first coating liquid pipe or the second coating liquid pipe,
There are two or more solvent tanks for storing different solvents for cleaning the piping of the coating unit section and the inside of the die head, the solvent tank has a tank switching valve, and the solvent tank is a solvent tank. Connected to the 1st switching valve by the piping for
A drying gas tank is connected to the first switching valve by a drying gas pipe;
The first switching valve and the coating liquid switching valve are connected by a cleaning pipe,
The pipe of the coating unit and the inside of the die head are cleaned by sequentially switching from a solvent compatible with the coating liquid to a highly washable solvent using two or more solvents, and then drying. A coating apparatus having a characteristic cleaning mechanism.

The invention described in claim 2
The coating apparatus having the cleaning mechanism according to claim 1, wherein the coating apparatus having the cleaning mechanism includes a solvent flow valve for controlling a flow rate of the solvent and a solvent flow meter.

The invention according to claim 3
The coating apparatus having the cleaning mechanism according to claim 1, wherein the coating apparatus having the cleaning mechanism includes a load cell that measures a storage weight for performing weight control of the solvent. .

The invention according to claim 4
The coating apparatus having the cleaning mechanism includes a drying gas flow rate control valve for controlling the flow rate of the drying gas, and a drying gas flow meter. A coating device having a cleaning mechanism.

  First, the first solvent used first by switching from a solvent compatible with the coating solution to a solvent having a high cleaning property by using two or more types of solvents for cleaning the inside of the pipe and the die head. Then, the coating solution is pushed out, and then the first solvent is extruded and washed with the second solvent. If the third solvent must be used, the second solvent and the subsequent extrusion are more effective for cleaning. By using a higher solvent, it is possible to prevent a solvent shock and perform a good cleaning with a small amount of a cleaning solvent without cleaning variations in a short time.

  In addition, the coating apparatus having the cleaning mechanism of the present invention prevents the solvent component used for cleaning from remaining, so that the cleaned part is completely dried after cleaning, so that the coating used next time after cleaning is used. Solvent shock does not occur because the working solution and the cleaning solvent used at the time of final cleaning are not mixed at all.

  Furthermore, the coating apparatus having the cleaning mechanism of the present invention is capable of controlling the flow rate of the solvent for cleaning, so that the reproducibility at the time of cleaning is excellent, efficient, and good cleaning can be effectively performed with a small amount of solvent. .

  Furthermore, by controlling the weight of the cleaning solvent, the reproducibility of the cleaning effect can be facilitated, and efficient cleaning with little cleaning variation can be performed with a small amount of solvent.

  A coating apparatus having a cleaning mechanism of the present invention will be described in detail below in accordance with an embodiment with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing an embodiment of a coating apparatus having the cleaning mechanism of the present invention. The coating apparatus having the cleaning mechanism of the present invention can be used in a known coating apparatus using a die head.

  In addition, the coating apparatus having the cleaning mechanism of the present invention is suitable for coating members such as color filters, liquid crystal materials, heat-sensitive recording materials, transdermal absorption preparations and the like that require high-precision and high-precision coating. As shown in FIG. 2, the coating apparatus having the cleaning mechanism of the present invention includes a coating unit unit 1, a cleaning processing unit 4 in which a solvent storage unit 3 and a dry gas unit unit 2 are provided.

  The coating unit 1 has a coating liquid storage tank 6 for storing the coating liquid to be applied, and the coating liquid from the slit nozzle when the coating liquid is supplied to the die head 5 in a uniform curtain shape. In order to form the coating liquid, a coating liquid filter 8 for removing foreign substances such as dust, a coating liquid supply pump 23 for transferring the coating liquid from the coating liquid storage tank 6, and a coating liquid The die head 5 formed in a curtain shape, the coating liquid receiving tray 13 for receiving the coating liquid falling from the die head 5, the coating liquid dropped on the coating liquid receiving tray 13, and the excess coating liquid supplied to the die head 5 are supplied. It consists of a waste liquid tank 7 to be stored, and each part except for the die head 5 and the coating liquid receiving tray 13 is piped with a resin pipe, a stainless steel pipe, or a metal pipe with a resin-processed inner surface.

  Further, as shown in the coating unit section 1 of FIG. 2, the coating liquid stored in the coating liquid storage tank 6 is driven from the coating liquid storage tank 6 by the driving of the coating liquid supply pump 23. The die head passes through the coating liquid supply pump 23 through the coating liquid filter 8 in the middle of the pipe 14, and further passes through the second coating liquid pipe 15 connected in the discharge direction of the coating liquid supply pump 23. The coating liquid is supplied to 5, and the excess coating liquid supplied to the die head 5 and the coating liquid that is flown in a curtain form from the die head 5 are collected in the waste liquid tank 7.

  The cleaning pipe 29 extending from the cleaning processing unit 4 is connected to the coating unit unit 1 in the coating liquid switching valve 10. At this time, as shown in FIG. 2, the coating liquid switching valve to be connected may be provided at any position of 10, 10 ′, 10 ″. Here, the case where the position is 10 is specifically described, but the scope of the present invention is not limited to this.

  FIG. 1 is a schematic configuration diagram showing an embodiment at the time of cleaning of a coating apparatus having a cleaning mechanism of the present invention. In the coating apparatus having the cleaning mechanism of the present invention, as shown in FIG. 1, the solvent storage unit 3 is provided with two or more solvent tanks 16 capable of storing two or more kinds of solvents in order to prevent a solvent shock. Yes.

  Each solvent tank 16 has a three-way cup-type tank switching valve 18 in the upper direction of the solvent tank 16 in order to sequentially switch from a solvent compatible with the coating liquid to a solvent having a high cleaning property. In addition, a load cell 19 for controlling the weight of the solvent is provided at the bottom of the solvent tank 16 in order to eliminate variations in washing. In addition, the tank switching valve 18 used in the present invention can use either an operation signal from the outside or the flow path switching by a manual operation. Depending on the specifications, a valve that operates with an operation signal from the outside or a valve that operates manually is selected as appropriate.

  Further, a solvent flow rate control valve 21 for controlling the flow rate of the solvent is provided to eliminate the variation in cleaning of the solvent transferred from the solvent tank 16, and the solvent flow rate is measured in the discharge direction of the solvent flow rate control valve 21. A solvent flow meter 17 is provided. Further, the solvent that has passed through the solvent flow meter 17 passes through a solvent filter 20 for removing foreign matters in the solvent, and is provided with a first switching valve 22 that crosses the gas from the dry gas unit 2. Further, at the time of cleaning, a solvent for cleaning is transferred from the coating liquid switching valve 10 of the coating unit unit 1, and the piping of the coating unit unit 1 or the inside of the die head is sequentially cleaned with a compatible solvent. . In addition, a solvent and a drying gas such as nitrogen may be mixed and sent to the coating unit unit 1 during cleaning to clean the piping or die head 5 of the coating unit unit. The solvent flows in the solvent pipe 30 until it reaches the first switching valve 22.

  The drying gas unit 2 includes a drying gas tank 26 for storing gas for drying the inside of the pipe or the die head 5, a drying gas flow rate control valve 27 for controlling the gas flow rate, and a drying gas flow rate control valve. The gas flow meter for drying 28 measures the flow rate of the gas that has passed through 27. Further, the gas that has passed through the drying gas flow meter 28 reaches the first switching valve 22 that intersects with the solvent transferred from the solvent tank 16, and is further dried from the coating liquid switching valve 10 of the coating unit section 1 during cleaning. This gas is transferred and dried after washing with the solvent in the piping of the coating unit 1 or the die head 5. The drying gas flows in the drying gas pipe 31 until it reaches the first switching valve 22.

  During cleaning / drying of the piping and the die head, the cleaning solvent flows backward in the piping upstream of the coating liquid switching valve 10 connected to the cleaning processing section, that is, the piping on the coating liquid storage tank 6 side. Therefore, a valve is provided in front of the coating liquid storage tank 6 to prevent the coating liquid storage tank 6 from being contaminated by connecting and switching to the waste liquid tank 7. Replace with a waste liquid can 9 to receive.

  Moreover, the solvent for washing | cleaning used for the coating apparatus which has the washing | cleaning mechanism of this invention is not specifically limited, The thing with compatibility with a coating liquid is selected suitably. For example, when the main solvent used in the coating liquid is a cyclohexanone solvent, it is washed with a cyclohexanone solvent at an extrusion pressure of 20 KPa to 40 KPa, and further washed with an extrusion pressure of 30 KPa to 45 KPa using a 2-butanone solvent. .

  As an application example of the present invention, it can be widely used as a processing machine, a processing machine, or a related device that requires color change or material change such as a printing machine, an adhesive processing machine, and a pigment processing machine.

It is explanatory drawing which shows one Example at the time of the washing | cleaning of the coating apparatus which has a washing | cleaning mechanism of this invention. It is explanatory drawing which shows one Example of the coating device which has the washing | cleaning mechanism of this invention. (A) It is a front view which shows the front of a die head. FIG. 4B is a sectional view showing a section taken along line AA ′ of FIG. It is a schematic block diagram which shows one implementation state of the conventional coating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coating unit part 2 ... Dry gas unit part 3 ... Solvent storage part 4 ... Cleaning process part 5 ... Die head 6 ... Coating liquid storage tank 7 ... Waste liquid tank 8 ... Filter for coating liquid 9 ... Waste liquid cans 10, 10 '10 "... coating liquid switching valve 11 ... coating liquid insertion valve 12 ... overflow switching valve 13 ... coating liquid tray 14 ... first coating liquid piping 15 ... second coating liquid piping 16 ... solvent tank DESCRIPTION OF SYMBOLS 17 ... Solvent flow meter 18 ... Tank switching valve 19 ... Load cell 20 ... Solvent filter 21 ... Solvent flow control valve 22 ... 1st switching valve 23 ... Coating liquid supply pump 24 ... 1st disposal valve 25 ... 2nd Disposal valve 26 ... Drying gas tank 27 ... Drying gas flow rate control valve 28 ... Drying gas flow meter 29 ... Cleaning pipe 30 ... Solvent pipe 31 ... Drying gas pipe 40 ... Ma Nihold 41 ... Slit nozzle

Claims (4)

A coating liquid storage tank, a coating liquid supply pump, and a die head are provided, and the coating liquid storage tank and the coating liquid supply pump are connected by a first coating liquid pipe, and the coating liquid supply In the coating apparatus in which the pump and the die head are connected by a second coating liquid pipe,
A coating liquid switching valve is provided on at least one of the first coating liquid pipe or the second coating liquid pipe,
There are two or more solvent tanks for storing different solvents for cleaning the piping of the coating unit section and the inside of the die head, the solvent tank has a tank switching valve, and the solvent tank is a solvent tank. Connected to the 1st switching valve by the piping for
A drying gas tank is connected to the first switching valve by a drying gas pipe;
The first switching valve and the coating liquid switching valve are connected by a cleaning pipe,
The pipe of the coating unit and the inside of the die head are cleaned by sequentially switching from a solvent compatible with the coating liquid to a highly washable solvent using two or more solvents, and then drying. A coating apparatus having a characteristic cleaning mechanism.   The coating apparatus having a cleaning mechanism according to claim 1, wherein the coating apparatus having the cleaning mechanism includes a solvent flow valve for controlling a flow rate of the solvent and a solvent flow meter.   The coating apparatus having the cleaning mechanism according to claim 1, wherein the coating apparatus having the cleaning mechanism includes a load cell that measures a liquid storage weight for performing weight control of the solvent. The coating apparatus having the cleaning mechanism includes a drying gas flow rate control valve for controlling the flow rate of the drying gas, and a drying gas flow meter. A coating device having a cleaning mechanism.

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