JP2010188289A - Liquid applying device and liquid applying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid applying device capable of reliably detecting defective liquid application which easily occurs when increasing the number of times of intermittent application of a liquid per a fixed length (for example, the length per one sheet of product) of a base material to be coated. <P>SOLUTION: The liquid intermittent application device 1 comprises: a signal generating means 3 which generates a periodical signal at a fixed interval of feeding length of the base material 2 to be coated during conveyance; an electromagnetic valve 4 which opens and closes the flow path of compressed fluid; a liquid application part 5 which moves a valve body with the compressed fluid from the electromagnetic valve 4 and switches liquid to be applied to the base material 2 to be coated into an ejection state or a non-ejection state; a pressure sensor 6 which measures an internal pressure in the flow path in the middle where the compressed fluid advances from the electromagnetic valve 4 toward the liquid application part 5 and, when the pressure of the predetermined threshold or more is detected, outputs an ON signal; and a sequencer 7 which receives and analyzes the signal, wherein the operation check of the electromagnetic valve 4 is performed based on the sum of transmission times of the ON signal from the pressure sensor between periodic signals. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid coating apparatus and a liquid coating method for intermittently coating a liquid on a substrate to be coated.

2. Description of the Related Art Conventionally, as a liquid application apparatus for applying a hot melt adhesive (hereinafter referred to as hot melt), an apparatus for applying hot melt to an application substrate from an application gun is known (for example, see Patent Document 1). . In addition, in a production line for absorbent articles such as sanitary napkins, it is also known that an adhesive is intermittently applied in a flow direction to a substrate to be applied that flows in one direction (for example, Patent Documents). 2).
Although not a liquid application technique, Patent Document 3 discloses an operation signal detector that detects the operation signal and a valve drive unit in a pneumatic operation valve that is driven by an electromagnetic valve that operates by an operation signal. An air pressure detector that detects the air pressure of the pneumatic cylinder and a displacement detector that detects the displacement of the valve rod that is the valve load section are provided, and a preset limit value or the like is set by inputting a signal from each detector. There is described a diagnostic device for a pneumatically operated valve comprising a diagnostic monitoring device for identifying and monitoring an abnormal part of the pneumatically operated valve.

JP 2000-167460 A JP 2004-202146 A Japanese Patent Laid-Open No. 7-119862

By the way, in the hot melt coating apparatus, switching between hot melt coating and non-coating is performed through an electromagnetic valve. For example, there is known a liquid coating apparatus that moves a valve body of a coating gun up and down by sending compressed air to the coating gun through an electromagnetic valve to switch between hot melt coating and non-coating. More specifically, the liquid application device transmits an on / off signal generated by the control circuit to the electromagnetic valve, opens the electromagnetic valve, and sends compressed air to the application gun via the electromagnetic valve. Raise and lower the valve body.
However, in the conventional liquid application device, there may be a malfunction that the valve rod of the solenoid valve does not move to a predetermined position. Even if such a problem occurs, the conventional liquid coating apparatus cannot confirm the malfunction of the liquid coating apparatus unless the on-site worker confirms the state of application of hot melt to the substrate to be coated. It was. However, according to the confirmation by the field worker, the operation of the production line cannot be stopped immediately when a malfunction of the liquid coating apparatus occurs, and the productivity of the product is lowered. In the technique of Patent Document 3, since the operation of the solenoid valve is determined based on the operation signal, the abnormality cannot be accurately detected when a manual setting error or failure or an operation signal abnormality occurs. .

By the way, when applying a hot melt to a substrate to be stretched or breathable or a flexible substrate to be coated, a hot melt is used to suppress a decrease in stretchability, breathability, flexibility, etc. In some cases, it is desired to apply the melt intermittently in the flow direction of the substrate to be coated. Further, when it is desired to reduce the amount of hot melt used, it may be desired to apply hot melt intermittently with respect to the flow direction of the substrate to be coated, regardless of the physical properties and properties of the substrate to be coated. .
From this point of view, intermittent application of hot melt is performed, but for the purpose of manufacturing higher quality products, hot melt is applied to two locations per product, so-called double hitting. There are also cases where intermittent application is performed three times or more.
However, in the intermittent application device that switches between hot melt application and non-application by moving the valve body of the application gun up and down by sending compressed air to the application gun through the electromagnetic valve, intermittently per product When the number of times of application increases, the ON / OFF signal interval to the solenoid valve gets closer, so the arrival delay of compressed air occurs, and the air pressure applied to the pressure sensor is smaller than the air pressure threshold that can be recognized by the pressure sensor There is.

This phenomenon will be specifically described with reference to FIGS. FIG. 7A is a timing chart when the transport speed of the substrate to be coated is low. As can be seen from this timing chart, application of hot melt is performed three times per product. The pulse A has a normal pulse width, and the pulses B and C have a narrower pulse width than the pulse A. The application time per product is shortened by this narrowing.
And when the conveyance speed of a to-be-coated base material becomes medium speed like FIG.7 (b), the pulse width of pulse A, B, C will become narrow compared with Fig.7 (a), and application | coating time will further shorten. When the transport speed of the substrate to be coated is increased as shown in FIG. 7C, the pulse widths of the pulses A, B, and C are narrower than those in FIG. 7B, and the coating time is further shortened. However, the air pressure sensed by the pressure sensor at the time of pulse C in FIG. 7C is smaller than a threshold value set in advance by the field worker or the like and input to the line equipment, and no pulse signal is transmitted from the pressure sensor. . This is because, as described above, when the number of intermittent applications per product increases, the interval between the ON / OFF signals of the solenoid valve becomes narrow, so that the arrival delay of compressed air occurs, and the air pressure applied to the pressure sensor is This is because it becomes smaller than the threshold value of the air pressure that can be recognized by the pressure sensor.

  FIG. 8A is a timing chart when the conveyance speed of the substrate to be coated is low. In the timing chart of FIG. 8A, the interval between the pulse B and the pulse C is narrower than the timing chart of FIG. And when the conveyance speed of a to-be-coated base material becomes medium speed like FIG.8 (b), the space | interval of the pulse B and the pulse C will further narrow. Further, as shown in FIG. 8C, when the transport speed of the substrate to be coated is increased, the interval between the pulse B and the pulse C is further narrowed to form a continuous pulse. In this case, the waveform of the air pressure near the pressure sensor becomes one peak as shown in FIG. As a result, the number of ON signals output from the pressure sensor is reduced by one compared to the cases of FIGS. 8A and 8B.

  As described above, in the above-described conventional liquid application apparatus, in the state shown in FIGS. 7C and 8C, the liquid application failure is detected by the ON signal output from the pressure sensor. Even if you try to do it, you may not be able to detect it accurately.

  The present invention is a liquid that can reliably detect liquid application defects that are likely to occur when the number of intermittent application times of liquid per certain length of the substrate to be coated (for example, the length of one product) is increased. It relates to providing a coating device.

  The present invention relates to a signal generating means for generating a periodic signal at a constant feed length interval of a substrate to be coated being conveyed, an electromagnetic valve for opening and closing a flow path of the compressed fluid, and a valve by the compressed fluid from the electromagnetic valve. A liquid application unit that moves a body to switch a liquid applied to the substrate to be applied to a discharge state or a non-release state; and an internal pressure of a flow path in the middle of the compressed fluid from the electromagnetic valve to the liquid application unit. A pressure sensor that measures and outputs an on signal when a pressure equal to or greater than a predetermined threshold is detected, and a sequencer that receives the on signal from the pressure sensor and analyzes the on signal, intermittently supplying liquid A liquid coating apparatus for coating, wherein the operation check of the electromagnetic valve is performed based on the sum of transmission times of ON signals from the pressure sensor between the periodic signals.

  The present invention also provides an electromagnetic valve that opens and closes a flow path of a compressed fluid, and moves the valve body by the compressed fluid from the electromagnetic valve so that the liquid applied to the substrate to be coated is released or not released. A liquid application method for intermittently applying a liquid to a substrate to be coated using a liquid coating apparatus having a liquid coating unit for switching, wherein a periodic signal is output at a constant feed length interval of the substrate to be coated. And generating an ON signal when the internal pressure of the flow path on the way from the electromagnetic valve to the liquid application part becomes equal to or higher than a predetermined threshold, and from the pressure sensor between the periodic signals. The present invention provides a liquid application method for applying the liquid while checking the operation of the electromagnetic valve based on the sum of transmission times of ON signals.

According to the liquid application apparatus of the present invention, it is possible to reliably prevent liquid application defects that are likely to occur when the number of intermittent application times of liquid per certain length of the substrate to be applied (for example, the length of one product) is increased. Can be detected.
According to the liquid application method of the present invention, it is possible to easily detect a liquid application failure while intermittently applying the liquid to the substrate to be applied being conveyed.

FIG. 1 is an explanatory view showing a first embodiment of the liquid coating apparatus of the present invention. FIG. 2 is an explanatory diagram illustrating an operation mechanism of the liquid application unit. FIG. 3 is a timing chart showing output waveforms from various devices constituting the liquid application device. FIG. 4 is an explanatory view showing a second embodiment of the liquid coating apparatus of the present invention. FIG. 5 is a timing chart showing output waveforms from various devices constituting the liquid coating apparatus. FIG. 6 is an explanatory diagram showing an example in which hot melt is applied at two locations along the width direction of the substrate to be coated. FIG. 7 is an explanatory diagram showing a timing chart of the applied voltage to the solenoid valve, the air pressure around the pressure sensor, and the output voltage of the pressure sensor when the on-time of the solenoid valve is made shorter than usual. FIG. 7A shows a case where the substrate to be coated is conveyed at a low speed, FIG. 7B shows a case where the substrate to be coated is conveyed at a medium speed, and FIG. The case where it is conveyed is shown. FIG. 8 shows the voltage applied to the solenoid valve, the air pressure around the pressure sensor, and the pressure sensor when the voltage application interval to the solenoid valve (interval between pulses B and C) is shorter than that in FIG. It is explanatory drawing which shows the timing chart of an output voltage. 8A shows a case where the substrate to be coated is conveyed at a low speed, FIG. 8B shows a case where the substrate to be coated is conveyed at a medium speed, and FIG. The case where it is conveyed is shown.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.
[First Embodiment]
FIG. 1 shows a first embodiment of the liquid coating apparatus of the present invention. As shown in the figure, the liquid coating apparatus 1 includes a roller 3 that rotates while being in contact with a substrate 2 to be coated, and an electromagnetic valve 4 that opens and closes a flow path of compressed air that is a compressed fluid. Yes. Here, the compressed fluid includes simple liquid having compressibility in addition to compressed air. In short, any fluid that can move the valve body is included in the compressed fluid. Further, the liquid coating apparatus 1 includes a liquid coating unit 5 that moves the valve body by compressed air from the electromagnetic valve 4 to switch the hot melt applied to the substrate to be coated 2 to a discharge state or a non-release state. . Furthermore, the liquid application device 1 measures the internal pressure of the flow path in the middle of the compressed air from the electromagnetic valve 4 toward the liquid application unit 5 and outputs an ON signal when a pressure equal to or higher than a predetermined threshold is detected. A sensor 6 is provided. The liquid application apparatus 1 also includes a sequencer 7 that receives an ON signal from the pressure sensor 6 and analyzes the ON signal.
The pressure sensor 6 is preferably set so that a threshold is set with 50% of the maximum pressure as a guide, and an ON signal is output when the threshold is exceeded.

For example, a reflection film F is attached to the rotation shaft of the roller 3, and the rotation number of the roller 3 is counted by the sequencer 7 using the rotation detector 8 that receives and emits light. More specifically, the roller 3 rotates once every time the substrate 2 to be coated flows for the length of one absorbent article, and the rotation detector 8 and the sequencer 7 each time the roller 3 rotates once. A periodic signal is generated once.
A rotary encoder 9 is attached to the rotation shaft of the roller 3. The number of pulses transmitted from the rotary encoder 9 is counted by the internal counter 7 a of the sequencer 7.
The roller 3, the reflection film F, the rotation detector 8 and the sequencer 7 function as signal generating means for generating a periodic signal at a constant feed length interval of the substrate 2 to be coated being conveyed.
The roller 3 is, for example, a roller cutter roller that cuts the substrate to be coated 2 into a length corresponding to one absorbent article, a roll of a conveyance means that conveys the substrate to be coated 2 (nip roller, driving or driven belt conveyor) Or a free roller that rotates in contact with the substrate 2 to be coated. The rotation speed of the roller 3 is determined by the relationship with the conveyance speed of the substrate 2 to be coated. The rotation speed (circumferential speed) of the roller 3 is preferably the same speed as the transport speed of the substrate 2 to be coated or a speed proportional to the transport speed. Moreover, it is preferable that the roller 3 rotates at a constant speed.

As the substrate 2 to be coated, a material made of any material that can be coated with a liquid is used. The substrate 2 to be coated is preferably a sheet-like material, and as the sheet-like material, a nonwoven fabric, a resin film, paper, a woven fabric, one or more laminates thereof, and a layer between these one or more laminates. Examples include a laminate in which non-sheet-like materials are interposed continuously or intermittently. Examples of the substrate 2 to be coated when the liquid coating apparatus 1 of the present embodiment is used for the production of absorbent articles such as sanitary napkins include the surface material, back material, release paper, and individual packaging sheet of the absorbent article. A belt-shaped original fabric such as
As an example of the fiber sheet, natural fibers such as cellulose fibers such as pulp fibers and cotton and / or synthetic fibers made from thermoplastic resins such as polyethylene, polypropylene, and polyester as a main component (dry weight of the sheet) Sheet-like material). Not only hydrophilic fibers but also sheets composed of hydrophobic and water-repellent fibers can be used. The fibrous sheet can contain pulverized pulp, inorganic or organic pigment components, and the like.

The substrate 2 to be coated is fed from a feed roller (not shown) and conveyed to the next process by a feed roller or the like. A liquid application unit 5 is provided in the transport path of the substrate 2 to be coated, hot melt is discharged from the liquid application unit 5, and a rectangular print P is formed on the substrate 2 to be coated. The prints P are formed at a predetermined interval.
Examples of the hot melt include SIS (styrene-isoprene-styrene block polymer), SIBS (styrene-isoprene-butadiene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block polymer), SEPS (styrene-ethylene- Styrene elastomers such as propylene-styrene block polymers; ethylene / vinyl acetate copolymers; elastomers such as polyesters, acrylics, and polyolefins; rubbers such as polyisobutylene, butyl rubber, polyisoprene, and natural rubber are preferably used. It is done. Among these, styrene-based elastomers are particularly preferably used in this embodiment because they can be applied uniformly. Also, the hot melt application method is not particularly limited, and known methods such as coater method, spiral method (omega method, dulauave method, etc.), spray method, curtain spray method, etc. can be used, but intermittent application is managed. In view of the above, preferred methods are a coater method, a curtain spray method, and a spray method.
Examples of products made of the substrate to be coated 2 include sanitary products, diapers for children and adults. The liquid application apparatus of the present invention can be preferably used for manufacturing any product that can apply a liquid by operating a liquid application part with a compressed fluid via an electromagnetic valve.

FIG. 2 shows a structure for operating the liquid application unit 5. As shown in FIG. 2, the liquid application unit 5 includes a valve body 10. The valve body 10 includes a needle portion 10a and a flange portion 10b formed on the rear end side of the needle portion 10a. A truncated cone-shaped plug portion 10a1 is formed at the tip of the needle portion 10a. Then, when the valve body 10 moves up and down, the plug portion 10a1 opens and closes the hot melt flow path, whereby the liquid application unit 5 is switched between a state in which the hot melt is released and a state in which the hot melt is not released.
In addition, compressed air is fed into the liquid application unit 5 through a solenoid valve 4 from a compressor (not shown). The valve body 10 moves up and down by the action of the compressed air. A pressure sensor 6 is provided in the flow path from the electromagnetic valve 4 to the liquid application unit 5. The pressure sensor 6 is connected to the calculation unit of the sequencer 7. A rotation detector 8 disposed close to the roller 3 is connected to the calculation unit. Then, based on the output from the pressure sensor 6 and the output from the rotation detector 8, the calculation unit of the sequencer 7 determines whether or not there is a solenoid valve failure, and when the calculation unit determines that a problem has occurred in the solenoid valve 4, The sequencer 7 instructs the product discharge mechanism of the production line to discharge the product.

  Next, a method for checking the failure of the electromagnetic valve 4 will be described. FIG. 3 is a timing chart showing the output waveforms of the pressure sensor 6, the rotation detector 8 and the rotary encoder 9, and the count number of the internal counter 7a. In the first embodiment of the liquid coating method of the present invention, hot melt (liquid) is applied to the substrate to be coated while transporting the electromagnetic valve described below using the above-described liquid coating apparatus 1 while performing a defect check on the electromagnetic valve. Apply intermittently.

  In the present embodiment, the count value of the internal counter 7a returns to zero each time the output signal from the rotation detector 8 becomes high. The internal counter 7a counts the number of pulses transmitted from the rotary encoder 9 in small increments. More specifically, when the output signal output from the pressure sensor 6 is in a high state (on signal), the number of pulses transmitted from the rotary encoder 9 is counted. That is, the operation check of the electromagnetic valve 4 is performed based on the sum of the transmission time (number of pulses) of the ON signal from the pressure sensor 6 during one rotation of the roller 3. More specifically, the number of pulses from the rotary encoder 9 while one ON signal is being transmitted from the pressure sensor 6 is integrated for one rotation of the roller 3, and this integrated pulse number is set in advance. The operation check of the solenoid valve is performed depending on whether or not it is larger than the value. Here, when the measured number of pulses is larger than the set value, the calculation unit determines that the solenoid valve is operating in a normal state. On the other hand, when the measured number of pulses is smaller than the set value, the number of pulses from the pressure sensor 6 is less than three, so the calculation unit determines that the solenoid valve is not operating in a normal state. Here, the normal state refers to a state where the pulse width and pulse interval of a pulse signal transmitted to the electromagnetic valve are not too narrow, and a state where the electromagnetic valve itself is not broken.

  In the example shown in FIG. 3, when the roller 3 makes one rotation and the output value from the rotation detector 8 becomes high, the output value becomes low and again becomes high. In the meantime, the ON signal is output from the pressure sensor 6 three times. The time during which the ON signal is output (transmitted) is the number of pulses input from the encoder 9 for the first ON signal, and the same number of pulses for the second and third ON signals. It is for two pulses. The total number of pulses corresponding to the total transmission time of the three ON signals is six times of 3 times × 2 pulses. FIG. 3 shows a case where the solenoid valve is operating normally. For example, if the number of pulses of 5 or more is input or recorded in the sequencer 7 as a set value indicating a normal state, the set value is displayed. The sequencer 7 detects an abnormality when the value falls below.

When it is determined by the calculation unit that the solenoid valve is not operating in a normal state (for example, hot melt is not applied or the amount applied is small), the substrate to be applied applied from the liquid application unit during this operation The product made of the material is determined to be defective and discharged from the production line. When a defective product is discharged from the production line, a cut sheet in a state before a product such as a diaper is produced can be discharged, or can be discharged after the product is completed. When such defective products occur continuously, the operation of the production line should be stopped. When the production line stops while the production line is operating smoothly, it is determined that the solenoid valve is not operating, and the calculation unit determines that the solenoid valve itself is defective.
Therefore, if the liquid coating apparatus is configured so that the above-described measurement method can be performed, it is possible to reliably detect hot melt application defects that are likely to occur when the number of intermittent hot melt applications per product is increased. be able to. Of course, the quality of hot melt application can be determined for all products.

  The cause of the malfunction of the solenoid valve that can be detected in the first embodiment is as follows. For example, as a cause of an abnormality in which the total transmission time of the ON signal output from the pressure sensor is less than a predetermined set value set as a set value indicating a normal state while the roll is rotating once, a solenoid valve For example, the pulse width or pulse interval of the pulse signal transmitted to the head is too narrow, the electromagnetic valve is broken, the rotation detector is broken, or the like. Even when the total transmission time of the ON signal output from the pressure sensor exceeds the predetermined set value, it can be detected as an abnormality, and the cause of the abnormality exceeding the predetermined set value is that the solenoid valve has failed. The rotation detector is broken, the coating gun is broken, and the like.

[Second Embodiment]
FIG. 4 shows a second embodiment of the liquid coating apparatus of the present invention. The liquid coating apparatus 1 according to the second embodiment is different from the liquid coating apparatus according to the first embodiment in that the rotary encoder 9 is not provided. In the second embodiment, the internal timer 7b of the sequencer 7 operates. In the second embodiment, sequence control for checking whether or not the electromagnetic valve 4 is malfunctioning is performed by the following processing. In the second embodiment of the liquid application method of the present invention, a hot melt is applied to the substrate to be coated while being checked for defects of a solenoid valve described below using the liquid application apparatus 1 of the second embodiment. (Liquid) is applied intermittently.

  Hereinafter, a method for checking the operation of the electromagnetic valve 4 will be described. FIG. 5 is a timing chart showing output waveforms of the pressure sensor 6 and the rotation detector 8. In the present embodiment, the time for one rotation of the rotation detector 8 is one period (T0 in the figure), and the time zone when the output signal from the pressure sensor 6 in this one period is in a high state is set. It is expressed as T1, T2, and T3. Then, the ratio of the high state in one cycle (X% in the figure) is calculated, and it is checked whether or not this ratio falls within a predetermined range. The periods T1, T2, and T3 when the pulse signal from the pressure sensor 6 is high are measured by the internal timer 7b. Also, the time T0 for one rotation of the rotation detector 8 is measured by the internal timer 7b.

Then, the operation of the electromagnetic valve 4 is checked based on the sum of transmission times of the ON signal from the pressure sensor 6 during the rotation of the roller 3 (T1 + T2 + T3). More specifically, the operation of the solenoid valve is checked based on whether or not the ratio of the time (T1 + T2 + T3) during which the ON signal is transmitted from the pressure sensor 6 to the time T0 in which the roller 3 rotates once is within an appropriate range. Is called. Here, when the measured ratio (X%) falls within a predetermined range, the calculation unit determines that the solenoid valve is operating normally. On the other hand, when X% exceeds the upper limit, it can be determined that the solenoid valve is malfunctioning.
For example, when X% falls below the lower limit, it can be determined that the number of pulses of the pressure sensor 6 in one cycle is two or less. On the other hand, when X% exceeds the upper limit, it can be determined that a failure has occurred in which the solenoid valve is always on.
When the ratio (X%) deviates from the appropriate range, the calculation unit determines that the liquid coating apparatus is malfunctioning. The cause of this malfunction is, for example, that the pulse width or pulse interval of the pulse signal transmitted to the solenoid valve is too narrow, the solenoid valve has failed, or the rotation detector has failed.
If the ratio (X%) does not fall within the proper range, the product is discharged from the production line.
Therefore, if the liquid coating apparatus is configured so that the above-described measurement method can be performed, it is possible to reliably detect hot melt application defects that are likely to occur when the number of intermittent hot melt applications per product is increased. be able to.

  The liquid coating apparatus 1 according to the second embodiment is less expensive than the liquid coating apparatus according to the first embodiment and has fewer wires than the liquid coating apparatus according to the first embodiment because the rotary encoder 9 is not provided. This reduces the possibility of equipment failure.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to those embodiment, It can change suitably.

For example, in the above-described embodiment, the device for applying hot melt from the liquid application unit 5 by turning on the electromagnetic valve 4 has been described. However, hot melt from the liquid application unit 5 by turning off the electromagnetic valve 4. You may make it apply | coat.
In the above-described embodiment, the example in which the long hot-melt prints P are formed at regular intervals along the transport direction has been described. However, the liquid application unit 5 has a plurality of nozzles, and corresponds to each nozzle. An electromagnetic valve for compressed air may be provided, and a plurality of small prints P may be formed in the width direction of the substrate 2 to be coated. For example, as shown in FIG. 6, two prints P may be formed along the width direction of the substrate 2 to be coated.

Further, the time for integrating the transmission time of the ON signal from the pressure sensor is not limited to the time for which the roll 3 makes one rotation, and any angle less than one rotation of the roll, for example, the roll 3 makes a half rotation or a quarter rotation. It is also possible to use a time during which the roll rotates more than once (360 degrees), for example, 1.5 rotations, or a time between two rotations.
Furthermore, in the above-described embodiment, an example in which hot melt is applied from the liquid application unit 5 has been described. However, the present invention can be applied to liquids other than hot melt, for example, adhesives other than hot melt adhesives, surface treatment agents, It can also be applied to skin care agents.

DESCRIPTION OF SYMBOLS 1 Liquid coating apparatus 2 Substrate to be coated 3 Roller 4 Electromagnetic valve 5 Liquid coating part 6 Pressure sensor 7 Sequencer 7a Internal counter 7b Internal timer 8 Rotation detector 9 Rotary encoder 10 Valve body 10a Needle part 10a1 Plug part 10b Flange part F Reflection Film P print

Claims (6)

A signal generating means for generating a periodic signal at a constant feed length interval of the substrate to be coated during conveyance;
A solenoid valve that opens and closes the flow path of the compressed fluid;
A liquid application unit that moves the valve body by the compressed fluid from the electromagnetic valve to switch the liquid applied to the substrate to be applied to a discharge state or a non-release state;
A pressure sensor that measures an internal pressure of a flow path in the middle of the compressed fluid from the electromagnetic valve toward the liquid application unit, and outputs an ON signal when a pressure equal to or higher than a predetermined threshold is detected;
A sequencer that receives an on signal from the pressure sensor and analyzes the on signal;
A liquid application apparatus for intermittently applying a liquid,
A liquid coating apparatus in which operation check of the electromagnetic valve is performed based on a sum of transmission times of ON signals from the pressure sensor between the periodic signals.   The liquid coating apparatus according to claim 1, wherein the signal generation unit includes a roller whose rotation speed is determined in relation to a conveyance speed of the substrate to be coated, and generates a periodic signal each time the roller rotates by a predetermined angle. . The roller is provided with a rotary encoder,
The number of pulses from the rotary encoder while one signal is transmitted from the pressure sensor is integrated between the periodic signals, and the electromagnetic wave is determined depending on whether or not the number of integrated pulses is greater than a predetermined set value. The liquid application apparatus according to claim 2, wherein an operation check of the valve is performed.   The liquid according to claim 2 or 3, wherein an operation check of the electromagnetic valve is performed depending on whether a ratio of a time during which an ON signal is transmitted from the pressure sensor to a time during which the roller makes one rotation is within an appropriate range. Coating device.   The liquid application apparatus according to claim 1, wherein the liquid is a hot melt adhesive. A solenoid valve that opens and closes a flow path of the compressed fluid; and a liquid application unit that moves the valve body by the compressed fluid from the solenoid valve to switch the liquid applied to the substrate to be coated to a discharge state or a non-release state. A liquid application method for intermittently applying a liquid to a substrate to be coated using a liquid application apparatus,
While generating a periodic signal at a constant feed length interval of the substrate to be coated, the internal pressure of the flow path in the middle of the compressed fluid from the electromagnetic valve to the liquid coating part is equal to or greater than a predetermined threshold value. Sometimes an on signal is output,
A liquid application method for applying the liquid while performing an operation check of the electromagnetic valve based on a sum of transmission times of ON signals from the pressure sensor between the periodic signals.

Images