Automatic standard box labeling machine based on PLC (Programmable Logic Controller) control and label separation method
By using vacuum suction cups and array adsorption hole technology, the problems of wrinkles and scratches caused by dust and foreign objects during label rolling are solved, achieving wrinkle-free and scratch-free firm adhesion of labels, thus improving the labeling accuracy and product quality of the labeling machine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI OCEAN UNIV
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-19
AI Technical Summary
Existing labeling machines are prone to label wrinkling and scratches from dust and foreign objects during the label rolling process, and traditional self-adhesive labels are prone to wrinkling and edge lifting during conveying.
The label is attached to the object using a vacuum suction cup, and the pressure is evenly distributed through an array of suction holes to avoid wrinkles. It also replaces the pressure roller to prevent scratches from dust and foreign objects. Combined with a visual inspection and rejection mechanism, the label quality is ensured.
It achieves firm label adhesion without wrinkles or scratches, improves labeling accuracy and product quality, and reduces defects during label transportation.
Smart Images
Figure CN122059151A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of automated packaging machinery, specifically relating to a standard box automatic labeling machine and label removal method based on PLC control. Background Technology
[0002] The basic principle of a labeling machine is to use a mechanical device to remove the label from the label feeding mechanism and affix it to the designated position on the product. In actual operation, although the labeling is initially completed after the product passes through the labeling module on the conveyor belt, it is often not guaranteed that the label will adhere perfectly to the product. To ensure that the label is firmly attached to the product surface, the product will then pass through a pressure roller, which uses the pressure roller to press the label and make the label adhere more tightly to the product surface.
[0003] Currently, for label rolling, CN213974807U discloses a pressure roller with its axis perpendicular to the direction of product movement. However, the above-mentioned rolling method may cause wrinkles to appear on the parts of the label that are not attached to the product. As disclosed in CN222006774U, in the prior art, traditional self-adhesive label conveying devices have the following problems: traditional self-adhesive labels are prone to wrinkles and edge lifting during processing or conveying. In addition, after long-term operation, some dust and foreign matter may adhere to the surface of the pressure roller, which may cause scratches on the label during subsequent rolling processes. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a PLC-controlled automatic labeling machine for standard boxes and a label removal method. The machine utilizes a vacuum suction cup to attach labels to the customized standard boxes to be labeled, and the vacuum suction cup also presses down to make the labels adhere more firmly and without wrinkles to the labeling box. In addition, by using the vacuum suction cup instead of the existing pressure roller, the problem of dust and foreign objects sticking to the labels can be avoided, thus preventing the labels from being scratched.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A standard box automatic labeling machine based on PLC control includes, frame, The tensioning conveyor mechanism, which is mounted on the frame, is used to tension the label paper to prevent the label tape from loosening or piling up, and to avoid wrinkles caused by poor conveying. A peeling mechanism, which is mounted on a frame, is used to peel labels off label paper; Drive mechanism one, which is mounted on the frame, with its free end pointing vertically downward; A vacuum suction cup is installed at the free end of the drive mechanism; the suction position on the vacuum suction cup corresponds to the label on the label paper. The vacuum suction cup is used to remove the label from the label paper; and the drive mechanism is used to drive the vacuum suction cup to press down so that the label is attached to the surface of the object to be attached. The adsorption site has several adsorption holes arranged in an array, which are used to apply uniform force to the surface of the label when adsorbing the label, so as to avoid label deformation or wrinkles caused by uneven local adsorption force.
[0006] Preferably, the labeling machine further includes a paper feeding mechanism, which is rotatably located above the top of the frame, and the paper feeding mechanism contains label paper.
[0007] Furthermore, the paper feeding mechanism is a label placement shaft, and limiting discs are fixedly sleeved on both ends of the label placement shaft. The ends of the label placement shaft are detachably and rotatably mounted on the frame, and the rolled label paper is sleeved in the label placement shaft between the two limiting discs.
[0008] Preferably, the frame has a fixing plate. The tensioning conveyor mechanism includes a label pressing roller 1, a guide roller 1, a label pressing roller 2, a guide roller 2, a guide roller 3, a tensioning roller 1, a guide roller 4, a guide roller 5, a take-up roller, a tensioning roller 2, and a traction roller; The direction of movement of the label paper after it is unwound from the paper feeding mechanism and wound onto the backing paper is taken as the direction of movement of the label paper. The guide rollers three, four, five, fixed plate, peeling plate, guide roller one, guide roller two, and traction roller are sequentially rotated and installed on the frame along the direction of movement of the label paper. The tension roller one, pressure roller one, pressure roller two, and tension roller two are also rotated and installed on the frame. The tension roller one is located near the guide roller four, the guide roller five, fixed plate, peeling plate, pressure roller one is located near the guide roller one, pressure roller two is located near the guide roller two, and tension roller two is located near the traction roller. The tension roller one corresponds to the guide rail five on the frame and can deflect relative to the guide rail five on the vertical plane of the frame. The tension roller one provides tension to the label paper to prevent it from collapsing. The tension roller two corresponds to the traction roller on the frame and can deflect relative to the traction roller on the vertical plane of the frame.
[0009] Preferably, the frame is also equipped with a second drive mechanism for driving the tensioning conveyor mechanism to convey the label paper.
[0010] Preferably, the second drive mechanism includes a belt, a pulley, a synchronous belt, a synchronous pulley, and an auxiliary pulley. The pulley, synchronous pulley, and auxiliary pulley are all rotatably mounted on the frame. The pulley is coaxial with the guide roller, the synchronous pulley is coaxial with the traction roller, and the auxiliary pulley is coaxial with the take-up roller. The belt is sleeved on both the pulley and the auxiliary pulley, and the synchronous belt is sleeved on both the synchronous pulley and the auxiliary pulley. Additionally, a stepper motor is fixedly connected to the vertical surface of the frame, and the auxiliary pulley is fixedly sleeved on the free end of the stepper motor.
[0011] Preferably, a label plate is detachably and fixedly sleeved on the shaft where the take-up roller is located, for winding the bottom paper.
[0012] Preferably, the peeling mechanism includes a peeling plate, which is located in front of the fixed plate along the direction of movement of the label paper, and is horizontally movably disposed on the vertical surface of the frame. The label paper passes sequentially through the label placement shaft, guide roller three, the gap between tension roller one and guide roller four, guide roller five, fixing plate, and peeling plate; while the base paper passes through the gap between pressure roller one and guide roller one, the gap between pressure roller two and guide roller two, and the gap between tension roller two and traction roller to reach the take-up roller.
[0013] Preferably, the peeling mechanism further includes a translational cylinder, the fixed end of which is horizontally fixed on the vertical surface of the frame, and the free end of which extends horizontally and is connected to one end of the peeling plate.
[0014] Preferably, the driving mechanism is a labeling cylinder, whose fixed end is vertically and movably mounted on the vertical surface of the frame, and whose free end extends vertically and is connected to the upper end of the vacuum suction cup. The suction position of the vacuum suction cup corresponds to the label on the label paper and is used to suck the label off the label paper.
[0015] Preferably, the frame is provided with a limiting mechanism to press the label paper down onto the fixed plate to prevent the label paper from moving during the labeling process, which would result in inaccurate labeling.
[0016] Preferably, the limiting mechanism includes a limiting cylinder and a limiting block. The limiting cylinder is connected to the fixed end of the stepper motor via a connecting piece, and the free end of the limiting cylinder is vertically downward and its end is connected to the limiting block. The lower part of the limiting block corresponds to the top of the fixed plate. In addition, the limiting cylinder and the pressure roller cooperate to press down and fix the label tape before it enters the peeling mechanism, ensuring that the label tape is flat and adheres to the surface of the fixed plate, eliminating local wrinkles.
[0017] Preferably, the labeling machine further includes a visual inspection and rejection mechanism, which is installed around the conveyor belt to identify defects such as wrinkles and bubbles, and to control the rejection mechanism to automatically remove unqualified products from the production line.
[0018] Furthermore, the visual inspection and automatic rejection mechanism includes an industrial camera, an image processing unit, and a rejection cylinder; the industrial camera is used to acquire images of labeled products; the image processing unit is configured to identify labeling defects by analyzing features in the image and output a control signal when a defect is identified; the rejection cylinder is used to remove defective products from the conveyor line.
[0019] The method for removing the label from the label paper is achieved using the standard box automatic labeling machine based on PLC control described above; that is, the detailed process of separating the label from the backing paper is as follows: The label paper moves along a preset path under the traction of the tensioning conveyor mechanism; when a label on the label paper moves to the peeling plate, the conveying stops, that is, when one of the labels on the label paper reaches the peeling plate, the stepper motor stops, so that the movement of the label paper with the label stops. The peeling plate in this mechanism has an airflow channel inside and is connected to a negative pressure source. Its working surface is provided with adsorption micropores for adsorbing and fixing the base paper. The peeling plate is in its initial position. The label is clamped by the tension roller and the traction roller. The traction roller is driven to rotate by the stepper motor through the pulley. The label is conveyed by the friction between the traction roller and the label. After the front edge of the label extends out of the tip of the peeling plate, the limiting mechanism presses the label paper. Then, the limiting cylinder drives the limiting block to press down the label paper. Finally, the vacuum suction cup picks up the label on the label paper. Subsequently, the air pores inside the peeling plate activate negative pressure adsorption; this negative pressure acts on the backing paper through the micropores on its working surface, firmly and flatly adsorbing and fixing the backing paper to the upper surface of the peeling plate. Simultaneously, the vacuum suction cup mounted on the linear bearing descends, its suction surface approaches the label, and negative pressure is activated, adsorbing the upper surface of the label. At this time, the lower surface of the label is bonded to the backing paper through the adhesive, and the backing paper is then adsorbed onto the peeling plate. The vacuum suction cup performs an upward movement. Since the backing paper has been firmly fixed by the negative pressure of the peeling plate, the label, under the lifting action of the vacuum suction cup, attempts to restore its flat state due to its inherent bending stiffness. This restoration tendency generates concentrated peeling stress between the leading edge of the label and the backing paper, thereby overcoming the cohesive force or interfacial adhesion force of the adhesive, allowing the label to peel smoothly from the backing paper.
[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, a vacuum suction cup is used to remove the label from the label paper; and a driving mechanism is used to drive the vacuum suction cup to press down, so that the label is attached to the surface of the object to be attached; the suction position has a number of suction holes arranged in an array, so that the surface of the label is evenly stressed when the label is adsorbed, avoiding label deformation or wrinkles caused by uneven local adsorption force.
[0021] 2. In this invention, when one of the labels on the paper to be labeled is located at the bottom of the vacuum suction cup, the free end of the translating cylinder is moved from the peeling plate toward the fixed plate by activating the translating cylinder, thereby driving the peeling plate toward the fixed plate. At this point, the backing paper adhered to by the label held by the vacuum suction cup is separated from the label. The separated backing paper is then driven by the stepper motor and enters the gap between the first pressure roller and the first guide roller, the gap between the second pressure roller and the second guide roller, and the gap between the second tension roller and the traction roller to reach the take-up roller. Moreover, this labeling process is an intermittent process, that is, when the vacuum suction cup adsorbs one of the labels and separates from the backing paper, the free end of the stepper motor is in a stationary state. Attached Figure Description
[0022] Figure 1 This is a front view of the present invention; Figure 2 This is a rear view of the present invention; Figure 3 This is a side view of the present invention; Figure 4 This is a perspective view of the present invention; Figure 5 for Figure 4 Enlarged images of some details; Figure 6 This is an enlarged schematic diagram showing the positions of the peeling plate and the fixing plate in this invention; Figure 7 This is a schematic diagram showing the positional relationship of the adsorption holes on the vacuum suction cup in this invention; Figure 8 This is a schematic diagram of the layout of the visual detection and rejection mechanism in this invention, and a schematic diagram of the walking path of the label paper in this invention. Figure 9 This is a schematic diagram of the label detachment process in this invention, where Figure a represents the unremoved stage and Figure b represents the detachment process. Figure 10 This is a schematic diagram of the travel path of the label paper in this invention.
[0023] In the diagram: 1. Frame; 2. Limiting plate; 3. Fixing plate; 4. Stepper motor; 5. Limiting cylinder; 6. Baffle; 7. Vacuum suction cup; 71. Suction hole; 8. Limiting block; 9. Peeling plate; 10. Label pressing roller 1; 11. Guide roller 1; 12. Label pressing roller 2; 13. Guide roller 2; 14. Conveyor belt; 15. Base; 16. Guide roller 3; 17. Tensioning roller 1; 18. Guide roller 4; 19. Guide roller 5; 20. Label plate; 21. Take-up roller; 22. Translation cylinder; 23. Tensioning roller 2; 24. Traction roller; 25. Fixing plate; 26. Mounting frame; 27. Belt; 28. Pulley; 29. Synchronous belt; 30. Synchronous pulley; 31. Linear bearing; 32. Label placement shaft; 33. Balance block; 34. Guide rail support plate; 35. Linear slide rail; 36. Base paper; 37. Label; 38. Industrial camera; 39. Light source; 40. Rejection cylinder. Detailed Implementation
[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments are described in detail with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand this invention, but does not constitute a limitation of this invention.
[0025] First, the following explanation is required in this invention: After the label 37 on the label paper is torn off, the remaining part is called the backing paper 36. Furthermore, the label paper in this invention is a self-adhesive label roll, and the information has been printed on it in advance, so there will be no blurry text. In addition, this automatic labeling machine is a core piece of equipment in the modern packaging industry used to improve packaging efficiency and quality; its functions cover a fully automated process including label supply, label suction, labeling and recycling, and it is applied to the batch packaging of standardized products.
[0026] like Figure 1-10 As shown, a standard box automatic labeling machine based on PLC control includes, Rack 1, The tensioning conveyor mechanism, which is mounted on the frame 1, is used to tension the label paper to prevent the label 37 from loosening or piling up, and to avoid wrinkles caused by poor conveying. A peeling mechanism, which is movably mounted on the frame 1, is used to peel off the label 37 from the label paper; Drive mechanism 1 is mounted on frame 1, with its free end pointing vertically downwards; A vacuum suction cup 7 is installed at the free end of the drive mechanism 1. The suction position on the vacuum suction cup 7 corresponds to the label 37 on the label paper. The vacuum suction cup 7 is used to remove the label 37 from the label paper. The drive mechanism 1 drives the vacuum suction cup 7 to press down, so that the label 37 is attached to the surface of the object to be attached. The suction position has several suction holes 71 arranged in an array to ensure that the surface of the label 37 is evenly stressed when it is attached, so as to avoid deformation or wrinkling of the label 37 due to uneven local suction force. In addition, it should be explained that before the vacuum suction cup 7 presses down to contact the label 37, an external purge air is used to briefly pre-blow air to eliminate local adhesion or small wrinkles between the label 37 and the backing paper 36. Then, the suction holes 71 on the vacuum suction cup 7 activate negative pressure to attach the label 37 to the vacuum suction cup 7 in a flat state. The vacuum suction cup 7 has an air suction port 7. When the labeling cylinder 3 pushes the vacuum suction cup 7 to attach the label 37 to the product (box) surface, the suction port 71 on the vacuum suction cup 7 can switch to positive pressure blowing instantly to assist the label 37 to detach smoothly. At the same time, the airflow helps to push the label 37 to the product (box) surface, further eliminating any possible small wrinkles. Furthermore, the vacuum suction and blowing are combined: before the vacuum suction cup 7 adsorbs the label 37, it uses external blowing air for a short pre-blowing to remove small particles from the adsorption surface of the vacuum suction cup 7 and the surface of the label 37. After adsorption, external blowing air is used again before labeling to ensure that the contact surface between the label 37 and the product (box) is dust-free. Semi-enclosed conveying environment: In addition, this equipment adopts a semi-enclosed structure to reduce external dust falling into the label 37 belt path and prevent dust from entering.
[0027] The labeling machine also includes a paper feeding mechanism, which is rotatably located on the top of the frame 1, and the paper feeding mechanism contains label paper. Specifically, the paper feeding mechanism is a label placement shaft 32, and the label placement shaft 32 remains stationary when the label roll rotates, ensuring the stability of the label roll during use and preventing label curling. To accommodate label rolls of different widths, limit plates 2 are fixedly sleeved on both ends of the label placement shaft 32, and both ends of the label placement shaft 32 are detachably and rotatably mounted on the frame 1. (More specifically, a mounting bracket 26 is fixedly connected to the top of the frame 1 via hexagonal bolts, and the mounting bracket 26 extends vertically upwards. The label placement shaft 32 is rotatably mounted on the mounting bracket 26 via bearings.) Extend the mounting bracket and connect it via a pin. By removing the pin, the label mounting shaft 32 and bearing can be removed from the mounting bracket 26, and the limiting plate 2 can be removed from the label mounting shaft 32. This allows for the installation or replacement of new rolls of label paper on the label mounting shaft 32 (and can accommodate self-adhesive label rolls of different inner diameters). The roll of label paper is fitted into the label mounting shaft 32 between the two limiting plates 2. The purpose is to adjust and place the label roll according to its actual width, ensuring the correct positioning of the label roll on the label mounting shaft 32, preventing misalignment of the labels and avoiding displacement or detachment during operation. In addition, a balance block 33 is fitted onto the label mounting shaft 32 between the mounting bracket 26 and one of the limiting plates 2.
[0028] The frame 1 has a fixed plate 25. The tensioning conveyor mechanism includes a label pressing roller 10, a guide roller 11, a label pressing roller 22, a guide roller 23, a guide roller 36, a tension roller 17, a guide roller 48, a guide roller 519, a take-up roller 21, a tension roller 23, and a traction roller 24. The direction of movement of the label paper after it is unwound from the paper feeding mechanism onto the backing paper 36 is taken as the direction of movement of the label paper. The guide roller 316, guide roller 418, guide roller 519, fixed plate 25, peeling mechanism, guide roller 11, guide roller 23, and traction roller 24 are sequentially rotated and mounted on the frame 1 along the direction of movement of the label paper. The tension roller 17 and label pressing roller 10 are also included. 0. Label pressing roller 12 and tension roller 23 are also rotatably mounted on frame 1. Tension roller 17 is located near guide roller 4 18, guide roller 5 19, fixing plate 25, peeling plate 9, label pressing roller 10 is located near guide roller 11, label pressing roller 22 is located near guide roller 2 13, and tension roller 23 is located near traction roller 24. Tension roller 17 corresponds to guide rail 5 19 on frame 1 and can deflect relative to guide rail 5 19 on the vertical plane of frame 1. Tension roller 1 provides tension to the label paper to prevent the label paper from collapsing. Tension roller 23 corresponds to traction roller 24 on frame 1 and can deflect relative to traction roller 24 on the vertical plane of frame 1.
[0029] A second drive mechanism is also installed on the frame 1 to drive the tensioning conveyor to transport the label paper. Specifically, the second drive mechanism includes a belt 27, a pulley 28, a synchronous belt 29, a synchronous pulley 30, and an auxiliary pulley. The pulley 28, the synchronous pulley 30, and the auxiliary pulley are all rotatably mounted on the frame 1. The pulley 28 is coaxial with the guide roller 16, the synchronous pulley 30 is coaxial with the traction roller 24, and the auxiliary pulley is coaxial with the take-up roller 21. The belt 27 is sleeved on the pulley 28 and the auxiliary pulley, and the synchronous belt 29 is sleeved on the synchronous pulley 30 and the auxiliary pulley. In addition, a stepper motor 4 (mainly connected by screws or bolts) is fixedly connected to the vertical surface of the frame 1. The pulley 28 is fixedly sleeved on the free end of the stepper motor 4. The rotation of the free end of the stepper motor 4 causes the pulley 28 to rotate, thereby driving the synchronous pulley and the auxiliary pulley to rotate, thus directly or indirectly driving the rotation of each roller, and finally making the label paper move on this equipment.
[0030] The drive mechanism is a linear bearing 31, whose fixed end is installed on the vertical surface of the frame 1, and whose movable end is connected to a fixed plate 3. The fixed plate 3 extends in the vertical direction and is connected to the upper end of the vacuum suction cup 7 at the bottom of the fixed plate 3. The suction position of the vacuum suction cup 7 corresponds to the label 37 on the label paper and is used to suck the label 37 off the label paper.
[0031] It should also be noted that a base 15 is installed at the bottom of the frame 1 (in addition, in order to ensure that the frame 1 is firmly installed on the base 15, a guide rail support plate 34 is fixed on the vertical surface of the frame 1 and the top of the base 1). The base 15 is also equipped with a product conveying mechanism, which is located near the vacuum suction cup 7. When the product is conveyed by the product conveying mechanism (mainly conveyed by the conveyor belt 14) to the bottom of the vacuum suction cup 7, the product conveying mechanism stops conveying the product, so that the product stops below the vacuum suction cup 7, and the label 37 can be pasted on the product using the vacuum suction cup 7.
[0032] A limiting mechanism is provided on the frame 1 to press the label paper down onto the fixed plate 25, preventing the label paper from moving during the labeling process and causing inaccurate labeling. In addition, the limiting mechanism cooperates with the pressure roller 10 to press and fix the label 37 before it enters the peeling mechanism, ensuring that the label 37 is flat and adhered to the surface of the fixed plate 25, eliminating local wrinkles. Specifically, the limiting mechanism includes a limiting cylinder 5 and a limiting block 8. The fixed end of the stepper motor 4 is connected to the limiting cylinder 5 through a connecting piece, and the free end of the limiting cylinder 5 is vertically downward and its end is connected to the limiting block 8. The lower part of the limiting block 8 corresponds to the top of the fixed plate 25.
[0033] It should be noted that the detailed process of label 37 detaching from the label paper, i.e., label 37 separating from the backing paper 36, in this invention is as follows (e.g. Figure 9 (ab process): The label paper moves along a preset path under the traction of the tensioning conveyor mechanism. That is, the label paper with label 37 passes sequentially through the label placement shaft 32, guide roller 3 16, the gap between tension roller 1 17 and guide roller 4 18, guide roller 5 19, fixing plate 25 and peeling plate 9 (it should be noted that in order to prevent the label paper from slipping on the peeling plate 9, two baffles 6 are set on the top of the peeling plate 9). When one of the labels 37 on the label paper moves to the peeling plate 9, the conveying stops. That is, when one of the labels 37 on the label paper reaches the peeling plate 9, the stepper motor 4 stops, so that the movement of the label paper with label 37 stops. The peeling plate 9 has an airflow channel inside and is connected to a negative pressure source. Its working surface is provided with adsorption micropores (not shown in the figure) for adsorbing and fixing the base paper 36. The peeling plate 9 is in its initial position. The label 37 is clamped by the tension roller 23 and the traction roller 24 (the tension roller 23 contacts the label tape under the action of gravity, increasing the friction and helping the traction roller 24 to drive the label tape more effectively, thereby avoiding the label paper from breaking). The stepper motor drives the traction roller 24 to rotate through the pulley 28. The label tape is conveyed by the friction between the traction roller 34 and the label tape (the structure after the label 37 and the backing paper 36 are combined) (specifically, the traction roller 34 generates friction with the label tape through the rubber layer on its surface, thereby pushing the label tape forward). After the leading edge of the label 37 extends out of the tip of the peeling plate 9, the limiting mechanism presses the label paper, that is, the limiting cylinder 5 drives the limiting block 8 to press down the label paper. Then, the vacuum suction cup 7 is used to pick up the label 37 on the label paper. Subsequently, the air pores inside the peeling plate 9 initiate negative pressure adsorption; this negative pressure acts on the back paper 36 through the micropores (adsorption micropores) on its working surface, firmly and flatly adsorbing and fixing the back paper 36 to the upper surface of the peeling plate 9. Simultaneously, the vacuum suction cup 7 mounted on the linear bearing 31 descends, its suction surface approaches the label 37, and negative pressure is activated, adsorbing the upper surface of the label 37. At this time, the lower surface of the label 37 is adhered to the backing paper 36 by adhesive, and the backing paper 36 is then adsorbed onto the peeling plate 9. The vacuum suction cup 7 performs an upward movement. Since the backing paper 36 has been firmly fixed by the negative pressure of the peeling plate 9, the label 37, under the lifting action of the vacuum suction cup 7, attempts to restore its flatness due to its inherent bending stiffness. This restoring tendency occurs between the leading edge of the label 37 and the backing paper 36. The concentrated peeling stress overcomes the cohesive force or interfacial adhesion force of the adhesive, allowing the label 37 to peel smoothly from the backing paper 36. Then, the translation cylinder 22 is activated, causing the free end of the translation cylinder to move from the peeling plate 9 toward the fixed plate 25, thereby driving the peeling plate 9 toward the fixed plate 25. The separated backing paper 36 is then driven by the stepper motor 4 into the gap between the pressure roller 10 and the guide roller 11, the gap between the pressure roller 22 and the guide roller 23, and the gap between the tension roller 23 and the traction roller 24, and finally reaches the take-up roller 21.
[0034] A label tray 20 is detachably and fixedly sleeved on the shaft where the take-up roller 21 is located (the detachable method can be achieved using existing technology, so it will not be described in detail here), used to wind the base paper 36. To further ensure labeling quality, an industrial camera 38 and a light source 39 for illuminating the label surface are installed in the middle of the conveyor belt 14. The industrial camera 38 is connected to an image processing unit, which is configured to identify defects such as wrinkles, bubbles, or misalignment of the label. The output of the image processing unit is connected to the input of a PLC controller. When a defect is detected, the image processing unit sends a non-compliance signal to the PLC. A rejection cylinder 40 is provided on the side of the conveyor belt 14. When the PLC receives the non-compliance signal, it controls the rejection cylinder 40 to actuate, pushing the object with the defective label out of the conveyor path, thus achieving automatic sorting. In addition, it should be noted that the stepper motor 4 and the transmission of various cylinders on this labeling machine are all controlled by a PLC using existing technology.
[0035] II. Method for applying label 37 without wrinkles When the vacuum suction cup 7 is activated, all the suction holes 71 on its suction surface generate negative pressure at the same time, which flattens and adsorbs the label 37. Then, the vacuum suction cup 7 carries the label 37 to the top of the product. The object to be labeled (product) is conveyed to the work station by the conveyor belt 14, and the linear bearing drives the vacuum suction cup 7 to carry the label 37 down to the surface of the object. During the descent, when the pressure sensor of the drive mechanism (preset on the drive mechanism) detects that the contact signal reaches a preset threshold, the system determines that the label 37 has contacted the object surface. The drive mechanism continues to push the vacuum suction cup 7 to move. During the pressing process, the airflow partitions of the vacuum suction cup 7 are coordinated and controlled according to the bonding expansion sequence: first, the vacuum of the suction hole 71 corresponding to the leading edge of the label 37 is released, so that the area is bonded under pressure; as the bonding surface expands backward, the vacuum of the subsequent partitions is closed in sequence to guide the label 37 to bond smoothly and promote the expulsion of air between the interfaces.
[0036] Once the vacuum in all the suction holes of all zones is closed, the label 37 adheres to the object surface entirely by pressure. At the moment the retraction begins, a brief, uniform positive pressure airflow is simultaneously introduced into the suction holes of all individual zones. This airflow helps overcome any residual adhesion between the label 37 and the suction cup surface, causing the label 37 to detach completely from the suction cup and ensuring it is firmly attached to the object surface. Subsequently, the vacuum suction cup 7 resets, ready for the next cycle.
[0037] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications or variations that can be made by those skilled in the art without creative effort within the scope of the appended claims are still within the scope of protection of this patent.
Claims
1. A standard box automatic labeling machine based on PLC control, characterized in that, include, frame, The tensioning conveyor mechanism, which is mounted on the frame, is used to tension the label paper to prevent the label tape from loosening or piling up, and to avoid wrinkles caused by poor conveying. A peeling mechanism, which is mounted on a frame, is used to peel labels off label paper; Drive mechanism one, which is mounted on the frame, with its free end pointing vertically downward; A vacuum suction cup is installed at the free end of the drive mechanism; the suction position on the vacuum suction cup corresponds to the label on the label paper. The vacuum suction cup is used to remove the label from the label paper; and the drive mechanism is used to drive the vacuum suction cup to press down so that the label is attached to the surface of the object to be attached. The adsorption site has several adsorption holes arranged in an array, which are used to apply uniform force to the surface of the label when adsorbing the label, so as to avoid label deformation or wrinkles caused by uneven local adsorption force.
2. The PLC-controlled automatic labeling machine for standard boxes according to claim 1, characterized in that: The labeling machine also includes a paper feeding mechanism, which is rotatably located above the top of the frame, and the paper feeding mechanism contains label paper.
3. The standard box automatic labeling machine based on PLC control according to claim 2, characterized in that: The frame has a fixing plate. The tensioning conveyor mechanism includes a label pressing roller 1, a guide roller 1, a label pressing roller 2, a guide roller 2, a guide roller 3, a tensioning roller 1, a guide roller 4, a guide roller 5, a take-up roller, a tensioning roller 2, and a traction roller; The direction of movement of the label paper after it is unwound from the paper feeding mechanism and wound onto the backing paper is taken as the direction of movement of the label paper. The guide rollers three, four, and five, the fixed plate, the peeling mechanism, guide roller one, guide roller two, and the traction roller are sequentially rotated and installed on the frame along the direction of movement of the label paper. The tension roller one, the pressure roller one, the pressure roller two, and the tension roller two are also rotated and installed on the frame. The tension roller one is located near the guide roller four, the guide roller five, the fixed plate, the peeling plate, the pressure roller one is located near the guide roller one, the pressure roller two is located near the guide roller two, and the tension roller two is located near the traction roller. The tension roller one corresponds to the guide rail five on the frame and can deflect relative to the guide rail five on the vertical plane of the frame. The tension roller one provides tension to the label paper to prevent it from collapsing. The tension roller two corresponds to the traction roller on the frame and can deflect relative to the traction roller on the vertical plane of the frame.
4. The PLC-controlled automatic labeling machine for standard boxes according to claim 3, characterized in that: The frame is also equipped with a second drive mechanism, which is used to drive the tensioning conveyor mechanism to convey the label paper. Preferably, the second drive mechanism includes a belt, a pulley, a synchronous belt, a synchronous pulley, and an auxiliary pulley, wherein the pulley, synchronous pulley, and auxiliary pulley are all rotatably mounted on the frame, and the pulley is coaxial with the guide roller, the synchronous pulley is coaxial with the traction roller, and the auxiliary pulley is coaxial with the take-up roller; the belt is sleeved on the pulley and the auxiliary pulley, and the synchronous belt is sleeved on the synchronous pulley and the auxiliary pulley.
5. The PLC-controlled automatic labeling machine for standard boxes according to claim 4, characterized in that: The peeling mechanism includes a peeling plate, which is located in front of the fixed plate along the direction of movement of the label paper, and is horizontally movable on the vertical surface of the frame. The label paper passes sequentially through the label placement shaft, guide roller three, the gap between tension roller one and guide roller four, guide roller five, fixing plate, and peeling plate; while the base paper passes through the gap between pressure roller one and guide roller one, the gap between pressure roller two and guide roller two, and the gap between tension roller two and traction roller to reach the take-up roller.
6. The PLC-controlled automatic labeling machine for standard boxes according to claim 5, characterized in that: One of the driving mechanisms is a labeling cylinder, whose fixed end is vertically and movably mounted on the vertical surface of the frame, and whose free end extends vertically and is connected to the upper end of the vacuum suction cup. The suction position of the vacuum suction cup corresponds to the label on the label paper and is used to suck the label off the label paper.
7. The PLC-controlled automatic labeling machine for standard boxes according to claim 6, characterized in that: The frame is equipped with a limiting mechanism to press the label paper down onto the fixed plate, preventing the label paper from moving during the labeling process and causing inaccurate labeling. In addition, the limiting mechanism works in conjunction with the pressure roller to press and fix the label paper before it enters the peeling mechanism, ensuring that the label paper is flat and adheres to the surface of the fixed plate, eliminating local wrinkles.
8. A label removal method, implemented using the PLC-controlled automatic labeling machine for standard boxes as described in any one of claims 1-7, characterized in that: Includes the following steps: The label paper moves along a preset path under the traction of the tensioning conveyor mechanism; when a label on the label paper moves to the peeling plate, the conveying stops; the peeling plate has an airflow channel inside and is connected to a negative pressure source, and its working surface is provided with adsorption micropores. The peeling plate is in its initial position, the label is clamped by the tension roller and the traction roller, and the traction roller is driven to rotate by the stepper motor through the pulley. The label is conveyed by the friction between the traction roller and the label. After the leading edge of the label extends out of the tip of the peeling plate, the limiting mechanism is activated to press the label paper. Subsequently, the air pores inside the peeling plate activate negative pressure adsorption; this negative pressure acts on the backing paper through the micropores on its working surface, firmly and flatly adsorbing and fixing the backing paper to the upper surface of the peeling plate; at the same time, the vacuum suction cup mounted on the linear bearing descends, its adsorption surface comes close to the label and activates negative pressure, adsorbing the upper surface of the label; at this time, the lower surface of the label is bonded to the backing paper by adhesive, and the backing paper is adsorbed on the peeling plate again. The vacuum suction cup makes an upward movement. Since the backing paper has been firmly fixed by the negative pressure of the peeling plate, the label, under the lifting action of the vacuum suction cup, attempts to restore its flat state due to its inherent bending stiffness. This recovery tendency creates concentrated peel stress between the label leading edge and the backing paper, thereby overcoming the cohesive force or interfacial adhesion force of the adhesive and allowing the label to peel smoothly from the backing paper.