A hot melt adhesive coating head and intelligent coating system

Abstract

This invention relates to the field of hot melt adhesive coating equipment technology, specifically to a hot melt adhesive coating head and intelligent coating system. The system includes a housing, a cover plate, fixing screws, a baffle, a support rod, and an adjustment structure. The housing has a material chamber and multiple liquid inlets. The support rod is rotatably mounted on the housing, and the baffle is fixed to the support rod and located at the housing outlet. The adjustment structure uses a reduction gear transmission to achieve precise adjustment of the baffle position. The heating structure includes a heating coil and a stirring screw to ensure uniform adhesive temperature. The locking structure uses a cylinder to drive a friction plate to lock the gear position. The intelligent coating system also includes an online rheological property simulation module, a control module, and a digital twin wear prediction module, enabling real-time monitoring of adhesive rheological properties, viscosity feedforward compensation control, and active compensation for coating head wear, significantly improving coating quality and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of hot melt adhesive coating equipment technology, and in particular to a hot melt adhesive coating head and intelligent coating system. Background Technology

[0002] Hot melt adhesive coating technology is widely used in packaging, printing, automotive interiors, and electronic component bonding, with the hot melt adhesive coating head being its core equipment. The performance of the coating head directly determines the quality of the coating, including key indicators such as coating uniformity, coating thickness accuracy, and coating speed stability. As industrial production demands increasingly higher coating precision, traditional hot melt adhesive coating heads have several shortcomings in their structural design and control methods.

[0003] Existing hot melt adhesive coating heads typically employ a fixed baffle structure, making online adjustment of the coating gap impossible. When wear causes changes in the outlet gap, the only solution is to stop the machine and replace the baffle, which not only increases maintenance costs but also severely impacts production efficiency. Furthermore, traditional coating head baffle adjustment mechanisms are usually manual, resulting in low adjustment accuracy, inconvenient operation, and the inability to achieve closed-loop control, making it difficult to meet the demands of high-precision coating. Summary of the Invention

[0004] The purpose of this invention is to provide a hot melt adhesive coating head and an intelligent coating system, which can solve the technical problems in the prior art such as the inability to adjust the coating head baffle online, the inability to monitor the rheological properties of the adhesive in real time, and the inability to actively compensate for the wear of the coating head.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a hot melt adhesive coating head, comprising a housing, a cover plate, a fixing screw, a baffle, a support rod, and an adjustment structure. The housing has a material chamber and multiple liquid inlet heads, which communicate with the material chamber. The cover plate is connected to the housing via the fixing screw. The support rod is rotatably mounted on the housing. The baffle is fixed to the support rod and located at the outlet of the housing.

[0006] The housing contains multiple flow channels.

[0007] The adjustment structure includes an adjustment motor, a first gear, and a second gear. The radius of the second gear is larger than that of the first gear. The second gear is fixedly connected to the support rod. The first gear meshes with the second gear. The output end of the adjustment motor is connected to the first gear.

[0008] The hot melt adhesive coating head further includes a heating structure, which includes a heating coil, an agitating screw, and an agitating motor. The heating coil is disposed on the housing, the agitating screw is rotatably connected to the housing and located inside the housing, and the output end of the agitating motor is connected to the agitating screw.

[0009] The hot melt adhesive coating head also includes a locking structure, which is used to lock the position of the second gear after the support rod is adjusted into place.

[0010] The locking structure includes a cylinder, a friction plate, and a clamping spring. The friction plate is slidably disposed on one side of the second gear. The output end of the cylinder is connected to the friction plate. The clamping spring is disposed between the cylinder and the friction plate.

[0011] Secondly, the present invention also provides an intelligent coating system, comprising:

[0012] The online rheological property simulation module is used to collect ultrasonic and pressure signals of the adhesive in real time, and to simulate the real-time viscosity and elastic modulus of the adhesive based on a pre-built rheological dynamics model.

[0013] The control module is used to receive the real-time viscosity and elastic modulus, combine them with the current displacement parameters of the glue supply module, generate a feedforward compensation signal, and send it to the heating structure to adjust the local viscosity of the glue in advance.

[0014] The digital twin wear prediction module constructs a virtual wear model at the outlet of the housing based on the cumulative working time, real-time working pressure, and derived adhesive abrasion characteristics of the adhesive supply module, and outputs a gap compensation command to the adjustment structure.

[0015] The online rheological property simulation module includes an ultrasonic transceiver unit, a temperature compensation subunit, and a main control unit.

[0016] The ultrasonic transceiver unit is installed on both sides of the pipeline of the glue supply module in a through-beam manner, and is used to transmit and receive ultrasonic signals that penetrate the glue liquid.

[0017] The temperature compensation subunit is located on the inner wall of the pipeline and is used to obtain the temperature of the adhesive liquid in the boundary layer of the pipeline in real time.

[0018] The main control unit is used to output the dynamic viscosity and elastic modulus of the adhesive in real time based on the propagation time difference and attenuation coefficient of the ultrasonic signal, combined with the temperature and pressure of the adhesive in the boundary layer of the pipe wall, and a pre-trained acoustic-rheological coupled neural network model.

[0019] The method of constructing a virtual wear model of the slit lip of the coating head based on the cumulative working time, real-time working pressure, and derived adhesive abrasion characteristic parameters of the adhesive supply module, and outputting a wear compensation command to the adjustment structure includes: obtaining the abrasion characteristic index of the current coating adhesive, wherein the abrasion characteristic index is obtained by looking up a table based on the filler type and proportion of the adhesive; calculating the virtual wear amount of the slit coating port based on the wear correction model according to the cumulative working time, real-time working pressure, and abrasion characteristic index of the adhesive supply module; and when the virtual wear amount exceeds a preset threshold, outputting a wear compensation command to the adjustment structure to adjust the baffle position to compensate for the wear gap.

[0020] The beneficial effects of this invention include: the design of rotating the baffle via the rotation of the support rod enables online adjustment of the coating head outlet gap, allowing for gap adjustment without stopping the machine, significantly improving production efficiency and coating accuracy. The reduction gear transmission design significantly improves the adjustment accuracy of the baffle position, ensuring precise control of the coating gap. The combined design of the heating structure and the stirring screw ensures uniform distribution of the adhesive temperature, improving the consistency of coating quality. The locking structure ensures the positional stability of the baffle after adjustment, preventing baffle displacement due to vibration or adhesive pressure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0022] Figure 1 This is a schematic diagram of the structure of the hot melt adhesive coating head provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the right side structure of the hot melt adhesive coating head provided in an embodiment of the present invention.

[0024] Figure 3 yes Figure 1 A magnified view of detail A.

[0025] Figure 4 This is a schematic diagram of the left side structure of the hot melt adhesive coating head provided in an embodiment of the present invention.

[0026] Figure 5 This is a schematic cross-sectional view of the hot melt adhesive coating head provided in an embodiment of the present invention.

[0027] Figure Labels

[0028] 1-Housing; 2-Cover plate; 3-Fixing screw; 4-Baffle; 5-Support rod; 6-Adjusting structure; 7-Material chamber; 8-Inlet head; 9-Flow channel; 10-Adjusting motor; 11-First gear; 12-Second gear; 14-Heating coil; 15-Agitating screw; 16-Agitating motor; 17-Locking structure; 18-Cylinder; 19-Friction plate; 20-Pressure spring. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0030] First embodiment:

[0031] Hot melt adhesive coating technology is widely used in packaging, printing, automotive interiors, and electronic component bonding, with the hot melt adhesive coating head being its core equipment. The performance of the coating head directly determines the coating quality, including key indicators such as coating uniformity, coating thickness accuracy, and coating speed stability. As industrial production demands increasingly higher coating precision, traditional hot melt adhesive coating heads have several shortcomings in their structural design and control methods. Existing hot melt adhesive coating heads typically employ a fixed baffle structure, making online adjustment of the coating gap impossible. When wear causes changes in the outlet gap, the only solution is to stop the machine and replace the baffle, which not only increases maintenance costs but also severely impacts production efficiency. Furthermore, the baffle adjustment mechanism of traditional coating heads is usually manual, resulting in low adjustment precision, inconvenient operation, and the inability to achieve closed-loop control, making it difficult to meet the demands of high-precision coating.

[0032] To address the aforementioned technical problems, this application provides a hot melt adhesive coating head capable of online adjustment of the coating gap. The rotatable support rod 5 drives the baffle 4 to change position, thereby dynamically adjusting the outlet gap to adapt to coating requirements under different working conditions.

[0033] Based on the above issues, please refer to Figures 1-5 This application provides a hot melt adhesive coating head, which includes a housing 1, a cover plate 2, a fixing screw 3, a baffle 4, a support rod 5, and an adjustment structure 6. The housing 1 has a material chamber 7 and multiple liquid inlets 8, which are connected to the material chamber 7. The cover plate 2 is connected to the housing 1 by the fixing screw 3. The support rod 5 is rotatably mounted on the housing 1. The baffle 4 is fixed on the support rod 5 and located at the outlet of the housing 1.

[0034] The working process and principle of this application are as follows: hot melt adhesive enters the material chamber 7 inside the housing 1 through multiple inlet heads 8 and flows towards the outlet under pressure. When it is necessary to adjust the coating thickness, the adjustment structure 6 is activated and outputs rotational motion. This motion is transmitted to the support rod 5, causing the support rod 5 to rotate around its axis. Since the baffle 4 is fixed on the support rod 5, the rotation of the support rod 5 forces the baffle 4 to deflect at an angle, thereby changing the horizontal gap between the lower edge of the baffle 4 and the lower edge (or upper edge, depending on the specific installation position) of the outlet of the housing 1. The change in gap directly affects the flow rate of the outflowing adhesive, thereby controlling the thickness of the adhesive layer coated on the substrate. The entire process does not require stopping the machine or disassembling parts; it can be completed simply by adjusting the structure 6, achieving efficient and precise online control.

[0035] As a preferred embodiment, the solution of this application is implemented as follows: On the packaging production line, a hot melt adhesive coating head is installed between the unwinding and rewinding devices. During operation, molten hot melt adhesive is injected into the material chamber 7 of the housing 1 through three horizontally evenly distributed inlet heads 8. After the adhesive pressure in the material chamber 7 tends to balance, it flows to the outlet. Initially, the baffle 4 and the outlet of the housing 1 form a preset gap, corresponding to the standard coating weight. As production progresses, if a deviation in coating thickness is detected (such as the gap widening due to wear of the baffle 4), the control system sends a command to drive the motor in the adjustment structure 6 to rotate. The motor drives the support rod 5 to rotate slightly, and the support rod 5 drives the baffle 4 to swing in the direction of reducing the gap until the gap returns to the set value, thereby compensating for the impact of wear and ensuring the consistency of coating quality.

[0036] Through the above technical solution, this application achieves the following beneficial effects: Because a support rod 5 rotatably mounted on the housing 1 and a baffle 4 fixed thereon are used, and the support rod 5 is driven to rotate by the adjustment structure 6, the position of the baffle 4 can be dynamically adjusted online. This solves the problem of needing to stop and replace the traditional fixed baffle 4 due to wear causing changes in the coating gap, significantly improving equipment maintenance efficiency and production continuity. Because the housing 1 is equipped with multiple liquid inlets 8 connected to the material chamber 7, it helps the adhesive to quickly achieve uniform pressure within the material chamber 7, reducing flow rate fluctuations caused by single-point feeding, thereby improving coating uniformity. Because the cover plate 2 is connected to the housing 1 by fixing screws 3, forming a reliable sealing structure, it can effectively prevent adhesive leakage under high temperature and high pressure working conditions, ensuring the stability of the coating process.

[0037] Furthermore, the housing 1 of the hot melt adhesive coating head is provided with multiple flow channels 9.

[0038] The flow channel 9 refers to a channel structure disposed inside the housing 1 to guide the flow of hot melt adhesive. The shape, size, and extension path of the flow channel 9 can be set according to actual conditions, for example, it can be straight, curved, or stepped, and this embodiment does not impose any special limitations on this. The function of the flow channel 9 is to serve as a transmission path for the adhesive from the inlet head 8 to the material chamber 7 or the outlet area, and it together with the inner wall of the housing 1 forms a closed fluid transport space. In the system linkage, the flow channel 9 is connected to the inlet head 8, receives the adhesive input from different inlet heads 8, and guides them to the designated confluence area or coating outlet, thereby avoiding disorderly mixing of multiple adhesive streams in the housing 1. Through this cooperation, the flow channel 9 can achieve independent control and orderly distribution of the flow rate of each adhesive stream, reduce mutual interference between fluids, and keep the adhesive in a stable flow state before entering the coating area.

[0039] The adjustment structure 6 includes an adjustment motor 10, a first gear 11 and a second gear 12. The radius of the second gear 12 is larger than that of the first gear 11. The second gear 12 is fixedly connected to the support rod 5. The first gear 11 meshes with the second gear 12. The output end of the adjustment motor 10 is connected to the first gear 11.

[0040] When it is necessary to adjust the coating gap or the position of the baffle 4, the control system sends a command to the adjusting motor 10, the output shaft of the adjusting motor 10 rotates and drives the first gear 11 to rotate; the first gear 11 acts as the driving wheel, driving the second gear 12 meshing with it to rotate; since the radius of the second gear 12 is larger than that of the first gear 11, this stage of transmission produces a deceleration effect, so that the speed of the second gear 12 is lower than that of the first gear 11 but the output torque is increased; the second gear 12 drives the support rod 5 fixedly connected to it to deflect, and the support rod 5 then drives the baffle 4 to move to the target position, completing the adjustment of the coating head outlet state.

[0041] The hot melt adhesive coating head also includes a heating structure, which includes a heating coil 14, an agitating screw 15, and an agitating motor 16. The heating coil 14 is mounted on the housing 1, the agitating screw 15 is rotatably connected to the housing 1 and located inside the housing 1, and the output end of the agitating motor 16 is connected to the agitating screw 15.

[0042] Once the hot melt adhesive enters the material cavity 7 of the housing 1, the heating coil 14 is energized, continuously supplying heat to the housing 1 to maintain the ambient temperature within the material cavity 7 above the melting temperature of the hot melt adhesive. Simultaneously, the stirring motor 16 starts and drives the stirring screw 15 to rotate within the material cavity 7. The rotating stirring screw 15 pushes the adhesive solution axially, creating turbulent or laminar flow mixing, thus ensuring that the temperature of each part of the adhesive solution tends to be uniform and maintaining a low viscosity to facilitate subsequent extrusion through the inlet head 8. The synergistic effect of the heating coil 14 and the stirring screw 15 ensures that the adhesive solution remains in a uniform, stable, and suitable flow condition throughout the entire coating preparation stage.

[0043] As a preferred embodiment, the solution of this application is implemented as follows: During the operation of the intelligent coating system, the control system controls the heating power of the heating coil 14 according to the preset process temperature parameters, so that the surface temperature of the shell 1 is maintained between 180°C and 200°C (the specific value depends on the type of adhesive); at the same time, the stirring motor 16 drives the stirring screw 15 to rotate continuously at a speed of 30-60 rpm. When the adhesive is injected into the material chamber 7 from the liquid inlet 8, it is immediately subjected to the shearing and pushing action of the stirring screw 15, and the newly injected low-temperature adhesive is quickly mixed with the high-temperature adhesive in the chamber, avoiding viscosity fluctuations caused by excessive temperature difference. If it is detected that the adhesive has not been used for a long time, the stirring screw 15 can be switched to a low-speed intermittent operation mode, which prevents the adhesive from settling and separating, and avoids excessive shearing that leads to a decrease in adhesive performance.

[0044] Furthermore, the hot melt adhesive applicator also includes a locking structure 17, which is used to lock the position of the second gear 12 after the support rod 5 is adjusted into place.

[0045] The locking structure 17 includes a cylinder 18, a friction plate 19, and a clamping spring 20. The friction plate 19 is slidably disposed on one side of the second gear 12. The output end of the cylinder 18 is connected to the friction plate 19. The clamping spring 20 is disposed between the cylinder 18 and the friction plate 19.

[0046] When the support rod 5 drives the baffle 4 to adjust to the target position, and then drives the second gear 12, which is fixedly connected to the support rod 5, to rotate into place, the control system issues a locking command. The cylinder 18 starts and pushes the piston rod to extend. The piston rod pushes the compression spring 20, and the compression spring 20 transmits the thrust to the friction plate 19, causing the friction plate 19 to press against the side of the second gear 12 in the sliding direction. Under the action of the compression spring 20, sufficient static friction is generated between the friction plate 19 and the second gear 12, thereby limiting the rotation of the second gear 12 and fixing the position of the support rod 5 and the baffle 4, preventing the position of the baffle 4 from shifting due to the pressure of the adhesive or vibration. When it is necessary to adjust the position of the baffle 4 again, the cylinder 18 retracts, driving the friction plate 19 to disengage from the second gear 12 and releasing the locking state. At this time, the adjusting motor 10 can drive the first gear 11 to drive the second gear 12 to rotate again.

[0047] Second Embodiment

[0048] This application also provides an intelligent coating system, including:

[0049] The online rheological property simulation module is used to collect ultrasonic and pressure signals of the adhesive in real time, and to simulate the real-time viscosity and elastic modulus of the adhesive based on a pre-built rheological dynamics model.

[0050] The control module receives real-time viscosity and elastic modulus, combines them with the current displacement parameters of the glue supply module, generates a feedforward compensation signal, and sends it to the heating structure to adjust the local viscosity of the glue in advance.

[0051] The digital twin wear prediction module constructs a virtual wear model at the outlet of the housing 1 based on the cumulative working time, real-time working pressure, and deduced adhesive abrasion characteristics parameters of the adhesive supply module, and outputs gap compensation commands to the adjustment structure 6.

[0052] The online rheological property simulation module refers to a processing unit with data acquisition and model calculation capabilities. Its function is to acquire characteristic signals reflecting the physical state of the adhesive in real time and calculate key rheological parameters. This module can communicate with sensors (such as ultrasonic transducers and pressure sensors) located near the adhesive supply line or coating head to obtain the propagation time difference, attenuation coefficient, and real-time pressure value of the ultrasonic signals penetrating the adhesive. The online rheological property simulation module internally stores or runs a pre-built rheological dynamics model. This model can be a mathematical model based on the acoustic-rheological coupling mechanism or a neural network model trained on historical data. The module inputs the acquired ultrasonic and pressure signals into the rheological dynamics model, processes them, and outputs the real-time viscosity and elastic modulus of the adhesive. The real-time viscosity and elastic modulus can be used to characterize the flow resistance and deformation recovery ability of the adhesive at specific temperatures and shear rates. The online rheological property simulation module establishes a data connection with the control module, transmitting the derived real-time viscosity and elastic modulus to the control module as input for subsequent control strategies. The specific implementation of the online rheological property simulation module can be set according to the actual situation. For example, it can be a dedicated algorithm program embedded in the main control board of the coating machine, or it can be an independently deployed edge computing device. This application embodiment does not make any special limitations on this.

[0053] The control module refers to a logic processing unit responsible for receiving multi-source data and generating control commands. Its role in the overall technical solution is to dynamically adjust the actions of the actuators based on real-time monitored adhesive state and system operating parameters. The control module communicates with the online rheological property simulation module to receive real-time viscosity and elastic modulus data. Simultaneously, the control module can also acquire the current displacement parameters of the adhesive supply module, which can refer to the pump speed, stroke, or flow rate setpoint driving the adhesive output. Based on the received real-time viscosity, elastic modulus, and displacement parameters of the adhesive supply module, the control module generates a feedforward compensation signal through a preset control algorithm. The feedforward compensation signal can be used to instruct the heating structure to adjust the heating power or heating distribution to change the local temperature of the adhesive in advance, thereby adjusting the local viscosity of the adhesive to meet the current coating process requirements. For example, when the calculated adhesive viscosity is too high, the control module can generate a feedforward compensation signal to increase the heating power; when the viscosity is too low, it generates a signal to decrease the heating power. The control module is electrically connected to the heating structure (such as heating coil 14, heating rod, etc.) and sends feedforward compensation signals to the heating structure for execution. The control module can be implemented as a microcontroller (MCU), programmable logic controller (PLC), or industrial computer. The control logic running inside it can be configured according to the specific coating process requirements, and this application embodiment does not impose any special limitations on this.

[0054] The digital twin wear prediction module refers to a functional module that simulates and predicts the wear state of a physical entity based on a virtual model. Its name derives from the use of digital means to construct a virtual mapping model corresponding to the physical coating head. This module interacts with components such as the glue supply module, pressure sensor, and adjustment structure 6. The digital twin wear prediction module acquires the cumulative working time and real-time working pressure of the glue supply module, as well as glue abrasion characteristic parameters obtained from the online rheological property simulation module or other methods. Glue abrasion characteristic parameters can refer to indicators reflecting the wear ability of filler particles in the glue on the contact surface, such as the abrasion index or wear coefficient. Based on these parameters, the digital twin wear prediction module constructs a virtual wear model of the outlet of housing 1 (i.e., the coating slit or die lip area) in virtual space. This virtual wear model can simulate the gradual material loss at the outlet of housing 1 over time and with increasing workload. By running the virtual wear model, the digital twin wear prediction module can predict the current wear amount or gap change trend and output gap compensation commands to the adjustment structure 6 accordingly. After receiving the gap compensation command, the adjustment structure 6 can drive the baffle 4 or related adjustment components to move, thereby compensating for the increase in gap caused by wear and maintaining the stability of the coating thickness. The calculation process of the digital twin wear prediction module can be completed on the local processor or uploaded to the cloud server for complex calculations and then the results are returned. This application embodiment does not impose any special limitations on this.

[0055] Specifically, the working process and principle of this application are as follows: During the operation of the intelligent coating system, the online rheological property simulation module first collects the ultrasonic and pressure signals of the adhesive in real time through sensors, and calculates the current real-time viscosity and elastic modulus using a built-in rheological dynamics model, thereby achieving online sensing of the rheological state of the adhesive. Subsequently, the control module receives these rheological parameters and, combined with the current discharge parameters of the adhesive supply module, calculates the required heat compensation amount through a feedforward control algorithm, generates a feedforward compensation signal, and sends it to the heating structure, prompting the heating structure to adjust the heating state in advance, optimize the local viscosity of the adhesive, and ensure that the adhesive is in the optimal flow state when entering the coating head. At the same time, the digital twin wear prediction module continuously monitors the cumulative working time, real-time working pressure, and abrasive characteristics of the adhesive supply module, and uses a constructed virtual wear model to simulate the wear process at the coating head outlet. When the model predicts that the wear amount reaches a certain level or the gap changes, the digital twin wear prediction module automatically generates a gap compensation command and sends it to the adjustment structure 6. The adjustment structure 6 then acts to adjust the position of the baffle 4 to compensate for the gap change caused by wear, thereby realizing the transformation from passive maintenance to active prediction and compensation.

[0056] Furthermore, the online rheological property simulation module includes an ultrasonic transceiver unit, a temperature compensation subunit, and a main control unit: the ultrasonic transceiver unit is installed on both sides of the adhesive supply module's pipeline in a through-beam configuration to transmit and receive ultrasonic signals that penetrate the adhesive; the temperature compensation subunit is located on the inner wall of the pipeline to acquire the temperature of the adhesive in the boundary layer of the pipeline in real time; the main control unit is used to output the dynamic viscosity and elastic modulus of the adhesive in real time based on the propagation time difference and attenuation coefficient of the ultrasonic signal, combined with the temperature and pressure of the adhesive in the boundary layer of the pipeline, and a pre-trained acoustic-rheological coupled neural network model.

[0057] The ultrasonic transceiver unit refers to the transducer assemblies installed on opposite sides of the adhesive supply module pipeline, whose function is to construct an ultrasonic detection channel through the adhesive flow field. This unit, in conjunction with the temperature compensation subunit and the main control unit, transmits ultrasonic pulses into the adhesive through the transmitting end, and the receiving end captures the transmitted signal, thereby obtaining the propagation time difference and signal attenuation coefficient of the ultrasonic wave in the adhesive medium. The propagation time difference reflects the change in the sound velocity of the adhesive, which is related to the density and compressibility of the adhesive; the attenuation coefficient reflects the absorption and scattering of sound wave energy by the adhesive, which is related to the viscous resistance of the adhesive. In practical implementation, the operating frequency of the ultrasonic transceiver unit can be set according to the type of adhesive and the pipeline size, for example, it can be any frequency between 1MHz and 5MHz; this embodiment does not impose any special limitation on this.

[0058] The temperature compensation subunit refers to a temperature sensor integrated into the inner wall of the pipe or embedded in a thin layer of the pipe wall. Its name derives from its specific purpose of collecting adhesive temperature data in the boundary layer region adjacent to the pipe wall. During the hot melt adhesive delivery process, due to heat exchange between the inside and outside of the pipe, the adhesive temperature near the pipe wall often exhibits a gradient difference compared to the central region of the pipe, and the propagation speed of ultrasound is extremely sensitive to temperature. This subunit works in conjunction with the ultrasonic transceiver unit, inputting the measured boundary layer temperature as a correction parameter to the main control unit to eliminate sound velocity measurement errors caused by uneven temperature distribution. The specific implementation of the temperature compensation subunit can be a thermocouple, a resistance temperature detector (RTD), or a thin-film temperature sensor. Its installation position should ensure direct contact or very close proximity to the boundary layer adhesive; this application does not impose any special limitations on this aspect.

[0059] The main control unit can refer to a microprocessor or industrial control computer with built-in data processing algorithms. Its functional role in the overall technical solution is to perform multi-source data fusion and rheological parameter calculation. This unit receives the propagation time difference and attenuation coefficient from the ultrasonic transceiver unit, and simultaneously reads the boundary layer temperature provided by the temperature compensation subunit and the pressure value monitored by the system in real time. The main control unit internally runs a pre-trained acoustic-rheological coupled neural network model. This model is trained based on a large amount of adhesive sample data under different temperatures, pressures, and rheological states, and can map the nonlinear relationship between ultrasonic acoustic characteristics and rheological parameters. Specific model inputs are: ultrasonic propagation time difference, attenuation coefficient, boundary layer temperature, pressure (plus optional shear rate / frequency, etc.); model outputs are: key rheological parameters (such as zero shear viscosity, power law exponent, yield stress, etc.). Using a "multi-source data fusion + pre-trained model" approach, the network is trained on a large number of temperature, pressure, and rheological state samples, enabling it to learn the nonlinear mapping between ultrasonic characteristics and rheological parameters.

[0060] Specifically, the working process and principle of this application are as follows: The ultrasonic transceiver unit first transmits ultrasonic signals to the flowing adhesive liquid. After the signal penetrates the adhesive liquid, it is captured by the receiving unit on the other side. The system calculates the propagation time difference and amplitude attenuation coefficient of the signal relative to the reference state. At the same time, the temperature compensation subunit monitors the adhesive liquid temperature of the boundary layer on the inner wall of the pipeline in real time and transmits the temperature data to the main control unit. The main control unit performs spatiotemporal alignment of the acquired acoustic parameters (time difference, attenuation coefficient) with environmental parameters (boundary layer temperature, system pressure) and inputs them into the preloaded acoustic rheological coupled neural network model. After forward inference calculation, the model outputs the dynamic viscosity value and elastic modulus value of the adhesive liquid under the current working conditions. If the boundary layer temperature fluctuates, the data from the temperature compensation subunit will correct the temperature drift of the acoustic parameters in real time to ensure the accuracy of the calculation results.

[0061] Furthermore, based on the cumulative working time of the glue supply module, the real-time working pressure, and the derived glue abrasion characteristic parameters, a virtual wear model of the slit lip of the coating head is constructed. The method of outputting wear compensation commands to the adjustment structure 6 includes: obtaining the abrasion characteristic index of the current coating glue, which is obtained by looking up a table based on the filler type and proportion of the glue; calculating the virtual wear amount of the slit coating opening based on the wear correction model according to the cumulative working time of the glue supply module, the real-time working pressure, and the abrasion characteristic index; and when the virtual wear amount exceeds a preset threshold, outputting a wear compensation command to the adjustment structure 6 to adjust the position of the baffle 4 to compensate for the wear gap.

[0062] Obtaining the abrasion characteristic index of the current coating adhesive can be achieved by querying a pre-set mapping table to determine a numerical parameter characterizing the adhesive's ability to abrade the material at the coating head outlet. In this application, the abrasion characteristic index serves as a fundamental input variable for quantifying the inherent wear properties of the adhesive, used to subsequently calculate the cumulative wear effect in conjunction with operating data. This technical feature has a data-coordinated relationship with the cumulative working time and real-time working pressure of the adhesive supply module; that is, the abrasion characteristic index provides the wear coefficient at the material level, while the working time and pressure provide the cumulative factors at the time and load levels, and all three work together in the wear correction model. The index can be obtained by looking up a table based on the type and proportion of filler in the adhesive. For example, if the adhesive contains high-hardness ceramic filler with a high proportion, the abrasion characteristic index obtained from the table will be larger; if the adhesive is mainly a low-hardness polymer matrix with fewer fillers, the abrasion characteristic index obtained from the table will be smaller. The specific filler type, proportion range, and corresponding index value can be set according to the actual application's adhesive formulation database; this application does not impose any special limitations on this.

[0063] The abrasion characteristic index, obtained by looking up a table based on the filler type and proportion of the adhesive, can refer to the system's internal storage of a lookup table containing different filler types, filling ratios, and their corresponding abrasion levels or index values. In this embodiment, when the system identifies or receives the currently used adhesive formulation information, it automatically retrieves this lookup table to match the corresponding index value. This lookup method simplifies the parameter configuration process in the overall technical solution, avoids complex real-time physical testing, and thus quickly provides accurate initial parameters for the wear model. This technical feature, combined with the construction of a virtual wear model for the coating head slit lip, enables the model to perform differentiated modeling for adhesives with different compositions. The result is the generation of a basic wear coefficient adapted to the current adhesive characteristics for subsequent calculations.

[0064] Based on the cumulative working time, real-time working pressure, and abrasion characteristic index of the glue supply module, the virtual wear amount of the slit coating nozzle is calculated using a wear correction model. This involves using a preset mathematical algorithm or logical model to fuse data from the time dimension (cumulative working time), mechanical dimension (real-time working pressure), and material dimension (abrasion characteristic index) to estimate the theoretical wear size change of the slit coating nozzle due to long-term operation. In this application, this virtual wear amount serves as the basis for determining whether mechanical compensation is necessary. This technical feature is linked to the abrasion characteristic index obtained in the preceding steps and the real-time collected operating data. The wear correction model can be an empirical formula, and the specific model form can be set based on experimental data of the actual wear mechanism; this application does not impose any special limitations on this. Through the above coordination, the system can dynamically quantify the wear state of the coating head, and its result is an output value representing the current increasing gap trend.

[0065] When the virtual wear exceeds a preset threshold, a wear compensation command is output to the adjustment structure 6 to adjust the position of the baffle 4 to compensate for the wear gap. This means that when the calculated virtual wear reaches or exceeds the system's set safety tolerance value, the control logic is triggered to generate a specific drive signal. The preset threshold can be set according to the accuracy requirements of the coating process, for example, it can be 0.01 mm or 0.05 mm, etc., and this application embodiment does not make any special limitation on this. There is a direct execution cooperation relationship between this technical feature and the adjustment structure 6. That is, once it is determined that the wear exceeds the standard, a command is immediately sent to the adjustment structure 6 to drive its action to change the position of the baffle 4 relative to the housing 1, thereby reducing the outlet gap and offsetting the increase in gap caused by wear. Its functional positioning in the overall technical solution is to realize the execution link in closed-loop control. The working result formed by the above cooperation is to restore the actual working gap of the coating head to the target range and maintain the stability of the coating thickness.

[0066] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A hot melt adhesive coating head, characterized in that, The device includes a housing, a cover plate, fixing screws, a baffle, a support rod, and an adjustment structure. The housing has a material chamber and multiple liquid inlets, which are connected to the material chamber. The cover plate is connected to the housing via the fixing screws. The support rod is rotatably mounted on the housing. The baffle is fixed to the support rod and located at the outlet of the housing.

2. The hot melt adhesive coating head as described in claim 1, characterized in that, The housing has multiple flow channels.

3. A hot melt adhesive coating head as described in claim 2, characterized in that, The adjustment structure includes an adjustment motor, a first gear, and a second gear. The radius of the second gear is larger than that of the first gear. The second gear is fixedly connected to the support rod. The first gear meshes with the second gear. The output end of the adjustment motor is connected to the first gear.

4. A hot melt adhesive coating head as described in claim 3, characterized in that, The hot melt adhesive coating head also includes a heating structure, which includes a heating coil, an agitating screw, and an agitating motor. The heating coil is disposed on the housing, the agitating screw is rotatably connected to the housing and located inside the housing, and the output end of the agitating motor is connected to the agitating screw.

5. A hot melt adhesive coating head as described in claim 4, characterized in that, The hot melt adhesive coating head also includes a locking structure, which is used to lock the position of the second gear after the support rod is adjusted into place.

6. A hot melt adhesive coating head as described in claim 5, characterized in that, The locking structure includes a cylinder, a friction plate, and a clamping spring. The friction plate is slidably disposed on one side of the second gear. The output end of the cylinder is connected to the friction plate. The clamping spring is disposed between the cylinder and the friction plate.

7. An intelligent coating system, comprising a hot melt adhesive coating head as described in any one of claims 6, characterized in that, include: The online rheological property simulation module is used to collect ultrasonic and pressure signals of the adhesive in real time, and to simulate the real-time viscosity and elastic modulus of the adhesive based on a pre-built rheological dynamics model. The control module is used to receive the real-time viscosity and elastic modulus, combine them with the current displacement parameters of the glue supply module, generate a feedforward compensation signal, and send it to the heating structure to adjust the local viscosity of the glue in advance. The digital twin wear prediction module constructs a virtual wear model at the outlet of the housing based on the cumulative working time, real-time working pressure, and derived adhesive abrasion characteristics of the adhesive supply module, and outputs a gap compensation command to the adjustment structure.

8. The intelligent coating system as described in claim 7, characterized in that, The online rheological property simulation module includes an ultrasonic transceiver unit, a temperature compensation subunit, and a main control unit. The ultrasonic transceiver unit is installed on both sides of the pipeline of the glue supply module in a through-beam manner, and is used to transmit and receive ultrasonic signals that penetrate the glue liquid. The temperature compensation subunit is located on the inner wall of the pipeline and is used to obtain the temperature of the adhesive liquid in the boundary layer of the pipeline in real time. The main control unit is used to output the dynamic viscosity and elastic modulus of the adhesive in real time based on the propagation time difference and attenuation coefficient of the ultrasonic signal, combined with the temperature and pressure of the adhesive in the boundary layer of the pipe wall, and a pre-trained acoustic-rheological coupled neural network model.

9. The intelligent coating system as described in claim 8, characterized in that, The method of constructing a virtual wear model of the slit lip of the coating head based on the cumulative working time, real-time working pressure, and derived adhesive abrasion characteristic parameters of the adhesive supply module, and outputting a wear compensation command to the adjustment structure includes: obtaining the abrasion characteristic index of the current coating adhesive, wherein the abrasion characteristic index is obtained by looking up a table based on the filler type and proportion of the adhesive; calculating the virtual wear amount of the slit coating opening based on the wear correction model according to the cumulative working time, real-time working pressure, and abrasion characteristic index of the adhesive supply module; and when the virtual wear amount exceeds a preset threshold, outputting a wear compensation command to the adjustment structure to adjust the baffle position to compensate for the wear gap.

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