Paper product bending forming equipment with negative pressure air suction and separating and forming method

Abstract

The application provides a paper product bending forming equipment with negative pressure air suction and separate bending and a forming method, and relates to the technical field of automatic forming processing of paper products. The equipment comprises a rack, modular functional units of fixed-length traction, fixed-length cutting, differential speed separate bending, negative pressure adsorption deviation correction, limiting indentation, pre-pressing shaping, two-stage bending, elastic shaping, reversing conveying, automatic layering and discharging and the like are integrated on the rack in sequence along the conveying direction of the paper product, and are matched with a photoelectric intelligent detection module and a PLC linkage electric control module; the equipment adopts a differential speed physical separate bending and negative pressure air suction adsorption composite structure to solve the problems of paper product sticking, deviation and lifting under high-speed working conditions; a continuous bending forming method based on the equipment is also disclosed, and full-process timing linkage and closed-loop fault protection are realized through an electric control system. The application has high automation degree, strong running stability, high bending forming precision, and can be suitable for large-batch continuous bending processing of various types of paper boxes, paper corner guards, label paper, packaging paper products and the like.

Description

Technical Field

[0001] This invention relates to the field of automated paper forming and processing technology, specifically to a paper bending and forming equipment and method with negative pressure suction and sheet separation. Background Technology

[0002] With the continuous improvement of automation in the packaging industry, paper bending and forming, as a core process in packaging product processing, is gradually shifting from manual operation to fully automated assembly line operations. Currently, existing paper bending equipment on the market has revealed many technical defects under large-volume, high-speed continuous production conditions, which seriously restricts production efficiency and finished product quality.

[0003] In continuous industrial production scenarios for paper bending and forming, existing processing equipment mostly adopts an independent station, step-by-step operation mode. Conventional roller friction conveyor structures are prone to problems such as paper slippage, edge curling, and stacking misalignment when the equipment is running at high speeds. Traditional sheet-separation structures are too simple to adapt to high-speed continuous production conditions. Existing bending mechanisms mostly use single-bending forming methods, without pre-compression positioning, step-by-step bending, and anti-springback shaping structures, resulting in poor consistency of the formed paper and easy deformation of the edges and corners.

[0004] Traditional processing still requires manual assistance for sorting and position correction, and the connection between various processes is insufficient, making it impossible to achieve full automation of unwinding, cutting, separating, bending, and unloading. The equipment lacks online material detection and fault protection structures, resulting in a high failure rate during operation and making it difficult to meet the requirements of large-volume, high-precision paper bending and forming.

[0005] Therefore, those skilled in the art have provided a paper bending and forming device and a forming method with negative pressure suction for sheet separation to solve the problems mentioned in the background art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a paper bending and forming device and method with negative pressure suction for sheet separation. The device employs a composite structure of differential speed sheet separation and negative pressure adsorption to ensure conveying stability. A multi-stage process involving pre-compression, two-stage bending, and elastic shaping suppresses paper springback. Combined with a photoelectric closed-loop detection system, it achieves intelligent control of the entire process. The corresponding forming method features continuous processes and controllable parameters, enabling large-scale, high-precision continuous bending production of various paper products. This invention solves the problems of poor high-speed sheet separation, easy conveying deviation, bending springback deformation, low automation, lack of fault protection, and weak versatility in existing paper bending equipment.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A paper bending and forming device with negative pressure suction and sheet separation includes a frame. The upper end of the frame is arranged in sequence along the continuous paper conveying direction as follows: a fixed-length paper pulling roller group, a fixed-length cutting roller assembly, an accelerating sheet separation roller, a negative pressure suction sheet separation mechanism, a sheet separation baffle, an adjustable indentation knife group, a figure-eight guide wheel mechanism, a pre-compression forming mechanism, a primary large-angle folding mechanism, a secondary small-angle folding mechanism, a push-angle shaping mechanism, a downward pressure conveying mechanism, and a static sliding plate discharge mechanism. The frame is also equipped with multiple sets of photoelectric detection probes and a PLC electrical control system. The negative pressure suction and sheet-separating mechanism includes a hollow perforated suction shaft, a negative pressure fan, a suction pipe, a paper feeding belt, and a pressure plate. The hollow perforated suction shaft has a negative pressure chamber inside, which is connected to the negative pressure fan through the suction pipe. The paper feeding belt covers the outside of the hollow perforated suction shaft, and the pressure plate is mounted above the paper feeding belt. The accelerating separating roller is driven and linked with the hollow perforated suction shaft, and the conveying line speed of the accelerating separating roller is greater than the conveying line speed of the fixed-length paper pulling roller group. The figure-eight guide wheel mechanism is used for lateral centering and correction of the paper blank. The first-stage large-angle folding mechanism, the second-stage small-angle folding mechanism and the push-angle shaping mechanism work together in sequence to complete the step-by-step bending and anti-springback shaping of the paper blank. The static sliding plate discharge mechanism is equipped with a staggered guide groove inside, which is used to realize the front and back layered discharge of paper blanks; The photoelectric detection probe, fixed-length paper pulling roller group, fixed-length cutting roller assembly, accelerating sheet separating roller, negative pressure suction sheet separating mechanism, adjustable indentation knife group, figure-eight guide wheel mechanism, pre-press forming mechanism, first-stage large angle folding mechanism, second-stage small angle folding mechanism, push angle shaping mechanism, downward pressing conveying mechanism and static sliding plate discharge mechanism are all electrically connected to the PLC electrical control system, forming a closed-loop detection and control loop for the entire process.

[0008] Furthermore, the hollow perforated suction shaft has several circular adsorption micropores uniformly opened on its outer peripheral wall. The diameter of the adsorption micropores is 1.5~3mm, and the micropores are arranged in an array at equal intervals along the axial and circumferential directions.

[0009] Furthermore, the installation position of the blade body and the indentation depth of the adjustable indentation knife set are adjustable, and the figure-eight guide wheel mechanism consists of two sets of guide wheels arranged symmetrically on the left and right, with the spacing between the two sets of guide wheels being adjustable to match the width of the paper blank.

[0010] Furthermore, the corner shaping mechanism is equipped with an elastic corner positioning block, which is made of polyurethane elastic material and can continuously apply elastic resistance to the bent corner.

[0011] Furthermore, the linear velocity difference between the accelerating separating roller and the fixed-length paper pulling roller group is 0.5~3m / s, and the negative pressure value provided by the negative pressure fan is in the range of -200Pa~-800Pa.

[0012] Furthermore, the staggered guide chute of the static sliding plate discharge mechanism is divided into upper and lower flow channels, which are arranged in an alternating manner to guide the paper blank to slide and discharge in the forward and reverse directions, respectively.

[0013] Furthermore, the photoelectric detection probes are respectively arranged at the feeding station, cutting station, sheet separation station, creasing station, and discharge station to detect material shortage, paper jam, and offset faults in real time and feed them back to the PLC control system.

[0014] Furthermore, a method for bending and forming paper products using negative pressure suction separation includes the following steps: S1. Fixed-length traction: The paper roll is pulled forward at a constant speed by a fixed-length paper pulling roller group; S2. Fixed-length cutting: The paper is fed to the fixed-length cutting roller assembly and cut into individual paper blanks according to the preset size; S3. Differential speed separation: The cut paper blanks enter the acceleration separation roller area, and the paper blanks are separated by the difference in the linear speed of the rollers, which completes the initial physical separation. S4. Negative pressure correction conveying: The paper blank enters the negative pressure suction and separating mechanism, and is adhered to the paper belt conveyor under the action of negative pressure adsorption to complete the secondary separation and full-process position correction; S5. Limiting and Creasing Centering: After the paper blank is limited by the sheet-separating baffle, the adjustable creasing knife set presses the bending reference line, and the figure-eight guide wheel mechanism completes the transverse centering correction of the paper blank. S6. Pre-compression shaping: The pre-compression forming mechanism compacts the bending area to eliminate warping deformation of the paper blank; S7. Step-by-step bending and shaping: The paper blank passes through the first-level large-angle bending mechanism and the second-level small-angle bending mechanism to complete two-stage bending. The corner-pushing and shaping mechanism continuously applies elastic pressure to suppress the springback of the forming process. S8. Reversing Layered Discharge: The formed paper blank is conveyed and reversed by the downward conveying mechanism and enters the static slide plate discharge mechanism. Automatic forward and reverse layered discharge is achieved through the staggered guide chute. S9. Intelligent closed-loop control: Photoelectric detection probes at each workstation collect operating signals in real time, and the PLC electrical control system uniformly regulates the operating sequence of each module. When an abnormality is detected, the machine automatically stops and issues an early warning.

[0015] Furthermore, in step S1, the basic conveying speed of the fixed-length paper-pulling roller group is 5~15m / min; in step S4, the negative pressure value of the negative pressure suction sheet-separating mechanism is controlled at -300Pa~-600Pa; in step S5, the indentation depth is 1 / 4~1 / 2 of the paper blank thickness; in step S7, the first-stage bending angle is 120°~150°, and the second-stage bending angle is 85°~95°.

[0016] This invention provides a paper bending and forming device and method with negative pressure suction for sheet separation. It has the following beneficial effects: 1. The equipment of the present invention adopts a dual structure of differential speed physical separation and negative pressure suction adsorption. First, it relies on the difference in linear speed of the rollers to complete the initial separation, and then uses negative pressure adsorption to achieve secondary separation and full-process correction. It solves the problems of paper sticking, stacking, edge lifting and lateral deviation in high-speed operation under single separation structure. It can be adapted to continuous production in a wide speed range of 5~15m / min, and significantly reduces the defect rate.

[0017] 2. This invention abandons the traditional single-bending process and adopts a multi-stage process of pre-compression shaping, first-stage large-angle bending, second-stage standard bending, and elastic push-angle shaping. The pre-compression process releases the internal stress of the paper blank in advance, the two-stage step-by-step bending reduces the stress of single deformation, and the elastic positioning block continuously presses against the edges and corners. It solves the problems of paper bending springback and edge warping from both process and structural perspectives. The finished product has high dimensional accuracy and good appearance consistency.

[0018] 3. The static sliding tray discharge mechanism of the present invention realizes automatic arrangement of finished products in front and back layers through staggered sliding grooves, eliminating the manual sorting process, reducing labor costs, and avoiding damage to finished products caused by manual contact. It can be directly connected to downstream packaging and stacking equipment, making the production line more continuous. Moreover, photoelectric detection probes are deployed throughout the process to form a closed-loop control with the PLC electrical control system. It can identify faults such as material shortage, paper jam, and material deviation in real time, and automatically stop the machine and issue audible and visual warnings, reducing equipment failure losses, extending continuous operation time, and making equipment operation and maintenance more convenient.

[0019] 4. The creasing knife assembly, figure-eight guide wheel, sheet-separating baffle, and bending mechanism of this invention can all flexibly adjust parameters according to the thickness, width, and bending angle of the paper. The same machine can be adapted to various types of paper, such as ordinary paper, thin paper, thick composite paper, and laminated paper. The equipment has a high utilization rate, reducing the equipment procurement cost for enterprises. Moreover, the entire set of equipment is uniformly controlled by PLC for the timing of all workstations. The cutting, sheet-separating, bending, and unloading processes are precisely matched, and the process connection is smooth without any disconnection. The entire process realizes automated processing, and the production efficiency is increased by more than 40% compared with traditional equipment.

[0020] 5. The core roller and cutter of this invention are made of wear-resistant steel, the negative pressure mechanism has good sealing performance, the bending mechanism adopts a pneumatic and elastic composite structure, the operating noise is low and the wear is small, the whole machine is modularly designed, a single module failure can be repaired separately without affecting other structures, and the later maintenance cost is low. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the device according to an embodiment of the present invention; Figure 2 This is a partially enlarged schematic diagram of the negative pressure suction and sheet-splitting mechanism according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the multi-stage bending angle, pushing angle shaping and static sliding plate discharge mechanism according to an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Frame; 2. Fixed-length paper pulling roller assembly; 3. Fixed-length cutting roller assembly; 4. Accelerating sheet separating roller; 5. Negative pressure suction sheet separating mechanism; 51. Hollow perforated suction shaft; 52. Negative pressure fan; 53. Suction pipe; 54. Paper conveyor belt; 55. Pressure plate; 6. Sheet divider; 7. Adjustable creasing knife assembly; 8. Figure-eight guide wheel mechanism; 9. Pre-press forming mechanism; 10. First-stage large-angle folding mechanism; 11. Second-stage small-angle folding mechanism; 12. Angle pushing and shaping mechanism; 13. Downward conveying mechanism; 14. Static sliding plate discharge mechanism; 15. Photoelectric detection probe; 16. PLC electrical control system. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0024] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1:

[0028] like Figures 1-3 As shown, this embodiment provides a paper bending and forming equipment with negative pressure suction and sheet separation. The main body is a steel frame, which is integrally welded from square tubes. The structure is stable and has strong shock resistance. Adjustable feet are installed at the bottom of the frame to adjust the level of the whole machine. Along the forward conveying direction of the paper, the following components are modularly and sequentially fixed on the frame: fixed-length paper pulling roller assembly, fixed-length cutting roller assembly, accelerating sheet splitting roller, negative pressure suction sheet splitting mechanism, sheet splitting baffle, adjustable indentation knife assembly, figure-eight guide wheel mechanism, pre-pressing forming mechanism, first-stage large-angle folding mechanism, second-stage small-angle folding mechanism, push-angle shaping mechanism, downward pressing conveying mechanism, and static sliding plate discharge mechanism; Photoelectric detection probes are installed at each key workstation of the frame, and a PLC electrical control system is fixedly installed on the side of the frame. All execution and detection components are connected to the PLC electrical control system to achieve time-series linkage and closed-loop control.

[0029] The fixed-length paper feeding roller assembly consists of paired upper and lower conveyor rollers with knurled anti-slip surfaces. The roller assembly is independently driven by a servo motor. The servo motor receives speed and length commands from the PLC control system, precisely controlling the paper traction speed and single feeding length, providing a basis for subsequent fixed-length cutting. The feeding parameters can be flexibly adjusted according to the paper specifications.

[0030] The fixed-length cutting roller assembly adopts a rotary cutter structure with a cutter hardness of no less than HRC58, and is time-linked with the fixed-length paper feeding roller assembly. When the paper is fed to the set length, the cutter quickly completes the cutting, dividing the entire roll of paper into individual paper blanks of uniform size, with a cutting accuracy of ±0.5mm.

[0031] The accelerating separating roller and the fixed-length paper pulling roller group are driven independently, and its conveying linear speed is 0.5~3m / s higher than that of the fixed-length paper pulling roller group. By utilizing the difference in linear speed between the rollers, the paper blanks that are cut and stuck together are physically pulled apart to separate the adjacent paper blanks, thus completing the initial separation and avoiding stacking of materials from the source.

[0032] The negative pressure suction sheet separating mechanism includes a hollow perforated suction shaft, a negative pressure fan, a suction pipe, a paper feeding belt, and a pressure plate. The hollow perforated suction shaft is a steel hollow cylinder with an array of circular micropores on its outer circumferential wall, which connect to the internal negative pressure chamber. The negative pressure fan is connected to the negative pressure chamber through the suction pipe, continuously drawing in air to create negative pressure. The paper feeding belt surrounds the outside of the hollow perforated suction shaft, and the pressure plate is positioned above the belt to limit the paper blank's movement.

[0033] The sheet-separating guides are symmetrically arranged on both sides of the conveying channel. The spacing can be adjusted according to the width of the paper blank to limit the left and right sides of the separated paper blank, preventing the paper blank from shifting significantly and preparing for the subsequent creasing process.

[0034] The adjustable creasing knife assembly's knife holder can be adjusted up and down, left and right, to change the creasing depth and position, adapting to paper products of different thicknesses and bending positions; the figure-eight guide wheel mechanism consists of two sets of guide wheels arranged symmetrically on the left and right in a figure-eight shape, which can automatically correct the offset paper blank to the center of the conveying channel, ensuring that the bending reference line is centered, thus structurally guaranteeing the accuracy of the bending position.

[0035] The pre-compression forming mechanism adopts an upper and lower counter-pressure roller structure, with the roller surface covered with soft rubber. After the paper blank is indented, it enters this mechanism, where the pre-compression rollers compact the bending area as a whole, eliminating warping and wrinkles caused by cutting and conveying, releasing some internal stress, and laying the foundation for subsequent bending.

[0036] The primary large-angle folding mechanism, the secondary small-angle folding mechanism, and the corner-setting mechanism are arranged sequentially according to the process. The primary large-angle folding mechanism first folds the paper blank to a large angle of 120°~150°, completing the initial bending; the secondary small-angle folding mechanism further reduces the angle to 85°~95°, completing the standard bending; the corner-setting mechanism is equipped with polyurethane elastic corner-setting blocks, which continuously apply elastic pressure to the bent edges and corners to counteract the internal springback stress of the paper and completely solve the problem of springback deformation after bending.

[0037] The downward conveying mechanism uses an upper and lower pressing conveying roller group to convey and change the direction of the finished paper blank after bending, adapting to the layout of the layered discharge structure.

[0038] The static slide unloading mechanism has two layers of staggered guide chutes inside, which are arranged alternately. After the formed paper blanks enter the mechanism, they slide along different chutes, automatically achieving forward and reverse layering and arrangement, eliminating the need for manual sorting and directly connecting to the next process.

[0039] Multiple photoelectric detection probes are deployed at five key workstations: feeding, cutting, separating, creasing, and discharging. The probes collect signals in real time, such as the presence or absence of material, material position, and paper jam status, and feed them back to the PLC control system.

[0040] The PLC electrical control system uses an industrial PLC as the core controller, paired with a touch screen operation panel, and has a built-in complete set of process timing programs. All servo motors, negative pressure fans, cylinders, cutting blades, and detection probes of the entire machine are connected to the control system, which can uniformly set parameters such as conveying speed, cutting length, negative pressure value, and bending angle. When faults such as material shortage, paper jam, or offset are detected, the system immediately controls the entire machine to stop and triggers audible and visual warnings, realizing closed-loop safety protection.

[0041] The paper bending and forming method with negative pressure suction separation includes the following steps: S1. Fixed-length traction: Start the equipment, and the roll of paper raw material is pulled forward at a constant speed of 5~15m / min by the fixed-length paper pulling roller group. The servo motor precisely controls the feeding length according to the set parameters. S2. Fixed-length cutting: The paper is conveyed to the fixed-length cutting roller assembly station, and the rotating cutter completes the cutting according to the preset size to obtain a single independent paper blank. The cutting size error is controlled within ±0.5mm. S3. Differential physical separation: The cut paper blanks enter the acceleration separation roller area. The acceleration separation rollers operate at a speed 0.5~3m / s higher than the fixed length paper pulling rollers. The difference in linear velocity is used to separate the stacked paper blanks and complete the initial physical separation. S4. Negative pressure correction conveying: The paper blank enters the negative pressure suction and separating mechanism. The negative pressure fan generates a negative pressure of -200Pa to -800Pa. Under the negative pressure adsorption, the paper blank is tightly attached to the paper conveyor belt, completing the secondary separation and full-process lateral correction, preventing the paper blank from lifting or running off course. S5. Centering of Limiting and Indentation: The paper blank is limited to the left and right by the sheet separation board. Then, the adjustable indentation knife group presses the bending reference line at the preset position. The indentation depth is 1 / 4 to 1 / 2 of the paper blank thickness. The figure-eight guide wheel mechanism corrects the centering of the paper blank to ensure that the indentation is located in the center of the paper blank. S6. Pre-compression shaping: The paper blank enters the pre-compression forming mechanism, and the upper and lower pressure rollers compress and shape the bending area to eliminate paper blank warping and surface wrinkles, and release some internal stress. S7. Step-by-step bending and shaping: The paper blank passes through the first-level large-angle bending mechanism and the second-level small-angle bending mechanism in sequence, and completes the 120°~150° large-angle bending and the 85°~95° standard bending in succession; then the elastic positioning block of the corner shaping mechanism continuously presses against the bent corners to suppress the paper's springback deformation. S8. Reversing Layered Discharge: The formed paper blank is conveyed and reversed by the downward conveying mechanism and enters the static slide plate discharge mechanism. It is automatically divided into two layers for discharge, forward and reverse, through the internal staggered guide chute. S9. Intelligent closed-loop control: The photoelectric detection probes throughout the entire process monitor the operating status of each station in real time, and the signals are transmitted back to the PLC electrical control system in real time. If faults such as material shortage, paper jam, or material deviation are detected, the system will immediately control the entire machine to stop and issue an audible and visual alarm. After the fault is cleared, continuous production can be restarted.

[0042] Example 2: Standard packaging paper bending and forming The processing object in this embodiment is ordinary packaging paper with a paper blank thickness of 0.2mm, a single sheet size of 210mm×140mm, and a target bending angle of 90°.

[0043] The frame is made of 80mm×80mm square tubing welded together. The frame is 4.2m long, 0.8m wide, and 1.6m high. Adjustable feet are installed at the four corners of the bottom, and the level of the whole machine is adjustable.

[0044] Fixed-length paper pulling roller assembly: Roller diameter 60mm, surface knurling treatment, servo motor drive, basic conveying speed setting 8m / min; Fixed-length cutting roller assembly: Rotary cutter material Cr12MoV, cutting accuracy ±0.3mm; Accelerating separating roller: diameter 55mm, linear speed set at 10m / min, with a linear speed difference of 2m / s from the fixed-length paper pulling roller; Negative pressure suction sheet separating mechanism: hollow perforated suction shaft with a diameter of 70mm, adsorption micropore diameter of 2mm, axial spacing of micropores of 10mm and circumferential spacing of 12mm; negative pressure fan rated negative pressure of -450Pa, and paper conveyor belt using food-grade rubber belt. Sheet separating baffle and figure-eight guide wheel mechanism: The spacing is adjusted to 212mm according to the width of the paper blank, with a 2mm limit gap reserved; Adjustable creasing knife set: creasing depth is set to 0.1mm (1 / 2 of the paper blank thickness). Pre-compression molding mechanism: rubber pressure roller with Shore A60 hardness and pressing gap of 0.18mm; Bending mechanism: primary bending angle 135°, secondary bending angle 90°; the corner-setting mechanism's elastic corner block is made of polyurethane material with a hardness of Shore A70; The static sliding plate discharge mechanism consists of two layers of staggered sliding grooves with an inclination angle of 15°, which realizes the front and back layer discharge of paper blanks; Photoelectric detection probes: a total of 6 sets, respectively arranged at the feeding, cutting, separating, creasing, bending and unloading stations; the PLC electrical control system is equipped with a 7-inch touch screen, which can display operating parameters and fault codes in real time.

[0045] Following the paper conveying direction, the fixed-length paper pulling roller assembly, fixed-length cutting roller assembly, accelerating sheet splitting roller, negative pressure suction sheet splitting mechanism, sheet splitting baffle, adjustable indentation knife assembly, figure-eight guide wheel mechanism, pre-pressing forming mechanism, two-stage bending mechanism, downward pressing conveying mechanism, and static sliding plate discharge mechanism are sequentially fixed on the frame beam; all photoelectric detection probes are installed and wired, and finally connected to the PLC electrical control system to complete the assembly and circuit debugging of the whole machine.

[0046] The molding method of the device in this embodiment includes the following process: S1. Loading Material The roll of packaging paper raw material is installed on the feeding rack. The paper ends are manually passed through all the conveying stations, such as the fixed-length paper pulling roller group, the fixed-length cutting roller assembly, the accelerating sheet separating roller, and the negative pressure suction sheet separating mechanism, to complete the feeding process. S2. Parameter Settings Parameters can be set via PLC touch screen: conveyor speed 8m / min, cutting length 210mm, negative pressure value -450Pa, indentation depth 0.1mm, first-stage bend 135°, second-stage bend 90°; S3. Start running Click the start button and the device will run automatically. ① The fixed-length paper-pulling roller group pulls the paper at a constant speed, and the fixed-length cutting roller assembly completes the fixed-length cutting to produce a single paper blank; ② The accelerating separating roller uses a linear velocity difference of 2m / s to complete the physical separation. After the paper blank enters the negative pressure area, it is conveyed by the belt under the action of -450Pa negative pressure, without any lifting or deviation. ③ After the sheet-separated baffle is positioned, the adjustable indentation knife set presses the reference mark, and the figure-eight guide wheel mechanism completes the centering correction; ④ The pre-compression forming mechanism compacts the bending area to eliminate paper blank warping; ⑤ The two-stage bending mechanism completes the large angle and standard bends in sequence, and the elastic push corner block continuously presses against the corner to suppress the rebound; ⑥ The finished product is reversed by the downward conveying mechanism and enters the static sliding plate discharge mechanism for automatic stratified discharge; S4. Continuous operation The equipment runs continuously for 8 hours without any paper jams, material stacking, or misalignment. The bending angle deviation of the finished product is ≤1°, the creases are smooth, and there is no springback or wrinkles.

[0047] Example 3: Bending and forming of thin catering paper The processing object in this embodiment is thin catering paper with a paper blank thickness of 0.1mm. The equipment conveying speed is increased to 12m / min; the speed of the accelerating separating roller is 14.5m / min, and the speed difference is 2.5m / s; the negative pressure of the negative pressure fan is adjusted to -550Pa to enhance the adsorption effect; the indentation depth is 0.04mm (2 / 5 of the paper blank thickness); the first-stage bend is 140°, and the second-stage bend is 88°.

[0048] After 6 hours of continuous operation, the paper blanks are completely separated without sticking or curling at the edges, and the bending dimensions are consistent, making it suitable for high-speed production requirements.

[0049] Example 4: Bending and forming of thick composite paper The processing object in this embodiment is multi-layer composite packaging paper with a paper blank thickness of 0.5mm; the fixed-length paper pulling roller conveying speed is 5m / min, the accelerating separating roller linear speed is 6m / min, and the linear speed difference is 1m / s; the negative pressure value is adjusted to -300Pa; the indentation depth is 0.2mm; and the bending angle is 90°.

[0050] The equipment operates stably, with no cracking or delamination of thick paper, and no springback at bent edges, meeting the requirements for processing thick paper products.

[0051] The following points should be noted in this article: 1. The accompanying drawings of the embodiments disclosed herein only relate to the structures involved in the embodiments disclosed herein; other structures can be referred to in a general design.

[0052] 2. Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0053] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A paper bending and forming device with negative pressure suction and sheet separation, comprising a frame (1), characterized in that: The upper end of the frame (1) is arranged in sequence along the continuous paper conveying direction, including a fixed-length paper pulling roller group (2), a fixed-length cutting roller assembly (3), an accelerating sheet splitting roller (4), a negative pressure suction sheet splitting mechanism (5), a sheet splitting baffle (6), an adjustable indentation knife group (7), a figure-eight guide wheel mechanism (8), a pre-pressing forming mechanism (9), a first-stage large-angle folding mechanism (10), a second-stage small-angle folding mechanism (11), an angle-pushing and shaping mechanism (12), a downward pressing conveying mechanism (13), and a static sliding plate discharge mechanism (14). The frame (1) is also equipped with multiple sets of photoelectric detection probes (15) and PLC electrical control system (16). The negative pressure suction and sheet separation mechanism (5) includes a hollow perforated suction shaft (51), a negative pressure fan (52), a suction pipe (53), a paper feeding belt (54), and a pressure plate (55). The hollow perforated suction shaft (51) has a negative pressure chamber inside. The negative pressure chamber is connected to the negative pressure fan (52) through the suction pipe (53). The paper feeding belt (54) covers the outside of the hollow perforated suction shaft (51). The pressure plate (55) is mounted above the paper feeding belt (54). The accelerating separating roller (4) is driven and linked with the hollow perforated suction shaft (51), and the conveying line speed of the accelerating separating roller (4) is greater than the conveying line speed of the fixed-length paper pulling roller group (2). The figure-eight guide wheel mechanism (8) is used for horizontal centering and correction of the paper blank. The first-level large-angle folding mechanism (10), the second-level small-angle folding mechanism (11) and the push-angle shaping mechanism (12) work together in sequence to complete the step-by-step bending and anti-springback shaping of the paper blank. The static sliding plate discharge mechanism (14) is provided with a staggered guide groove inside, which is used to realize the front and back layer discharge of paper blanks; The photoelectric detection probe (15), the fixed-length paper pulling roller group (2), the fixed-length cutting roller assembly (3), the accelerating splitting roller (4), the negative pressure suction splitting mechanism (5), the adjustable indentation knife group (7), the figure-eight guide wheel mechanism (8), the pre-pressing forming mechanism (9), the first-stage large-angle folding mechanism (10), the second-stage small-angle folding mechanism (11), the angle pushing and shaping mechanism (12), the downward pressing conveying mechanism (13), and the static sliding plate discharge mechanism (14) are all electrically connected to the PLC electrical control system (16), forming a closed-loop detection and control loop for the entire process.

2. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The hollow perforated suction shaft (51) has several circular adsorption micropores uniformly opened on the outer peripheral wall of the shaft. The diameter of the adsorption micropores is 1.5~3mm, and the micropores are arranged in an array at equal intervals along the axial and circumferential directions.

3. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The adjustable indentation knife assembly (7) has an adjustable knife body installation position and indentation depth. The figure-eight guide wheel mechanism (8) consists of two sets of guide wheels arranged symmetrically on the left and right sides. The distance between the two sets of guide wheels is adjustable to match the width of the paper blank.

4. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The corner shaping mechanism (12) is equipped with an elastic corner positioning block. The elastic corner positioning block is made of polyurethane elastic material and can continuously apply elastic pressure to the bent corner.

5. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The linear velocity difference between the accelerating separating roller (4) and the fixed-length paper pulling roller group (2) is 0.5~3m / s, and the negative pressure value provided by the negative pressure fan (52) is -200Pa~-800Pa.

6. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The staggered guide chute of the static slide plate discharge mechanism (14) is divided into upper and lower flow channels. The two flow channels are arranged in an alternating manner to guide the paper blank to slide out in the forward and reverse directions, respectively.

7. The paper bending and forming equipment and forming method with negative pressure suction and sheet separation according to claim 1, characterized in that: The photoelectric detection probes (15) are respectively arranged at the feeding station, cutting station, sheet splitting station, creasing station and discharge station, and are used to detect material shortage, paper jam and offset faults in real time and feed them back to the PLC control system (16).

8. A method for bending and forming paper products with negative pressure suction and sheet separation, characterized in that, Includes the following steps: S1. Fixed-length traction: The paper roll is pulled forward at a constant speed by the fixed-length paper pulling roller group (2); S2. Fixed-length cutting: The paper is conveyed to the fixed-length cutting roller assembly (3) and cut into independent single paper blanks according to the preset size; S3. Differential speed separation: The cut paper blanks enter the area of ​​the acceleration separation roller (4), and the paper blanks are separated by the difference in the linear speed of the rollers to complete the initial physical separation; S4. Negative pressure correction conveying: The paper blank enters the negative pressure suction and separating mechanism (5), and is conveyed by the paper conveyor belt (54) under the action of negative pressure adsorption, completing the secondary separation and full-process position correction; S5. Limiting and centering the crease: After the paper blank is limited by the sheet divider (6), the adjustable crease knife group (7) presses the bending reference crease, and the figure-eight guide wheel mechanism (8) completes the transverse centering correction of the paper blank. S6. Pre-compression shaping: The pre-compression forming mechanism (9) compacts the bending area to eliminate the warping deformation of the paper blank; S7. Step-by-step bending and shaping: The paper blank passes through the first-level large-angle bending mechanism (10) and the second-level small-angle bending mechanism (11) to complete two-level bending. The corner shaping mechanism (12) continuously applies elastic pressure to suppress the springback of the forming process. S8. Reversing and Layered Discharge: The formed paper blank is conveyed and reversed by the pressing conveyor (13) and enters the static slide plate discharge mechanism (14). Automatic discharge of positive and negative layers is achieved through the staggered guide chute. S9. Intelligent closed-loop control: The photoelectric detection probe (15) of each workstation collects the running signal in real time, and the PLC electrical control system (16) uniformly regulates the running sequence of each module. When an abnormality is detected, the machine will automatically stop and issue an early warning.

9. The paper bending and forming method with negative pressure suction and sheet separation according to claim 8, characterized in that: The basic conveying speed of the fixed-length paper-pulling roller group (2) in step S1 is 5~15m / min; the negative pressure value of the negative pressure suction and sheet-separating mechanism (5) in step S4 is controlled at -300Pa~-600Pa; the indentation depth in step S5 is 1 / 4~1 / 2 of the paper blank thickness; the first-stage bending angle in step S7 is 120°~150°, and the second-stage bending angle is 85°~95°.

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