Method and system for calculating pre-registration oven parameters of water-based ink paper gravure press

Abstract

The invention discloses a water-based ink paper gravure press pre-registration oven parameter calculation method and system, and belongs to the technical field of paper gravure press electronic shaft control systems. The calculation method comprises the following steps that printing process parameters and environmental parameters are collected, and the evaporation rate of water in paper and the evaporation rate of water in ink are calculated; in combination with the evaporation rate of water in the ink, according to an ink water evaporation rate equation and a constant-speed drying stage energy conservation equation, the oven temperature and the front oven air speed are obtained; calculating the wind speed of the reverse drying oven according to a paper water evaporation rate equation and a constant-speed drying stage energy conservation equation in combination with the paper water evaporation rate; and assigning the oven temperature, the front oven air speed and the back oven air speed to the corresponding pre-registration oven parameter variables. The method is used for solving the problems of large error and long adjustment time caused by dependence on worker experience in the pre-registration oven parameter setting process, can improve the pre-registration oven parameter setting efficiency and precision, reduces the waste of paper base materials in the pre-registration link, and has the characteristics of simple calculation, high precision and high efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic axis control systems of paper gravure printing machines, and in particular relates to a method and system for calculating parameters of a pre-registration oven of a water-based ink paper gravure printing machine. Background Art

[0002] As the core equipment of packaging and printing equipment, water-based ink paper gravure printing machine is widely used in food, beverage, cigarette, medicine, cosmetics, clothing, decorative paper and other industrial fields. The pre-registration link is the core step for paper gravure printing machine to achieve high-efficiency start-up printing production. The precise setting of oven pre-registration parameters is also the basis for achieving high-precision control of lateral expansion and contraction registration error.

[0003] However, in actual engineering printing, the pre-registration parameter setting of the oven depends on the operator's experience and printing formula parameters. It is affected by many factors such as ink and paper printing adaptability, hot air evaporation and drying, paper deformation and expansion, and the coupling mechanism is complex, resulting in a complex and inefficient oven parameter setting process. There is also a large error with the actual oven parameter setting, which seriously hinders the development of paper gravure printing machines towards high speed, high efficiency and intelligence. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a method and system for calculating the pre-registration oven parameters of a water-based ink paper gravure printing machine, so as to solve the problems of large errors and long adjustment time caused by relying on workers' experience in the process of setting the pre-registration oven parameters, which can improve the efficiency and accuracy of setting the pre-registration oven parameters, reduce the waste of paper substrate in the pre-registration link, and has the characteristics of simple calculation, high accuracy and high efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for calculating parameters of a pre-registration oven of a water-based ink paper gravure printing machine, comprising the following steps:

[0007] Collect printing process parameters and environmental parameters, and calculate the evaporation rate of water in paper and ink;

[0008] Combined with the evaporation rate of water in the ink, the oven temperature and the front oven wind speed are obtained according to the ink evaporation rate equation and the energy conservation equation in the constant drying stage;

[0009] Combined with the evaporation rate of water in the paper, the wind speed of the reverse oven is calculated according to the evaporation rate equation of water in the paper and the energy conservation equation in the constant drying stage;

[0010] Assign the oven temperature, front oven wind speed and back oven wind speed to the corresponding pre-register oven parameter variables.

[0011] In one embodiment, the printing process parameters include printing speed, ink application amount, water content in ink, and water absorption rate of paper; and the environmental parameters include ambient humidity and ambient temperature.

[0012] In one embodiment, the process of calculating the evaporation rate of water in paper and the evaporation rate of water in ink is as follows:

[0013] Obtain and calculate the evaporation rate of water in the paper based on the water mass in the ink absorbed by the paper, the length of the paper in the oven and the printing speed;

[0014] The evaporation rate of water in the ink is obtained and calculated based on the water mass in the ink after printing, the length of paper in the oven and the printing speed.

[0015] In one embodiment, the calculation formula for the evaporation rate of water in the paper is as follows:

[0016]

[0017] In the formula, m′ p is the evaporation rate of water in paper, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed;

[0018] The calculation formula of the water evaporation rate in the ink is as follows:

[0019]

[0020] In the formula, m s ' is the evaporation rate of water in the ink, m s is the water mass in the initial state of the ink, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

[0021] In one embodiment, the specific expression for calculating the oven temperature is:

[0022]

[0023] Where, T A is the oven temperature, m s ' is the evaporation rate of water in the ink, h fg is the latent heat of vaporization of water, ρ A is the hot air density, c A is the specific heat capacity of hot air, T s is the ink temperature when drying is completed, k c is the convective mass transfer coefficient of the front oven, and Le is the Lewis number.

[0024] In one embodiment, the convective mass transfer coefficient k of the front oven is calculated c The specific expression is as follows:

[0025]

[0026] In the formula, k c is the convective mass transfer coefficient of the front oven, R u is the universal gas constant, A s is the ink printing area, M s is the molar mass of water in the ink, P s is the saturated vapor pressure of the ink, m s ' is the evaporation rate of water in the ink, T s It is the ink temperature when drying is completed.

[0027] In one embodiment, the specific expression for calculating the front oven wind speed is:

[0028]

[0029] Where, V1 is the front oven wind speed, L c is the characteristic length, ρ A is the hot air density, u is the oven temperature T A Re is the Reynolds number.

[0030] In one embodiment, the specific expression for calculating the wind speed of the reverse oven is:

[0031]

[0032] Where V2 is the wind speed of the reverse oven, α, β and δ are empirical parameters, and their value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, and K ct is the convection mass transfer coefficient of the reverse oven, B is the nozzle diameter, ρ A is the hot air density, c A is the specific heat capacity of hot air, Le is the Lewis number, λ A is the thermal conductivity of hot air, u is the oven temperature T A Dynamic viscosity of air under c is the characteristic length.

[0033] In one embodiment, the convection mass transfer coefficient K of the counter oven is ct The calculation method is as follows:

[0034]

[0035] In the formula, K ct is the convection mass transfer coefficient of the reverse oven, A is the paper area, Mw is the molar mass of water, ΔH v is the enthalpy of water vapor evaporating from the paper, ΔH s is the adsorption heat of water in paper, m′ p is the evaporation rate of water in paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in paper, P tot is the saturated vapor pressure in the environment, ρ A is the hot air density, c A is the specific heat of hot air, and Le is the Lewis number.

[0036] The present invention also provides a system for calculating parameters of a pre-registration oven for a water-based ink paper gravure printing machine, comprising:

[0037] The water evaporation rate acquisition module is used to collect printing process parameters and environmental parameters, and calculate the water evaporation rate in the paper and the water evaporation rate in the ink;

[0038] The oven temperature and front oven wind speed acquisition module is used to obtain the oven temperature and front oven wind speed based on the ink water evaporation rate equation and the energy conservation equation in the constant drying stage in combination with the water evaporation rate in the ink;

[0039] The reverse oven wind speed acquisition module is used to calculate the reverse oven wind speed based on the water evaporation rate in the paper, the water evaporation rate equation in the paper, and the energy conservation equation in the constant speed drying stage;

[0040] The parameter assignment module is used to assign the oven temperature, the front oven wind speed and the back oven wind speed to the corresponding pre-register oven parameter variables.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The method for calculating the pre-registration oven parameters of the water-based ink paper gravure printing machine proposed in the present invention divides the printing and drying process into two links: the evaporation of water in the ink absorbed by the paper and the evaporation of water in the ink, and the front oven evaporates the water in the water-based ink, and the back oven evaporates the water in the ink absorbed by the paper. Based on the evaporation rate of water in the paper and the water-based ink, according to the water drying rate equation and energy balance equation of the paper and the water-based ink, the theoretical oven temperature and the front and back oven wind speed required for the complete evaporation of the water in the ink absorbed by the paper and the water in the ink are calculated, and finally, the calculated oven temperature and front and back oven wind speed are assigned to the corresponding pre-registration oven parameter variables. The method proposed in the present invention avoids the setting method that is heavily dependent on the experience of the operator and the printing formula, realizes the accurate calculation of the oven parameters during the pre-registration of the paper gravure printing machine, and solves the problem of long time and low precision in the setting of oven parameters during the pre-registration of the water-based ink paper gravure printing machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the calculation flow of the method for calculating the parameters of the pre-registration oven of the water-based ink paper gravure printing machine provided by the present invention;

[0044] Figure 2 It is a schematic diagram of a calculation flow of a method for calculating parameters of a pre-registration oven of a water-based ink paper gravure printing machine provided by an embodiment;

[0045] Figure 3 This is a schematic diagram of the water drying principle of water-based ink paper printing in the present invention;

[0046] Figure 4 This is a schematic diagram of the oven structure of the water-based ink paper gravure printing machine of the present invention;

[0047] Figure 5 It is a schematic diagram of a system for calculating parameters of a pre-registration oven for a water-based ink paper gravure printing machine in the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0051] The present invention aims at the technical problems of large errors and long adjustment time caused by relying on workers' experience in the process of setting pre-registration oven parameters. By collecting physical parameters such as printing speed, ink, paper, etc., the oven temperature and the front and back oven wind speed are calculated according to the evaporation rate equation of water in ink and paper and the energy conservation equation in the constant speed drying stage. A pre-registration oven parameter calculation method in the key technical field of electronic axis control system of water-based ink paper gravure printing machine is proposed. The calculation speed of oven pre-registration parameters is improved while ensuring accuracy, reducing the waste of paper substrate in the pre-registration link, and providing key technical support for the one-key startup of packaging printing equipment and the development of pre-registration system.

[0052] The above-mentioned method for calculating the parameters of a pre-registration oven for a water-based ink paper gravure printing machine includes the following steps: collecting printing speed, ink application amount and physical parameters of paper ink, and calculating the evaporation rate of water content of the ink paper; calculating the oven temperature and the front oven wind speed according to the evaporation rate equation of the water-based ink and the energy conservation equation in the constant-speed drying stage; calculating the back oven wind speed according to the evaporation rate equation of water content in the paper and the energy conservation equation in the constant-speed drying stage; and assigning the calculated oven temperature, front oven wind speed and back oven wind speed to the corresponding pre-registration oven parameter variables.

[0053] like Figure 1 As shown, the method for calculating the pre-registration oven parameters of a water-based ink paper gravure printing machine proposed in the present invention realizes the accurate calculation of the oven parameters during the pre-registration of the paper gravure printing machine, and solves the problem of time-consuming and low-precision oven parameter setting during the pre-registration of the water-based ink paper gravure printing machine.

[0054] Specifically, Figure 1 As shown, the method for calculating the parameters of the pre-registration oven of the water-based ink paper gravure printing machine comprises the following steps:

[0055] S1: Collect printing process parameters and environmental parameters, and calculate the evaporation rate of water in paper and ink;

[0056] Among them, the printing process parameters include printing speed, ink application amount, water content in ink, and water absorption rate of paper; and the environmental parameters include ambient humidity and ambient temperature.

[0057] The process of calculating the evaporation rate of water in paper and the evaporation rate of water in ink is as follows:

[0058] S01: Obtain and calculate the evaporation rate of water in the paper based on the water mass in the ink absorbed by the paper, the length of the paper in the oven and the printing speed;

[0059] S02: Obtain and calculate the evaporation rate of water in the ink based on the water mass in the ink after printing, the length of the paper in the oven and the printing speed.

[0060] Specifically, the calculation formula for the evaporation rate of water in paper is as follows:

[0061]

[0062] In the formula, m′ p is the evaporation rate of water in paper, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

[0063] Specifically, the calculation formula for the evaporation rate of water in the ink is as follows:

[0064]

[0065] In the formula, m s ' is the evaporation rate of water in the ink, m s is the water mass in the initial state of the ink, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

[0066] S2: Combined with the evaporation rate of water in the ink, the oven temperature and the front oven wind speed are obtained according to the ink evaporation rate equation and the energy conservation equation in the constant drying stage;

[0067] The specific expression for calculating the oven temperature is:

[0068]

[0069] Where, T A is the oven temperature, m s ' is the evaporation rate of water in the ink, h fg is the latent heat of vaporization of water, ρ A is the hot air density, cA is the specific heat capacity of hot air, T s is the ink temperature when drying is completed, k c is the convective mass transfer coefficient of the front oven, and Le is the Lewis number.

[0070] Calculate the convective mass transfer coefficient k of the above front oven c The specific expression is as follows:

[0071]

[0072] In the formula, k c is the convective mass transfer coefficient of the front oven, R u is the universal gas constant, A s is the ink printing area, M s is the molar mass of water in the ink, P s is the saturated vapor pressure of the ink, m s ' is the evaporation rate of water in the ink, T s It is the ink temperature when drying is completed.

[0073] The specific expression for calculating the front oven wind speed is:

[0074]

[0075] Where, V1 is the front oven wind speed, L c is the characteristic length, ρ A is the hot air density, u is the oven temperature T A Re is the Reynolds number.

[0076] S3: Combined with the evaporation rate of water in the paper, the reverse oven wind speed is calculated according to the evaporation rate equation of water in the paper and the energy conservation equation in the constant drying stage;

[0077] The specific expression for calculating the wind speed of the reverse oven is:

[0078]

[0079] Where V2 is the wind speed of the reverse oven, α, β and δ are empirical parameters, and their value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, and K ct is the convection mass transfer coefficient of the reverse oven, B is the nozzle diameter, ρ A is the hot air density, c A is the specific heat capacity of hot air, Le is the Lewis number, λ A is the thermal conductivity of hot air, u is the oven temperature T A Dynamic viscosity of air under c is the characteristic length.

[0080] Convective mass transfer coefficient K of the reverse oven ct The calculation method is as follows:

[0081]

[0082] In the formula, K ct is the convection mass transfer coefficient of the reverse oven, A is the paper area, M w is the molar mass of water, ΔH v is the enthalpy of water vapor evaporating from the paper, ΔH s is the adsorption heat of water in paper, m′ p is the evaporation rate of water in paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in paper, P tot is the saturated vapor pressure in the environment, ρ A is the hot air density, c A is the specific heat of hot air, and Le is the Lewis number.

[0083] S4: Assign the oven temperature, the front oven wind speed, and the back oven wind speed to the corresponding pre-registration oven parameter variables.

[0084] See also Figure 2 In another embodiment, a method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine comprises the following steps:

[0085] Step 1: Collect printing speed, inking amount, physical parameters of ink and paper, and ambient humidity and temperature;

[0086] Step 2: Calculate the evaporation rate of water in paper and ink:

[0087] Compared with film printing, the process of paper drying in the hot air oven after printing not only includes the evaporation of water in the ink, but also includes the evaporation of water absorbed by the paper in the ink, such as Figure 3 In order to simplify the modeling of the drying mechanism of ink and paper, it is assumed that when the paper enters the drying oven, the front oven dries the ink, and the back oven dries the moisture in the paper. The front and back ovens are separated by paper, and the drying of ink and paper does not affect each other, as shown in Figure 2. Figure 4 shown.

[0088] During the hot air drying process, the evaporation stage of water in paper and ink mainly includes the constant speed drying and the decreasing speed drying stage. Most of the water in paper and ink evaporates in the constant speed drying stage, and the water in the decreasing speed stage is negligible. Therefore, the evaporation rate of water in paper is:

[0089]

[0090] In the formula, m′ p is the evaporation rate of water in paper, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

[0091] Evaporation rate of water in ink:

[0092]

[0093] In the formula, m s ' is the evaporation rate of water in the ink, m s is the water mass in the initial state of the ink, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

[0094] Step 3: Calculate the oven temperature T based on the ink water evaporation rate equation and the energy conservation equation in the constant drying stage. A , the front oven speed V1, the specific expression is:

[0095]

[0096] Where, T A is the oven temperature, m s ' is the evaporation rate of water in the ink, h fg is the latent heat of vaporization of water, ρ A is the hot air density, c A is the specific heat capacity of hot air, T s is the ink temperature when drying is completed, the value range is [100℃, 120℃], k c is the convective mass transfer coefficient of the front oven, Le is the Lewis number, and the specific expression is as follows:

[0097]

[0098] In the formula, k c is the convective mass transfer coefficient of the front oven, R u is the universal gas constant, A s is the ink printing area, M s is the molar mass of water in the ink, P s is the saturated vapor pressure of the ink, m s ' is the evaporation rate of water in the ink, T s It is the ink temperature when drying is completed.

[0099] Among them, Le is the Lewis number, and the specific calculation expression is as follows:

[0100]

[0101] Among them, λA is the thermal conductivity of hot air, ρ A is the hot air density, c A is the specific heat capacity of hot air, D A is the diffusion coefficient of water vapor in hot air.

[0102] Furthermore, according to the convection heat transfer coefficient, the front oven speed V1 is calculated, and the specific expression is:

[0103]

[0104] Where, V1 is the front oven wind speed, L c is the characteristic length, u is the oven temperature T A The dynamic viscosity of air under , Re is the Reynolds number, and the specific calculation method is:

[0105]

[0106] Among them, α, β and δ are empirical parameters, and their value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, B is the nozzle diameter, is the Nusselt number, which is calculated as follows:

[0107]

[0108] In the formula, is the convective heat transfer coefficient. The relationship between the convective heat transfer coefficient and the convective mass transfer coefficient is as follows:

[0109]

[0110] Step 4: Calculate the reverse oven wind speed V2 based on the water evaporation rate equation in the paper and the energy conservation equation in the constant drying stage. The specific expression is:

[0111]

[0112] Where V2 is the wind speed of the reverse oven, α, β and δ are empirical parameters with value ranges of [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30], respectively, B is the nozzle diameter, ρ A is the hot air density, c A is the specific heat capacity of hot air, Le is the Lewis number, λ A is the thermal conductivity of hot air, u is the oven temperature T A Dynamic viscosity of air under c is the characteristic length, K ct is the convection mass transfer coefficient of the reverse oven, which is calculated as follows:

[0113]

[0114] In the formula, K ct is the convection mass transfer coefficient of the reverse oven, A is the paper area, M w is the molar mass of water, ΔH v is the enthalpy of water vapor evaporating from the paper, ΔH s is the adsorption heat of water in paper, m′ p is the evaporation rate of water in paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in paper, P tot is the saturated vapor pressure in the environment, ρ A is the hot air density, c A is the specific heat of hot air, and Le is the Lewis number.

[0115] Step 5: Set the calculated oven temperature T A , the front oven wind speed V1, and the back oven wind speed V2 are assigned to the corresponding pre-register oven parameter variables.

[0116] In a specific embodiment, the method for calculating the parameters of the pre-registration oven of the water-based ink paper gravure printing machine comprises the following steps:

[0117] Step 1: Collect printing process parameters and environmental parameters, specifically:

[0118] Printing speed: 300m / min, ink volume: 3g / m 2 , water content in water-based ink: 33%, paper: 220g white cardboard, water absorption rate 10%, ambient temperature: 20℃, ambient humidity 30%, paper length in the oven L = 5m,

[0119] Step 2: Based on the above-collected printing speed, ink amount and material parameters, calculate the evaporation rate of water in the paper and ink; the calculation expression of the evaporation rate of water in the paper and ink is shown in formula (1) and formula (2);

[0120] From formula (1), we can know that the evaporation rate of water in paper is: m′ p =0.0005kg / s;

[0121] From formula (2), we can know that the evaporation rate of water in ink is: m s ′=0.0045kg / s;

[0122] Step 3: Calculate the oven temperature T based on the ink water evaporation rate equation and the energy conservation equation in the constant drying stage. A , the front oven wind speed V1, the calculation results are as follows:

[0123] Oven temperature: TA =142℃

[0124] Front oven wind speed: V1 = 0.86m 3 / s=3096m 3 / h

[0125] Step 4: Calculate the reverse oven wind speed V2 based on the water evaporation rate equation in the paper and the energy conservation equation in the constant drying stage. The calculation results are as follows;

[0126] Reverse oven parameter V2 = 0.35m 3 / s=1260m 3 / h

[0127] Step 5: Set the calculated oven temperature T A , the front oven wind speed V1, and the back oven wind speed V2 are assigned to the corresponding pre-register oven parameter variables.

[0128] In one embodiment, if Figure 5 As shown, a pre-registration oven parameter calculation system for a water-based ink paper gravure printing machine is provided, including a water evaporation rate acquisition module, an oven temperature and a front oven wind speed acquisition module, a back oven wind speed acquisition module, and a parameter adjustment assignment module;

[0129] The water evaporation rate acquisition module is used to collect printing process parameters and environmental parameters, and calculate the water evaporation rate in the paper and the water evaporation rate in the ink;

[0130] The oven temperature and front oven wind speed acquisition module is used to obtain the oven temperature and front oven wind speed based on the ink water evaporation rate equation and the energy conservation equation in the constant drying stage in combination with the water evaporation rate in the ink;

[0131] The reverse oven wind speed acquisition module is used to calculate the reverse oven wind speed based on the water evaporation rate in the paper, the water evaporation rate equation in the paper, and the energy conservation equation in the constant speed drying stage;

[0132] The parameter assignment module is used to assign the oven temperature, the front oven wind speed and the back oven wind speed to the corresponding pre-register oven parameter variables.

[0133] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for calculating the parameters of a pre-register oven for a water-based ink paper gravure printing machine, characterized in that: The following steps are involved: Collect printing process parameters and environmental parameters, and calculate the evaporation rate of water in paper and ink; Combined with the evaporation rate of water in the ink, the oven temperature and the front oven wind speed are obtained according to the ink evaporation rate equation and the energy conservation equation in the constant drying stage; Combined with the evaporation rate of water in the paper, the wind speed of the reverse oven is calculated according to the evaporation rate equation of water in the paper and the energy conservation equation in the constant drying stage; Assign the oven temperature, front oven wind speed and back oven wind speed to the corresponding pre-register oven parameter variables.

2. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that: The printing process parameters include printing speed, ink application amount, water content in ink, and water absorption rate of paper; the environmental parameters include ambient humidity and ambient temperature.

3. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that: The process of calculating the evaporation rate of water in paper and the evaporation rate of water in ink is as follows: Obtain and calculate the evaporation rate of water in the paper based on the water mass in the ink absorbed by the paper, the length of the paper in the oven and the printing speed; The evaporation rate of water in the ink is obtained and calculated based on the water mass in the ink after printing, the length of paper in the oven and the printing speed.

4. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 3, characterized in that: The calculation formula of the water evaporation rate in the paper is as follows: Where m′ p is the evaporation rate of water in paper, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed; The calculation formula of the water evaporation rate in the ink is as follows: In the formula, m s ' is the evaporation rate of water in the ink, m s is the water mass in the initial state of the ink, m p is the mass of water absorbed by the paper from the ink, L is the length of the paper in the oven, and v is the printing speed.

5. The method for calculating parameters of pre-register oven for water-based ink paper gravure printing machine according to claim 1, characterized in that: The specific expression for calculating the oven temperature is: Where, T A is the oven temperature, m s ' is the evaporation rate of water in the ink, h fg is the latent heat of vaporization of water, ρ A is the hot air density, c A is the specific heat capacity of hot air, T s is the ink temperature when drying is completed, k c is the convective mass transfer coefficient of the front oven, and Le is the Lewis number.

6. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 5, characterized in that: Calculate the convective mass transfer coefficient k of the front oven c The specific expression is as follows: In the formula, k c is the convective mass transfer coefficient of the front oven, R u is the universal gas constant, A s is the ink printing area, M s is the molar mass of water in the ink, P s is the saturated vapor pressure of the ink, m s ' is the evaporation rate of water in the ink, T s It is the ink temperature when drying is completed.

7. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that: The specific expression for calculating the front oven wind speed is: Where, V1 is the front oven wind speed, L c is the characteristic length, ρ A is the hot air density, u is the oven temperature T A Re is the Reynolds number.

8. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that: The specific expression for calculating the wind speed of the reverse oven is: Where V2 is the wind speed of the reverse oven, α, β and δ are empirical parameters, and their value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, and K ct is the convection mass transfer coefficient of the reverse oven, B is the nozzle diameter, ρ A is the hot air density, c A is the specific heat capacity of hot air, Le is the Lewis number, λ A is the thermal conductivity of hot air, u is the oven temperature T A Dynamic viscosity of air under c is the characteristic length.

9. The method for calculating parameters of a pre-register oven for a water-based ink paper gravure printing machine according to claim 8, characterized in that: The convection mass transfer coefficient K of the reverse oven ct The calculation method is as follows: In the formula, K ct is the convection mass transfer coefficient of the reverse oven, A is the paper area, M w is the molar mass of water, ΔH v is the enthalpy of water vapor evaporating from the paper, ΔH s is the adsorption heat of water in paper, m′ p is the evaporation rate of water in paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in paper, P tot is the saturated vapor pressure in the environment, ρ A is the hot air density, c A is the specific heat of hot air, and Le is the Lewis number.

10. A system for calculating parameters of pre-register oven for water-based ink paper gravure printing machine, characterized in that: include: The water evaporation rate acquisition module is used to collect printing process parameters and environmental parameters, and calculate the water evaporation rate in the paper and the water evaporation rate in the ink; The oven temperature and front oven wind speed acquisition module is used to obtain the oven temperature and front oven wind speed based on the ink water evaporation rate equation and the energy conservation equation in the constant drying stage in combination with the water evaporation rate in the ink; The reverse oven wind speed acquisition module is used to calculate the reverse oven wind speed based on the water evaporation rate in the paper and the energy conservation equation in the constant speed drying stage in combination with the water evaporation rate in the paper; The parameter assignment module is used to assign the oven temperature, the front oven wind speed and the back oven wind speed to the corresponding pre-register oven parameter variables.

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