Double-sided bonding process of diffusion film letter-shaped adhesive

Abstract

The application discloses a double-sided bonding process of diffusion film mouth-shaped glue and belongs to the technical field of optical film processing. The application realizes one-time bonding of mouth-shaped glue on the upper and lower surfaces of a release paper base material through synchronous operation of two groups of independent glue bonding mechanisms, greatly improves the alignment accuracy and bonding efficiency of double-sided mouth-shaped glue, adopts an integrated composite die to synchronously generate a crease reference line at the center position of double-sided mouth-shaped glue, and combines a hierarchical folding and pressing wheel module to realize directional folding and pressing, realizes automatic production of the whole process from unwinding, slitting, double-sided glue bonding, die cutting, folding, shape die cutting to cutting, detection and sorting, improves product yield, production efficiency and process stability, and is suitable for large-scale continuous production of high-precision diffusion films.

Description

Technical Field

[0001] This invention relates to the field of optical film processing technology, and in particular to the double-sided bonding process of diffusion film lettering adhesive. Background Technology

[0002] In the diffusion film lamination process, for the lamination of the "U"-shaped adhesive backing, a single die is used to cut and laminate the adhesive backing onto only one surface of the diffusion film. When it is necessary to laminate the adhesive backing onto both sides of the diffusion film, it must be done in two steps. After laminating one side, the semi-finished product must be transferred and repositioned before laminating the second side. The two independent positioning processes are prone to cumulative errors, making it difficult to guarantee the relative positional accuracy of the adhesive backing on both sides. Furthermore, the two independent die-cutting and lamination processes increase equipment downtime and manual intervention, resulting in a long production cycle. The existing process is difficult to complete the precise lamination of double-sided adhesive backing and subsequent folding and shaping simultaneously on a continuous production line in a roll-to-roll manner. Summary of the Invention

[0003] The purpose of this invention is to provide a double-sided bonding process for diffusion film lettering adhesive to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] The double-sided lamination process of diffusion film lettering adhesive includes:

[0006] The entire roll of release paper is fed into an automatic unwinding device, and the release paper, which is conveyed in a straight line, is slit into strips of a fixed width to obtain standard width release paper substrate.

[0007] Two independent adhesive applicator mechanisms are activated to operate synchronously, applying letter-shaped adhesive, including front and back adhesive, at preset intervals on the upper surface of the standard width release paper substrate, while retaining the original release paper with the back adhesive, thus obtaining a composite film material with double letter-shaped adhesive.

[0008] The composite membrane material with double-sided adhesive is fed to a pre-assembled integrated composite die. The die is used for punching, and a crease baseline is generated at the center of the two sets of adhesive to obtain a composite membrane material with creases.

[0009] Based on the preset product stacking requirements, a diffusion film is bonded to the surface of the adhesive on the front of the creased composite film to obtain the film material to be folded.

[0010] Using the crease reference line as a reference, the film material to be folded is folded and pressed in an oriented manner, so that the half of the release paper where the reverse adhesive is located is flipped along the crease reference line, and the reverse adhesive is pressed onto the other side of the diffusion film, resulting in a folded semi-finished product with the square adhesive on both sides.

[0011] The folded semi-finished product is die-cut into its overall shape according to the preset product outline to obtain the diffusion film finished product. The diffusion film finished product is then cut into fixed length pieces and quality inspected to sort out qualified and defective products.

[0012] Furthermore, before the fixed-width stripping, the process also includes:

[0013] Based on the target product width parameters, the cutting size and feeding straightness threshold of the slitting machine are preset, and the release paper's trajectory data is collected in real time based on the tension control system and photoelectric correction components.

[0014] The material feeding trajectory data is compared with the preset feeding straightness threshold, the trajectory deviation value is calculated, and the S-shaped offset of the release paper is determined based on the trajectory deviation value.

[0015] When it is determined that there is an S-shaped deviation in the release paper, the action parameters of the photoelectric correction component are updated in real time based on the trajectory deviation value to continuously correct the release paper feeding posture.

[0016] Once the release paper feeding trajectory data is within the preset feeding straightness threshold and the straight feeding is maintained, the fixed-width slitting operation is performed according to the preset slitting machine cutting size.

[0017] Furthermore, the step of applying lettering adhesive to the upper surface of the standard width release paper substrate includes:

[0018] Based on the dimensions and adhesion position tolerance standards of the square-shaped adhesive, the adhesive application coordinates, adhesive application pressure, and running speed parameters of two sets of independent adhesive application mechanisms are preset;

[0019] Based on the real-time acquisition of positioning mark position data on the upper surface of standard width release paper substrate by the vision positioning component, the positioning mark position data is compared with the preset adhesive application coordinates to determine whether the alignment accuracy of the adhesive application mechanism meets the bonding position tolerance standard.

[0020] When the alignment accuracy meets the bonding position tolerance standard, control the two sets of independent adhesive application mechanisms to operate synchronously and apply the lettering adhesive to the upper surface of the standard width release paper substrate according to the preset spacing.

[0021] After the adhesive is applied, the original release paper with the adhesive on the reverse side is retained, resulting in a composite film material with double-sided adhesive.

[0022] Furthermore, the pre-assembled integrated composite die includes two sets of die-cutting cavities, a central screed cutter, and a positioning structure.

[0023] Based on the preset reference axis according to the direction of release paper travel, install the composite die to the die-cutting station;

[0024] The first angle between the transverse cutting edge line and the reference axis and the second angle between the longitudinal cutting edge line and the reference axis of the composite die are detected. The first angle and the second angle are compared with the preset standard values ​​respectively, and the angle deviation is calculated.

[0025] When the angular deviation exceeds the allowable tolerance, the composite die is moved until both the lateral and longitudinal angles reach the preset standard values.

[0026] At the same time, the height difference between each die-cutting station of the composite die and the equipment reference plane is detected. When the height difference exceeds the threshold, the shims of the die mounting base are adjusted so that all die-cutting cavities are on the same horizontal reference plane.

[0027] Furthermore, the generation of the crease baseline specifically includes:

[0028] Based on the standard parameters of the finished product dimensions and crease depth of the square-shaped adhesive, the pressing stroke, cutting contour parameters and center line cutter half-cut depth parameters of the integrated composite die are preset;

[0029] During the operation, the pressing displacement data of the composite die is acquired in real time based on the die-cutting sensor. The pressing displacement data is compared with the preset pressing stroke in real time to determine the execution progress and positioning status of the composite die.

[0030] When the composite die reaches the preset pressing stroke, the two sides of the die-cutting cavity of the letterform simultaneously perform the cutting operation, and the composite film material is half-cut by the center line cutter, generating crease baselines on the release paper at the center position of the two sets of letterforms.

[0031] Furthermore, the specific process of attaching the diffusion film includes:

[0032] The bonding coordinates, bonding pressure, and material conveying speed of the diffusion film are preset, and the crease baseline position data and the position data of the letter-shaped adhesive are extracted. The diffusion film is then positioned in conjunction with the auxiliary film bonding mechanism.

[0033] Based on the positioning results, a diffusion film is bonded to the adhesive surface of the creased composite film. During the operation, the status of the release paper on the adhesive surface of the reverse side is monitored in real time. If the release paper is detected to fall off, a stop warning is triggered in time.

[0034] After the diffusion film is laminated, the diffusion film lamination position data and release paper status data are synchronized to the rear folding pressure roller module.

[0035] Furthermore, the specific process for directional folding and pressing of the folding pressure roller module is as follows:

[0036] Obtain the actual angular deviation data after parallel calibration of the composite die, and dynamically correct the preset standard folding center line based on the actual angular deviation data;

[0037] Based on the crease baseline position data and the state data of the reverse adhesive release film, the folding angle, pressing pressure, folding travel speed and lateral alignment deviation threshold of the pressing roller module are preset;

[0038] The folding pressure roller module includes a first-stage guide roller and a second-stage pressing roller, and the preset folding angle includes a first folding angle and a second folding angle.

[0039] The actual trajectory of the crease baseline is acquired in real time, and the actual trajectory of the crease baseline is compared with the preset standard fold center line to calculate the lateral offset and angular deflection.

[0040] When the lateral offset or angular deflection exceeds the preset alignment deviation threshold, a lateral adjustment command or an angle correction command is generated. Adjustments are made based on the lateral adjustment command and the angle correction command until the crease baseline coincides with the standard fold center line.

[0041] The first-stage guide wheel is controlled by the preset folding angle. The first-stage guide wheel lifts the film material to be folded upward along the fold line until the preset first folding angle is reached.

[0042] The folding angle and tearing condition of the folding reference line of the film material to be folded are monitored in real time. When it is determined that there is no abnormal tearing at the folding reference line and the folding angle reaches the preset first folding angle, a secondary folding signal is generated.

[0043] Based on the secondary folding signal, the second-stage pressing roller is controlled to fold the film material to be folded to the preset second folding angle according to the preset pressing pressure and folding travel speed. This causes the reverse adhesive to flip over with the release paper to the other side of the diffusion film and press the reverse adhesive onto the surface of the diffusion film under the preset pressure, while the front adhesive remains bonded to the original bonding surface of the diffusion film.

[0044] The pressing pressure value is monitored in real time, and a pressing completion signal is generated when the pressing pressure value reaches the preset pressure threshold.

[0045] Furthermore, the directional folding and pressing also includes:

[0046] During the folding and pressing action, real-time pressure data of the first-stage guide wheel and the second-stage pressing wheel in the folding and pressing wheel module are collected.

[0047] The real-time pressure data is compared one by one with the pressure standard value at the corresponding time point in the preset standard pressure curve to calculate the pressure deviation value, and the pressure deviation value is used to determine whether there is uneven compression.

[0048] When uneven pressure is detected, a corresponding pressure adjustment command is generated based on the pressure deviation value distribution data.

[0049] Further, the overall shape die-cutting specifically includes:

[0050] Extract the width parameter, the position data of the double-sided mouth-shaped adhesive, the horizontal reference plane data of the composite die, and the position data of the crease reference line, fuse them to generate the global alignment reference for the shape die-cutting station, and set the cutting contour, the downward pressure stroke, and the punching force parameters of the shape die-cutting die;

[0051] Identify the crease reference line on the folded semi-finished product, perform a secondary comparison based on the recognition result and the global alignment reference, and calculate and compensate for the cumulative position deviation of the folded semi-finished product;

[0052] Generate a die compensation adjustment instruction based on the cumulative position deviation, adjust the position of the shape die-cutting die, control the cutting contour of the shape die-cutting die to align with the target area on the film material, and perform the overall shape punching of the shape die-cutting die according to the preset cutting contour to form a continuous diffusion film finished product.

[0053] Further, sorting out qualified products and defective products includes:

[0054] According to the requirements of the finished product single-piece size, preset the cutting interval and cutting length of the cutting knife;

[0055] Transport the continuous diffusion film finished product to the cutting station, perform fixed-length automatic cutting according to the preset cutting interval and cutting length of the cutting knife, and separate to obtain independent single-piece finished products;

[0056] Obtain the position data of the mouth-shaped adhesive, the external dimension data, and the film body appearance image data of the single-piece finished product respectively;

[0057] Compare the position data of the mouth-shaped adhesive and the external dimension data with the drawing standard parameters respectively, and at the same time compare the film body appearance image data with the standard sample drawing, and sequentially judge whether the double-sided mouth-shaped adhesive alignment accuracy, the product size, the film body state, and the integrity of the release paper are qualified;

[0058] When the detection determines that it is a qualified product, it is transferred to the packaging process. When the detection determines that it is a defective product, it is separately sorted, marked, and the type of defect is recorded.

[0059] Compared with the prior art, the beneficial effects of the present invention are:

[0060] 1. This invention simultaneously creates two parallel die-cutting cavities for the letterform adhesive on an integrated composite die, and adds a line-filtering cutter at the center point between the two sets of adhesive pieces. Combined with two independent adhesive application mechanisms operating synchronously, the two parallel letterform adhesive pieces are bonded and die-cut on the release paper in a single operation, while simultaneously pressing out the center crease baseline. This solution, through subsequent folding, positions the two letterform adhesive pieces on opposite sides of the diffusion film, eliminating the need for secondary positioning. This completely solves the technical bottleneck of traditional processes that only allow single-sided adhesive application and require two positioning steps for double-sided application, improving the relative positional accuracy and production efficiency of the double-sided letterform adhesive. It provides a feasible continuous production solution for the double-sided adhesive structure of the diffusion film.

[0061] 2. This invention adds a modified folding pressure roller module to the laminating machine, and combines it with the crease reference line generated by the dotted line knife at the center of the die to achieve directional folding and pressing. During die installation, ensure that the horizontal and vertical directions are 90 degrees and on the same parallel line to eliminate tilting errors; during die cutting, press continuous crease lines on the release paper at the center of the two sets of adhesive strips in a half-cut manner, without cutting the film body; then, fold along the crease reference line using the folding pressure roller, causing the release paper on the half containing the reverse adhesive to flip, pressing the reverse adhesive onto the other side of the diffusion film, while the front adhesive remains bonded to the original bonding surface of the diffusion film, effectively avoiding film tearing during folding and ensuring accurate bonding position and uniform pressing of the double-sided adhesive strips.

[0062] 3. This invention forms a complete continuous roll-to-roll production line, from slitting release paper, applying double adhesive side-by-side, first die-cutting, applying diffusion film (single-sided), folding and pressing, die-cutting the outer shape, to cutting and inspecting the finished product. During production, the front end ensures the release paper feed is straight and without S-shaped deviation through correction; before die-cutting, the parallelism and perpendicularity of the die are calibrated; when applying the diffusion film, the original release film of the reverse side of the lettering adhesive is retained to prevent mis-adhesion; finally, after cutting, the double-sided lettering adhesive after folding is checked to ensure it meets the drawing requirements. This reduces the cumulative errors caused by manual handling and secondary positioning, significantly improving product consistency and yield. Furthermore, the status of each step can be recorded and traced, facilitating quality analysis and process optimization. Attached Figure Description

[0063] Figure 1 This is a flowchart of the double-sided lamination process of the diffusion film lettering adhesive of the present invention.

[0064] Figure 2 This is a schematic diagram of the integrated composite die-cutting module of the present invention. Detailed Implementation

[0065] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0066] Please see Figures 1-2 The present invention provides the following technical solutions:

[0067] The double-sided lamination process of diffusion film lettering adhesive includes:

[0068] The entire roll of release paper is fed into the automatic unwinding equipment. Based on the target product width parameters, the cutting size of the slitting machine and the feeding straightness threshold are preset. Based on the tension control system and photoelectric correction components, the release paper's trajectory data is collected in real time.

[0069] The material feeding trajectory data is compared with the preset feeding straightness threshold, the trajectory deviation value is calculated, and the S-shaped offset of the release paper is determined based on the trajectory deviation value.

[0070] When it is determined that there is an S-shaped deviation in the release paper, the action parameters of the photoelectric correction component are updated in real time based on the trajectory deviation value to continuously correct the release paper feeding posture.

[0071] Until the release paper feeding trajectory data is within the preset feeding straightness threshold and the straight feeding is maintained, the fixed width slitting operation is performed according to the preset slitting machine cutting size;

[0072] A slitting machine is used to slit the release paper that is conveyed in a straight line into strips of a fixed width. Substrate with S-shaped offset is removed to obtain standard width release paper substrate, which serves as the base carrier for subsequent adhesive bonding and die-cutting processes.

[0073] Two independent adhesive application mechanisms are started to operate synchronously, and two square-shaped adhesives, including front adhesive and back adhesive, are applied side by side to the upper surface of the standard width release paper substrate, with a preset gap between the two square adhesives; at the same time, the original release paper of the back adhesive is retained, that is, the temporary protective film on the surface of the back adhesive, to obtain a composite film material with double square adhesives.

[0074] The composite film material with double-sided adhesive is conveyed to the pre-assembled integrated composite die. The composite die is equipped with blades corresponding to the two adhesives and a central dotted line blade located at the center of the two blades. Based on the composite die, a punching action is performed to generate crease reference lines on the release paper at the center of the two sets of adhesives, thus obtaining a composite film material with creases.

[0075] Based on the preset product stacking requirements, a diffusion film is attached to the surface of the adhesive on the front side of the creased composite film material. At this time, the adhesive on the back side is still covered by the original release film and does not contact the diffusion film, thus obtaining the film material to be folded.

[0076] In this embodiment, the specific process of attaching the diffusion film includes:

[0077] According to the product stacking drawings, the bonding coordinates, bonding pressure and material conveying speed of the diffusion film are preset, the crease baseline position data and the position data of the letter-shaped adhesive are extracted, and the diffusion film is positioned in conjunction with the auxiliary film bonding mechanism.

[0078] Based on the positioning results, a diffusion film is attached to the surface of the single-sided adhesive of the crease-covered composite film. During the operation, the original release paper of the reverse adhesive is monitored in real time. If the release paper is detected to fall off, a stop warning is triggered in time.

[0079] After the diffusion film is laminated, the diffusion film lamination position data and the reverse adhesive release paper status data are synchronized to the rear folding pressure roller module for pressure and position matching in the folding process;

[0080] Using the crease baseline as a reference for folding, the folding pressure roller module is used to fold and press the film material to be folded in an orientation, so that the half of the release paper where the reverse adhesive is located is flipped along the crease line, pressing the reverse adhesive onto the other side of the diffusion film, while the front adhesive remains bonded to the original bonding surface of the diffusion film, thus obtaining a folded semi-finished product.

[0081] The folded semi-finished product is die-cut according to the preset product outline, and excess scrap is removed to obtain a continuous diffusion film. The diffusion film is then cut to a fixed length. Based on the single-sheet size requirements, the cutting interval and cutting length are preset. The continuous diffusion film is then transported to the cutting station, where it is automatically cut to a fixed length according to the preset cutting interval and cutting length to obtain individual finished products. Quality inspection is carried out through a combination of machine vision inspection and manual re-inspection, including checking the position of the lettering, the overall size, the film appearance, and the integrity of the release paper. Data on the position of the lettering, the overall size, and the film appearance of each finished product are obtained. The alignment accuracy of the double-sided lettering, the product size, the film condition, and the integrity of the release paper are judged sequentially to determine whether they are qualified. Based on the inspection results, qualified and defective products are sorted. Qualified products are transferred to the packaging and shipping process, while defective products are individually marked, and the defect type is recorded and retained.

[0082] In this embodiment, tension control and photoelectric correction components monitor and correct S-shaped offsets in real time to ensure the straightness of the film material after slitting. Two independent adhesive application mechanisms operate synchronously, applying two rectangular adhesives side-by-side to the release paper while retaining the original release film of the reverse adhesive to avoid adhesion and improve efficiency and positional accuracy. A single die-cutting station simultaneously completes the cutting of the two rectangular adhesives and the half-cut pressing of the center crease baseline, ensuring precise crease positioning without cutting the release paper. The diffusion film is positioned and applied based on the crease baseline. The release paper status is monitored in real time, and any abnormalities are detected. The system automatically stops the machine to prevent accidental adhesion; the bonding data is synchronized to the folding process to achieve parameter linkage; using the crease as the folding reference, a folding pressure roller module is used for directional pressing to ensure precise bonding of the double-sided lettering adhesive; the folding trajectory and pressure data are traceable, facilitating quality optimization; the overall shape die-cutting, fixed-length cutting, machine vision inspection, and manual re-inspection are integrated, automatically sorting qualified and defective products and recording the type of defect, achieving closed-loop quality control throughout the entire process; this improves the accuracy, efficiency, automation level, and product yield of the diffusion film double-sided lettering adhesive bonding.

[0083] In this embodiment, the step of applying lettering adhesive to the upper surface of the standard width release paper substrate includes:

[0084] Based on the dimensions and adhesion position tolerance standards of the square-shaped adhesive, the adhesive application coordinates, adhesive application pressure, and running speed parameters of two sets of independent adhesive application mechanisms are preset;

[0085] Based on the real-time acquisition of positioning mark position data on the upper surface of standard width release paper substrate by the vision positioning component, the positioning mark position data is compared with the preset adhesive application coordinates to determine whether the alignment accuracy of the adhesive application mechanism meets the bonding position tolerance standard.

[0086] When the alignment accuracy meets the bonding position tolerance standard, control the two sets of independent adhesive application mechanisms to operate synchronously, and apply the lettering adhesive, front adhesive and back adhesive to the upper surface of the standard width release paper substrate according to the preset spacing.

[0087] After the adhesive is applied, the original release paper with the adhesive on the reverse side is retained, resulting in a composite film material with double-sided adhesive.

[0088] The double-sided adhesive tape is applied at a position that corresponds one-to-one with the position of the subsequent die-cutting station, providing a precise alignment basis for the die-cutting process.

[0089] In this embodiment, the pre-assembled integrated composite die includes two symmetrically arranged sets of die-cutting cavities for the form-shaped adhesive, a central filtering cutter located at the center-to-center distance between the two sets of die-cutting cavities, and a positioning structure. The two sets of die-cutting cavities for the form-shaped adhesive and two independent adhesive application mechanisms are on the same travel axis, and the positioning structure is symmetrically arranged on both sides of the composite die.

[0090] Based on the preset reference axis according to the direction of release paper travel, install the composite die to the die-cutting station;

[0091] Using a laser alignment instrument or visual calibration component, the first angle between the transverse cutting edge line and the reference axis and the second angle between the longitudinal cutting edge line and the reference axis of the composite die are detected. The first angle and the second angle are compared with the preset 90° standard value, and the angle deviation is calculated.

[0092] When the angular deviation exceeds the allowable tolerance, the composite die is rotated or translated by the fine-tuning mechanism until both the lateral and longitudinal angles reach the preset standard value of 90° ±0.1°.

[0093] Meanwhile, a horizontal sensor is used to detect the height difference between each die-cutting station of the composite die and the equipment reference plane. When the height difference exceeds the threshold, the shims or bolts of the die mounting base are adjusted so that all die-cutting cavities are on the same horizontal reference plane.

[0094] After calibration, fix the composite die to ensure the accuracy of die-cutting and creasing positions, and achieve precise alignment with the two sets of independent adhesive application mechanisms at the front end;

[0095] In this embodiment, with the release paper travel direction as the X-axis, the film width direction as the Y-axis, and the film thickness direction as the Z-axis, the positional relationships of each component are defined as follows:

[0096] The release paper is laid flat on a horizontal surface and arranged side by side along the Y-axis. The front adhesive and the back adhesive are then attached side by side to the upper surface of the release paper, with a preset gap between the two adhesive strips.

[0097] The cut lines of the two sets of square-shaped die-cutting cavities are perfectly aligned in the Y-axis direction. The central dotted line cutter is located on the Y-axis centerline between the two sets of die-cutting cavities, and the half-cutting depth of the central dotted line cutter only acts on the release paper (without cutting the adhesive layer and the backing paper). The crease baseline is located on the upper surface of the release paper.

[0098] The diffusion film unwinding shaft is positioned above the release paper conveying path. After passing through the guide roller, the diffusion film is introduced along the negative Z-axis and comes into contact with and bonded to the front adhesive on the release paper at the bonding station.

[0099] After lamination, the diffusion film adheres to the surface of the adhesive on the front side and moves horizontally along the positive X-axis along with the release paper;

[0100] Using the crease line pressed out by the dotted line in the center as the boundary, the left half, including the release paper, front adhesive, and diffusion film, should remain horizontal and stationary.

[0101] The right half contains release paper, reverse adhesive and its original release film. It is flipped upward around the crease baseline at an angle of 180°, so that the reverse adhesive is pressed downward onto the upper surface of the diffusion film, thus completing the double-sided adhesive application.

[0102] In this embodiment, generating the crease baseline specifically includes:

[0103] Based on the standard parameters of the finished product dimensions and crease depth of the embossed adhesive, the pressing stroke, cutting contour parameters and half-cutting depth parameters of the integrated composite die are preset. The center line cutter cuts into half the thickness of the release paper substrate without cutting the release paper, but only pressing continuous crease lines as the reference for subsequent mechanical folding.

[0104] During the operation, the pressing displacement data of the composite die is acquired in real time based on the die-cutting sensor. The pressing displacement data is compared with the preset pressing stroke in real time to determine the execution progress and positioning status of the composite die.

[0105] When the composite die reaches the preset pressing stroke, the two sides of the die-cutting cavity simultaneously perform cutting operations to remove excess glue edges. The composite film material is then partially cut by the center line cutter, generating crease baselines on the release paper at the center of the two sets of glue.

[0106] In this embodiment, the horizontal and vertical angles of the die-cutting mold are precisely calibrated using a laser / visual calibration and fine-tuning mechanism. A horizontal sensor is used to adjust each die-cutting cavity to the same horizontal reference plane, eliminating die-cutting position errors caused by die installation misalignment and ensuring precise alignment with the front-end adhesive applicator. Simultaneously, the die-cutting sensor monitors the pressing stroke in real time to ensure proper cutting. The central crease cutter cuts at half the thickness, forming continuous crease lines without cutting the release paper. The two sets of rectangular adhesive die-cutting cavities cut synchronously, removing excess adhesive edges and improving die-cutting efficiency and crease position consistency.

[0107] In this embodiment, the specific process of directional folding and pressing of the folding pressure roller module is as follows:

[0108] Obtain the actual angle deviation data after parallel calibration of the composite die, and dynamically correct the preset standard folding center line based on the actual angle deviation data to eliminate the influence of residual die installation error on folding accuracy;

[0109] Based on the crease baseline position data and the state data of the back adhesive release paper, the folding angle, pressing pressure, folding travel speed and lateral alignment deviation threshold of the pressing roller module are preset;

[0110] The folding pressure roller module includes a first-stage guide roller and a second-stage pressing roller, and the preset folding angle includes a first folding angle and a second folding angle.

[0111] The film material to be folded is transported to the inlet of the folding pressure roller module, and the actual travel trajectory of the folding baseline is obtained in real time. The actual travel trajectory of the folding baseline is compared with the preset standard folding center line, and the lateral offset and angular deflection are calculated.

[0112] When the lateral offset or angular deflection exceeds the preset alignment deviation threshold, a lateral adjustment command for the folding pressure roller module or an angle correction command for the first-stage guide roller is generated. Adjustments are made based on the lateral adjustment command and the angle correction command, and the relative position of the pressure roller and the film material is continuously updated until the crease baseline coincides with the standard folding center line.

[0113] Based on the preset folding angle, the first-stage guide wheel moves and lifts the film material to be folded upward along the fold line, causing the release paper on the half where the reverse adhesive is located to start to flip upward and separate from the side where the front adhesive and diffusion film are located, until the preset first folding angle is reached, so that the side of the film material to be folded with the diffusion film attached begins to rotate and separate relative to the other side.

[0114] The folding angle and tearing condition of the folding reference line of the film material to be folded are monitored in real time. When it is determined that there is no abnormal tearing at the folding reference line and the folding angle reaches the preset first folding angle, a secondary folding signal is generated.

[0115] Based on the secondary folding signal, the second-stage pressing roller is controlled to fold the film material to be folded to the preset second folding angle according to the preset pressing pressure and folding travel speed. This causes the reverse adhesive to flip over with the release paper to the other side of the diffusion film and press the reverse adhesive onto the surface of the diffusion film under the preset pressure, while the front adhesive remains bonded to the original bonding surface of the diffusion film.

[0116] The pressing pressure value is detected in real time. When the pressing pressure value reaches the preset pressure threshold and remains stable, a pressing completion signal is generated, and the actual pressing trajectory data is recorded.

[0117] During the folding and pressing action, real-time pressure data of the first-stage guide wheel and the second-stage pressing wheel in the folding and pressing wheel module are collected in real time based on the online pressure sensor array;

[0118] The real-time pressure data is compared one by one with the pressure standard value at the corresponding time point in the preset standard pressure curve, the pressure deviation value is calculated, and the pressure deviation value is used to determine whether there is uneven compression caused by excessive or insufficient local pressure.

[0119] When uneven pressing is detected, a corresponding pressure adjustment command is generated based on the pressure deviation value distribution data, and the pressure output parameters of the subsequent first-stage guide wheel and second-stage pressing wheel are updated in real time based on the pressure adjustment command.

[0120] After folding, the actual folding and pressing trajectory data, real-time pressure data, and pressure deviation value distribution data are synchronized to the machine vision inspection stage for correlation analysis with the final product inspection results. When subsequent inspections discover batch defects caused by folding issues, the preset action parameters in this process are traced and updated based on the correlation analysis results.

[0121] In this embodiment, based on the bonding area, adhesive layer thickness, and required pressing strength of the adhesive, a preset standard pressure curve was calculated using a mechanical model, and the standard pressure values ​​at different time points were recorded:

[0122]

[0123] In the formula, for The standard pressure value corresponding to the preset standard pressure curve is used to compare with the real-time pressure data collected by the online pressure sensor and calculate the pressure deviation value. The preset target pressing pressure; This is the pressing time, used to locate the corresponding time point on the standard pressure curve; The pressure rise time constant is related to the material's elastic modulus and the adhesive layer thickness. During the pressing process, an online pressure sensor array collects real-time pressure data from the first-stage guide wheel and the second-stage pressing wheel, and compares this data with the corresponding time points in the formula. The system compares and calculates the pressure deviation value to determine if there is uneven pressing. When the deviation exceeds the threshold, a pressure adjustment command is generated to update the pressure output parameters of the pressure roller in real time.

[0124] In this embodiment, the folding center line is dynamically corrected by acquiring the parallel calibration data of the composite die-cutting mold, eliminating the impact of residual die-cutting mold installation errors on folding accuracy; the folding baseline trajectory is compared in real time and automatically corrected to ensure accurate folding positioning; the first-stage guide wheel and the second-stage pressing wheel are used for graded folding to effectively avoid film tearing; the pressure distribution is monitored in real time by an online pressure sensor and compared with a standard pressure curve, and the pressure of subsequent pressing wheels is adjusted in time when uneven pressing is detected to ensure uniform bonding of the double-sided lettering adhesive; at the same time, the folding trajectory and pressure data are synchronized to the detection stage to achieve quality traceability and parameter self-optimization, thereby improving folding consistency, product yield, and process stability.

[0125] In this embodiment, the overall shape die-cutting specifically includes:

[0126] Extract the width parameters, double-sided adhesive label position data, composite die horizontal reference surface data and crease reference line position data, and fuse them to generate a global alignment reference for the shape die-cutting station. Then, set the cutting contour, pressing stroke and punching force parameters of the shape die-cutting die according to the product shape drawing.

[0127] After the folded semi-finished product is transported to the shape die-cutting station, the visual positioning component is used to identify the crease baseline on the folded semi-finished product. Based on the identification result, a second comparison is made with the global alignment baseline to calculate and compensate for the cumulative position deviation generated during the movement of the folded semi-finished product.

[0128] Based on the cumulative position deviation, a die-cutting die compensation adjustment command is generated to adjust the position of the outer die-cutting die, control the cutting contour of the outer die-cutting die to align with the target area on the membrane material, and perform overall outer die-cutting according to the preset cutting contour to remove the waste material at the edges of the membrane material, so that each independent finished product is separated in the width direction of the membrane material, while retaining the longitudinal continuous carrier edge of the membrane material to form a continuous diffusion membrane finished product.

[0129] In the above embodiments, a global alignment benchmark is generated by integrating data from multiple processes such as slitting, adhesive application, and die-cutting. Combined with visual positioning, secondary comparison and dynamic compensation are performed, which significantly eliminates the cumulative positional deviation during the film material's movement, improves die-cutting accuracy and finished product consistency. The die position can be finely adjusted in real time to ensure that the cutting outline is precisely aligned with the target area. The longitudinal carrier edge is retained after punching, which ensures the stability of continuous production, reduces edge waste and defect rate, and improves production efficiency and product yield.

[0130] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A double-sided lamination process for diffusion film lettering adhesive, characterized in that, include: The entire roll of release paper is fed into an automatic unwinding device, and the release paper, which is conveyed in a straight line, is slit into strips of a fixed width to obtain standard width release paper substrate. Two independent adhesive applicator mechanisms are activated to operate synchronously, applying letter-shaped adhesive, including front and back adhesive, at preset intervals on the upper surface of the standard width release paper substrate, while retaining the original release paper with the back adhesive, thus obtaining a composite film material with double letter-shaped adhesive. The composite membrane material with double-sided adhesive is fed to a pre-assembled integrated composite die. The die is used for punching, and a crease baseline is generated at the center of the two sets of adhesive to obtain a composite membrane material with creases. Based on the preset product stacking requirements, a diffusion film is bonded to the surface of the adhesive on the front of the creased composite film to obtain the film material to be folded. Using the crease reference line as a reference, the film material to be folded is folded and pressed in an oriented manner, so that the half of the release paper where the reverse adhesive is located is flipped along the crease reference line, and the reverse adhesive is pressed onto the other side of the diffusion film, resulting in a folded semi-finished product with the square adhesive on both sides. The folded semi-finished product is die-cut into its overall shape according to the preset product outline to obtain the diffusion film finished product. The diffusion film finished product is then cut into fixed length pieces and quality inspected to sort out qualified and defective products.

2. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 1, characterized in that, Before the fixed-width stripping, the following is also included: Based on the target product width parameters, the cutting size and feeding straightness threshold of the slitting machine are preset, and the release paper's trajectory data is collected in real time based on the tension control system and photoelectric correction components. The material feeding trajectory data is compared with the preset feeding straightness threshold, the trajectory deviation value is calculated, and the release paper is judged to have an S-shaped offset based on the trajectory deviation value. When it is determined that there is an S-shaped deviation in the release paper, the action parameters of the photoelectric correction component are updated in real time based on the trajectory deviation value to continuously correct the release paper feeding posture. Once the release paper feeding trajectory data is within the preset feeding straightness threshold and the straight feeding is maintained, the fixed-width slitting operation is performed according to the preset slitting machine cutting size.

3. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 1, characterized in that, The step of applying lettering adhesive to the upper surface of a standard width release paper substrate includes: Based on the dimensions and adhesion position tolerance standards of the square-shaped adhesive, the adhesive application coordinates, adhesive application pressure, and running speed parameters of two sets of independent adhesive application mechanisms are preset; Based on the real-time acquisition of positioning mark position data on the upper surface of standard width release paper substrate by the vision positioning component, the positioning mark position data is compared with the preset adhesive application coordinates to determine whether the alignment accuracy of the adhesive application mechanism meets the bonding position tolerance standard. When the alignment accuracy meets the bonding position tolerance standard, control the two sets of independent adhesive application mechanisms to operate synchronously and apply the lettering adhesive to the upper surface of the standard width release paper substrate according to the preset spacing. After the adhesive is applied, the original release paper with the adhesive on the reverse side is retained, resulting in a composite film material with double-sided adhesive.

4. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 1, characterized in that, The pre-assembled integrated composite die includes two sets of three-dimensional die-cutting cavities, a central screw cutter, and a positioning structure. Based on the preset reference axis according to the direction of release paper travel, install the composite die to the die-cutting station; The first angle between the transverse cutting edge line and the reference axis and the second angle between the longitudinal cutting edge line and the reference axis of the composite die are detected. The first angle and the second angle are compared with the preset standard values ​​respectively, and the angle deviation is calculated. When the angular deviation exceeds the allowable tolerance, the composite die is moved until both the lateral and longitudinal angles reach the preset standard values. At the same time, the height difference between each die-cutting station of the composite die and the equipment reference plane is detected. When the height difference exceeds the threshold, the shims of the die mounting base are adjusted so that all die-cutting cavities are on the same horizontal reference plane.

5. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 4, characterized in that, The generation of the crease baseline specifically includes: Based on the standard parameters of the finished product dimensions and crease depth of the square-shaped adhesive, the pressing stroke, cutting contour parameters and center line cutter half-cut depth parameters of the integrated composite die are preset; During the operation, the pressing displacement data of the composite die is acquired in real time based on the die-cutting sensor. The pressing displacement data is compared with the preset pressing stroke in real time to determine the execution progress and positioning status of the composite die. When the composite die reaches the preset pressing stroke, the two sides of the die-cutting cavity of the letterform simultaneously perform cutting operations, and the composite film material is partially cut by the center line cutter, generating crease baselines on the release paper at the center of the two sets of letterforms.

6. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 5, characterized in that, The specific process of bonding the diffusion film includes: The bonding coordinates, bonding pressure, and material conveying speed of the diffusion film are preset, and the crease baseline position data and the position data of the letter-shaped adhesive are extracted. The diffusion film is then positioned in conjunction with the auxiliary film bonding mechanism. Based on the positioning results, a diffusion film is bonded to the adhesive surface of the creased composite film. During the operation, the status of the release paper on the adhesive surface of the reverse side is monitored in real time. If the release paper is detected to fall off, a stop warning is triggered in time. After the diffusion film is laminated, the diffusion film lamination position data and release paper status data are synchronized to the rear folding pressure roller module.

7. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 6, characterized in that, The specific process for directional folding and pressing of the folding pressure roller module is as follows: Obtain the actual angular deviation data after parallel calibration of the composite die, and dynamically correct the preset standard folding center line based on the actual angular deviation data; Based on the crease baseline position data and the state data of the reverse adhesive release film, the folding angle, pressing pressure, folding travel speed and lateral alignment deviation threshold of the pressing roller module are preset; The folding pressure roller module includes a first-stage guide roller and a second-stage pressing roller, and the preset folding angle includes a first folding angle and a second folding angle. The actual trajectory of the crease baseline is acquired in real time, and the actual trajectory of the crease baseline is compared with the preset standard fold center line to calculate the lateral offset and angular deflection. When the lateral offset or angular deflection exceeds the preset alignment deviation threshold, a lateral adjustment command or an angle correction command is generated. Adjustments are made based on the lateral adjustment command and the angle correction command until the crease baseline coincides with the standard fold center line. The first-stage guide wheel is controlled by the preset folding angle. The first-stage guide wheel lifts the film material to be folded upward along the fold line until the preset first folding angle is reached. The folding angle and tearing condition of the folding reference line of the film material to be folded are monitored in real time. When it is determined that there is no abnormal tearing at the folding reference line and the folding angle reaches the preset first folding angle, a secondary folding signal is generated. Based on the secondary folding signal, control the operation of the second-stage pressing wheel. The second-stage pressing wheel folds the to-be-folded film material to a preset second folding angle according to the preset pressing pressure and folding traveling speed, so that the reverse side glue is flipped to the other side of the diffusion film along with the release paper, and the reverse side glue is pressed onto the surface of the diffusion film under the preset pressure, while the front side glue remains adhered to the original bonding surface of the diffusion film; Real-time detect the pressing pressure value, and generate a pressing completion signal when the pressing pressure value reaches the preset pressure threshold.

8. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 7, characterized in that, The performing of the directional folding and pressing further includes: During the execution of the folding and pressing operation, real-time collect the real-time pressure data of the first-stage guiding wheel and the second-stage pressing wheel in the folding and pressing wheel module; Compare the real-time pressure data with the pressure standard value at the corresponding time point in the preset standard pressure curve, calculate the pressure deviation value, and judge whether there is uneven pressing according to the pressure deviation value; When it is determined that there is uneven pressing, generate a corresponding pressure adjustment instruction according to the pressure deviation value distribution data.

9. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 1, characterized in that, The overall shape die-cutting specifically includes: Extract the width parameter, the position data of the double-sided mouth-shaped glue, the horizontal reference plane data of the composite die, and the position data of the crease reference line, fuse them to generate the global alignment reference for the shape die-cutting station, and set the cutting contour, the downward stroke, and the punching force parameters of the shape die-cutting tool; Identify the crease reference line on the semi-finished product of the对折成型 (it seems there is a misspelling here, it might be "double-fold forming"), and based on the recognition result and the global alignment reference, perform a secondary comparison, calculate and compensate for the cumulative position deviation of the semi-finished product of the double-fold forming; Generate a tool compensation adjustment instruction based on the cumulative position deviation, adjust the position of the shape die-cutting tool, control the cutting contour of the shape die-cutting tool to align with the target area on the film material, and perform the overall shape punching of the shape die-cutting tool according to the preset cutting contour to form a continuous diffusion film finished product.

10. The double-sided lamination process of the diffusion film lettering adhesive as described in claim 9, characterized in that, Sort out the qualified products and defective products, including: According to the requirements of the finished product single-piece size, preset the cutting interval and cutting length of the cutting knife; Transport the continuous diffusion film finished product to the cutting station, perform fixed-length automatic cutting according to the preset cutting interval and cutting length of the cutting knife, and separate to obtain independent single-piece finished products; Respectively obtain the position data of the mouth-shaped glue, the external dimension data, and the film body appearance image data of the single-piece finished product; Compare the position data of the mouth-shaped glue and the external dimension data with the drawing standard parameters respectively, and at the same time compare the film body appearance image data with the standard sample drawing, and sequentially judge whether the alignment accuracy of the double-sided mouth-shaped glue, the product size, the film body state, and the integrity of the release paper are qualified; When the detection determines that it is a qualified product, transfer it to the packaging process. When the detection determines that it is a defective product, separately sort, label, and record the defective type.

Images