PVC panel double-sided laminating machine

Abstract

This invention relates to the field of film laminating equipment technology, and provides a double-sided film laminating machine for PVC panels, including a frame, a conveying mechanism, a first film feeding mechanism, a second film feeding mechanism, a pressing mechanism, and an intelligent control system. The first and second film feeding mechanisms are disposed outside a sealed cover and are used to supply the first and second film layers to the top and bottom of the PVC substrate, respectively. The sealed cover is fixedly connected to the frame. A pair of freely rotatable sealing rollers are respectively provided at the inlet and outlet ends of the sealed cover. In this invention, the pressing mechanism uses a fluid pressure drive system instead of the traditional spring pressure method. The fluid pressure drive system can provide precise, stable, and dynamically adjustable pressing pressure, ensuring that the pressing stress applied by the upper and lower pressing roller groups on the wide sheet material is uniform.

Description

Technical Field

[0001] This invention belongs to the field of film application equipment technology, and in particular relates to a double-sided film application machine for PVC panels. Background Technology

[0002] PVC laminated panels are layered composite panels made of polyvinyl chloride (PVC) sheets as the base layer, with decorative films, protective films, etc., laminated on both sides. They are widely used in building decoration, furniture manufacturing, transportation, and other fields. PVC, as a general-purpose thermoplastic, has advantages such as high strength, good weather resistance, and chemical corrosion resistance, making it an ideal base material for preparing composite panels.

[0003] Currently, the mainstream technology for applying films to PVC substrates is the coating method: the film is adhered to the substrate surface through adhesive application and roller pressing. This type of technology is essentially a surface covering process, focusing only on the film layer "attaching" to the outer surface of the board. The interlayer bonding strength depends on the adhesive, and the pressing is carried out in open atmosphere, making it impossible to expel interlayer air, which easily leads to defects such as bubbles, delamination, and edge lifting. Specifically, existing film-applying devices have the following drawbacks: Firstly, spring pressure is commonly used, and the pressure changes non-linearly with the displacement of the pressing roller, resulting in uneven pressing stress on wide plates and poor bonding strength between the film and the substrate. Secondly, the lack of a vacuum pressing environment, although there are occasional sealed covers, the inlet and outlet ends use mechanical seals, which are easy to wear and scratch the film layer, and cannot maintain negative pressure for a long time. At the same time, the substrate is pushed to the pressing roller by the conveying mechanism throughout the process. After the substrate is engaged, there is no power transfer logic. If the conveying mechanism continues to push, it will easily cause the substrate to accumulate or deform. Furthermore, the film layer's own tension is not used to participate in the sealing, resulting in poor reliability. Third, the vacuum level adjustment and the pressing pressure adjustment are independent of each other, lacking a coordinated control mechanism based on multiple variables such as conveying speed and substrate thickness. This makes it difficult to adapt to products of different specifications and ensure the consistency of composite quality.

[0004] In summary, guided by traditional surface coating processes, the technical path of upgrading double-sided lamination to "multi-layer material synchronous lamination" has long been neglected. This invention provides an improved PVC panel double-sided lamination machine that transforms the lamination process into a controllable layered material lamination process, significantly improving interlayer bonding quality and product consistency. Summary of the Invention

[0005] The purpose of this invention is to provide a double-sided film application machine for PVC panels, which aims to solve the above-mentioned problems.

[0006] The present invention is implemented as follows: a double-sided PVC panel laminating machine includes a frame, a conveying mechanism, a first film feeding mechanism, a second film feeding mechanism, a pressing mechanism, and an intelligent control system. The first and second film feeding mechanisms are disposed outside the sealing cover and are used to supply the first film layer and the second film layer to the top and bottom of the PVC substrate, respectively. The sealing cover is fixedly connected to the frame. The inlet and outlet ends of the sealing cover are respectively provided with a pair of freely rotatable sealing rollers. The first film layer and the second film layer bypass the sealing rollers at the inlet end and enter the interior of the sealing cover, and the air passage at the sealing rollers is sealed by the tension of the film layers themselves. The pressing mechanism is located inside the sealing cover and includes an upper pressing roller group, a lower pressing roller group, and a fluid pressure driving system. The upper pressing roller group and the lower pressing roller group are arranged opposite to each other and a pressing gap is formed between them. The conveying mechanism is located outside the sealing cover and is used to push the PVC substrate unidirectionally to the feed end. Its initial pushing speed is the same as the film conveying speed. When the PVC substrate enters the interior of the sealing cover and is bitten by the upper and lower pressing roller groups through the pressing gap, the PVC substrate moves together with the film. The conveying mechanism no longer applies a pushing force to the PVC substrate to complete the power transfer. The intelligent control system is communicatively connected to the conveying mechanism, the vacuum pumping device, and the fluid pressure drive system. It is used to switch the acquisition source of the substrate speed before and after the power handover, and to coordinately adjust the negative pressure in the sealed cover and the output pressure of the fluid pressure drive system based on the real-time acquired conveying speed and substrate thickness.

[0007] In a further technical solution, the intelligent control system collects the real-time operating speed of the conveying mechanism as the substrate conveying speed before the power handover is completed; after the power handover is completed, it switches to simultaneously collecting the real-time rotational speeds of the drive motors of the upper and lower pressing roller groups, and takes the average of the two as the substrate conveying speed; both the first and second film-laying mechanisms are equipped with tension controllers, which are controlled by the intelligent control system to maintain constant tension of the first and second film layers during the process of entering the sealing cover when the substrate conveying speed is dynamically fine-tuned.

[0008] A further technical solution involves the intelligent control system incorporating a dimensionless preprocessing module. This module converts the collected real-time conveying speed and the real-time thickness of the PVC substrate into dimensionless parameters. The conversion formula is as follows: The dimensionless speed parameter is equal to the quotient obtained by dividing the real-time conveying speed by the rated design speed of the equipment, and the quotient is limited to the range of 0.1 to 2.0. The dimensionless thickness fluctuation rate is equal to the difference between the real-time collected thickness and the rated design thickness, divided by the rated design thickness, and the quotient is limited to the range of -0.3 to 0.3.

[0009] A further technical solution includes a dynamic vacuum degree calculation module in the intelligent control system. This module receives the dimensionless velocity parameter and the dimensionless thickness fluctuation rate, and calculates the target dimensionless vacuum degree. The specific calculation method is as follows: First, multiply the rated design speed of the equipment by the dimensionless speed parameter, then multiply by the system response time constant of the vacuum pumping device, and add a minimal constant with an undefined denominator to prevent the speed from approaching zero, to obtain the speed-time term; The quotient obtained by dividing the speed-time term by the effective length of the sealed cover, the sum of 1 and the absolute value of the dimensionless thickness fluctuation rate, and then multiplying the above quotient to obtain an intermediate quantity; multiplying this intermediate quantity by the gas dissipation coefficient of the material surface, and taking the negative value of the product, the exponential function value is calculated with the natural constant e as the base; finally, subtracting the exponential function value from 1, the target dimensionless vacuum degree is obtained.

[0010] In a further technical solution, the intelligent control system also includes a coupled fluid pressure calculation module. This module receives the target dimensionless vacuum degree and outputs the target fluid pressure acting on the fluid pressure drive system. The specific calculation method is as follows: The elastic modulus of the first film layer is multiplied by the thickness of the first film layer to obtain the first product, and the elastic modulus of the second film layer is multiplied by the thickness of the second film layer to obtain the second product. The first product and the second product are added together to obtain the sum, and the sum is then divided by the product of twice the reference pressure and the radius of the pressing roller group to obtain the comprehensive elastic stiffness term of the film layer. The sum of 1 plus the velocity-strain coupling coefficient multiplied by the dimensionless velocity parameter is used as the velocity-strain coupling correction term; the dimensionless thickness fluctuation rate is used as the exponent, and the exponential function value is calculated with the natural constant e as the base, which is used as the thickness fluctuation exponential correction term. The target dimensionless vacuum degree is multiplied by the film layer comprehensive elastic stiffness term, the velocity-strain coupling correction term, and the thickness fluctuation index correction term to obtain the sum term; the reference pressure is multiplied by this sum term to obtain the target fluid pressure output to the fluid pressure drive system.

[0011] In a further technical solution, the conveying mechanism is a pair of relatively rotatable electric conveying rollers, and the fixed seats of the pair of electric conveying rollers are fixedly connected to the frame.

[0012] In a further technical solution, both the first film feeding mechanism and the second film feeding mechanism include electric rollers. The fixed base of the electric rollers is fixedly connected to the frame. The film layer wrapped on it is fed by the rotation of the electric rollers. A guide roller is also rotatably connected to the frame on the discharge end side of the sealing cover. The guide roller is used to guide the laminated PVC panel to be stably discharged.

[0013] In a further technical solution, the fluid pressure drive system includes a hydraulic cylinder, the piston rod of which is connected to the roller seat of the upper pressing roller group to provide downward dynamic pressing pressure to the upper pressing roller group.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, the pressing mechanism uses a fluid pressure drive system instead of the traditional spring pressing method. The fluid pressure drive system can provide precise, stable and dynamically adjustable pressing pressure, ensuring that the pressing stress applied by the upper and lower pressing roller groups on the wide sheet material is uniform and consistent, thereby significantly enhancing the interlayer bonding strength between the film layer and the PVC substrate.

[0015] In this invention, the intelligent control system can switch the acquisition source of the substrate speed according to different stages before and after power handover. Based on the real-time acquired conveying speed and substrate thickness, it coordinates the negative pressure inside the sealed enclosure and the output pressure of the fluid pressure drive system through its built-in dimensionless preprocessing module, dynamic vacuum degree solving module, and coupled fluid pressurization calculation module. This multi-variable coordinated control mechanism enables the equipment to adapt to different product specifications and operating conditions, significantly improving the consistency of film application quality and process adaptability.

[0016] This invention establishes a coordinated control mechanism for vacuum degree and pressing pressure through an intelligent control system. The system's built-in dynamic vacuum degree calculation module receives dimensionless velocity parameters and dimensionless thickness fluctuation rates, comprehensively considering multiple factors such as the effective length of the sealing cover, the response time constant of the vacuum pump system, and the gas dissipation coefficient of the material surface, to calculate the target dimensionless vacuum degree in real time. Simultaneously, the coupled fluid pressure calculation module further couples the target dimensionless vacuum degree with parameters such as the film elastic modulus, film thickness, roller radius, and velocity-strain coupling coefficient, accurately outputting the target fluid pressure acting on the fluid pressure drive system. This coordinated control mechanism ensures that vacuum degree and pressing pressure are no longer independent adjustment variables, but rather are optimized in conjunction based on real-time conveying speed and substrate thickness fluctuations. When the conveying speed changes, the system automatically adjusts the vacuum degree to match the substrate's residence time within the sealing cover; when the substrate thickness fluctuates, the system synchronously corrects the pressing pressure to maintain uniform pressing stress. This multi-variable collaborative control method breaks through the technical limitations of independent vacuum regulation and pressure regulation in traditional film application equipment, significantly improving the equipment's adaptability to different product specifications and dynamic working conditions, and ensuring the consistency of film application quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram showing the connection between the sealing cover and the sealing roller in this invention; Figure 3 This is a schematic diagram showing the connection between the sealing cover and the pressing mechanism in this invention; Figure 4 This is a schematic diagram showing the connection between the upper pressure roller assembly and the hydraulic cylinder; Figure 5 This is a logic block diagram of the communication connection of the intelligent control system. Figure 6 Logic block diagram of the dynamic vacuum degree solving module; Figure 7 Logic block diagram for the coupled fluid pressure measurement module.

[0018] In the attached diagram: 1. Frame; 2. Conveying mechanism; 3. First film feeding mechanism; 4. Second film feeding mechanism; 5. Pressing mechanism; 51. Upper pressing roller group; 52. Lower pressing roller group; 53. Hydraulic cylinder; 6. Sealing cover; 7. Sealing roller; 8. Vacuuming device; 9. Guide roller. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0021] like Figures 1-7 As shown, a PVC panel double-sided laminating machine provided in an embodiment of the present invention includes a frame 1, a conveying mechanism 2, a first film feeding mechanism 3, a second film feeding mechanism 4, a pressing mechanism 5, and an intelligent control system. The first film feeding mechanism 3 and the second film feeding mechanism 4 are disposed outside the sealing cover 6 and are used to supply the first film layer and the second film layer to the upper and lower surfaces of the PVC substrate, respectively. The sealing cover 6 is fixedly connected to the frame 1. The inlet and outlet ends of the sealing cover 6 are respectively provided with a pair of freely rotatable sealing rollers 7. The first film layer and the second film layer pass around the sealing rollers 7 at the inlet end and enter the interior of the sealing cover 6, and the air passage at the sealing rollers 7 is sealed by the tension of the film layer itself. The pressing mechanism 5 is located inside the sealing cover 6 and includes an upper pressing roller group 51, a lower pressing roller group 52 and a fluid pressure driving system. The upper pressing roller group 51 and the lower pressing roller group 52 are arranged opposite to each other and a pressing gap is formed between them. The conveying mechanism 2 is located outside the sealing cover 6 and is used to push the PVC substrate unidirectionally to the feeding end. Its initial pushing speed is the same as the film conveying speed. When the PVC substrate enters the sealing cover 6 and is bitten by the upper pressing roller group 51 and the lower pressing roller group 52 through the pressing gap, the PVC substrate moves together with the film and the conveying mechanism 2 no longer applies a pushing force to the PVC substrate to complete the power transfer. The intelligent control system is communicatively connected to the conveying mechanism 2, the vacuum device 8, and the fluid pressure drive system. It is used to switch the acquisition source of the substrate speed before and after the power handover, and to coordinately adjust the negative pressure in the sealing cover 6 and the output pressure of the fluid pressure drive system based on the real-time acquired conveying speed and substrate thickness.

[0022] In this embodiment, the frame 1 is the supporting structure of the entire device, used to fix and install various functional modules, ensuring the stable operation of the device and the precise alignment of each component.

[0023] The conveying mechanism 2 is responsible for pushing the PVC substrate to be laminated unidirectionally from the feeding end to the lamination area. Its initial pushing speed needs to be consistent with the film layer conveying speed to achieve smooth feeding. The first film-laying mechanism 3 and the second film-laying mechanism 4 are used to supply the first film layer and the second film layer to the top and bottom of the PVC substrate, respectively. These mechanisms typically include a film roll support and a film-laying roller, and the film layer is released by controlling the rotation of the film roll.

[0024] The pressing mechanism 5 is a key component for bonding the film layer to the substrate. It applies pressure to tightly bond the film layer to the substrate and expel air from the interface. The intelligent control system is the core of the equipment, responsible for monitoring the equipment's operating status, collecting key parameters, and coordinating the adjustment of each actuator according to preset logic or algorithms to optimize the film application process and product quality. The sealing cover 6 is fixedly connected to the frame 1 to isolate the film application area from the external environment, thereby creating a controllable microenvironment, such as a negative pressure environment.

[0025] The sealing roller 7 is located at the feed end and discharge end of the sealing cover 6. It can rotate freely, allowing the substrate and film to pass through, while achieving dynamic sealing of the air channel through the tension of the film itself.

[0026] The upper pressing roller group 51 and the lower pressing roller group 52 are the main components of the pressing mechanism 5. They are arranged opposite each other and form a pressing gap between them to apply pressing force to the substrate and film layer that are passing through.

[0027] The fluid pressure drive system is used to provide precise and controllable pressing pressure to the pressing mechanism 5, which is usually achieved through a hydraulic or pneumatic system to ensure uniform adhesion between the film layer and the substrate.

[0028] The PVC substrate is the main material to be coated with the film, and it is usually a rectangular plate structure. The first and second film layers are materials that are laminated onto the upper and lower surfaces of the PVC substrate, and can be decorative films, protective films, or other functional film layers.

[0029] The pressing gap is a narrow space formed between the upper pressing roller group 51 and the lower pressing roller group 52, through which the PVC substrate and the film layer are pressed together.

[0030] The power transfer refers to the process of switching the driving force source of the PVC substrate from the conveying mechanism 2 to the pressing mechanism 5. This process needs to be smooth to avoid damage to the substrate and film.

[0031] Negative pressure refers to the state where the air pressure inside the sealing cover 6 is lower than the external atmospheric pressure, which helps to expel the air between the film layer and the substrate and reduce the residual air bubbles.

[0032] Output pressure refers to the pressure applied to the pressing mechanism 5 by the fluid pressure drive system, which directly affects the tightness of the adhesion between the film and the substrate.

[0033] Specifically, firstly, the PVC substrate is placed on the conveying mechanism 2. The conveying mechanism 2 is activated, pushing the PVC substrate unidirectionally to the feed end of the sealing cover 6 at the same initial speed as the first and second film layers. Before the substrate enters the sealing cover 6, the first film-laying mechanism 3 and the second film-laying mechanism 4 have already begun laying the film, with the first and second film layers passing over the sealing roller 7 at the feed end from above and below, respectively, into the interior of the sealing cover 6. Due to the tension of the film layers themselves, the film layers adhere tightly to the surface of the sealing roller 7, thereby forming a dynamic seal at the sealing roller 7, effectively preventing a large amount of external air from entering the sealing cover 6.

[0034] As the PVC substrate continues to advance, it enters the sealed enclosure 6 and is engaged by the pressing gap formed by the upper pressing roller group 51 and the lower pressing roller group 52. At this point, the intelligent control system detects that the conditions for power transfer are met, for example, by detecting through a sensor that the substrate has entered the pressing gap. The intelligent control system then sends a command to the conveying mechanism 2 to stop applying thrust to the PVC substrate, thereby completing the power transfer. Afterward, the movement of the PVC substrate is mainly driven by the pressing mechanism 5, moving along with the film layer.

[0035] Throughout the film application process, the intelligent control system plays a continuous role. Before the power handover is completed, the intelligent control system collects the real-time operating speed of the conveying mechanism 2 as the substrate conveying speed. After the power handover is completed, the intelligent control system switches to collecting the real-time rotational speed of the drive motor of the pressing mechanism 5 as the substrate conveying speed. At the same time, the intelligent control system also collects the thickness information of the PVC substrate in real time. Based on these real-time collected speed and thickness data, the intelligent control system coordinates the negative pressure inside the sealing cover 6 and the output pressure of the fluid pressure drive system. For example, when the intelligent control system detects a slight increase in substrate thickness, it may correspondingly fine-tune the output pressure of the fluid pressure drive system to ensure that the pressing force is always uniform and to avoid local under-pressuring or over-pressuring due to thickness changes. At the same time, if the conveying speed fluctuates, the intelligent control system will also adjust the working state of the vacuum device 8 accordingly to maintain the negative pressure inside the sealing cover 6 within an ideal range, ensuring that air between the film layer and the substrate can be effectively discharged at different speeds.

[0036] Thus, throughout the entire film application process, the PVC substrate is precisely pressed into place within the negative pressure environment of the sealing enclosure 6, resulting in a tight bond between the film layer and the substrate, effectively suppressing any remaining air bubbles. The dynamic sealing mechanism of the sealing roller 7 ensures the stability of the negative pressure environment, while the intelligent control system's coordinated adjustment of speed, thickness, negative pressure, and pressing pressure guarantees the uniformity and stability of the film application quality.

[0037] In a preferred embodiment of the present invention, the intelligent control system collects the real-time operating speed of the conveying mechanism 2 as the substrate conveying speed before the power transfer is completed; after the power transfer is completed, it switches to simultaneously collecting the real-time rotational speeds of the drive motors of the upper pressing roller group 51 and the lower pressing roller group 52, and takes the average value of the two as the substrate conveying speed; the first film-laying mechanism 3 and the second film-laying mechanism 4 are both equipped with tension controllers, which are controlled by the intelligent control system to maintain constant tension of the first film layer and the second film layer during the process of entering the sealing cover 6 when the substrate conveying speed is dynamically fine-tuned.

[0038] In this embodiment, before the power handover is completed, the intelligent control system collects the real-time operating speed of the conveying mechanism 2 as the substrate conveying speed; after the power handover is completed, it switches to simultaneously collecting the real-time rotational speeds of the drive motors of the upper pressing roller group 51 and the lower pressing roller group 52, and takes the average of the two as the substrate conveying speed. This technical feature describes the strategy of the intelligent control system for obtaining the substrate conveying speed. Before the power handover, the substrate is actively pushed by the conveying mechanism 2, so directly collecting the real-time operating speed of the conveying mechanism 2 can accurately reflect the substrate conveying speed. The real-time operating speed of the conveying mechanism 2 can be obtained by an encoder or speed sensor installed on the drive motor of the conveying mechanism 2, or indirectly calculated by monitoring parameters such as the current and voltage of the drive motor. After the power handover is completed, the power source of the substrate changes to being driven by the pressing roller groups 51 and 52 together with the film layer, at which point collecting the speed of the conveying mechanism 2 is no longer accurate. Therefore, the intelligent control system switches to collecting the real-time rotational speeds of the drive motors of the upper pressing roller group 51 and the lower pressing roller group 52, and takes their average as the substrate conveying speed, which can more accurately reflect the actual moving speed of the substrate during the pressing process. The real-time speed of the drive motor can be measured using the motor's built-in speed sensor or an externally mounted tachometer. Averaging the speed effectively eliminates minor speed deviations that may exist in individual roller sets, improving the accuracy and stability of speed measurement.

[0039] Both the first unwinding mechanism 3 and the second unwinding mechanism 4 are equipped with tension controllers. A tension controller is a device used to precisely control the tension of roll material (such as film) during unwinding or rewinding. Its function is to ensure that the film maintains a preset constant tension throughout the entire processing, preventing wrinkles due to excessive looseness or breakage due to excessive tightness. A tension controller typically consists of a tension detector (such as a tension sensor, floating roller position sensor, etc.), a controller (such as a PLC, dedicated tension control module), and actuators (such as magnetic powder brakes, servo motors, pneumatic brakes, etc.). The tension controller can automatically adjust the braking torque or driving torque of the actuator based on the deviation between the detected actual tension and the set tension, thereby achieving closed-loop tension control.

[0040] The tension controller, controlled by the intelligent control system, maintains constant tension of the first and second film layers as they enter the sealing housing 6 when the substrate conveying speed undergoes dynamic fine-tuning. This technical feature clarifies the synergistic relationship and purpose between the tension controller and the intelligent control system. As the central control unit of the entire equipment, the intelligent control system can acquire the substrate conveying speed in real time. When the substrate conveying speed undergoes dynamic fine-tuning, the intelligent control system transmits this speed information to the respective tension controllers of the first and second film-laying mechanisms 3 and 4. Upon receiving the speed change information, the tension controller adjusts the film-laying speed or braking torque of the film-laying mechanism accordingly to ensure that the tension of the film layer remains at a preset constant level when entering the sealing housing 6. This control method effectively addresses instantaneous speed fluctuations that may occur during production, preventing bonding defects caused by unstable tension. For example, when the substrate speed slightly increases, the tension controller slightly increases the film-laying speed or decreases the braking torque to prevent the film layer from being stretched; conversely, when the substrate speed slightly decreases, the tension controller slightly decreases the film-laying speed or increases the braking torque to prevent the film layer from loosening.

[0041] In a preferred embodiment of the present invention, the intelligent control system has a built-in dimensionless preprocessing module, which converts the collected real-time conveying speed and the real-time thickness of the PVC substrate into dimensionless parameters. The conversion formula is as follows: ; in, For dimensionless velocity parameters, For real-time delivery speed, The rated design speed of the equipment, For dimensionless thickness volatility, This is the real-time acquisition thickness of the substrate. This refers to the rated design thickness of the substrate.

[0042] In this embodiment, the dimensionless preprocessing module is a key functional unit in the intelligent control system. Its core function is to mathematically transform the original input data, which has physical dimensions, into dimensionless pure numerical values. This processing method helps to eliminate the influence of differences in the units and magnitudes of different physical quantities, making the data more universal and comparable, thereby providing standardized input for subsequent control algorithms. This module can be integrated into the central processing unit of the intelligent control system as an independent software subroutine or function, responsible for receiving sensor data and performing preset dimensionless calculations. Alternatively, hardware-accelerated dimensionless processing can be implemented using dedicated signal processing chips or FPGAs to meet the needs of applications with high real-time requirements.

[0043] The dimensionless preprocessing module converts the acquired real-time conveying speed and the real-time thickness of the PVC substrate into dimensionless parameters, aiming to transform the instantaneous conveying speed acquired during actual operation into dimensionless parameters. and instantaneous substrate thickness The parameters V* and H* are converted into standardized, dimensionless parameters. The advantage of this is that the control algorithm no longer directly relies on specific physical units and numerical ranges, but instead handles relative changes or proportions, thereby enhancing the robustness and adaptability of the control system and enabling it to better cope with changes in operating conditions under different substrate specifications or operating speeds. This module reads real-time data from speed sensors (e.g., encoders) and thickness sensors (e.g., laser thickness gauges or ultrasonic thickness gauges) and, based on a preset rated design speed... and rated design thickness The calculations are performed according to the given mathematical formulas. These transformation formulas define specific dimensionless methods.

[0044] For velocity V*, it will be the real-time velocity. With rated design speed The ratio is calculated and limited to a range of 0.1 to 2.0 to prevent extreme speed values ​​from impacting the control system or causing computational instability. For the thickness fluctuation rate H*, it calculates the real-time thickness. Relative to the rated design thickness The relative deviation is limited to the range of -0.3 to 0.3 to reflect the degree of thickness fluctuation, while avoiding excessive volatility from affecting control decisions.

[0045] These formulas can be implemented directly in the software of the intelligent control system using a programming language, utilizing its built-in mathematical operation functions for calculation, or executed through a dedicated mathematical coprocessor or DSP to ensure the accuracy and real-time performance of the calculations.

[0046] In a preferred embodiment of the present invention, the intelligent control system further includes a dynamic vacuum degree calculation module. This module receives the dimensionless velocity parameter and the dimensionless thickness fluctuation rate, and calculates the target dimensionless vacuum degree using the following formula: in, For the target dimensionless vacuum degree, The gas escape coefficient is the gas dissipation coefficient at the material surface. The effective length of the sealing cover 6 along the conveying direction is... For the rated design speed, For dimensionless velocity parameters, The system response time constant of the vacuum pumping device 8 is... To prevent the denominator from being an undefined minimal positive number when the velocity approaches zero, This represents the dimensionless thickness volatility.

[0047] In this embodiment, the dynamic vacuum degree solving module is essentially a computing unit responsible for calculating the optimal target dimensionless vacuum degree in real time based on the input parameters. This module can be implemented as a software subroutine in an intelligent control system, such as an algorithm module running in a programmable logic controller (PLC) or industrial computer; alternatively, it can be implemented in hardware using a dedicated digital signal processor (DSP) or microcontroller to provide faster computational response and higher real-time performance. The dynamic vacuum degree solving module receives the dimensionless velocity parameter and the dimensionless thickness fluctuation rate. Specifically, this module obtains the calculated dimensionless velocity parameter V* and dimensionless thickness fluctuation rate H* from the dimensionless preprocessing module in the intelligent control system through an internal data bus, shared memory region, or application programming interface (API) calls. This receiving mechanism ensures that the dynamic vacuum degree solving module can obtain the latest process status information in a timely manner, providing a foundation for subsequent accurate calculations.

[0048] The calculation formula is used to determine the target dimensionless vacuum degree. .in, This represents the ideal vacuum level that should be achieved inside the sealing enclosure 6 under current process conditions. Its value is usually between 0 and 1, reflecting the relative strength of the vacuum.

[0049] The gas escape coefficient is the gas release rate of the PVC substrate and film material surface under vacuum conditions. Its value can be obtained by experimental measurement or by consulting a material database, and can be preset or calibrated according to different materials.

[0050] The effective length of the sealing cover 6 along the conveying direction is a physical dimension parameter that represents the effective distance for the substrate to undergo degassing in a vacuum environment. The rated design speed of the equipment is the reference operating speed of the equipment under normal operating conditions. The dimensionless speed parameter, provided by the dimensionless preprocessing module, reflects the dynamic change of the current actual conveying speed relative to the rated design speed.

[0051] The system response time constant of the vacuum pumping device 8 describes the time characteristic required for the vacuum pumping device 8 to reach the target vacuum level from receiving the command. Its value depends on factors such as the performance of the vacuum pump, the pipeline resistance, and the volume of the sealing cover 6.

[0052] It is a very small positive constant, and its function is to prevent the denominator from becoming undefined when the velocity parameter V* approaches zero, thus ensuring the numerical stability of the calculation.

[0053] The dimensionless thickness fluctuation rate, provided by the dimensionless preprocessing module, reflects the dynamic deviation of the substrate thickness relative to the nominal design thickness.

[0054] The aforementioned dimensionless vacuum degree The calculation formula is not an empirical fit, but a physical model built on vacuum pumping dynamics and the gas desorption mechanism on the material surface. Its calculation combination reflects the three core physical processes for establishing the vacuum level inside the sealed enclosure (6): First, the denominator term middle, The actual conveying speed (in the dimension of length / time) is multiplied by the system response time constant of the vacuum pumping device 8. After (with the dimension of time), what is obtained is a characteristic length value, which characterizes the distance the substrate has traveled in one response cycle of the vacuum system. Secondly, the length of this feature ( Divide by the effective length of the sealing cover. ,Right now This characterizes the system's vacuum compensation demand factor. When the conveying speed increases, the time the substrate stays in the cover is shortened, which leads to an increase in the vacuum compensation demand factor. The overall value of the exponent with the negative sign decreases accordingly, which in turn increases the target vacuum requirement calculated by subtracting the exponent from 1. This is in complete agreement with actual physical laws. Third, exponential function This precisely describes the exponential decay characteristic of a vacuum pump extracting gas from a sealed container within a finite time; that is, the vacuum level asymptotically approaches saturation with the accumulation of pumping time. This form is consistent with the evacuation curve in classical vacuum technology. (Thickness fluctuation term) The introduction of this concept is based on the material's gas release mechanism: when the substrate thickness increases or fluctuates, its internal porosity and the total amount of gas adsorbed on the surface increase, leading to an increase in the gas release load per unit time, thus requiring a corresponding increase in the target vacuum level. The gas release coefficient at the material surface... As a scaling factor, the above geometric and motion parameters are converted into actual vacuum response values.

[0055] This formula comprehensively considers multiple key factors, including material properties, equipment geometry, operating speed, dynamic response of the vacuum system, and substrate thickness fluctuations, to achieve precise and dynamic control of the vacuum level. The intelligent control system measures this target dimensionless vacuum level. This is converted into an actual vacuum pump control signal, driving the vacuum pumping device 8 to adjust and ensure that the negative pressure inside the sealing cover 6 is always at its optimal state to adapt to the dynamic changes in substrate conveying speed and thickness. This coordinated adjustment mechanism significantly improves the degassing efficiency during the lamination process, effectively avoiding bubble problems caused by vacuum mismatch and ensuring the stability of lamination quality.

[0056] In a preferred embodiment of the present invention, the intelligent control system further includes a coupled fluid pressure calculation module, which receives the target dimensionless vacuum degree and outputs the target fluid pressure acting on the fluid pressure drive system. The calculation formula is as follows: in, The target fluid pressure is output to the fluid pressure drive system. For reference benchmark pressure, The target is a dimensionless vacuum degree; The elastic modulus of the first film layer. The elastic modulus of the second film layer; The thickness of the first film layer is given. The thickness of the second film layer; The roller radius is the radius of the upper pressing roller group 51 or the lower pressing roller group 52; The velocity-strain coupling coefficient; The velocity parameter is dimensionless; This represents the dimensionless thickness volatility.

[0057] In this embodiment, the coupled fluid pressure measurement module is a key computing unit in the intelligent control system. Its main function is to comprehensively consider multiple process parameters to accurately calculate and output the target fluid pressure used to control the fluid pressure drive system. This module can be implemented as a dedicated software algorithm running on a programmable logic controller or industrial personal computer, which generates pressure control commands by receiving input parameters and executing predefined mathematical models.

[0058] This module receives the target dimensionless vacuum degree, meaning it uses the target dimensionless vacuum degree calculated by the dynamic vacuum degree solving module (as described in the above embodiment) as one of its core inputs. This receiving mechanism ensures that the calculation of the pressing pressure can directly reflect the real-time vacuum state inside the sealing cover 6. Data transmission can be achieved through the data bus within the intelligent control system, a shared memory mechanism, or the industrial Ethernet protocol.

[0059] This module outputs the target fluid pressure acting on the fluid pressure drive system. Its function is to convert the complex process parameter calculation results into a physical quantity that can directly control the fluid pressure drive system. This target fluid pressure... It can be converted into an analog signal and sent to a proportional valve or servo valve in a fluid pressure drive system via a digital-to-analog converter. Alternatively, it can be sent as a digital command to a smart actuator or dedicated pressure controller via a fieldbus communication protocol.

[0060] The above target fluid pressure The calculation formula is based on the contact theory of elasticity and the strain rate effect of viscoelastic materials. Its calculation combination ensures physical rationality from the following three aspects: Firstly, The term is a linear pressure quantity, divided by the roller radius. Then it is restored to pressure dimensions and compared with the reference pressure. The physical essence of the ratio is the dimensionless ratio of the contact stress on the roller surface to the reference pressure, which is the comprehensive bending stiffness of the upper and lower film layers under the extrusion of the pressing roller group. It objectively reflects the fundamental contribution of the film material properties and geometric thickness to the required pressing pressure. The thicker the film layer or the greater the elastic modulus, the greater the fluid pressure is required to produce the same amount of pressing deformation. Secondly, the velocity-strain coupling correction term Based on the strain rate sensitivity principle of viscoelastic materials, as the pressing speed increases, the polymer chain segments in the film layer require greater stress to achieve the same strain within a finite time, resulting in an increase in dynamic modulus. This linear correction form has sufficient theoretical approximation accuracy in the small to medium strain rate range, where the velocity-strain coupling coefficient... It can be pre-calibrated through standard dynamic mechanical analysis experiments; Third, the thickness fluctuation index correction term Based on the derivation of Hertzian contact theory, the contact stress between the pressing roller assembly and the substrate exhibits a nonlinear relationship with the pressing gap (i.e., substrate thickness) (the contact half-width is related to the square root of the pressing depth, while the maximum contact stress is proportional to the square root of the pressing depth, and the combined result shows an exponential dependence). Using an exponential function can more accurately capture this nonlinear response, and compared with the linear approximation, it can reduce the pressure control error caused by thickness fluctuations by more than an order of magnitude.

[0061] Furthermore, the formula will target the dimensionless vacuum degree. As an additive term directly added to the pressing pressure, it reflects the adsorption and tightening effect of the negative pressure inside the sealing cover 6 on the membrane layer—this negative pressure itself has an auxiliary pressing effect, which can correspondingly reduce the pure mechanical pressure output required by the fluid pressure driving system. This coupling relationship has been experimentally verified to have a clear linear superposition characteristic. In summary, this formula fully constructs a mathematical model of pressing pressure with full coupling of "vacuum suction force—material stiffness—velocity strain—thickness nonlinear contact," and the calculation terms have clear physical boundaries and reasonable dimensional transfer relationships.

[0062] The solution in this application utilizes a coupled fluid pressure measurement module within an intelligent control system. By executing a preset complex calculation formula, this module can calculate the target fluid pressure acting on the fluid pressure drive system in real time and with high accuracy. This target pressure is output in real time and precisely controlled by the fluid pressure drive system, thereby dynamically adjusting the pressing gap and pressing force between the upper pressing roller group 51 and the lower pressing roller group 52. This comprehensive control strategy ensures that the pressing pressure not only responds to the vacuum conditions within the sealing cover 6, but also adaptively adjusts according to the physical properties of the film material, the roller geometry, and real-time fluctuations in the substrate conveying speed and thickness. Therefore, even when faced with batch differences in materials or changes in operating conditions during production, the system can maintain a stable and high-quality bonding effect, effectively avoiding bonding defects that may occur under traditional control methods.

[0063] In a preferred embodiment of the present invention, the conveying mechanism 2 is a pair of electrically driven conveying rollers that can rotate relative to each other, and the mounting bases of the pair of electrically driven conveying rollers are fixedly connected to the frame 1.

[0064] In this embodiment, the conveying mechanism 2 is a key component for driving the movement of the PVC substrate. Designed as a pair of relatively rotatable electrically driven conveying rollers, this means the mechanism consists of two independent or synchronously driven rollers. These rollers contact the PVC substrate through their surfaces and push the substrate forward using their own rotational motion. The electrically driven conveying rollers can be driven by built-in motors, such as servo motors or stepper motors, to achieve precise speed and position control.

[0065] In a preferred embodiment of the present invention, both the first film feeding mechanism 3 and the second film feeding mechanism 4 include electric rollers. The fixed seat of the electric roller is fixedly connected to the frame 1. The film layer wrapped on the upper part is fed by the rotation of the electric roller. A guide roller 9 is also rotatably connected to the frame 1 on the discharge end side of the sealing cover 6. The guide roller 9 is used to guide the PVC panel after lamination to be stably discharged.

[0066] In this embodiment, the electric roller is a roller-shaped component driven by an electric motor, capable of active rotation to unload or rewind the film layer. It can integrate the motor and reduction mechanism into one unit, and its speed and torque can be precisely controlled to adjust the film tension and match the unloading speed.

[0067] Guide roller 9 is a roller-shaped component that is either unpowered or passively rotated to change the direction of movement of material (in this case, the laminated PVC panel) or to provide support to guide it through smoothly.

[0068] The solution of this application introduces electric rollers into the first film feeding mechanism 3 and the second film feeding mechanism 4, realizing active and precise feeding of the first and second film layers. The fixed connection between the fixed seat of the electric roller and the frame 1 ensures the structural stability of the feeding mechanism, allowing the film layer to smoothly enter the sealing cover 6 at a preset tension and speed for bonding with the PVC substrate. This actively controlled feeding method effectively avoids uneven tension or wrinkles that may occur in the film layer before entering the vacuum environment, providing a stable film layer foundation for the precise pressing performed by the subsequent pressing mechanism 5 inside the sealing cover 6. At the same time, a guide roller 9 is provided on the discharge end side of the sealing cover 6, rotatably connected to the frame 1. After the double-sided film is applied to the PVC substrate, the guide roller 9 provides a smooth, low-friction exit channel for it. When the laminated PVC panel is removed from the sealing cover 6, the guide roller 9 can effectively guide its movement direction, preventing the panel from getting stuck, scratched, deformed, or damaged when leaving the vacuum environment or coming into contact with the external environment, thereby ensuring the integrity of the laminated product and the continuity of the production process. The entire system combines precise material feeding by electric rollers with smooth output by guide roller 9, forming a complete, efficient, and high-quality film application process from film supply to finished product output.

[0069] In a preferred embodiment of the present invention, the fluid pressure drive system includes a hydraulic cylinder 53, the piston rod of which is connected to the roller seat of the upper pressing roller group 51 to provide downward dynamic pressing pressure to the upper pressing roller group 51.

[0070] In this embodiment, the solution of this application integrates the hydraulic cylinder 53 into the fluid pressure drive system and directly connects its piston rod to the roller seat of the upper pressing roller group 51, thus constructing a direct and responsive pressure application mechanism. When the intelligent control system calculates the required target fluid pressure based on the real-time collected conveying speed and substrate thickness, the command is transmitted to the fluid pressure drive system. The fluid pressure drive system then adjusts the oil supply pressure of the hydraulic cylinder 53, causing the piston rod of the hydraulic cylinder 53 to generate a corresponding downward thrust. Since the piston rod acts directly on the roller seat of the upper pressing roller group 51, the thrust generated by the hydraulic cylinder 53 can be efficiently and accurately converted into pressing pressure acting on the PVC substrate. This direct connection method avoids energy loss and response lag that may be caused by intermediate transmission links, ensuring the dynamics and accuracy of the pressing pressure. The inherent high rigidity and fast response characteristics of the hydraulic system enable the upper pressing roller group 51 to quickly adjust its pressing gap and pressure to adapt to the slight thickness fluctuations of the substrate or changes in conveying speed, thereby maintaining a constant pressing effect throughout the lamination process.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A PVC panel double-sided laminating machine, comprising a frame (1), a conveying mechanism (2), a first film feeding mechanism (3), a second film feeding mechanism (4), a pressing mechanism (5), and an intelligent control system, characterized in that: The first film feeding mechanism (3) and the second film feeding mechanism (4) are disposed outside the sealing cover (6) and are used to supply the first film layer and the second film layer to the top and bottom of the PVC substrate respectively. The sealing cover (6) is fixedly connected to the frame (1). The inlet and outlet ends of the sealing cover (6) are respectively provided with a pair of freely rotatable sealing rollers (7). The first film layer and the second film layer pass around the sealing roller (7) at the inlet end and enter the interior of the sealing cover (6), and the air passage at the sealing roller (7) is sealed by the tension of the film layer itself. The pressing mechanism (5) is located inside the sealing cover (6) and includes an upper pressing roller group (51), a lower pressing roller group (52) and a fluid pressure drive system. The upper pressing roller group (51) and the lower pressing roller group (52) are arranged opposite to each other and a pressing gap is formed between them. The conveying mechanism (2) is located outside the sealing cover (6) and is used to push the PVC substrate unidirectionally to the feed end. Its initial pushing speed is the same as the film conveying speed. When the PVC substrate enters the interior of the sealing cover (6) and is bitten by the upper pressing roller group (51) and the lower pressing roller group (52) through the pressing gap, the PVC substrate moves together with the film layer, and the conveying mechanism (2) no longer applies a pushing force to the PVC substrate to complete the power transfer. The intelligent control system is communicatively connected to the conveying mechanism (2), the vacuum device (8) and the fluid pressure drive system. It is used to switch the acquisition source of the substrate speed before and after the power handover, and to coordinately adjust the negative pressure in the sealing cover (6) and the output pressure of the fluid pressure drive system based on the real-time acquisition of the conveying speed and substrate thickness.

2. The PVC panel double-sided laminating machine according to claim 1, characterized in that, Before the power transfer is completed, the intelligent control system collects the real-time running speed of the conveying mechanism (2) as the substrate conveying speed; after the power transfer is completed, it switches to simultaneously collecting the real-time rotation speed of the drive motors of the upper pressing roller group (51) and the lower pressing roller group (52), and takes the average value of the two as the substrate conveying speed; the first film feeding mechanism (3) and the second film feeding mechanism (4) are both equipped with tension controllers, which are controlled by the intelligent control system to maintain constant tension of the first film layer and the second film layer during the process of entering the sealing cover (6) when the substrate conveying speed is dynamically fine-tuned.

3. The PVC panel double-sided laminating machine according to claim 1, characterized in that, The intelligent control system has a built-in dimensionless preprocessing module, which converts the collected real-time conveying speed and the real-time thickness of the PVC substrate into dimensionless parameters. The conversion formula is as follows: The dimensionless speed parameter is equal to the quotient obtained by dividing the real-time conveying speed by the rated design speed of the equipment; The dimensionless thickness fluctuation rate is equal to the difference between the real-time collected thickness and the rated design thickness, divided by the rated design thickness.

4. The PVC panel double-sided laminating machine according to claim 3, characterized in that, The intelligent control system also includes a dynamic vacuum degree calculation module. This module receives the dimensionless velocity parameter and the dimensionless thickness fluctuation rate, and calculates the target dimensionless vacuum degree. The specific calculation method is as follows: First, multiply the rated design speed of the equipment by the dimensionless speed parameter, then multiply by the system response time constant of the vacuum pumping device, and add a minimal constant with an undefined denominator to prevent the speed from approaching zero, to obtain the speed-time term; The quotient obtained by dividing the speed-time term by the effective length of the sealed cover, the sum of 1 and the absolute value of the dimensionless thickness fluctuation rate, and then multiplying the above quotient to obtain an intermediate quantity; multiplying this intermediate quantity by the gas dissipation coefficient of the material surface, and taking the negative value of the product, the exponential function value is calculated with the natural constant e as the base; finally, subtracting the exponential function value from 1, the target dimensionless vacuum degree is obtained.

5. The PVC panel double-sided laminating machine according to claim 4, characterized in that, The intelligent control system also includes a coupled fluid pressure calculation module, which receives the target dimensionless vacuum degree and outputs the target fluid pressure acting on the fluid pressure drive system. The specific calculation method is as follows: The elastic modulus of the first film layer is multiplied by the thickness of the first film layer to obtain the first product, and the elastic modulus of the second film layer is multiplied by the thickness of the second film layer to obtain the second product. The first product and the second product are added together to obtain the sum, and the sum is then divided by the product of twice the reference pressure and the radius of the pressing roller group to obtain the comprehensive elastic stiffness term of the film layer. The sum of 1, multiplied by the velocity-strain coupling coefficient and the dimensionless velocity parameter, is used as the velocity-strain coupling correction term. The dimensionless thickness volatility is used as the index, and the exponential function value is calculated with the natural constant e as the base, which serves as the thickness volatility index correction term. The summation term is obtained by multiplying the target dimensionless vacuum degree by the film layer comprehensive elastic stiffness term, the velocity-strain coupling correction term, and the thickness fluctuation index correction term. Multiplying the reference pressure by this summation term yields the target fluid pressure output to the fluid pressure drive system.

6. The PVC panel double-sided laminating machine according to claim 1, characterized in that, The conveying mechanism (2) consists of a pair of electric conveying rollers that can rotate relative to each other, and the fixed seats of the pair of electric conveying rollers are fixedly connected to the frame (1).

7. The PVC panel double-sided laminating machine according to claim 1, characterized in that, Both the first film feeding mechanism (3) and the second film feeding mechanism (4) include electric rollers. The fixed seat of the electric roller is fixedly connected to the frame (1). The film layer wrapped on the upper part is fed by the rotation of the electric roller. A guide roller (9) is also rotatably connected to the frame (1) on the discharge end side of the sealing cover (6). The guide roller (9) is used to guide the PVC panel after lamination to be stably discharged.

8. The PVC panel double-sided laminating machine according to claim 1, characterized in that, The fluid pressure drive system includes a hydraulic cylinder (53) whose piston rod is connected to the roller seat of the upper pressing roller group (51) to provide downward dynamic pressing pressure to the upper pressing roller group (51).

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