Defect treatment system for spunlace non-woven fabric

Abstract

The invention discloses a defect treatment system for spunlace non-woven fabric. The system comprises a detection unit; a non-contact marking unit; a slitting and rewinding unit; the control unit is in communication connection with the detection unit, the non-contact marking unit and the slitting and rewinding unit and is configured to respond to the defect signal and determine delay trigger time based on the distance between the detection unit and the non-contact marking unit and the conveying speed of the non-woven fabric; after the delay triggering time, controlling a non-contact marking unit to spray a non-contact mark corresponding to the defect type to the side edge of the non-woven fabric; and under the condition that the unwinding length of the non-woven fabric by the slitting and rewinding unit is matched with the corresponding running length of the non-woven fabric when the defect signal is generated, the slitting and rewinding unit is controlled to remove the defective area on the non-woven fabric. The non-contact marking unit is matched with the control unit to determine the delay triggering time, so that the problem of inaccurate marking caused by shaking and airflow disturbance during high-speed operation of the non-woven fabric is solved.

Description

Technical Field

[0001] This invention relates to the field of spunlace nonwoven fabric technology, and more particularly to a defect treatment system for spunlace nonwoven fabric. Background Technology

[0002] In the field of spunlace nonwoven fabric production and post-processing technology, the winding process, as the final and crucial step in winding nonwoven fabric into rolls, directly affects the quality control of the final product. Therefore, real-time detection and marking of fabric defects during the winding process is a core requirement for ensuring product quality. Common fabric defects include holes, stains, black spots, foreign objects, and metallic impurities. Currently, the industry commonly uses mechanical labeling machines as the main equipment for online defect marking. These machines are mostly pneumatically or servo-driven contact marking devices. Their working principle is that after a defect is detected by a defect detector, a signal is sent to trigger the labeling machine to perform the labeling action. However, spunlace nonwoven fabric is thin and light, and it is prone to violent shaking and airflow disturbance in the frame during high-speed operation, which is known in the industry as "fabric pop-out" or "fabric drift". This makes it impossible for the label arm of the labeling machine to make stable and accurate contact with the fabric surface, resulting in frequent labeling failures, serious misalignment of the marking position, and a persistently high rate of missing labels. This makes it difficult to meet the production line's requirements for the accuracy, real-time performance and reliability of defect marking.

[0003] Existing technologies, such as Chinese patent CN117299612A, disclose an environmentally friendly, washable spunlace nonwoven fabric and its preparation process, including a spunlace step, a drying step, a stain detection step, a quantitative spraying step, a winding step, an inspection step, a slitting step, a rejection step, and a packaging step. It also includes an inspection system comprising a first acquisition module, a second acquisition module, a comparison module, and a rejection module. Acquisition module one is used for the stain detection step, acquisition module two for the inspection module, and the rejection module for the rejection step. Both acquisition modules one and two are used to acquire images of the nonwoven fabric and send the acquired images to the comparison step. The comparison step compares the received images with a standard image; if they are different, a rejection signal is sent to the rejection module, which rejects the nonwoven fabric upon receiving the rejection signal. However, this method detects the color of the sprayed coating during the nonwoven fabric preparation process, aiming to reduce the flow of nonwoven fabric with color impurities into the market, which differs from the technical problem solved by this application. Furthermore, the slitting and rewinding system relies on defect data transmitted during the winding stage for defect selection. However, due to inaccurate or missing markings in the early stages, coupled with the meter positioning deviation inherent in the slitting and rewinding system itself, operators find it difficult to accurately locate the corresponding position of the defect in the first instance. This necessitates a second manual visual inspection, which not only significantly reduces production efficiency and increases the time and labor costs of the rewinding process, but also may result in the failure to detect defects due to human negligence. Missing markings can directly lead to unqualified products flowing into the next production stage, seriously affecting the quality of the final product.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] This application provides a defect handling system for spunlace nonwoven fabrics, which solves the technical problem of inaccurate defect marking in existing nonwoven fabrics and achieves the technical effect of improving the accuracy of defect marking in nonwoven fabrics.

[0006] In a first aspect, this application provides a defect treatment system for spunlace nonwoven fabric, comprising: The detection unit is used to detect whether there are defects in the nonwoven fabric on the conveying mechanism. If there are defects, the defect type is determined and a defect signal corresponding to the defect type is generated. The non-contact marking unit is located downstream of the detection unit along the non-woven fabric conveying direction. The non-contact marking unit is used to spray non-contact markings onto the side of the non-woven fabric. The types of non-contact markings correspond one-to-one with the defect types. The slitting and rewinding unit is used to remove defective areas from the nonwoven fabric. The control unit, which is communicatively connected to the detection unit, the non-contact marking unit, and the slitting and rewinding unit, is configured as follows: In response to a defect signal, the delayed trigger time is determined based on the distance between the detection unit and the non-contact marking unit, as well as the conveying speed of the nonwoven fabric. After a delayed trigger time, the control non-contact marking unit sprays a non-contact mark corresponding to the defect type onto the side of the non-woven fabric. When the unwinding length of the nonwoven fabric in the slitting and rewinding unit matches the running length of the nonwoven fabric when the defect signal is generated, the slitting and rewinding unit is controlled to remove the defective areas on the nonwoven fabric.

[0007] In some embodiments of this application, based on the foregoing scheme, the detection unit includes: an image detection device and a metal detection device; the defect types include the presence of blemishes and the presence of metal; The image detection equipment is used to monitor the surface image data of the non-woven fabric on the conveying mechanism. It compares the surface image data with standard image data through a preset image processing algorithm. If the comparison result shows that there are defects on the non-woven fabric, a defect signal is generated. Metal detection equipment is used to detect whether there is metal on the non-woven fabric on the conveying mechanism. When metal is detected on the non-woven fabric, a metal signal is generated; defect signals include blemish signals and metal signals.

[0008] In some embodiments of this application, based on the foregoing scheme, in response to a defect signal, a delayed trigger time is determined based on the distance between the detection unit and the non-contact marking unit, and the conveying speed of the nonwoven fabric, including: In response to a defect signal, the defect delay trigger time is determined based on the distance between the image detection device and the non-contact marking unit and the conveying speed of the nonwoven fabric. In response to a metal signal, the metal delay trigger time is determined based on the distance between the metal detection device and the non-contact marking unit and the conveying speed of the non-woven fabric.

[0009] In some embodiments of this application, based on the aforementioned scheme, after a delayed triggering time, the non-contact marking unit is controlled to spray a non-contact mark corresponding to the defect type onto the side of the nonwoven fabric, including: After the defect delay trigger time has elapsed, the non-contact marking unit is controlled to spray the defect mark onto the side of the nonwoven fabric. After a metal delay trigger time, the non-contact marking unit is controlled to spray metal marks onto the side of the non-woven fabric; the non-contact marking includes defect marks and metal marks.

[0010] In some embodiments of this application, based on the aforementioned scheme, when the comparison result indicates the presence of defects on the nonwoven fabric, a defect signal is generated, including: Based on the comparison results, the types of defects existing on the nonwoven fabric are identified, and signals corresponding to the types of defects are generated as defect signals.

[0011] In some embodiments of this application, based on the foregoing scheme, the system further includes a marking machine, and the marking machine and the non-contact marking unit are sequentially arranged on the same side of the conveying mechanism; The control unit is connected in communication with the marking machine, and the control unit is also configured to: In response to a defect signal, the label delay trigger time is determined based on the distance between the detection unit and the marking machine, as well as the conveying speed of the nonwoven fabric. After the label delay trigger time, the control marking machine affixes the label to the side of the non-woven fabric, and the label placement position matches the marking position of the non-contact marking.

[0012] In some embodiments of this application, based on the aforementioned scheme, when the unwinding length of the nonwoven fabric by the slitting and rewinding unit matches the running length of the nonwoven fabric corresponding to the generation of the defect signal, controlling the slitting and rewinding unit to remove defective areas from the nonwoven fabric includes: The defect types, defect locations, and non-contact marking information of nonwoven fabrics are associated and stored to form a defect database; During the unwinding process, the unwinding length of the nonwoven fabric by the slitting and shearing equipment is compared with the associated length coordinates in the defect database according to the associated data in the defect database. When the unwinding length reaches the associated length coordinate, the slitting and rewinding unit is stopped, and the defective areas on the nonwoven fabric are removed according to the non-contact markings on the nonwoven fabric. After the rejection is completed, the control of the roll cutting equipment is resumed until all defects in the database are processed or the entire roll of nonwoven fabric is cut.

[0013] In some embodiments of this application, based on the foregoing scheme, the features of the non-contact marking include at least one of color, shape, or pattern.

[0014] In some embodiments of this application, based on the foregoing scheme, the non-contact marking unit includes an inkjet printer, which is fixed to the bracket of the conveying mechanism by an adjustable mounting bracket, with the printhead of the inkjet printer facing the side of the non-woven fabric. The inkjet printer is equipped with a color mark sensor, which communicates with the control unit to monitor the position of the nonwoven fabric edge and calibrate the spray angle and height of the printhead so that the printhead and the nonwoven fabric surface maintain a preset non-contact distance.

[0015] In some embodiments of this application, based on the aforementioned scheme, the non-contact markings sprayed by the inkjet printer are located within 2 cm of the edge of the nonwoven fabric. The inkjet printer includes multiple color spray channels, with each color corresponding to a defect type.

[0016] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. By using a non-contact marking unit in conjunction with the delay trigger time calculated by the control unit, the marking failure and positional offset problems caused by the shaking and airflow disturbance of the non-woven fabric during high-speed operation of traditional contact labeling are completely avoided, ensuring that the marking corresponds precisely to the defect position and greatly improving the reliability and accuracy of defect marking.

[0017] 2. The detection unit integrates image detection equipment and metal detection equipment, which can not only comprehensively monitor various defects such as surface defects and metal impurities, but also accurately identify the specific type of defect, providing an accurate basis for subsequent targeted marking and processing, and solving the pain points of traditional detection being singular and having unclear defect type distinction.

[0018] 3. The types of non-contact markings correspond one-to-one with the defect types, and the marking features can take the form of various forms such as color, shape or pattern, enabling operators to quickly identify the defect type through the markings in subsequent processes without additional inspection and judgment, which significantly improves the pertinence and efficiency of defect handling.

[0019] 4. The system adds a marking machine and a non-contact marking unit, which are set opposite each other on both sides of the conveying mechanism. The label placement position matches the non-contact marking, forming a dual marking verification mechanism. This further reduces the risk of omissions that may occur with a single mark and provides more comprehensive protection for defect tracing.

[0020] 5. The control unit associates and stores defect types, locations, and marking information to form a defect database. The slitting and rewinding unit automatically slows down and stops by comparing the unwinding length with the coordinate information in the database in real time. This transforms the traditional manual defect finding into precise positioning, greatly reducing manual intervention and improving the efficiency and accuracy of the slitting and rewinding process.

[0021] 6. The inkjet printer is fixed by an adjustable mounting bracket and is equipped with a color mark sensor to calibrate the spray angle and height of the printhead in real time, ensuring that the printhead maintains a stable non-contact distance from the fabric surface. At the same time, the marking is limited to a preset area on the edge of the fabric, which avoids damage to the fabric surface caused by contact marking and ensures the consistency of the marking position.

[0022] 7. The slitting and rewinding unit can automatically resume operation after removing defective areas until all defects are processed or the entire roll is slitting is completed. This eliminates the need for operators to frequently manually control start and stop, effectively ensuring the continuity of the production process, reducing process interruption time, and improving overall production efficiency.

[0023] 8. The inkjet printer is equipped with multiple color spray channels, each color corresponding to a defect type. Combined with the visual features of non-contact marking, the distinction between defect types is more intuitive and easier to understand, helping operators to make quick judgments during the picking and processing process, and further shortening the defect processing time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of a defect treatment system for spunlace nonwoven fabric provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the principle of a defect treatment system for spunlace nonwoven fabric provided in this application embodiment; In the above diagram: 11. Image detection equipment; 12. Metal detection equipment; 21. Inkjet printer; 22. Marking machine; 3. Winding machine; 4. Slitting and rewinding unit; 5. Dryer; 6. Gram weight and moisture content analyzer. Detailed Implementation

[0026] This application provides a defect handling system for spunlace nonwoven fabrics, which solves the technical problem of inaccurate defect marking in existing nonwoven fabrics.

[0027] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0028] Example 1 This application provides embodiments such as Figure 1 The defect handling system for spunlace nonwoven fabric shown includes: a detection unit, a non-contact marking unit, a slitting and rewinding unit 4, and a control unit.

[0029] It should be noted that the detection unit and the non-contact marking unit are sequentially arranged in front of the winding machine 3. The winding machine 3 winds up the nonwoven fabric, and a slitting and rewinding unit 4 is provided at the outlet of the winding machine 3 to further sort and slit the nonwoven fabric.

[0030] The detection unit is used to detect whether there are defects in the nonwoven fabric on the conveying mechanism. If defects are found, the unit determines the defect type and generates a defect signal corresponding to that type. The detection unit includes an image detection device 11 and a metal detection device 12. The image detection device 11 monitors the surface image data of the nonwoven fabric on the conveying mechanism and compares the surface image data with standard image data using a preset image processing algorithm. If the comparison result indicates the presence of defects on the nonwoven fabric, a defect signal is generated. The metal detection device 12 detects whether there is metal on the nonwoven fabric on the conveying mechanism and generates a metal signal if metal is detected.

[0031] For example, the detection unit integrates two complementary detection devices to achieve comprehensive coverage and accurate judgment of common defects in spunlace nonwoven fabrics. The image detection device 11 uses a high-definition image acquisition component in conjunction with an image analysis module. During operation, it continuously acquires surface image data of the nonwoven fabric during transmission. Then, through preset image processing algorithms (such as feature extraction, grayscale comparison, and morphological analysis), it compares the acquired real-time surface image data frame-by-frame with pre-stored defect-free standard image data. This not only quickly determines the presence of various defects such as holes, stains, black spots, and foreign objects, but also further identifies the specific type of defect and generates corresponding defect signals, providing a basis for subsequent differentiated marking. The metal detection device 12 uses a specific detection principle (such as electromagnetic induction) to monitor in real time whether there are metal impurities inside and on the surface of the nonwoven fabric. Once metal is detected, it immediately generates a unique metal signal, ensuring that no metal defects are missed. The two detection devices work together to comprehensively capture different types of defects that may occur during the nonwoven fabric production process, and the generated defect signals match the defect types one-to-one, providing accurate and reliable input information for subsequent linkage control and marking.

[0032] The non-contact marking unit is positioned downstream of the detection unit along the non-woven fabric conveying direction. This unit sprays non-contact markings onto the sides of the non-woven fabric, and the types of non-contact markings correspond one-to-one with defect types. Defect types include the presence of blemishes and the presence of metal. The characteristics of the non-contact markings include at least one of color, shape, or pattern.

[0033] The non-contact marking unit includes an inkjet printer 21, which is fixed to the support of the conveying mechanism via an adjustable mounting bracket. The printhead of the inkjet printer 21 faces the side of the non-woven fabric. The inkjet printer 21 is equipped with a color mark sensor, which is communicatively connected to the control unit to monitor the position of the non-woven fabric edge and calibrate the spray angle and height of the printhead to maintain a preset non-contact distance between the printhead and the non-woven fabric surface.

[0034] For example, the non-contact marking unit avoids direct contact with the high-speed moving thin non-woven fabric, thus circumventing many drawbacks of traditional contact marking. This unit uses an inkjet printer 21 as the marking device. The inkjet printer 21 is fixed to the support of the conveying mechanism via an adjustable mounting bracket. The operator can flexibly adjust the height and horizontal position of the bracket according to the actual working conditions such as the width of the non-woven fabric and the conveying height, ensuring that the printhead is always aligned with the side area of ​​the non-woven fabric. The color mark sensor configured in the inkjet printer 21 communicates with the control unit in real time, continuously monitoring the dynamic position of the non-woven fabric edge. When the non-woven fabric experiences a slight shift due to high-speed operation, the color mark sensor can quickly capture the shift signal and feed it back to the control unit. The control unit then drives the printhead to calibrate the spray angle and height in real time, ensuring that the printhead and the non-woven fabric surface maintain a stable preset non-contact distance. This avoids fabric damage or marking shift caused by printhead contact with the fabric surface, while also ensuring that the marking accurately falls within the preset area on the fabric edge. Meanwhile, the inkjet printer 21 can provide various marking features such as color, shape or pattern, and each marking feature corresponds one-to-one with the defect type identified by the detection unit (such as a specific color corresponding to a certain type of defect, and another color corresponding to metal impurities), so that operators in subsequent processes can quickly identify the defect type through the markings, providing intuitive guidance for defect handling.

[0035] The slitting and rewinding unit 4 is used to remove defective areas on the nonwoven fabric. It not only has the basic winding and slitting functions of traditional slitting and rewinding equipment, but also achieves automated positioning and precise removal of defects through linkage with the control unit.

[0036] For example, the slitting and rewinding unit 4 first loads the stored defect database, which contains information such as the defect type, the corresponding length coordinates, and marking features for each roll of nonwoven fabric. When the slitting and rewinding unit 4 starts the unwinding process, its own configured length detection component (such as an encoder) collects the unwinding length data in real time and compares it with the defect length coordinates in the defect database. When the unwinding length approaches the target defect coordinates, the slitting and rewinding unit 4 automatically decelerates under the command of the control unit to avoid positioning deviation due to inertia. When the unwinding length accurately matches the defect coordinates, the equipment automatically stops. At this time, the operator can quickly find the defect location based on the non-contact markings on the side of the nonwoven fabric and complete the manual confirmation and removal of the defect area. After the defect is removed, the operator only needs to issue a continue operation command, and the slitting and rewinding unit 4 can automatically resume operation and continue to execute the subsequent unwinding, comparison, positioning, and removal processes until all defects in the database are processed, and finally the compliant slitting and rewinding of the entire roll of nonwoven fabric is completed, ensuring that the finished product is free of defect residue.

[0037] The control unit is communicatively connected to the detection unit and the non-contact marking unit, and is configured to execute steps S1-S3.

[0038] Step S1: In response to the defect signal, determine the delayed trigger time based on the distance between the detection unit and the non-contact marking unit and the conveying speed of the nonwoven fabric. Step S2: After the delayed trigger time, control the non-contact marking unit to spray the non-contact mark corresponding to the defect type onto the side of the non-woven fabric. Step S3: When the unwinding length of the nonwoven fabric by the slitting and rewinding unit 4 matches the running length of the nonwoven fabric when the defect signal is generated, the slitting and rewinding unit 4 is controlled to remove the defective area on the nonwoven fabric.

[0039] Regarding step S1, in response to the defect signal, the delayed trigger time is determined based on the distance between the detection unit and the non-contact marking unit and the conveying speed of the nonwoven fabric, including steps S11-S12.

[0040] Step S11: In response to the defect signal, the defect delay trigger time is determined based on the distance between the image detection device 11 and the non-contact marking unit and the conveying speed of the nonwoven fabric. Step S12: In response to the metal signal, determine the metal delay trigger time based on the distance between the metal detection device 12 and the non-contact marking unit and the conveying speed of the non-woven fabric.

[0041] The defect signal originates from the real-time monitoring and identification of the detection unit. The detection unit generates corresponding signals through the collaborative work of the image detection device 11 and the metal detection device 12: The image detection device 11 continuously collects surface image data of the nonwoven fabric during transmission, compares it with standard image data through a preset image processing algorithm, and if defects such as holes, stains, or black spots are found, it will not only determine the existence of defects, but also further identify the type of defects on the nonwoven fabric based on the comparison results, and generate a signal corresponding to the type of defect as a defect signal; The metal detection device 12 monitors the nonwoven fabric in real time through a specific detection principle. When metal impurities are detected, it immediately generates a unique metal signal to ensure that metal defects are accurately captured.

[0042] There is a strict one-to-one correspondence between defect signals and defect types: each defect type corresponds to a unique defect signal. For example, different types of defects (such as white spots and black spots) correspond to different defect signals, and metal impurities correspond to independent metal signals. This matching relationship provides the core basis for the subsequent control unit to issue targeted marking instructions and achieve accurate association between defect types and markings.

[0043] For example, based on the surface image data collected by the image detection device 11, the system extracts various features (such as area, perimeter, shape, aspect ratio, color, gray value, etc.), identifies the types of defects on the nonwoven fabric based on the comparison results (such as foreign objects, stains / oil spots, holes / holes, cloudiness / uneven weight, water needle marks, fuzz / pilling, wrinkles), and then enables the non-contact marking unit to spray the corresponding markings (such as large white, medium white, small white, large black, medium black, small black).

[0044] For example, when the control unit receives a defect signal sent by the detection unit, it first distinguishes the signal type: if it is a defect signal, it calls the pre-stored fixed distance parameter between the image detection device 11 and the non-contact marking unit, and simultaneously obtains the current real-time conveying speed of the nonwoven fabric. The real-time conveying speed is collected in real time by the system's matching speed measurement component (e.g., an encoder). The defect delay trigger time is calculated through preset logic, which exactly compensates for the time it takes for the defect to be transmitted from the location of the image detection device 11 to the location of the marking unit. If it is a metal signal, the same method calls the fixed distance parameter between the metal detection device 12 and the non-contact marking unit, and combines it with the real-time conveying speed of the nonwoven fabric at the same moment to calculate the metal delay trigger time, ensuring that the marking action is triggered exactly when the metal defect is transmitted to the marking unit.

[0045] Regarding step S2, after the delayed trigger time, the non-contact marking unit is controlled to spray the non-contact marking corresponding to the defect type onto the side of the non-woven fabric, including steps S21-S22.

[0046] Step S21: After the defect delay trigger time has elapsed, control the non-contact marking unit to spray the defect mark onto the side of the nonwoven fabric. Step S22: After the metal delay trigger time has elapsed, control the non-contact marking unit to spray metal marks onto the side of the non-woven fabric; the non-contact marking includes defect marks and metal marks.

[0047] For example, when the control unit detects that the defect delay trigger time has expired, it immediately sends a trigger command and a marking feature command corresponding to the defect type to the non-contact marking unit (such as inkjet printer 21). Under the real-time calibration of the color mark sensor, inkjet printer 21 accurately adjusts the spraying angle and height of the printhead to ensure that the printhead maintains a preset non-contact distance from the non-woven fabric surface. Then, it sprays a defect mark (such as a mark of a specific color and shape) corresponding to the defect type on a preset area on the side of the non-woven fabric. When the metal delay trigger time expires, the control unit also sends a trigger command and a marking feature command corresponding to the metal defect to inkjet printer 21. Inkjet printer 21 sprays metal marks according to preset rules, and the features of the defect marks and metal marks are clearly distinguishable, allowing operators to quickly identify the defect type through the marks. At the same time, the non-contact spraying method completely avoids the problems of mark offset and missing marks caused by the high-speed shaking of the non-woven fabric in traditional contact marking.

[0048] Regarding step S3, when the unwinding length of the nonwoven fabric by the slitting and rewinding unit 4 matches the running length of the nonwoven fabric when the defect signal is generated, the slitting and rewinding unit 4 is controlled to remove the defective area on the nonwoven fabric, including steps S31-S34.

[0049] Step S31: The defect type, defect location, and non-contact marking information of the nonwoven fabric are associated and stored to form a defect database; Step S32: During the unwinding process, the unwinding length of the nonwoven fabric by the slitting and shearing equipment is compared with the associated length coordinates in the defect database according to the associated data in the defect database. Step S33: When the unwinding length reaches the associated length coordinate, control the slitting and rewinding unit 4 to stop, and remove the defective areas on the non-woven fabric according to the non-contact markings on the non-woven fabric. Step S34: After the rejection is completed, control the slitting and cutting equipment to resume operation until all defects in the database are processed or the entire roll of nonwoven fabric is slitting.

[0050] For example, while generating a defect signal and triggering the marker, the control unit associates and stores the defect type, the corresponding running length coordinates, and the characteristic information of the non-contact marker, forming a unique defect database for each roll of nonwoven fabric. This provides complete data support for subsequent slitting and rewinding. When the slitting and rewinding unit 4 starts the unwinding process, it loads the defect database of the fabric roll through the data interface. Its own configured length detection component collects the unwinding length data in real time and compares it with the defect-related length coordinates in the database. When the unwinding length approaches the match of the associated length coordinate of a certain defect, the control unit controls the slitting and rewinding unit 4 to automatically decelerate. When the unwinding length fully reaches the coordinate, the equipment automatically stops. The operator can quickly locate the defect location based on the non-contact markers on the side of the nonwoven fabric and accurately remove the defect area. After the defect is removed, the operator issues a continue operation command, and the slitting and rewinding unit 4 resumes operation, repeating the above comparison, positioning, and removal process until all defects in the database are processed or the entire roll of nonwoven fabric is slitting and rewinding, ensuring that the final product is free of defect residue.

[0051] Example 2 Based on the same inventive concept, Embodiment 2 adds a marking machine 22 to Embodiment 1. The marking machine 22 and the non-contact marking unit are arranged sequentially on the same side of the conveying mechanism.

[0052] The control unit is communicatively connected to the marking machine 22, and the control unit is also configured to: In response to a defect signal, the label delay trigger time is determined based on the distance between the detection unit and the marking machine 22, as well as the conveying speed of the nonwoven fabric. After the label delay trigger time, the control marking machine 22 affixes the label to the side of the non-woven fabric, and the label placement position matches the marking position of the non-contact marking.

[0053] For example, during the equipment installation and configuration phase, the marking machine 22 and the non-contact marking unit (inkjet printer 21) are sequentially positioned on the same side of the conveying mechanism. Specifically, the inkjet printer 21 is located on one side of the non-woven fabric's edge, while the marking machine 22 is positioned on the other side. The marking target areas of both are aligned with the side of the non-woven fabric, ensuring that the subsequently formed label and the non-contact inkjet marking accurately correspond in the width direction of the non-woven fabric, providing a two-way reference for subsequent manual verification. Simultaneously, the marking machine 22 establishes a stable communication connection with the control unit, incorporating it into the system's unified linkage control system to achieve signal synchronization with the detection unit and the non-contact marking unit.

[0054] During the nonwoven fabric conveying and inspection process, when the detection unit (image detection device 11 or metal detection device 12) detects a defect and generates a corresponding defect signal (blemish signal or metal signal), this signal is synchronously transmitted to the control unit. The control unit, while responding to the non-contact marking unit, also initiates the control logic for the marking machine 22. At this time, the control unit calls the pre-stored fixed distance parameters between the detection unit and the marking machine 22, combines this with the real-time nonwoven fabric conveying speed data collected by the encoder, and calculates the label delay trigger time according to the linkage control logic matching Embodiment 1. This time precisely compensates for the time it takes for the defect to be conveyed from the location of the detection unit to the location of the marking machine 22, ensuring that the label placement timing accurately matches the defect location and avoiding positional deviations caused by the high-speed conveying of the nonwoven fabric.

[0055] When the label delay trigger time expires, the control unit immediately sends a labeling trigger command to the marking machine 22. Upon receiving the command, the marking machine 22 accurately affixes the physical label to the side area of ​​the non-woven fabric according to preset labeling rules. The label's placement is perfectly aligned with the non-contact marking unit (inkjet printer 21) spraying the non-contact mark along the length of the non-woven fabric, achieving a correspondence between the sprayed mark on one side and the physical label on the other. For example, if the inkjet printer 21 sprays a yellow mark corresponding to a black defect on the left edge of the non-woven fabric, the marking machine 22 simultaneously affixes a label at the same length on the right edge of the non-woven fabric. This ensures that during subsequent slitting and rewinding processes, operators can quickly locate defects by comparing the marks on both sides.

[0056] In the subsequent slitting and rewinding stage, the defect database loaded by slitting and rewinding unit 4 stores not only defect types, length coordinates, and non-contact marking features, but also synchronously associates the location information of the label markings. When slitting and rewinding unit 4 automatically stops based on the length coordinates in the defect database, the operator can verify defects through dual references: on the one hand, check the non-contact spray markings on one side of the fabric edge (such as tiny dot-like markings of a specific color), and on the other hand, check the corresponding physical label on the other side of the fabric edge. The precise correspondence between the two can not only quickly locate the specific location of the defect, but also effectively avoid the possible omission of a single marking (such as non-contact markings being unclear due to ink problems, or labels being slightly offset due to fabric shaking), further reducing the risk of missing defects.

[0057] Throughout the implementation process, the label delay trigger time calculation and labeling position control of the marking machine 22 are uniformly scheduled by the control unit. Its parameters (such as the distance between the detection unit and the marking machine 22) can be preset according to the equipment installation layout. Moreover, the labeling action and the non-contact marking action are synchronized in the time dimension and correspond in the spatial dimension. It not only retains the high-speed adaptability of the non-contact marking in Embodiment 1, but also improves the anti-interference of the marking through the supplement of physical labels. It is especially suitable for production scenarios with higher requirements for defect traceability and solves the traceability failure problem that may occur in the single marking mode.

[0058] Example 3 Based on the same inventive concept, in Embodiment 3, the non-contact marking unit includes a multi-color inkjet printer 21, building upon Embodiment 1.

[0059] During the equipment configuration and calibration phase, the non-contact marking unit uses a multi-color inkjet printer 21 as the core execution component. The inkjet printer 21 is equipped with multiple independent color spray channels (such as red, blue, yellow, etc.), and each color channel is pre-established with a unique correspondence with a specific defect type. For example, the red channel is pre-set to correspond to white spot defects, the blue channel to correspond to metal impurities, and the yellow channel to correspond to black spot defects. This correspondence is pre-stored in the database of the control unit.

[0060] The inkjet printer 21 is fixed to the support of the conveying mechanism via an adjustable mounting bracket. The printhead faces the side area of ​​the non-woven fabric. It is equipped with a color mark sensor and communicates with the control unit. The operator can precisely calibrate the printhead position by adjusting the bracket parameters and combining the real-time feedback from the color mark sensor. On the one hand, this ensures that the printhead maintains a stable preset non-contact distance from the non-woven fabric surface, avoiding mark offset caused by fabric vibration during high-speed conveying. On the other hand, it strictly limits the printhead spraying range to within 2 cm of the non-woven fabric edge. By calibrating the printhead's spraying pressure and ink flow, the printed marks form a tiny dot structure with a diameter controlled to a preset small size, minimizing the mark's occupation of the effective usable area of ​​the non-woven fabric and its impact on the fabric's appearance.

[0061] During the high-speed conveying and defect detection of nonwoven fabric, the detection unit (image detection device 11 or metal detection device 12) monitors the fabric surface status in real time: the image detection device 11 can not only determine the existence of defects through image processing algorithms, but also accurately identify the specific type of defects (such as white spots, black spots, etc.) and generate defect signals corresponding to the defect types; when the metal detection device 12 detects metal impurities, it generates metal signals. These signals containing defect type information are synchronously transmitted to the control unit. After receiving the signals, the control unit, on the one hand, uses the linkage control logic of Embodiment 1 to call the fixed distance parameter between the detection unit and the inkjet printer 21, and calculates the accurate delay trigger time by combining the nonwoven fabric conveying speed collected in real time by the encoder, so as to compensate for the time taken for the defect to be conveyed from the detection position to the marking position; on the other hand, the control unit matches the corresponding color channel from the preset database according to the specific type contained in the defect signal, generates a color selection instruction, and forms a coordinated control signal with the delay trigger instruction.

[0062] When the delayed trigger time expires, the control unit simultaneously sends a trigger command and a color selection command to the multi-color inkjet printer 21. Upon receiving the command, the inkjet printer 21 immediately activates the corresponding color injection channel. Under the real-time calibration of the color mark sensor, it injects tiny dot-like marks (e.g., diameter ≤ 5mm) into a preset area within 2 cm of the nonwoven fabric edge. For example, when a white spot defect is detected, the red channel is activated to inject red micro-dots; when a metallic impurity is detected, the blue channel is activated to inject blue micro-dots, ensuring that the mark color strictly corresponds to the defect type. Simultaneously, thanks to the control unit's precise calculation of the delay time, the position of the actual defect on the nonwoven fabric and the left-right spacing of the inkjet mark are strictly controlled within a reasonable range, achieving precise alignment between the defect and the mark, completely avoiding the traceability failure problem caused by positional deviations in traditional marking.

[0063] In the subsequent slitting and rewinding stage, the defect database stored in the control unit records information such as defect type, precise length coordinates, and mark position, and also synchronously associates the color information corresponding to the mark. When the slitting and rewinding unit 4 loads the defect database of the fabric roll to be processed and starts unwinding, its length detection component compares the unwinding length with the defect coordinates in the database in real time, and automatically slows down and stops when the target coordinate is reached. At this time, the operator does not need to use additional detection equipment to determine the defect type; they only need to observe the multi-colored micro-dot marks on the fabric edge to quickly identify the defect attributes. For example, seeing a red micro-dot indicates a corresponding white spot defect, and seeing a blue micro-dot indicates a metal impurity. Combined with the mark position, the defect range can be instantly locked, significantly shortening the defect confirmation time. At the same time, the tiny dot marks are only located on the edge of the fabric edge and will not affect the use of the main area of ​​the nonwoven fabric, thus avoiding material waste caused by excessively large marks. In addition, the fixed correspondence between color and defect type can standardize the operation process, reduce the operator's identification error, and is especially suitable for production scenarios where multiple types of defects coexist, further improving the efficiency of the slitting and rewinding process and the accuracy of defect removal.

[0064] Example 4 Based on the same inventive concept, Embodiment Four adds a dryer 5 and a weight moisture analyzer 6 to Embodiment One. (Reference) Figure 2 , Figure 2 The red line represents the nonwoven fabric. The conveying mechanism moves from right to left, and along the conveying direction, it includes, in sequence, a dryer 5, an image detection device 11, a metal detection device 12, a basis weight and moisture meter 6, an inkjet printer 21, a marking machine 22, a winding machine 3, and a slitting and rewinding unit (not shown in the figure). The dryer 5 is used to dry the spunlace nonwoven fabric, and the basis weight and moisture meter 6 is used to detect the moisture content and basis weight of the spunlace nonwoven fabric.

[0065] For example, the gram weight moisture analyzer 6 uses the β-ray penetration method to detect gram weight and the microwave method to detect moisture.

[0066] Beta-ray penetration method: When beta rays (a high-energy electron beam) penetrate a material, they interact with the atoms of the material, losing energy and causing the ray intensity to decrease. The thicker and denser the material (i.e., the higher the basis weight), the more rays are absorbed, and the weaker the rays that penetrate. The system has built-in calibrated parameters that can directly convert the measured ray intensity ratio into the basis weight value of the nonwoven fabric.

[0067] Microwave method: Water molecules are polar molecules. When microwaves (electromagnetic waves of a specific frequency) pass through materials containing moisture, the electric field changes rapidly, forcing the water molecules to rotate back and forth in polarization. This process consumes microwave energy, leading to energy attenuation and phase shift. The higher the moisture content of the material, the stronger its absorption of microwave energy. The system accurately calculates the moisture content of the material by comparing the energy attenuation or phase shift of the transmitted and received microwaves.

[0068] The system displays real-time distribution maps of three key parameters—dry basis weight, total basis weight, and moisture content—across the entire width of the nonwoven fabric, thereby monitoring product quality. If these three parameters do not meet standard requirements, the control unit sends corresponding control commands to the inkjet printer 21 or the marking machine 22, causing the corresponding actuator to mark the nonwoven fabric.

[0069] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0070] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A defect treatment system for spunlace nonwoven fabric, characterized in that, include: The detection unit is used to detect whether there are defects in the nonwoven fabric on the conveying mechanism. If there are defects, the defect type is determined and a defect signal corresponding to the defect type is generated. A non-contact marking unit is positioned downstream of the detection unit along the non-woven fabric conveying direction. The non-contact marking unit is used to spray non-contact markings onto the side of the non-woven fabric. The types of non-contact markings correspond one-to-one with the defect types. The slitting and rewinding unit is used to remove defective areas from the nonwoven fabric. The control unit, which is communicatively connected to the detection unit, the non-contact marking unit, and the slitting and rewinding unit, is configured as follows: In response to a defect signal, the delayed trigger time is determined based on the distance between the detection unit and the non-contact marking unit, as well as the conveying speed of the nonwoven fabric. After a delayed trigger time, the control non-contact marking unit sprays a non-contact mark corresponding to the defect type onto the side of the non-woven fabric. When the unwinding length of the nonwoven fabric in the slitting and rewinding unit matches the running length of the nonwoven fabric when the defect signal is generated, the slitting and rewinding unit is controlled to remove the defective areas on the nonwoven fabric.

2. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, The detection unit includes: an image detection device and a metal detection device; the defect types include the presence of blemishes and the presence of metal. The image detection device is used to monitor the surface image data of the nonwoven fabric on the conveying mechanism. It compares the surface image data with standard image data through a preset image processing algorithm. If the comparison result shows that there are defects on the nonwoven fabric, a defect signal is generated. The metal detection device is used to detect whether there is metal on the non-woven fabric on the conveying mechanism. When metal is detected on the non-woven fabric, a metal signal is generated. The defect signal includes a defect signal and a metal signal.

3. The defect treatment system for spunlace nonwoven fabric as described in claim 2, characterized in that, The method of determining the delayed trigger time in response to a defect signal, based on the distance between the detection unit and the non-contact marking unit and the conveying speed of the nonwoven fabric, includes: In response to a defect signal, the defect delay trigger time is determined based on the distance between the image detection device and the non-contact marking unit and the conveying speed of the nonwoven fabric. In response to a metal signal, the metal delay trigger time is determined based on the distance between the metal detection device and the non-contact marking unit and the conveying speed of the non-woven fabric.

4. The defect treatment system for spunlace nonwoven fabric as described in claim 3, characterized in that, After a delayed triggering time, the non-contact marking unit is controlled to spray a non-contact mark corresponding to the defect type onto the side of the nonwoven fabric, including: After the defect delay trigger time has elapsed, the non-contact marking unit is controlled to spray the defect mark onto the side of the nonwoven fabric. After a metal delay trigger time, the non-contact marking unit is controlled to spray metal marks onto the side of the non-woven fabric; the non-contact marking includes defect marks and metal marks.

5. The defect treatment system for spunlace nonwoven fabric as described in any one of claims 2-4, characterized in that, When the comparison result indicates the presence of defects on the nonwoven fabric, generating a defect signal includes: Based on the comparison results, the types of defects existing on the nonwoven fabric are identified, and a signal corresponding to the type of defect is generated as the defect signal.

6. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, The system also includes a marking machine, which is arranged sequentially on the same side of the conveying mechanism as the non-contact marking unit; The control unit is communicatively connected to the marking machine, and the control unit is further configured to: In response to a defect signal, the label delay trigger time is determined based on the distance between the detection unit and the marking machine, as well as the conveying speed of the nonwoven fabric. After the label delay trigger time, the control marking machine affixes the label to the side of the non-woven fabric, and the label placement position matches the marking position of the non-contact marking.

7. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, When the unwinding length of the nonwoven fabric in the slitting and rewinding unit matches the running length of the nonwoven fabric when the defect signal is generated, controlling the slitting and rewinding unit to remove defective areas from the nonwoven fabric includes: The defect types, defect locations, and non-contact marking information of nonwoven fabrics are associated and stored to form a defect database; During the unwinding process, the unwinding length of the nonwoven fabric by the slitting and shearing equipment is compared with the associated length coordinates in the defect database according to the associated data in the defect database. When the unwinding length reaches the associated length coordinate, the slitting and rewinding unit is stopped, and the defective areas on the nonwoven fabric are removed according to the non-contact markings on the nonwoven fabric. After the rejection is completed, the control of the roll cutting equipment is resumed until all defects in the database are processed or the entire roll of nonwoven fabric is cut.

8. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, The features of the non-contact marking include at least one of color, shape, or pattern.

9. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, The non-contact marking unit includes an inkjet printer, which is fixed to the support of the conveying mechanism by an adjustable mounting bracket, with the printhead of the inkjet printer facing the side of the non-woven fabric. The inkjet printer is equipped with a color mark sensor, which is connected to the control unit to monitor the position of the nonwoven fabric edge and calibrate the spray angle and height of the printhead so that the printhead and the nonwoven fabric surface maintain a preset non-contact distance.

10. The defect treatment system for spunlace nonwoven fabric as described in claim 1, characterized in that, The non-contact markings sprayed by the inkjet printer are located within 2 cm of the edge of the non-woven fabric. The inkjet printer includes multiple color spray channels, with each color corresponding to a defect type.

Images