In-Line Impedance Analysis Device for ESD-Coated Fabrics and Quality Monitoring System Including the Same

Abstract

The present invention relates to an inline impedance analysis device for an ESD-coated fabric and a quality monitoring system including the same. More specifically, the invention relates to a system that measures and analyzes the impedance (including resistance value) of the fabric surface during the process in which an ESD-coated plastic fabric is transferred for a winding process after processing, and thereby monitors the quality of the ESD-coated plastic fabric. The inline impedance analysis device for an ESD-coated fabric is a device installed in an ESD-coated fabric manufacturing line to inspect the quality of the fabric in real time, and comprises an impedance measuring unit for measuring the electrical characteristics of the fabric surface; The quality monitoring system for an ESD-coated fabric according to the present invention comprises: a control unit connected to the impedance measuring unit; wherein the impedance measuring unit includes a support frame disposed on the conveying path of the fabric and a sensor module mounted on the support frame to measure electrical characteristics of the surface of the fabric; and wherein the control unit includes a judgment unit that determines whether there is a quality defect by comparing an impedance measurement value obtained from the sensor module with a preset allowable range and generates a defect detection signal when a defect is determined, wherein the control unit further includes an environment sensor, and the judgment unit further includes an environment correction algorithm that converts the impedance measurement value into a standard environment value based on data received from the environment sensor. The quality monitoring system for an ESD-coated fabric according to the present invention is a quality monitoring system including the inline impedance analysis device, and includes a local alarm unit that receives a defect detection signal from the control unit and outputs it visually or audibly.

Description

Technology Field

[0001] The present invention relates to an inline impedance analysis device for an ESD-coated fabric and a quality monitoring system including the same. More specifically, the invention relates to a system that measures and analyzes the impedance (including resistance value) of the surface of an ESD-coated plastic fabric (hereinafter referred to as "ESD-coated fabric") as it is transported for a winding process after processing, and thereby monitors the quality of the ESD-coated plastic fabric. Background Technology

[0003] With the recent advancement of the semiconductor, display, and electronic component industries, the demand for ESD (Electrostatic Discharge) coated fabrics used as packaging for these components is surging. In particular, since the surface impedance and resistance values ​​of ESD coating films are critical factors directly linked to a product's electrostatic protection performance, precisely managing these parameters throughout the entire production process and ensuring their reliability has emerged as a top priority.

[0004] However, conventional technologies currently used in the industrial field have several limitations. First, they rely on a sampling method that manually measures only a portion of the produced fabric at regular intervals, making it difficult to perfectly represent the quality of the entire product. Furthermore, because the system is centered on post-processing—primarily conducting inspections after the winding process or just before shipment—immediate action is impossible in the event of an anomaly.

[0005] The biggest problem arising from this is the difficulty in real-time detection and accurate identification of defective areas. If production continues without detecting defects during the process, the inability to pinpoint the exact location of the defect later ultimately results in massive costs, requiring the disposal of the entire roll, including intact parts, or the performance of extensive rework.

[0007] In this regard, examining conventional technologies, first, Registered Patent No. 10-1364468 (Polycarbonate film manufacturing apparatus and manufacturing method using the same) discloses a technology for measuring the thickness of a film and removing static electricity from the surface (static elimination). However, this focuses only on physical thickness management and suppressing static electricity generation, and has limitations in determining defects by detecting the surface impedance—an electrical performance characteristic of the fabric itself—in real time.

[0008] Furthermore, Public Patent No. 10-2013-0005507 (Method and apparatus for manufacturing an antistatic treated polymer film) relates to the manufacturing process itself, which imparts an antistatic function through an ion implantation method within a vacuum chamber, while Registered Patent No. 10-1674003 (Apparatus and method for aging an antistatic film) deals with a process of aging the film by controlling temperature and humidity. These technologies merely provide an environment for manufacturing high-quality films and do not include quality control means to detect changes in impedance on the surface of the material being transported and respond in real time.

[0009] Furthermore, registered patent No. 10-2878054 (automatic defect detection system for both sides of fabric) proposes a technology for determining external defects, such as foreign substances or scratches on the surface of a fabric, through optical means. However, there is a problem in that defects in antistatic performance cannot be completely detected by a method that simply inspects the appearance.

[0010] Therefore, there is an urgent need for a technical alternative that can measure surface impedance in real time during the rolling and transport of ESD-coated fabrics to detect the exact location where performance degradation occurs and take immediate action. Prior art literature

[0012] (Patent Document 0001) KR 10-1364468 B1(Patent Document 0002) KR 10-2013-0005507 A(Patent Document 0003) KR 10-1674003 B1(Patent Document 0004) KR 10-2878054 B1 The problem to be solved

[0013] The present invention aims to provide a fabric quality detection method that monitors performance defects invisible to the naked eye and minimizes process losses by capturing variability in the electrical characteristics of a product in a dynamic in-line state in real time, without impairing the production continuity of the ESD fabric. means of solving the problem

[0015] The inline impedance analysis device for an ESD-coated fabric according to the present invention is a device installed in an ESD-coated fabric manufacturing line to inspect the quality of the fabric in real time, and comprises: an impedance measuring unit (1) for measuring electrical characteristics of the fabric surface; and a control unit (2) connected to the impedance measuring unit. The impedance measuring unit (1) comprises a support frame (11) disposed on the fabric transport path and a sensor module (12) mounted on the support frame to measure electrical characteristics of the fabric surface. The control unit (2) comprises a judgment unit (21) that determines whether there is a quality defect by comparing the impedance measurement value obtained from the sensor module (12) with a preset allowable range and generates a defect detection signal when a defect is determined. The control unit (2) further comprises an environment sensor (23), and the judgment unit (21) further comprises an environment correction algorithm that converts the impedance measurement value into a standard environment value based on data received from the environment sensor.

[0016] In addition, the sensor module (12) is characterized by being a contact electrode sensor (121a) that measures DC resistance by physically contacting the surface of the fabric and includes at least one of a parallel electrode, a four-point probe, and a conductive roller electrode.

[0017] In addition, the sensor module (12) is characterized as being a non-contact electrode sensor (121b) that is spaced apart from the surface of the fabric and measures impedance based on one of the following methods: capacitance change, electrostatic induction, or eddy current.

[0018] In addition, the impedance measuring unit (1) includes a converter that converts the measured analog value into digital and a first wireless communication unit (13), and the control unit includes a second wireless communication unit (22) that transmits and receives data to and from the first wireless communication unit.

[0019] delete

[0021] The quality monitoring system for the ESD-coated fabric of the present invention is a quality monitoring system including the inline impedance analysis device, and includes a local alarm unit (31) that receives a defect detection signal from the control unit (2) and outputs it visually or audibly.

[0022] In addition, the quality monitoring system for the ESD-coated fabric further includes a remote alarm unit (32) that receives a defect detection signal from the control unit (2) and transmits a notification message to the manager's mobile terminal.

[0023] In addition, it is characterized by further including a process coordinate mapping unit (33) that is synchronized with an encoder that detects the rotational speed of the fabric conveying means, and maps and stores the physical coordinates of the defect occurrence point within the fabric based on the encoder value at the time when the impedance measurement value is outside the allowable range.

[0024] In addition, the invention is characterized by further including a database (35) that stores the impedance measurement values ​​in a time series and a trend analysis unit (34) that analyzes the change trend of the measurement values ​​accumulated in the database and generates a preliminary warning signal for a process abnormality when the measurement values ​​gradually approach a control limit line even if they are within an allowable range. Effects of the invention

[0026] The present invention creates the following organic effects by automating the quality control procedure performed after the ESD (anti-static) coating process of a plastic fabric.

[0028] First, by monitoring the impedance, such as the resistance value of the fabric being transported, in real time through electrodes placed on both sides of the fabric and a resistance measuring unit, measurement errors that occurred in the conventional manual method can be overcome, and the objectivity and precision of quality judgment can be dramatically improved.

[0030] Second, it maximizes production efficiency by enabling real-time 100% inspection that takes place simultaneously with the production process. This eliminates the need for separate additional inspection processes or manual labor, thereby reducing operating costs such as labor expenses, while also enhancing the quality stability of the final product by fundamentally preventing defective fabric from entering subsequent processes.

[0032] Third, automating repetitive manual inspection processes significantly reduces worker fatigue and prevents quality accidents caused by human error. This goes beyond mere process convenience, leading to enhanced safety in the work environment and increased reliability of the entire manufacturing system.

[0034] Finally, the detection system according to the present invention is not limited to specific specifications and can be flexibly applied to various ESD-coated fabric production lines. Furthermore, since it offers excellent technical scalability to other quality control processes based on impedance measurement, it possesses high industrial utility value across related industries. Brief explanation of the drawing

[0036] FIG. 1 is a diagram illustrating an overview of the impedance analysis device for an ESD-coated fabric of the present invention and a quality monitoring system including the same. FIG. 2 is a block diagram illustrating the configuration of the quality monitoring system of the present invention. FIG. 3 is a diagram illustrating an overview of an embodiment of measuring the impedance of the upper and lower surfaces of an ESD-coated fabric in the analysis device and quality monitoring system of the present invention. FIG. 4 is a drawing illustrating an embodiment in which the quality monitoring system of the present invention is applied to the ESD fabric processing process. FIG. 5 is a drawing illustrating an embodiment of a sensor module including a contact-type electrode sensor, which is a component of the present invention. FIG. 6 is a drawing illustrating an embodiment of a sensor module including a non-contact electrode sensor, which is a component of the present invention. FIG. 7 is a drawing illustrating an embodiment in which a first communication unit is applied to a sensor module, which is a component of the present invention. Specific details for implementing the invention

[0037] The following provides detailed information on implementing an inline impedance analysis device for an ESD-coated fabric and a quality monitoring system including the same according to the present invention.

[0039] In this specification, "impedance measurement" means detecting electrical characteristics including electrical resistance components of a measurement target using an alternating current or direct current signal, and includes contact-type resistance measurement.

[0041] The technical concept of the present invention is to monitor whether the data measuring the electrical characteristics of the surface of an ESD (Electrostatic Discharge) coated plastic fabric using an impedance measuring tool, as shown in FIGS. 1 to 4, deviates from the impedance value of a normal range pre-set by the user, and to perform this in-line while the fabric is being processed and wound.

[0043] The configuration and embodiment of the inline impedance analysis device for an ESD-coated fabric according to the present invention is a device installed in an ESD-coated fabric manufacturing device (M) as shown in FIGS. 1 to 7, and comprises an impedance measuring unit (1) for measuring electrical characteristics of the fabric surface and a control unit (2) connected to the impedance measuring unit, wherein the impedance measuring unit (1) comprises a support frame (11) disposed on at least one side of the upper and lower sides of the ESD-coated fabric being transported, and a sensor module (12) mounted on the support frame to measure electrical characteristics of the fabric surface, and the control unit (2) comprises a judgment unit (21) that generates a detection signal to indicate a quality defect at a corresponding location when the impedance measurement value obtained from the sensor module (12) deviates from a preset allowable range.

[0045] The support frame (11) is positioned on the conveying path of the fabric and, as shown in FIGS. 1 and 4, can be installed in the form of a rod parallel to a conveyor roller on at least one side of the upper and lower sides of the fabric, and can also be positioned in various other structures and forms so that the electrode sensor (121) of the sensor module (12) is close enough to detect the electrical characteristics of the fabric surface or grounded.

[0047] Since the impedance for measurement and analysis of the present invention refers to electrical characteristics including direct current and alternating current, the sensor module (12) must be configured to measure the direct current resistance component and the alternating current resistance component. To measure the impedance including the direct current resistance (DC Resistance) component, the sensor module (12) may include a contact electrode sensor (121a) that measures the impedance by physically contacting the surface of an ESD-coated fabric as shown in the example in FIG. 5.

[0048] The contact electrode sensor (121a) may include a parallel electrode sensor as shown in FIG. 1 and 4, a four-point probe, and any one of a conductive roller electrode.

[0049] The aforementioned parallel electrode sensor method involves contacting a pair of electrodes arranged parallel to each other at a set interval on the surface of a fabric, and calculates surface resistance based on the amount of current flowing between the two electrodes. The parallel electrode method has the advantage of being easy to maintain due to its simple structure, and allows for the rapid measurement of the average resistance value over a specific area by adjusting the length and spacing of the electrodes.

[0050] A four-point probe method can be applied for precise sheet resistance measurement. The four-point probe includes four conductive probes arranged in a line, and the resistance value is calculated by applying a constant current through the two outer probes and measuring the voltage drop occurring between the two inner probes. This method minimizes measurement errors caused by contact resistance, making it particularly advantageous for processes that require the detection of minute resistance changes in an ESD coating layer with high precision.

[0051] The above-described conductive roller electrode method rotates in contact with the surface of the conveyed fabric, and since the entire or part of the outer surface of the roller is formed of a conductive material, it performs uninterrupted real-time resistance monitoring while the fabric is being conveyed. The conductive roller electrode is an optimized form for reducing noise caused by friction, minimizing fabric damage, and securing resistance data along the entire length of the fabric without reducing the speed of the production line.

[0053] The sensor module (12) may include a non-contact electrode sensor (121b) that measures impedance based on a change in capacitance and is spaced apart from the surface of the fabric as in the embodiment of FIG. 6. The non-contact electrode sensor (121b) may include either an electrostatic induction type sensor or a capacitance type sensor that utilizes the surface charge redistribution phenomenon caused by the application of an alternating electric field, and may include an eddy current type sensor that measures a change in current induced by the application of an alternating magnetic field.

[0054] The above-mentioned electrostatic induction method measures the electric field induced by charges formed on the surface of the fabric into the sensor electrode. It calculates the resistance state by applying a constant voltage to the surface of the fabric or by measuring the amount of induced charge formed by the electric field generated naturally during the process in the sensor head. This method has the advantage of enabling stable measurement even on high-speed transport lines because the sensor and the fabric do not come into direct contact, and it has a long lifespan due to the absence of sensor wear. However, to maintain measurement precision, it is desirable to incorporate a mechanical design that maintains a constant gap between the sensor and the fabric.

[0055] The aforementioned capacitive sensing method treats the space between the fabric and the sensor as a single capacitor and measures the change in dielectric constant or charge accumulation capacity as the fabric passes between two parallel electrodes. While the capacitive method offers the multifunctional advantage of being able to simultaneously detect changes in fabric thickness or internal physical defects in addition to measuring surface resistance, it is sensitive to changes in ambient humidity or temperature; therefore, it is effective to enhance measurement reliability by applying a separate environmental compensation algorithm.

[0056] In the case of fabrics containing the above-mentioned highly conductive material (e.g., carbon nanotubes, metal coatings, etc.), the eddy current method can be applied. When an alternating magnetic field is generated in a coil within the sensor, eddy currents are generated on the surface of the fabric; the principle is to inversely calculate the sheet resistance by detecting changes in the magnetic field caused by the eddy currents. This method has the characteristic of providing very precise data for determining the thickness or uniformity of the coating.

[0058] Although the transmission of impedance values ​​between the impedance measuring unit (1) and the control unit (2) can basically be done using a wired method, depending on the conditions of the work facility, it may be necessary to transmit and receive data wirelessly between the impedance measuring unit (1) and the control unit (2). To this end, as shown in the embodiment illustrated in FIG. 7, the impedance measuring unit (1) may include a converter that converts the measured analog value into digital and a first wireless communication unit (13), and the control unit (2) may include a second wireless communication unit (22) that transmits and receives data to and from the first wireless communication unit, thereby enabling the mutual exchange of digital data. The first and second wireless communication units may use short-range wireless communication protocols such as Wi-Fi, Bluetooth, and Zigbee, as well as various known communication protocols.

[0060] The control unit (2) may include an environmental correction logic that reflects changes in the surrounding environment in real time to ensure reliability of the impedance measurement value of the ESD-coated fabric being transported. Generally, since the electrical characteristics of the surface of the ESD-coated fabric vary depending on changes in the surrounding temperature and humidity, the present invention may further include an environmental sensor (23) that detects temperature and humidity on one side of the support frame (11) or inside the control unit (2). The judgment unit (21) can maintain consistent quality judgment standards regardless of seasonal or workplace environmental changes by performing a correction algorithm that converts the measured impedance value into a standard environmental value (e.g., 25°C, 50% RH) based on real-time temperature / humidity data obtained from the environmental sensor (23).

[0062] The quality monitoring system including the inline impedance analysis device of the ESD-coated fabric of the present invention further includes a monitoring unit (3) as in the embodiment shown in FIGS. 1 to 4. The monitoring unit includes a local monitoring unit (3) that provides an alarm to a user through a visual or auditory output means when it receives the defect detection signal from the control unit (2). The visual output means includes various known display means such as a warning light, an HMI screen, and a monitor, and the auditory output means includes various known sound output means such as a buzzer, a siren, and a speaker.

[0064] Additionally, the monitoring unit (3) may include a remote alarm unit (32) that, when receiving the defect detection signal from the control unit (2) to send an alarm or warning to the user terminal (U) of a remote manager as in the embodiment shown in FIG. 2, sends a message such as a warning, alarm, or the status of the fabric to the user's mobile terminal through a messenger sending logic for mobile transmission. The messenger sending logic is a logic that can connect to an API server (A) provided by a messenger transmission business operator, and includes a logic that performs a message transmission request to a text message (SMS) transmission API, a KakaoTalk API, as well as various other APIs.

[0066] The quality monitoring system including the inline impedance analysis device for the ESD-coated fabric of the present invention may include a process coordinate mapping unit (33) that maps the coordinates where a defect occurs during the process of the ESD-coated fabric in real time and stores them in a database (35) in order to perform precise monitoring as shown in FIG. 2. The control unit (2) is configured to receive an encoder signal installed on the rotation axis of the conveyor line (M) to precisely calculate the conveying speed and distance of the fabric. The judgment unit (21) acquires the encoder value at the moment when the impedance measurement value deviates from a preset allowable range and is judged as a defect, calculates the physical distance from the starting point of the fabric to the point where the defect occurs, and maps it to real-time process coordinates. This location information can be provided to the user in real time through the local alarm unit (31) or the remote alarm unit (32), and enables partial removal or subsequent action by quickly tracking only the defective section in the final roll fabric after winding is completed.

[0068] The quality monitoring system including the inline impedance analysis device of the ESD-coated fabric of the present invention may further include a database (35) that stores the impedance measurement values ​​in a time series for data logging and trend analysis, which involves storing defect detection signal data from the control unit (2) in a database (35) as shown in FIG. 2, analyzing the quality change trend based on the accumulated data, and predicting and monitoring the occurrence of defects, and a trend analysis unit (34) that analyzes the change trend of the measurement values ​​accumulated in the database and generates a preliminary warning signal for process abnormalities when the measurement values ​​gradually approach the control limit line even if they are within the allowable range.

[0069] Through the above trend analysis unit (34), the present invention can perform a statistical quality control function to manage the soundness of the entire production process, going beyond simple dichotomous judgment. The control unit (2) includes a data logging module that stores impedance data acquired in real time in a time series, and the judgment unit (21) analyzes the variable trend of the resistance value based on the accumulated data. Through this, even if the current measured value is within the allowable range, if a tendency is detected where the resistance value gradually rises or falls and approaches the management limit line, the control unit (2) can generate a preliminary warning signal for a process abnormality. This provides a basis for predictive maintenance that can predict and respond to the coating liquid application status of the production line or the wear of the equipment in advance, and ultimately implements a smart factory-linked quality monitoring system that maximizes production yield.

[0071] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to the specific embodiments described above. Any simple design modifications or substitutions of components that can be performed by those skilled in the art should be interpreted as falling within the scope of the present invention. Furthermore, the impedance determination logic described in the present invention may be optimized and implemented in various ways depending on the type of plastic material or the characteristics of the manufacturing process, and it is obvious that such variations are also within the technical identity of the appended claims. Explanation of the symbols

[0073] 1: Impedance measuring section 11: Support frame 12: Sensor module 121a: Contact electrode sensor 121b: Non-contact electrode sensor 13: Converter and first communication unit 2: Control unit 21: Judgment unit 22: Second Communication Unit 23: Environmental Sensor 3: Monitoring Section 31: Local Alarm Section 32: Remote alarm unit 33: Process coordinate mapping unit 34: Trend Analysis Department 35: Database M: Fabric processing machine E: Fabric A: Message transmission API server U: User terminal

Claims

Claim 1 An inline impedance analysis device for an ESD-coated fabric, comprising: an impedance measuring unit for measuring electrical characteristics of the fabric surface; and a control unit connected to the impedance measuring unit, wherein the impedance measuring unit includes a support frame disposed on the conveying path of the fabric and a sensor module mounted on the support frame to measure electrical characteristics of the fabric surface, and wherein the control unit includes a judgment unit that determines whether there is a quality defect by comparing an impedance measurement value obtained from the sensor module with a preset allowable range and generates a defect detection signal when a defect is determined, wherein the control unit further includes an environment sensor, and the judgment unit further includes an environment correction algorithm that converts the impedance measurement value into a standard environment value based on data received from the environment sensor. Claim 2 An inline impedance analysis device for an ESD-coated fabric according to claim 1, wherein the sensor module is a contact-type electrode sensor that measures DC resistance by physically contacting the surface of the fabric and includes at least one of a parallel electrode, a four-probe probe, and a conductive roller electrode. Claim 3 An inline impedance analysis device for an ESD-coated fabric according to claim 1, wherein the sensor module is a non-contact electrode sensor spaced apart from the surface of the fabric and measures impedance based on any one of capacitance change, electrostatic induction, or eddy current. Claim 4 An inline impedance analysis device for an ESD-coated fabric according to claim 1, wherein the impedance measuring unit includes a converter that converts a measured analog value into a digital value and a first wireless communication unit, and the control unit includes a second wireless communication unit that transmits and receives data to and from the first wireless communication unit. Claim 5 delete Claim 6 A quality monitoring system for an ESD-coated fabric comprising an inline impedance analyzer according to any one of claims 1 to 4, and a local alarm unit that receives a defect detection signal from the control unit and outputs it visually or audibly. Claim 7 In claim 6, the quality monitoring system for an ESD-coated fabric further comprises a remote alarm unit that receives a defect detection signal from the control unit and transmits a notification message to a manager's mobile terminal. Claim 8 A quality monitoring system for an ESD-coated fabric according to claim 6, further comprising a process coordinate mapping unit that is synchronized with an encoder detecting the rotational speed of a fabric conveying means and maps and stores the physical coordinates of a defect occurrence point within the fabric based on the encoder value at the time when the impedance measurement value deviates from the allowable range. Claim 9 A quality monitoring system for an ESD-coated fabric according to claim 6, further comprising: a database that stores the impedance measurement values ​​in a time series; and a trend analysis unit that analyzes the change trend of the measurement values ​​accumulated in the database and generates a preliminary warning signal for a process abnormality when the measurement values ​​gradually approach a control limit line even if they are within an allowable range.

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