Hot melt adhesive coating equipment

Abstract

The invention provides hot melt adhesive coating equipment, and belongs to the technical field of processing machinery, the hot melt adhesive coating equipment comprises a first emptying shaft group, a stretching shaft group, a coating compression roller group and a second emptying shaft group which are arranged in sequence; the stretching shaft group comprises a plurality of discharging shafts which are continuously arranged and is used for discharging and guiding a first base material; the stretching shaft group comprises a stretching shaft A, a stretching shaft B, a stretching shaft C and a stretching shaft D which are oppositely arranged in pairs, and is used for stretching the first base material by adjusting the up-down and left-right positions of the stretching shafts A, B, C and D, so that the front covering effect of the first base material is changed into a new pattern; the stretching shaft group comprises two coating compression rollers which are tightly connected, and the two coating compression rollers rotate relatively to form advancing power of the first base material and the second base material and are used for carrying out compression roller type coating treatment on the first base material and the second base material; the problem that an existing stretching mechanism is difficult to finely adjust the surface texture of a base material can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of processing equipment, and in particular, relates to a hot melt adhesive coating device. Background Art

[0002] Hot melt adhesive coating process is widely used in many fields such as textile, electronics, packaging, etc. It can quickly and efficiently coat hot melt adhesive on the surface of the substrate to achieve bonding of different substrates. This coating process has the advantages of simple operation, low cost and high strength, and occupies an important position in the manufacture of various adhesive products.

[0003] At present, hot melt adhesive coating equipment mainly includes parts such as feeding mechanism, stretching mechanism, coating roller and post-processing mechanism. Its working principle is: first, the first substrate (such as hot melt adhesive) and the second substrate (such as non-woven fabric or fabric) are fed into the equipment through the feeding mechanism; then, the stretching mechanism stretches and deforms the first substrate to change its surface texture; next, the two substrates are pressed between the coating rollers to achieve the coating of hot melt adhesive. Finally, the coated substrate is cured or further processed by the post-processing mechanism.

[0004] However, there are still some problems in the actual application of existing hot melt adhesive coating equipment: first, the stretching effect of the stretching mechanism on the substrate is often difficult to control accurately, and it is difficult to achieve fine adjustment of the surface texture of the substrate; second, the heating control of the coating roller is often insufficient, and it is difficult to maintain the optimal working temperature of the hot melt adhesive, thus affecting the coating quality; in addition, the overall tension control of the equipment is also relatively extensive, and it is difficult to ensure that the substrate maintains an ideal tension state throughout the coating process. These problems will make it difficult for the performance and consistency of the final product to meet user needs. Summary of the invention

[0005] In view of this, the present invention provides a hot melt adhesive coating device, which can solve the problem of the existing stretching mechanism that it is difficult to finely adjust the surface texture of the substrate.

[0006] The present invention is achieved in that:

[0007] The present invention provides a hot melt adhesive coating device, which includes a first feeding shaft group, a stretching shaft group, a coating pressure roller group and a second feeding shaft group arranged in sequence; the first feeding shaft group includes a plurality of continuously arranged feeding shafts, which are used to feed and guide a first substrate; the stretching shaft group includes four stretching shafts A, B, C, and D which are arranged opposite to each other in pairs, which are used to stretch the first substrate by adjusting the up, down, left, and right positions of A, B, C, and D, so that the first substrate changes from a front covering effect to a new texture; the coating pressure roller group includes two tightly connected coating pressure rollers, which rotate relative to each other to form a driving force for the first substrate and the second substrate, and are used to perform pressure roller coating treatment on the first substrate and the second substrate; the second feeding shaft group is used to feed and guide the second substrate; the travel direction of the second substrate is to travel in the opposite direction to the first substrate, and the first substrate and the second substrate are tightly abutted between the coating pressure roller group.

[0008] The technical effects of a hot melt adhesive coating device provided by the present invention are as follows: First, the stretching mechanism of the present invention adopts a stretching axis group composed of four stretching axes A, B, C, and D. By accurately adjusting the up, down, left, and right positions of the four stretching axes, the stretching deformation of the first substrate (hot melt adhesive) can be effectively controlled, thereby achieving fine adjustment of its surface texture. At the same time, by establishing mathematical models such as the stretching moment balance equation and the material deformation equation, the deformation of the substrate during the stretching process can be accurately predicted and controlled to ensure that the stretching effect meets the requirements.

[0009] Secondly, the present invention has also made innovations in the design of the coating roller group. The surface of the roller is treated with Teflon material and ground with micron-level precision, which can not only improve the adhesion of the hot melt adhesive, but also minimize the generation of friction heat. At the same time, a special heating device is also set on the outer wall of the roller group, and a temperature sensor is equipped to monitor the temperature in real time, so as to accurately control the working temperature of the hot melt adhesive and ensure the coating quality.

[0010] In addition, the present invention also provides a special tension control component between the first unwinding shaft group and the stretching shaft group, including a tension sensor and a tension adjustment roller. The component can monitor and adjust the tension value of the first substrate (hot melt adhesive) in real time to ensure that it maintains an ideal tension state throughout the coating process, further improving the stability of the coating quality.

[0011] In summary, the present invention proposes a new design solution for the key problems existing in the existing hot melt adhesive coating equipment. The equipment has been deeply studied and optimized in terms of stretching control, temperature control and tension control, which can not only effectively solve the problems in the existing technology, but also significantly improve the performance and consistency of the coated products, bringing users a better use experience.

[0012] On the basis of the above technical solution, a hot melt adhesive coating device of the present invention can also be improved as follows:

[0013] Wherein, the first substrate is glue, and the second substrate is a non-woven fabric or a fabric substrate.

[0014] Wherein, the odd-numbered unloading shafts and the even-numbered unloading shafts in the first unloading shaft group are respectively arranged on both sides of the first substrate.

[0015] Furthermore, the odd-numbered unloading shafts and the even-numbered unloading shafts in the second unloading shaft group are respectively arranged on both sides of the second substrate.

[0016] Among them, the four stretching axes A, B, C and D, wherein the two stretching axes A and C and the two stretching axes B and D are respectively arranged on both sides of the first substrate.

[0017] Furthermore, the positional relationship between the four stretching axes A, B, C, and D is determined by a group of position equations formed by the material parameters of the first substrate and the second substrate and the rotation speed of the coating roller, substrate tension, stretching axis spacing, substrate thickness, and ambient temperature.

[0018] Furthermore, the first unloading shaft group includes at least three unloading shafts, and the spacing between adjacent unloading shafts is adjustable, and each unloading shaft is provided with an independent braking device for adjusting the tightness of the first substrate.

[0019] Furthermore, the surfaces of the two rollers of the coating roller group are both treated with Teflon material, and the pressure between the rollers can be adjusted by a cylinder, and the surfaces of the rollers are ground with micron-level precision.

[0020] Furthermore, the second unloading shaft group includes a plurality of continuously arranged unloading shafts, each of which is driven by a reduction motor, a tension detection device is provided between adjacent unloading shafts, and the axial directions of each unloading shaft are arranged in parallel, and the distance between the axes is adjustable; the surface of the unloading shaft is provided with an anti-slip texture to ensure the stable transportation of the second substrate.

[0021] It also includes a tension control component arranged between the first unloading shaft group and the stretching shaft group, and the tension control component includes a tension sensor and a tension adjustment roller, which are used to monitor and adjust the tension value of the first substrate in real time; it also includes a temperature control system, and the temperature control system includes a heating device and a temperature sensor, wherein the heating device is arranged on the outer wall of the coating roller group to maintain the working temperature of the hot melt adhesive; the temperature sensor is used to monitor the surface temperature of the coating roller group in real time.

[0022] The position equation group of the vector group formed by the four stretching axes A, B, C, and D is specifically expressed as follows:

[0023] 1.Basic vector definition:

[0024]

[0025]

[0026] 2. Tensile moment balance equation:

[0027]

[0028] Where, T i (i=1,2,3,4) is the tension value of each section of the substrate, in N; θ i (i=1,2,3,4) is the angle between each vector and the horizontal direction, in rad.

[0029] 3. Material deformation equation:

[0030]

[0031] In the formula, Δl i is the deformation of the substrate in the i-th section, in mm; l i is the original length, in mm; α i is the temperature compensation coefficient, ranging from 0.8 to 1.2; E i is the elastic modulus, in MPa; A i is the cross-sectional area in mm 2 β i is the coefficient of thermal expansion, in units of 1 / °C; ΔT i is the temperature change value, in °C; ∈ i is the nonlinear deformation error term, ranging from -0.1 to 0.1.

[0032] 4. Geometric constraint equations:

[0033]

[0034] 5. The relationship equation between roller speed and tension:

[0035]

[0036] In the formula, v r is the roller linear speed, in m / min; k1, k2, k3 are unknown coefficients, obtained through experimental fitting; μ i is the friction coefficient, ranging from 0.1 to 0.3.

[0037] Parameter acquisition method:

[0038] 1.T iObtained through real-time measurement by tension sensor;

[0039] 2. θ i Obtained through angle sensor measurement;

[0040] 3.E i ,A i Obtained through material property parameter table query;

[0041] 4. ΔT i Obtained through temperature sensor measurement;

[0042] 5. The steps to obtain k1, k2, and k3 are as follows:

[0043] Step 1: Measure the tension value at different roller speeds;

[0044] Step 2: Use the least squares method to fit and get the coefficient value.

[0045] Equation principle explanation:

[0046] 1. The basic vector definition is expressed in Cartesian coordinate system, which is convenient for calculation and control;

[0047] 2. The tensile moment balance equation is based on the principle of statics to ensure system stability;

[0048] 3. The material deformation equation comprehensively considers Hooke's law and thermal expansion effect, and introduces nonlinear error terms to improve accuracy;

[0049] 4. The geometric constraint equation ensures the closure and continuity of the quadrilateral;

[0050] 5. The relationship equation between roller speed and tension adopts the form of quadratic function, which can better describe the nonlinear characteristics.

[0051] Compared with the prior art, the hot melt adhesive coating device provided by the present invention has the following beneficial effects:

[0052] First, the stretching mechanism of the present invention adopts a stretching axis group composed of four stretching axes A, B, C, and D. By accurately adjusting the up, down, left, and right positions of the four stretching axes, the stretching deformation of the first substrate (hot melt adhesive) can be effectively controlled, thereby achieving fine adjustment of its surface texture. At the same time, by establishing mathematical models such as the stretching moment balance equation and the material deformation equation, the deformation of the substrate during the stretching process can be accurately predicted and controlled to ensure that the stretching effect meets the requirements.

[0053] Secondly, the present invention has also made innovations in the design of the coating roller group. The surface of the roller is treated with Teflon material and ground with micron-level precision, which can not only improve the adhesion of the hot melt adhesive, but also minimize the generation of friction heat. At the same time, a special heating device is also set on the outer wall of the roller group, and a temperature sensor is equipped to monitor the temperature in real time, so as to accurately control the working temperature of the hot melt adhesive and ensure the coating quality.

[0054] In addition, the present invention also provides a special tension control component between the first unwinding shaft group and the stretching shaft group, including a tension sensor and a tension adjustment roller. The component can monitor and adjust the tension value of the first substrate (hot melt adhesive) in real time to ensure that it maintains an ideal tension state throughout the coating process, further improving the stability of the coating quality.

[0055] In summary, the present invention proposes a new design solution for the key problems existing in the existing hot melt adhesive coating equipment. The equipment has been deeply studied and optimized in terms of stretching control, temperature control and tension control, which can not only effectively solve the problems in the existing technology, but also significantly improve the performance and consistency of the coated products, bringing users a better use experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0057] Figure 1 It is a schematic structural diagram of the first and second embodiments of a hot melt adhesive coating device;

[0058] Figure 2 It is a structural schematic diagram of an embodiment corresponding to rights 3 and 4 of a hot melt adhesive coating device.

[0059] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0060] 10. First unloading shaft group; 11. Unloading shaft; 20. Stretching shaft group; 21. Stretching shaft; 30. Coating roller group; 40. Second unloading shaft group; 50. Tension control assembly; 60. First substrate; 70. Second substrate. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0062] like Figure 2 As shown, an embodiment of a hot melt adhesive coating device provided by the present invention, in this embodiment, includes a first feeding shaft group 10, a stretching shaft group 20, a coating roller group 30 and a second feeding shaft group 40 arranged in sequence; the first feeding shaft group includes a plurality of continuously arranged feeding shafts 11, which are used to feed and guide the first substrate; the stretching shaft group includes four stretching shafts 21 A, B, C, and D which are arranged opposite to each other in pairs, which are used to stretch the first substrate 60 by adjusting the up, down, left, and right positions of A, B, C, and D, so that the first substrate changes from a front covering effect to a new texture; the coating roller group includes two tightly connected coating rollers, which rotate relative to each other to form a driving force for the first substrate and the second substrate, and are used to perform roller coating treatment on the first substrate and the second substrate 70; the second feeding shaft group is used to feed and guide the second substrate; the travel direction of the second substrate is to travel in the opposite direction to the first substrate, and the first substrate and the second substrate are tightly abutted between the coating roller group.

[0063] This set of equations introduces a temperature compensation coefficient to improve the adaptability to temperature changes; considers nonlinear deformation errors to improve model accuracy; establishes a correlation between roller speed and tension to achieve speed-tension closed-loop control; and uses a matrix form to express force balance for ease of numerical calculation.

[0064] Wherein, in the above technical solution, the first substrate is glue, and the second substrate is a non-woven fabric or a fabric substrate.

[0065] Wherein, in the above technical solution, the odd-numbered unloading axes and the even-numbered unloading axes in the first unloading axis group are respectively arranged on both sides of the first substrate.

[0066] Furthermore, in the above technical solution, the odd-numbered unloading shafts and the even-numbered unloading shafts in the second unloading shaft group are respectively arranged on both sides of the second substrate.

[0067] Among them, in the above technical solution, there are four stretching axes A, B, C, and D, among which the two stretching axes A and C and the two stretching axes B and D are respectively arranged on both sides of the first substrate.

[0068] Furthermore, in the above technical scheme, the positional relationship between the four stretching axes A, B, C, and D is determined by a group of position equations formed by material parameters of the first substrate and the second substrate, as well as the rotation speed of the coating roller, substrate tension, stretching axis spacing, substrate thickness, and ambient temperature.

[0069] Furthermore, in the above technical solution, the first unloading shaft group includes at least three unloading shafts, and the spacing between adjacent unloading shafts is adjustable, and each unloading shaft is provided with an independent braking device for adjusting the tightness of the first substrate.

[0070] Furthermore, in the above technical solution, the surfaces of the two rollers of the coating roller group are treated with Teflon material, and the pressure between the rollers can be adjusted by a cylinder, and the surfaces of the rollers are ground with micron-level precision.

[0071] Furthermore, in the above technical scheme, the second unloading shaft group includes a plurality of continuously arranged unloading shafts, each of which is driven by a reduction motor, a tension detection device is provided between adjacent unloading shafts, and the axial directions of each unloading shaft are arranged in parallel, and the distance between the axes is adjustable; the surface of the unloading shaft is provided with an anti-slip texture to ensure the stable transportation of the second substrate.

[0072] Among them, in the above technical scheme, it also includes a tension control component 50 arranged between the first unloading shaft group and the stretching shaft group, the tension control component includes a tension sensor and a tension adjustment roller, which are used to monitor and adjust the tension value of the first substrate in real time; it also includes a temperature control system, the temperature control system includes a heating device and a temperature sensor, wherein the heating device is arranged on the outer wall of the coating roller group, for maintaining the working temperature of the hot melt adhesive; the temperature sensor is used to monitor the surface temperature of the coating roller group in real time.

[0073] The hot melt adhesive coating device comprises a first feeding shaft group, a stretching shaft group, a coating roller group and a second feeding shaft group which are arranged in sequence. The first feeding shaft group is used for feeding and guiding the first substrate (such as glue). The stretching shaft group comprises four stretching shafts A, B, C and D. By adjusting the up, down, left and right positions of the four stretching shafts, the first substrate can be stretched so that the first substrate changes from a front covering effect to a new texture. The coating roller group comprises two closely connected coating rollers, which are used for forming the driving force of the first substrate and the second substrate (such as a non-woven fabric or a fabric substrate), and performing roller coating treatment on the two substrates. The second feeding shaft group is used for feeding and guiding the second substrate, and the traveling direction of the second substrate is opposite to that of the first substrate. The first substrate and the second substrate are closely abutted between the coating roller group.

[0074] The first unloading shaft group includes a plurality of unloading shafts arranged in series. The unloading shafts with odd numbers and the unloading shafts with even numbers are respectively arranged on both sides of the first substrate to ensure the smooth unloading of the first substrate. The second unloading shaft group also includes a plurality of unloading shafts arranged in series, and the unloading shafts with odd numbers and the unloading shafts with even numbers are also respectively located on both sides of the second substrate. Each unloading shaft is driven by a reduction motor, and a tension detection device is also provided between adjacent unloading shafts to monitor and adjust the tension of the substrate in real time. The surface of the unloading shaft is also provided with anti-slip patterns to ensure the stable conveying of the substrate.

[0075] The four stretching axes A, B, C, and D in the stretching axis group are arranged opposite to each other. Among them, the two stretching axes A and C and the two stretching axes B and D are respectively located on both sides of the first substrate. The specific position relationship of these four stretching axes is determined by the following position equation group:

[0076] 1.Basic vector definition:

[0077]

[0078] 2. Tensile moment balance equation:

[0079]

[0080] 3. Material deformation equation:

[0081]

[0082] 4. Geometric constraint equations:

[0083]

[0084] 5. The relationship equation between roller speed and tension:

[0085]

[0086] By real-time monitoring of the tension value T of the substrate i , angle θ i , Temperature change ΔT i By combining the material properties and the coefficients k1, k2, and k3 obtained by experimental fitting, the optimal position relationship of the four stretching axes can be determined to achieve precise stretching of the first substrate.

[0087] The coating roller group includes two rollers, both of which are treated with Teflon material and polished with micron-level precision. The pressure between the two rollers can be adjusted by a cylinder. The functions of the roller group are: 1) to provide driving force for the first substrate and the second substrate; 2) to perform roller coating treatment on the two substrates.

[0088] In order to maintain the working temperature of the hot melt adhesive, the equipment is also equipped with a temperature control system. The temperature control system includes a heating device and a temperature sensor. The heating device is set on the outer wall of the coating roller group for continuous heating. The temperature sensor is used to monitor the surface temperature of the coating roller group in real time and feed it back to the control system for closed-loop control.

[0089] A tension control component is provided between the first unwinding shaft group and the stretching shaft group, including a tension sensor and a tension adjustment roller. The component can monitor and adjust the tension value of the first substrate in real time to ensure that the substrate maintains appropriate tension during the stretching process.

[0090] It should be noted that the variables involved in the present invention are explained in detail as shown in Table 1:

[0091] Table 1 Explanation of variables

[0092]

[0093]

[0094] Example 1: Manually set the ABCD stretch axis position

[0095] like Figure 1 As shown, a hot melt adhesive coating production enterprise hopes to use the hot melt adhesive coating equipment proposed by the present invention for production. When used for the first time, the process personnel decided to manually adjust the positions of the four stretching axes A, B, C, and D.

[0096] First, the process personnel preliminarily determined the approximate positions of each stretching axis based on the material properties of the first substrate (hot melt adhesive) and the second substrate (non-woven fabric) required for production. Specifically, the two stretching axes A and C are set on the left and right sides of the first substrate, and the two stretching axes B and D are set on the upper and lower sides of the first substrate. The preliminarily determined coordinates are: A (0, 0), B (300, 400), C (600, 0), D (300, 400). The unit is mm.

[0097] Next, the process personnel turned on the equipment and observed the actual feeding of the first substrate in the stretching shaft group. It was found that the first substrate had some wavy deformation when passing through the stretching shaft group, which seriously affected the subsequent coating effect. By repeatedly adjusting the position of each stretching axis, the ideal position was finally found after the fourth adjustment: A (50, 0), B (320, 380), C (550, 0), D (320, 380).

[0098] After determining the position of the stretching axis, the process personnel also need to use the tension sensor to monitor the tension changes of the first substrate in real time during the stretching process, and adjust the tension through the tension adjustment roller to ensure that it always remains within a reasonable range. At the same time, it is also necessary to adjust the heating temperature of the coating roller to ensure that the hot melt adhesive is kept at the optimal working temperature.

[0099] After repeated debugging, we finally achieved a satisfactory coating effect. The first substrate and the second substrate fit tightly between the coating roller group, and the hot melt adhesive is evenly coated on the surface of the non-woven fabric, forming a good bond. Through testing, it was found that the peel strength, heat resistance and other indicators of the coated product met the user's requirements.

[0100] In general, although this method of manually adjusting the position of the stretching axis can ultimately achieve the desired coating effect, the process is cumbersome and requires repeated adjustments. At the same time, since it is impossible to accurately predict the deformation of the substrate, it is difficult to ensure that each adjustment can achieve the best state. Therefore, if the production scale is large or the product quality requirements are high, this manual adjustment method is obviously not suitable.

[0101] Example 2: Setting the ABCD stretching axis position by position equations

[0102] In order to further improve the production efficiency and product quality stability of the hot melt adhesive coating equipment, the enterprise decided to adopt the automated control method based on the mathematical model proposed in the present invention to determine the optimal positions of the four stretching axes A, B, C, and D.

[0103] First, according to production requirements, the process personnel obtained the relevant physical parameters of the first substrate (hot melt adhesive) and the second substrate (non-woven fabric). Among them, the elastic modulus of the hot melt adhesive is E1 = 120MPa, and the cross-sectional area is A1 = 0.2mm 2 , thermal expansion coefficient β1 = 0.00012 / ℃; elastic modulus of non-woven fabric E2 = 80MPa, cross-sectional area A2 = 0.5mm 2 , thermal expansion coefficient β2 = 0.00009 / ℃.

[0104] Then, the process personnel substitute these parameters into the mathematical model proposed by the present invention and solve it using a computer program. The specific steps are as follows:

[0105] 1.Basic vector definition:

[0106]

[0107]

[0108] 2. Tensile moment balance equation:

[0109]

[0110] Among them, T1 = 50N, T2 = 45N, T3 = 48N, T4 = 52N, θ1 = 0.3rad, θ2 = 1.2rad,

[0111] θ3=2.1rad,θ4=0.8rad.

[0112] 3. Material deformation equation:

[0113]

[0114] Among them, l1=120mm, l2=180mm, l3=150mm, l4=130mm, ΔT1=20℃, ΔT2=18℃, ΔT3=22℃, ΔT4=19℃, ∈1=0.02, ∈2=0.03, ∈3=0.04, ∈4=0.05.

[0115] 4. Geometric constraint equations:

[0116]

[0117] 5. The relationship equation between roller speed and tension:

[0118]

[0119] After experimental fitting, k1 = 0.002, k2 = 0.1, k3 = 5, μ1 = 0.15, μ2 = 0.18, μ3 = 0.16, μ4 = 0.14. When the roller linear speed v r When =8m / min, the tension values ​​of each section of the substrate are: T1=50.12N, T2=45.26N, T3=48.09N, T4=51.88N.

[0120] Through the above series of calculations, the optimal position coordinates of the four stretching axes A, B, C, and D are finally determined as: A (60, 0), B (310, 370), C (540, 0), and D (310, 370). This position scheme not only meets the torque balance and geometric constraints, but also ensures that the first substrate (hot melt adhesive) maintains an ideal deformation state during the stretching process, creating good prerequisites for the subsequent coating process.

[0121] Compared with the manual adjustment method in Example 1, this automated adjustment method based on a mathematical model has the following advantages:

[0122] 1. It can more accurately predict and control the deformation of the first substrate (hot melt adhesive) during the stretching process, thereby ensuring that its surface texture reaches an ideal state and laying the foundation for the subsequent coating process.

[0123] 2. By establishing a correlation between the roller speed and tension, the roller speed can be adjusted in real time to ensure that the first substrate and the second substrate maintain appropriate tension during the coating process, further improving the stability of the coating quality.

[0124] 3. The entire adjustment process is completed automatically by the computer without manual intervention, which greatly shortens the equipment debugging time and improves production efficiency.

[0125] 4. This method is highly versatile. As long as the corresponding material parameters are input, the optimal stretching axis position can be quickly determined. It is suitable for hot melt adhesive coating production of different specifications and different substrates.

[0126] Specifically, the principle of the present invention is: the core innovation in the design of the hot melt adhesive coating equipment proposed by the present invention is mainly reflected in the stretching mechanism, temperature control system and tension control components.

[0127] First, the stretching mechanism uses a stretching axis group consisting of four stretching axes A, B, C, and D. By adjusting the positions of these four stretching axes, the stretching deformation of the first substrate (hot melt adhesive) can be accurately controlled. Compared with traditional uniaxial stretching, this stretching method has stronger controllability and flexibility.

[0128] In order to achieve precise control of the stretching process, the present invention establishes a complete set of mathematical models.

[0129] First, the basic vector relationship between the four stretching axes is defined:

[0130]

[0131] Then, the tensile moment equilibrium equation is established to ensure that the entire tensile system is in a static equilibrium state:

[0132]

[0133] In addition, the material deformation equation and geometric constraint equation were established, which comprehensively considered the influence of temperature, tension and other factors on the tensile deformation of the substrate:

[0134]

[0135] By measuring and controlling these parameters in real time, the positions of the four stretching axes can be precisely adjusted, thereby achieving fine adjustment of the surface texture of the first substrate (hot melt adhesive).

[0136] Secondly, the present invention has also made innovations in the design of the temperature control system. A special heating device is set on the outer wall of the coating roller group, and a temperature sensor is equipped to monitor the temperature in real time. Through closed-loop control, it can ensure that the hot melt adhesive is always kept at the optimal working temperature, avoiding coating quality problems caused by high or low temperature.

[0137] Finally, the present invention also makes an optimized design in terms of tension control. A tension control component is added between the first unwinding shaft group and the stretching shaft group, including a tension sensor and a tension adjustment roller. The component can monitor and adjust the tension value of the first substrate (hot melt adhesive) in real time to ensure that it maintains an ideal tension state throughout the coating process, thereby further improving the stability of the coating quality. At the same time, the correlation equation between the pressure roller speed and the tension is also established:

[0138]

[0139] By real-time measurement and control of the pressure roller speed and the coefficient obtained by fitting, the tension value of the first substrate can be effectively adjusted to achieve precise control of the tension.

[0140] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A hot melt adhesive coating device, characterized in that: It includes a first unloading shaft group, a stretching shaft group, a coating roller group and a second unloading shaft group arranged in sequence; the first unloading shaft group includes a plurality of continuously arranged unloading shafts for unloading and guiding the first substrate; the stretching shaft group includes four stretching shafts A, B, C, and D which are arranged opposite to each other in pairs, and are used to stretch the first substrate by adjusting the up, down, left, and right positions of A, B, C, and D, so that the first substrate changes from a front covering effect to a new texture; the coating roller group includes two tightly connected coating rollers, which rotate relative to each other to form a driving force for the first substrate and the second substrate, and are used to perform roller coating treatment on the first substrate and the second substrate; the second unloading shaft group is used to unload and guide the second substrate; the traveling direction of the second substrate is to travel in the opposite direction to the first substrate, and the first substrate and the second substrate are tightly abutted between the coating roller group.

2. A hot melt adhesive coating device according to claim 1, characterized in that: The first substrate is glue, and the second substrate is a non-woven fabric or a fabric substrate.

3. The hot melt adhesive coating device according to claim 1, characterized in that: The odd-numbered unloading shafts and the even-numbered unloading shafts in the first unloading shaft group are respectively arranged on both sides of the first substrate.

4. A hot melt adhesive coating device according to claim 3, characterized in that: The odd-numbered unloading shafts and the even-numbered unloading shafts in the second unloading shaft group are respectively arranged on both sides of the second substrate.

5. The hot melt adhesive coating device according to claim 1, characterized in that: The four stretching axes A, B, C, and D, wherein the two stretching axes A and C and the two stretching axes B and D are respectively arranged on both sides of the first substrate.

6. A hot melt adhesive coating device according to claim 5, characterized in that: The positional relationship between the four stretching axes A, B, C, and D is determined by a group of position equations formed by the material parameters of the first substrate and the second substrate and the rotation speed of the coating roller, substrate tension, stretching axis spacing, substrate thickness, and ambient temperature.

7. A hot melt adhesive coating device according to claim 6, characterized in that: The first unloading shaft group includes at least three unloading shafts, and the spacing between adjacent unloading shafts is adjustable. Each unloading shaft is provided with an independent braking device for adjusting the tightness of the first substrate.

8. The hot melt adhesive coating device according to claim 7, characterized in that: The surfaces of the two pressure rollers of the coating pressure roller group are both processed with Teflon material, and the pressure between the pressure rollers can be adjusted by a cylinder, and the surfaces of the pressure rollers are ground with micron-level precision.

9. The hot melt adhesive coating device according to claim 8, characterized in that: The second unloading shaft group includes a plurality of unloading shafts arranged in series, each of which is driven by a reduction motor, a tension detection device is provided between adjacent unloading shafts, and the axes of each unloading shaft are arranged in parallel, and the distance between the axes is adjustable; the surface of the unloading shaft is provided with anti-slip textures to ensure stable transportation of the second substrate.

10. The hot melt adhesive coating device according to claim 1, characterized in that: It also includes a tension control component arranged between the first unloading shaft group and the stretching shaft group, and the tension control component includes a tension sensor and a tension adjustment roller, which are used to monitor and adjust the tension value of the first substrate in real time; it also includes a temperature control system, and the temperature control system includes a heating device and a temperature sensor, wherein the heating device is arranged on the outer wall of the coating roller group to maintain the working temperature of the hot melt adhesive; the temperature sensor is used to monitor the surface temperature of the coating roller group in real time.

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