JP2009109366A - Wet film thickness control method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wet film thickness control method and its device for measuring a wet film thickness of a coating film on a coating device without undergoing disturbances caused by a dry environment, etc. and controlling the film thickness so that it falls within a proper range. <P>SOLUTION: This wet film thickness control method comprises a tension measurement process for a base material, a thickness measurement process for the base material; a cutting process for acquiring a fully pre-coated sample of a prescribed width for measurement; a winding process for the sample; a total length measurement process for the sample; a total mass measurement process for the sample; a true-thickness calculation process for calculating the true thickness of the base material from the tension and measured thickness; a wet film thickness calculation process for calculating the wet film thickness of the sample in a winding body; a film thickness suitability determination process for determining whether the calculated film thickness is within, or without a suitable film thickness range; and a manipulation process for manipulating coating conditions for a coating part, if the thickness is determined to be without the range. A method to which this method is applied is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical field of controlling the coating method and apparatus and the thickness of the coating film obtained thereby. In particular, a wet film thickness control method capable of measuring a wet film thickness of a coating film without being disturbed by a dry environment on the coating apparatus and controlling the wet film thickness to be within an appropriate range. And related to the device.

An optical method is well known as one of methods for measuring a film thickness on a substrate obtained by coating in a coating apparatus that uses a web substrate as a coating target. For example, the coating film is irradiated with white light at a constant incident angle, the reflected or transmitted light is dispersed to measure the spectral intensity waveform, and the film is measured from the wavelength position of the intensity of the spectral intensity caused by the interference phenomenon caused by the thin film. A method for measuring the thickness is known (Patent Document 1).
JP 61-246607

  However, in this conventional method, there is a problem that an error occurs in the drying section of the coating apparatus due to a change in gas refractive index (temperature, density change due to atmospheric pressure, gas concentration, etc.). Although it is possible to correct fluctuations in the gas refractive index, setting a correction value for each coating condition or measurement condition is a heavy operational burden. Further, although vibration and wrinkles are unavoidable on the web substrate that travels, a large error occurs depending on the vibration and wrinkle conditions. Since the generation time cannot be predicted and the error value cannot be captured, the correction cannot be performed, and the reliability of the measured value cannot be obtained. Therefore, there is a problem that it is extremely difficult or impossible to control the wet film thickness based on the film thickness obtained by this method.

  The present invention has been made to solve the above problems. Its purpose is to measure the wet film thickness of the coating film without being disturbed by the drying environment on the coating device, and to control the wet film thickness to be within the proper range. It is to provide a control method and apparatus.

A wet film thickness control method according to claim 1 of the present invention is a wet film thickness control method for measuring a wet film thickness in a coating apparatus having a coating part and a drying part, and is applied to a substrate before coating. For tension measurement process for measuring tension, thickness measurement process for measuring the thickness of the base material, and for measuring the coated base material by cutting and separating the base material after coating by a predetermined width along the running direction A cutting process for obtaining a sample, a winding process for winding the measurement sample to form a winding body, a full length measuring process for measuring the total length of the measurement sample in the winding body, and the winding body The total mass measurement process for measuring the total mass of the base material portion and the coating portion of the measurement sample, and the true thickness of the base material from the tension and the measurement thickness (true thickness) = (measurement) True thickness calculated by applying the formula of (thickness) x (1 + (coefficient) x (tension)) Calculation process and wet film thickness of the measurement sample in the wound body (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width) × (full length) ) / ((Coating fluid density) × (predetermined width) × (full length)) applying the formula of wet film thickness, and whether the calculated wet film thickness is within the range of the applicable film thickness A film thickness conformity determination process for determining whether the film is out of the range; and an operation process for operating the coating condition of the coating portion when the determination is out of the range.
A wet film thickness control apparatus according to claim 2 of the present invention is a wet film thickness control apparatus for measuring a wet film thickness in a coating apparatus having a coating part and a drying part, and a substrate before coating A tension measuring means for measuring the tension applied to the substrate, a thickness measuring means for measuring the thickness of the substrate, and the coated substrate is cut and separated by a predetermined width along the running direction. Cutting means for obtaining a measurement sample; winding means for winding the measurement sample to form a wound body; full-length measuring means for measuring a total length of the measurement sample in the wound body; and the winding A total mass measuring means for measuring the total mass of the measurement sample in the body consisting of the base material portion and the coating portion; and the true thickness of the base material from the tension and the measurement thickness (true thickness) = Calculate by applying the formula (measured thickness) x (1 + (coefficient) x (tension)) Thickness calculating means, and the wet film thickness of the measurement sample in the winding body is (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width) × ( (Wet length)) / ((coating liquid density) × (predetermined width) × (full length)) A film thickness conformity determining means for determining whether the coating is outside the range; and an operating means for operating the coating condition of the coating portion when the determination is out of the range.

According to the wet film thickness control method of the first aspect of the present invention, there is provided a wet film thickness control method for measuring a wet film thickness in a coating apparatus having a coating part and a drying part, The tension applied to the previous substrate is measured, the thickness of the substrate is measured in the thickness measurement process, and the coated substrate is cut and separated by a predetermined width along the running direction in the cutting process. A finished measurement sample is obtained, the measurement sample is wound up in the winding process to form a wound body, and the entire length of the measurement sample in the winding body is measured in the full length measurement process. In the mass measurement process, the total mass composed of the base material portion and the coating portion of the measurement sample in the winding body is measured, and in the true thickness calculation process, the true thickness of the base material is calculated from the tension and the measurement thickness. Saga (true thickness) = Measurement thickness) × (1+ (coefficient) × (tension)) is applied and calculated, and in the wet film thickness calculation process, the wet film thickness of the measurement sample in the winding body is (wet film thickness) = Applying the formula ((total mass)-(base material density) x (true thickness) x (predetermined width) x (full length)) / ((coating solution density) x (predetermined width) x (full length)) In the film thickness conformity determination process, it is determined whether the calculated wet film thickness is within the range of the conformable film thickness or out of the range, and when the determination is out of the range in the operation process, the coating part The coating conditions are manipulated. That is, it is an indirect measurement method that obtains a wet film thickness by calculating from dimensional measurement and mass measurement, and is a non-optical measurement method. Therefore, a wet film thickness control method capable of measuring a wet film thickness of a coating film without being disturbed by a dry environment or the like on the coating apparatus and controlling the wet film thickness to be within an appropriate range. Is provided.
Moreover, according to the wet film thickness control apparatus according to claim 2 of the present invention, the wet film thickness control apparatus measures a wet film thickness in a coating apparatus having a coating part and a drying part, and comprises a tension measuring means. The tension applied to the base material before coating is measured, the thickness of the base material is measured by a thickness measuring means, and the base material after coating is cut and separated by a predetermined width along the running direction by a cutting means. A measurement sample coated on the entire surface is obtained, a winding body is formed by winding the measurement sample by a winding means, and the total length of the measurement sample in the winding body is measured by a full length measuring means, The total mass consisting of the base material portion and the coating portion of the measurement sample in the wound body is measured by the total mass measuring means, and the true thickness of the base material is determined from the tension and the measured thickness by the true thickness calculating means. Thickness is (true thickness) = (measured thickness × (1+ (coefficient) × (tension)) is applied and calculated, and the wet film thickness of the measurement sample in the winding body is calculated by the wet film thickness calculation means (wet film thickness) = ((total mass )-(Base material density) × (true thickness) × (predetermined width) × (full length)) / ((coating liquid density) × (predetermined width) × (full length))) It is determined whether the calculated wet film thickness is within or outside the range of the conformable film thickness by the film thickness conformity determining means, and when the determination is out of the range by the operating means, the coating condition of the coating part Is operated. That is, it is an indirect measurement method that obtains a wet film thickness by calculating from dimensional measurement and mass measurement, and is a non-optical measurement method. Therefore, a wet film thickness control device capable of measuring the wet film thickness of the coating film without being disturbed by a dry environment or the like on the coating apparatus and controlling the wet film thickness to be within an appropriate range. Is provided.

Next, embodiments of the present invention will be described with reference to the drawings. An example of a coating apparatus to which the wet film thickness controller of the present invention is applied is shown in FIG. In FIG. 1, 200 is a base material, 120 is a coating unit, 131 is a first drying unit, 132 is a second drying unit, 133 is a third drying unit, 140 is a winding unit, and 10 is a tension / thickness measuring unit. , 20 is a winding unit, and 30 is an arithmetic unit.
In the coating apparatus, the base material (web) 200 is mounted on a paper feeding unit (not shown) as a wound body in a wound form. The paper feed unit is provided with a mechanism (not shown) for applying tension, and appropriate tension is applied to the base material 200 that is unwound and fed. The base material 200 unwound from the winding body in the paper feeding unit is fed to the coating unit 120 where the base material 200 is coated. The substrate 200 is fed in the order of the first drying unit 131, the second drying unit 132, and the third drying unit 133, and the coating liquid on the surface of the substrate 200 is dried while passing through the substrate. And the base material 200 with which the dried coating film was formed is wound up in the winding-up part 140, and forms a winding body.

The tension / thickness measuring section 10, the winding section 20, and the calculating section 30 in FIG. 1 are components of the wet film thickness control apparatus of the present invention applied to this coating apparatus.
The tension / thickness measuring unit 10 measures the tension and thickness of the substrate 200 immediately before being supplied to the coating unit 120. Here, the measured thickness is referred to as a measured thickness.
The winding unit 20 is a part that winds a sample for measuring wet film thickness that is cut and separated from the substrate 200 near the outlet of the first drying unit 131 to form a winding body. In the winding unit 20, the total mass of the sample is measured.
The computing unit 30 computes the true thickness of the substrate 200 based on the measured tension and thickness (measured thickness) of the substrate 200. Moreover, the calculating part 30 calculates a wet film thickness based on the true thickness, the total mass, and other data. In addition, the calculation unit 30 controls the winding unit 20 that is performed when the mass of the sample winding body 21 is measured. In addition, the calculation unit 30 determines whether the calculated wet film thickness is within or outside the range of the suitable film thickness. Moreover, the calculating part 30 operates the coating conditions of a coating part, when the determination is out of the range. Details of these operations will be described later.

FIG. 2 shows the details of the tension / thickness measuring unit 10 of the wet film thickness control apparatus of the present invention. In FIG. 2, 300 is a coating solution, 121 is a coating solution tank, 122 is a coating roller, 123 is a backup roller, 11a and 11b are tension measuring units, and 12 is a thickness measuring unit. In FIG. 2, the same parts as those in FIG.
The coating liquid tank 121, the coating roller 122, and the backup roller 123 are components of the coating unit 120. The coating liquid tank 121 is filled with the coating liquid 300, and the lower part of the coating roller 122 is immersed in the coating liquid 300. When the coating roller 122 rotates, a coating film of the coating liquid 300 is formed on the entire peripheral surface of the coating roller 122. As shown in FIG. 2, the substrate 200 is transferred between the coating roller 122 and the backup roller 123. The backup roller 123 is a roller that can be moved and stopped between a position where the coating roller 122 is pressed and a position where it is separated. At the position where the backup roller 123 is pressed, the substrate 200 is brought into contact with the coating roller 122 by the backup roller 123. Then, the coating liquid 300 having a film formed on the peripheral surface of the coating roller 122 is transferred to the surface of the substrate 200 by contact, and coating is performed.

  The amount of the coating liquid 300 transferred to the substrate 200, that is, the wet film thickness varies depending on the amount of the coating liquid 300 formed on the peripheral surface of the coating roller 122. Therefore, although it differs depending on the coating method, the amount is regulated by some method. In general, before the peripheral surface of the coating roller 122 moves away from the coating liquid 300 in the coating liquid tank 121 and contacts the surface of the substrate 200, the coating roller 300 is extraneous. A small amount of the coating liquid 300 is scraped off. For the scraping, a rotating roller or a knife edge having a predetermined gap between the coating roller 122 and the like is used. If the coating roller 122 is a gravure roller, a doctor blade is used.

In many cases, the thickness when the wet film thickness formed on the substrate 200 is dried, that is, the dry film thickness is important. When importance is attached to the dry film thickness, the wet film thickness is managed as one of management methods for obtaining a predetermined dry film thickness. Of course, even if the wet film thickness is constant, the dry film thickness changes when the composition of the coating liquid 300 changes. The composition of the coating liquid 300 includes volatile components that are lost by drying and non-volatile components that are not lost by drying. Since the main component of the volatile component is a solvent, the dry film thickness is also regulated by adjusting the ratio of the solvent component in the coating liquid 300.
As described above, the wet film thickness is generally a film thickness immediately after coating, but here the wet film thickness is a film thickness calculated by a mathematical formula defined in the present invention.

The tension measuring units 11a and 11b and the thickness measuring unit 12 are components of the tension / thickness measuring unit 10 shown in FIG. FIG. 3 shows an enlarged view (enlarged view of A in FIG. 2) of the tension / thickness measuring unit 10 in the wet film thickness control apparatus of the present invention. In FIG. 3, 114 is a guide roller, 11b is a tension measuring unit, 200 is a base material, and 12 is a thickness measuring unit.
The guide roller 114 is a guide roller for detecting the tension applied to the substrate 200. The substrate 200 is wound around the guide roller 114, and when tension is applied to the substrate 200, a force is applied to the guide roller 114. The guide roller 114 is rotatably supported by shafts on both sides of the guide roller 114.

  The tension measurement unit 11b includes a detection unit (for example, a load cell) and an amplification unit. The detecting unit of the tension measuring unit 11b detects the force applied to the guide roller 114 from a slight displacement of the bearing of the guide roller 114. The amplifying unit of the tension measuring unit 11b converts the displacement into a tension and outputs a tension signal. In the conversion of the displacement into the tension, of course, the winding angle of the substrate 200 around the guide roller 114, the direction of the displacement, and the like are taken into consideration. In FIG. 3, only the tension measuring unit 11 b (the detecting unit) is shown, but there is also a tension measuring unit 11 a provided on the other bearing of the guide roller 114. The tension of the substrate 200 is usually an added value of the tension detected by both the tension measuring unit 11a and the tension measuring unit 11b.

The thickness measuring unit 12 is a part that measures the thickness of the substrate 200. The base material 200 is an elastic material (for example, a plastic film), and its thickness changes with a change in tension. Therefore, as shown in FIG. 3, the thickness measuring unit 12 and the tension measuring units 11a and 11b are arranged close to each other, and the thickness and the tension are measured at substantially the same place and at the same time.
As the thickness measuring unit 12, for example, an optical displacement meter that detects the position of a laser spot formed on the surface of the substrate 200 by irradiating a laser beam and measures the distance based on the principle of triangulation is used. Can do. In this measurement, the difference in position between the front surface and the back surface (back surface) of the substrate 200 is the thickness of the substrate 200. Therefore, the position of the back surface of the base material 200 needs to be fixed. Therefore, although not shown in FIG. 3, the position of the back surface of the substrate 200 is fixed by winding the vicinity of the position of the laser spot around the guide roller.

Details of the winding unit 20 of the wet film thickness control device of the present invention are shown in FIGS. 4 to 6, 201 is a sample, 120 is a first drying section, 21 is a sample winding body, 22 is a Mimi winding body, 23 is a mass measuring section, 24 is a linear motion motor, 25 is a chamber, and 26 is A cutting part, 27a and 27b are cutting blades, 28a and 28b are cleaning liquid tanks, and 29a and 29b are cleaning pads. 4 to 6, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.
FIG. 4 shows an enlarged view (enlarged view of B in FIG. 2) of the constituent parts that sample the base material 200 and form the sample winding body 21 in the wet film thickness control apparatus of the present invention. As shown in FIG. 4, the substrate 200 travels while being guided by the guide roller through the first drying unit 120. A cutting unit 26 is provided in the first drying unit 120, and the base material 200 is cut (slit) in the traveling direction at the cutting unit 26, and the sample 201 that is a part of the base material 200 is cut out.

  In the example shown in FIG. 4, slits are made at two locations near one side of the substrate 200. Due to the slit, the base material 200 is a part of the base material 200 on the outer side of the slit portion, that is, the Mim 22a, a part of the intermediate base material 200, that is, the sample 201, and a part of the inner base material 200, that is, a coated product. And is divided into three. Mimi 22a is an uncoated part or an unstable part of the coating amount and therefore cannot be used for measurement of wet film thickness. Mimi 22a is wound up to form Mimi winding body 22b and discarded. Since the sample 201 is a stable part of the coating amount, it can be used for measuring the wet film thickness. The sample 201 is wound up in the winding unit 20 to form the sample winding body 21.

FIG. 5 shows an enlarged view (an enlarged view of C in FIG. 4) of the cutting portion 26 in the wet film thickness control apparatus of the present invention. In FIG. 5, 27a and 27b are cutting blades, 28a and 28b are cleaning liquid tanks, and 29a and 29b are cleaning pads.
The cutting blades 27 a and 27 b are cutting blades for performing slits at two locations near one side of the base material 200. In the example shown in FIG. 5, the cutting blades 27a and 27b are round blades having blades formed on the circumference of the disk. The cutting blades 27a and 27b cut the substrate 200 while rotating. Part of a specific blade in the rotating cutting blades 27a and 27b circulates between a cutting position that contacts and cuts the substrate 200 and a cleaning position that is immersed and cleaned in the cleaning layers 28a and 28b.

The cleaning layers 28a and 28b are cleaning layers for cleaning the cutting edges of the cutting blades 27a and 27b. The cleaning layers 28a and 28b are filled with a cleaning liquid, and when the cutting edges of the rotating cutting blades 27a and 27b reach the cleaning position, the cleaning layers 28a and 28b are immersed in the cleaning liquid for cleaning. A coating film (wet film) formed on the substrate 200 is mainly attached to the cutting edges of the cutting blades 27a and 27b. Therefore, a cleaning liquid having a property of dissolving the coating film can be used as the cleaning liquid. Although the solvent of the coating liquid 300 can be used, since it is used in the drying section, it is preferable to use a slow-drying cleaning liquid even if the solubility is low.
The cleaning pads 29a and 29b are cleaning pads accommodated in the cleaning layers 28a and 28b, and have an action of scraping off dirt adhering to the rotating cutting blades 27a and 27b by a chemical action of the cleaning liquid and a mechanical action due to friction. Have. The cleaning pads 29a and 29b have a property of sufficiently absorbing and holding the cleaning liquid. Moreover, it has the moderate softness | flexibility which closely_contact | adheres to the both sides | surfaces of the cutting blades 27a and 27b, and the contact surface with respect to the cutting blades 27a and 27b is a rough surface of friction. As a material for the cleaning pads 29a and 29b, for example, sponge, cloth, nonwoven fabric, cotton, felt, or the like can be used.

FIG. 6 shows an enlarged view (an enlarged view of D in FIG. 4) of the winding unit 20 in the wet film thickness control device of the present invention. In FIG. 6, 20 is a winding unit, 21 is a sample winding body, 23 is a mass measuring unit, and 24 is a linear motion motor.
The sample winding body 21 is a winding body in which the sample 201 is wound around a paper tube. The take-up shaft of the take-up unit 20 is provided with a chucking mechanism for supporting the paper tube. The paper tube can take either a gripping state in which the paper tube is fixed to the winding shaft by the chucking mechanism or an open state in which the paper tube is not fixed to the winding shaft. As the chucking mechanism, for example, a mechanism in which two truncated cone-shaped gripping tools called chucking cones are used and the surfaces having a narrow diameter in the frustum shape face each other can be applied. By bringing the two chucking cones close to each other, it is possible to obtain a gripping state in which the paper tube is gripped by being fitted into inner circle portions on both sides of the paper tube. Since the chucking cone rotates with the take-up shaft, it can be taken up in the gripping state. On the other hand, when the distance between the two chucking cones is increased, the paper tube is separated from both sides and released from the take-up shaft, and an open state can be obtained.

  The winding shaft of the winding unit 20 is rotationally driven by a rotating mechanism (not shown) such as a motor. At that time, a predetermined torque is applied to the winding shaft. Therefore, the sample 201 is wound in a state where a predetermined tension is applied. This tension is usually set so as to be almost the same value as the tension acting on the substrate 200 in the coating apparatus. Further, since the rotation is driven so that the torque is not the rotation speed but the specified value, the sample 201 is wound at the rotation speed of the winding shaft in synchronization with the supply speed of the sample 201 (the traveling speed of the base material 200). It is.

  The direct acting motor 24 is a direct acting motor for reducing the mass of the winding unit 20 by an apparent amount by applying a constant force (lifting force) to be pulled upward to the winding unit 20. is there. That is, the linear motion motor 24 used here is not a motor for movement or positioning. The linear motion motor 24 can be constituted by, for example, a guide rail for linear motion (straight advance), a drive mechanism that linearly moves the stage along the guide rail, and a control mechanism that generates a constant force. Instead of the direct acting motor 24, an air cylinder mechanism for applying a certain force to be pulled upward by a predetermined air pressure, a spring mechanism for lifting just like a spring (measurement), or the like may be used.

The mass measuring unit 23 is a part that measures the mass of the sample winding body 21. However, the winding unit 20 is mounted on the mass measuring unit 23, and it is possible to measure directly from the total mass (gravity acting on the total mass) of the sample winding unit 21 and the winding unit 20 combined. This is a mass obtained by subtracting a constant force (mass obtained by dividing the lifting force by the gravitational constant) generated by the linear motor 24. Therefore, the constant force (lifting force) generated by the linear motor 24 is set so as to cancel out the mass of the winding unit 20 (gravity acting on the winding unit 20). Thereby, the measurement area | region of the mass measurement part 23 can be made into the maximum mass of the sample winding body 21, and a high measurement precision can be obtained.
The mass measuring unit 23 is set to a zero point so as to cancel out the mass of the paper tube of the sample winder 21.
Therefore, in a state where the sample 201 is not wound at all on the paper tube of the sample winder 21, the mass measurement value output from the mass measurement unit 23 becomes zero.

  As described above, the calculation unit 30 calculates the true thickness of the base material 200 based on the measured tension and thickness (measurement thickness) of the base material 200. In addition, the calculation unit 30 calculates the wet film thickness based on the true thickness, the total mass, and other data (setting values, etc.). As the arithmetic unit 30, a data processing device such as a PLC (Programmable Logic Controller) personal computer can be used.

  The calculation of the true thickness of the substrate 200 is performed in the true thickness calculation process of the calculation unit 30 or by the true thickness calculation means. The arithmetic unit 30 calculates the true thickness of the base material 200 from the measured tension and the measured thickness of the base material 200 (true thickness) = (measured thickness) × (1+ (coefficient) × ( Calculate by applying the formula of tension))). (Coefficient) is a coefficient that varies depending on the item of the substrate 200, and the value can be determined by experiment. When (tension) is 0, (true thickness) = (measured thickness). (Coefficient) is data registered in the calculation unit 30 as a set value before the calculation is performed.

  The calculation of the wet film thickness is performed in the wet film thickness calculation process of the calculation unit 30 or by the wet film thickness calculation means. The calculation unit 30 is a calculation unit that calculates the wet film thickness based on the set value and the measurement value. In the calculation of the wet film thickness, the calculation unit 30 calculates the wet film thickness in the sample winding body 21 as (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width)). Calculation is performed by applying a mathematical formula of x (full length) / ((coating liquid density) x (predetermined width) x (full length)). Here, (total mass) is the mass of the sample winding body 21 including the wet film and the substrate portion, (substrate density) is the density of the substrate 200, and (true thickness) is the tension of the sample winding body 21. The thickness corrected for fluctuation, (predetermined width) is the width of the sample winding body 21, (full length) is the total length of the sample 201 wound around the sample winding body 21, and (coating liquid density) is the coating liquid 300. Density. In the above formula, the portion of (base material density) × (true thickness) × (predetermined width) × (full length) corresponds to the mass of the base material portion of the sample winding body 21.

Note that the (full length) of the sample 201 wound around the sample winding body 21 is the travel distance of the sample 201 from the time when the operation of winding the sample 201 after slitting to the paper tube is started to the time when the measurement is performed. be equivalent to. The travel distance of the sample 201 can be measured using a length measuring device before being wound on a paper tube. Further, the travel distance of the sample 201 is equal to the travel distance of the base material 200 measured by the coating apparatus from the start time to the measurement time. The calculation unit 30 inputs such a travel distance and uses the input data in the calculation.
Further, (base material density), (predetermined width), and (coating liquid density) are data registered in the calculation unit 30 as set values before the calculation is performed.

The determination as to whether the calculated wet film thickness is within or outside the range of the suitable film thickness is performed in the determination process of the calculation unit 30 or by the determination means. The range of the suitable film thickness is data that is registered in the calculation unit 30 as a set value before performing the determination.
The calculation unit 30 compares the calculated wet film thickness with the range of the suitable film thickness, and outputs a signal for maintaining the coating conditions when it is within the range, and a signal for correcting the coating conditions when it is out of the range. That is, an operation signal is output. The coating conditions to be corrected are the ratio of the solvent component contained in the coating liquid 300, the amount of the coating liquid 300 transferred to the substrate 200, and the like. Moreover, when the solvent component ratio and the amount of the coating liquid 300 to be transferred are maintained constant, the drying output (temperature, air volume, etc.) of the first drying unit 131 is the coating condition to be corrected.

  The operation of the coating conditions is performed in the operation process or by operation means. For example, when the coating condition to be corrected is the solvent component ratio, the output of a solvent supply means (not shown) for supplying the solvent to the coating liquid tank 121 is operated. That is, when the wet film thickness is larger than the range of the suitable film thickness, the output of the solvent supply means is increased, and when the wet film thickness is smaller than the range of the suitable film thickness, the output of the solvent supply means is decreased. For example, when the coating condition to be corrected is the drying output of the first drying unit 131, the output of the first drying unit 131 is operated. That is, when the wet film thickness is larger than the range of the suitable film thickness, the output of the first drying unit 131 is increased, and when the wet film thickness is smaller than the range of the suitable film thickness, the output of the first dry unit 131 is decreased. To do.

The configuration has been described above. Next, the operation of the wet film thickness control method and apparatus of the present invention will be described. FIG. 7 is a flowchart showing the operation process in the wet film thickness control method and apparatus of the present invention.
First, in step S1 (input of set value) in FIG. 7, the operator of the wet film thickness control apparatus sets (base material density) (predetermined value) to the wet film thickness control apparatus, that is, to the calculation unit 30. Enter (width), (coating liquid density), and (applicable film thickness range) and register. The setting value may be input at any time before the calculation in wet film thickness measurement.

Next, in step S2 (tension measurement), when the coating is started and the coating state is stabilized, the operator inputs an instruction to start the wet film thickness measurement to the wet film thickness controller. The calculation unit 30 of the wet film thickness control apparatus inputs the tension of the base material 200 output from the tension measurement unit 11a.
Next, in step S3 (thickness measurement), the calculation unit 30 of the wet film thickness control device inputs the thickness of the substrate 200 output by the thickness measurement unit 12.
Next, in step S4 (sampling), the winding unit 20 of the wet film thickness control device winds the sample 201 cut and separated by the slit to form the sample winding body 21. This slit is a slit that the cutting unit 26 performs on the coated substrate 200 that has passed through the coating unit 120 from the tension / thickness measurement unit 10 and has reached the first drying unit 131.
Next, in step S5 (full length measurement), the calculation unit 30 of the wet film thickness control device starts the operation of winding the sample 201 after slitting onto the paper tube, that is, starts forming the sample winding body 21. After that, the travel distance of the sample 201 up to the time when the measurement is executed is input from a length measuring device (not shown). Even if it is not a length measuring device, the travel distance of the base material 201 may be input from the control unit of the coating apparatus. The time point at which the measurement is performed is performed based on an instruction input to the wet film thickness control apparatus by the operator. Further, a predetermined travel distance, that is, the time when the total length of the sample winding body 21 becomes a predetermined value can be set as the time point when the measurement is executed. The predetermined travel distance (predetermined total length) in this case is set in step S1 (set value input).

  Next, in step S <b> 6 (mass measurement), the mass measuring unit 23 of the wet film thickness control device measures the mass of the sample winding body 21. As described above, the mass of the winding unit 20 is canceled by the linear motion motor 24 and the mass of the paper tube is canceled by the zero adjustment of the mass measuring unit 23. The actual mass can be measured.

Next, in step S7 (true film thickness calculation), the calculation unit 30 calculates a true thickness that is the true thickness of the base material 200 from the measured tension and measured thickness of the base material 200 (true thickness) = Calculation is performed by applying a mathematical formula of (measured thickness) × (1+ (coefficient) × (tension)).
Next, in step S8 (wet film thickness calculation), the calculation unit 30 is a calculation unit that calculates the wet film thickness based on the set value and the measured value. In the calculation of the wet film thickness, the calculation unit 30 calculates the wet film thickness in the sample winding body 21 as (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width)). Calculation is performed by applying a mathematical formula of x (full length) / ((coating liquid density) x (predetermined width) x (full length)).

Next, in step S9 (film thickness suitability?), The calculation unit 30 determines whether the calculated wet film thickness is within or outside the range of the compatible film thickness. When the determination is within the range, the process proceeds to step S11. When the determination is out of range, the process proceeds to step S10.
Next, in step S10 (coating / drying condition operation), the calculation unit 30 compares the calculated wet film thickness with the suitable film thickness range, and if within the range, outputs a signal for maintaining the coating condition. When it is out of the range, a signal for correcting the coating condition, that is, an operation signal is output. Then, the coating conditions are operated in the operation process or by the operation means. This operation is performed so that the wet film thickness is within the range of the suitable film thickness.
Next, in step S11 (measurement end?), The arithmetic unit 30 determines whether or not to end the measurement. If the operator inputs an instruction to end measurement, or is set not to repeat measurement, the process ends. Otherwise, the process returns to step S2 and the subsequent steps described above are repeated.

  The sample winding body 21 need not be formed by winding the sample 201 around a new paper tube for each measurement. The sample 201 of the current measurement may be wound on the paper tube while the sample 201 of the previous measurement remains on the paper tube. In that case, the current total mass is different from the previous total mass. That is, the calculation is performed by applying the formula of (current total mass) = (measured value of current mass) − (previous total mass). This method is suitable when the measurement is repeated.

It is a figure which shows an example of the coating device to which the wet film thickness control apparatus of this invention is applied. It is a figure which shows the detail about the tension | tensile_strength measuring part of the wet film thickness control apparatus of this invention. It is an enlarged view (enlarged view of A in FIG. 2) of the tension / thickness measuring unit 10 in the wet film thickness control device of the present invention. It is a figure which shows the detail about the winding part 20 of the wet film thickness control apparatus of this invention. It is an enlarged view (enlarged view of C in FIG. 4) of the cutting part in the wet film thickness control apparatus of this invention. It is an enlarged view (enlarged view of D in FIG. 4) of the winding part 20 in the wet film thickness control apparatus of this invention. It is a flowchart which shows the process of the operation | movement in the wet film thickness control method and apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tension / thickness measuring unit 11a, 11b Tension measuring unit 12 Thickness measuring unit 20 Winding unit 21 Sample winding body 22 Mimi winding body 23 Mass measuring unit 24 Linear motion motor 25 Chamber 26 Cutting unit 27a, 27b Cutting blade 28a, 28b Cleaning liquid tank 29a, 29b Cleaning pad 30 Calculation unit 114 Guide roller 11b Tension measuring unit 120 Coating unit 121 Coating liquid tank 122 Coating roller 123 Backup roller 131 First drying unit 132 Second drying unit 133 Third drying Part 140 Winding part 200 Base material 201 Sample 300 Coating liquid

Claims (2)

A wet film thickness control method for measuring a wet film thickness in a coating apparatus having a coating part and a drying part,
A tension measurement process for measuring the tension applied to the substrate before coating;
A thickness measurement process for measuring the thickness of the substrate;
A cutting process in which the substrate after coating is cut and separated in a predetermined width along the running direction to obtain a measurement sample that has been coated on the entire surface,
A winding process of winding the measurement sample to form a wound body;
A full length measurement process for measuring the full length of the measurement sample in the winding body;
A total mass measurement process for measuring the total mass consisting of the base material portion and the coating portion of the sample for measurement in the wound body;
True thickness calculated from the tension and the measured thickness by applying the formula (true thickness) = (measured thickness) × (1+ (coefficient) × (tension)) Calculation process,
The wet film thickness of the measurement sample in the wound body is (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width) × (full length)) / (( Wet film thickness calculation process for calculating by applying a formula of (coating liquid density) × (predetermined width) × (full length)),
A film thickness conformity determination process for determining whether the calculated wet film thickness is within or outside the range of the conformable film thickness;
When the determination is out of range, an operation process for operating the coating condition of the coating part,
A method for controlling a wet film thickness, comprising: A wet film thickness control device for measuring a wet film thickness in a coating apparatus having a coating part and a drying part,
Tension measuring means for measuring the tension applied to the base material before coating;
A thickness measuring means for measuring the thickness of the substrate;
A cutting means for cutting and separating the base material after coating at a predetermined width along the running direction to obtain a measurement sample that has been coated on the entire surface,
Winding means for winding the measurement sample to form a wound body;
Full length measuring means for measuring the total length of the measurement sample in the winding body;
A total mass measuring means for measuring a total mass composed of a base material part and a coating part of the measurement sample in the winding body;
True thickness calculated from the tension and the measured thickness by applying the formula (true thickness) = (measured thickness) × (1− (coefficient) × (tension)) Computing means;
The wet film thickness of the measurement sample in the wound body is (wet film thickness) = ((total mass) − (base material density) × (true thickness) × (predetermined width) × (full length)) / (( Wet film thickness calculation means for calculating by applying a formula of (coating liquid density) × (predetermined width) × (full length)),
Film thickness conformity determining means for determining whether the calculated wet film thickness is within or outside the range of the conformable film thickness,
When the determination is out of range, an operation means for operating a coating condition of the coating part,
A wet film thickness control device comprising:

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