Temperature gradient regulation process in bio-base membrane processing

Abstract

The present application relates to the field of degradable agricultural mulching film hot-pressing composite shaping processing technology, and discloses a temperature gradient regulation process in biological base film processing, which uses a laminator to apply initial contact pressure to a laminated assembly composed of a thermoplastic plastic layer and a porous base material layer and set an asymmetric steady-state thermal gradient field, collects temperature difference and heat flux in real time during laminating heating to calculate transient equivalent thermal resistance and its time rate of change, and turns off the active heating source and opens the forced cooling loop when the absolute value of the negative mutation of the time rate of change exceeds the infiltration phase change threshold, and uses the residual heat in the assembly to drive the thermoplastic plastic melt to fill the porous base material layer. The present application realizes the instant reshaping of the heat boundary in the infiltration stage through the extraction of material phase change heat coupling characteristics, eliminates the thermal degradation of the skeleton fiber caused by the thermal overload in the later stage, and cooperatively improves the mechanical interlocking quality and the ultimate tensile strength of the mulching film.

Description

Technical Field

[0001] This invention belongs to the field of hot-pressing composite shaping and processing technology of biodegradable agricultural mulch film, and particularly relates to a temperature gradient control process in the processing of biological base film. Background Technology

[0002] Currently, in the hot pressing process for preparing multiphase bio-based materials, laminating natural polymer fiber skeletons with thermoplastic resins is a common method for producing high-strength biodegradable agricultural mulch films. The processing mainly relies on the upper and lower pressure surfaces of the hot pressing mechanism to apply contact pressure and heat to the laminated structure, causing the thermoplastic resin to flow and deform to impregnate the porous fiber network. Since the activation and migration of amorphous resin macromolecular chain segments depend on specific temperature conditions, and natural porous fibers exhibit a specific degree of thermosensitive characteristics in the temperature-bearing range, the heat transfer law of the two-phase materials during the densification and composite process directly determines the mechanical interlocking quality of the final mulch film.

[0003] However, such composite laminate systems exhibit drastic nonlinear thermodynamic evolution within the closed heated cavity. With the continuous application of contact pressure and the melting of the thermoplastic resin, the voids within the fibers, initially filled with air of extremely low thermal conductivity, gradually transform into a densely packed state of polymer melt. This material rheological displacement and phase change recombination process causes an irreversible, step-like decrease in the equivalent thermal resistance along the thickness direction of the composite layer within a very short period. Furthermore, the molding process control logic exhibits lag. For example, Chinese invention patent application CN119458923A discloses an intelligent temperature control system and method for hot-pressing composite equipment. It pre-constructs a static mathematical model encompassing mold temperature, part surface temperature, and ambient temperature, and calculates heating parameters based on production cycle time to achieve on-demand heating. However, in the actual continuous processing of biofilm, the heat transfer boundary of the multiphase interlayer material undergoes unsteady evolution, resulting in a significant decrease in thermal resistance. The above solutions rely on static function models and data fitting, which are dynamically affected by material batches, fiber density, and micro-wetting speed. They are macroscopic predictions of the heat transfer endpoint and cannot detect and capture the real-time thermorheological changes caused by the air displacement effect at the interface. The fundamental mismatch between the static model preset and the dynamic phase change evolution makes it impossible for the control system to shut off the overload heat flow at the moment of thermal resistance collapse. The natural fibers at the support position are subjected to thermal energy damage and thermal degradation. Traditional static isothermal hot pressing or asymmetric thermal field control methods with preset fixed temperature differences lack the dynamic response capability to this transient thermal resistance decay. This causes the heat flow to enter the resin melting and diffusion stage and cause heat flux overload. The natural fibers at the structural support position are frequently subjected to overload heat energy damage and thermal degradation. Blindly adopting linear intervention methods such as lowering the set temperature of the pressure bearing surface or reducing the holding time will result in defects such as excessively high resin melt viscosity, poor wetting performance, and insufficient mechanical misalignment strength.

[0004] Therefore, the technical problem to be solved by this invention is how to utilize the abrupt change in heat transfer characteristics caused by the phase change of multiphase sandwich materials to achieve dynamic interactive adjustment of the thermal boundary, thereby promoting full flow and wetting of the resin while blocking overload heat flux to prevent degradation of the heat-sensitive fiber. Summary of the Invention

[0005] The present invention aims to solve the problem of heat flux overload caused by the step-like decrease in the heat transfer resistance of the interlayer material under laminated composite conditions, which leads to thermal degradation of natural fibers and incomplete resin impregnation.

[0006] In this technical solution, a temperature gradient control process for biofilm processing includes the following steps:

[0007] Step S101: Control the upper and lower pressure plates in the independent dual-drive temperature control assembly to implement asymmetric steady-state heat conduction heating on the laminated assembly. The laminated assembly includes a thermoplastic plastic layer and a porous substrate layer. The heat flux data and temperature data characterizing the internal heat transfer state of the laminated assembly are obtained in real time by a matrix heat flow meter and thermocouple embedded inside the laminated assembly.

[0008] Step S102: Calculate the time change rate of the equivalent thermal conductivity coefficient of the laminated assembly in real time based on the heat flux data and temperature data. When the time change rate of the equivalent thermal conductivity coefficient exceeds the wetting phase change threshold determined by variance smoothing of the initial heat flux characteristic sequence of the initial heating stage, it is determined that the front edge of the thermoplastic melt generated by the melting of the thermoplastic layer has squeezed out the pore air of the porous substrate layer and cut into the porous substrate layer.

[0009] In step S103, at the instant when the change rate of the equivalent thermal conductivity coefficient generated in step S102 exceeds the threshold of the wetting phase change, the current input of the electric heating tube of the upper platen in the independent dual-drive temperature control assembly is cut off, and the solenoid valve of the forced water cooling micro-circulation pipeline built into the upper platen is opened simultaneously to control the surface temperature of the upper platen to drop back to 145°C within 3 seconds. The residual heat inside the laminated assembly body drives the thermoplastic melt to fill the porous substrate layer to complete the final state micro-topological interlocking.

[0010] Step S104: Adjust the cooling medium flow rate of the solenoid valve in the forced water-cooled micro-circulation pipeline to implement multi-stage nonlinear cooling, including a rapid cooling section, an isothermal relaxation section, and a natural convection section, on the laminated assembly that has completed the final state micro-topological interlocking.

[0011] Preferably, step S104 includes the following sub-steps: Step S1041, in the rapid cooling stage, the solenoid valve of the forced water cooling microcirculation pipeline is adjusted to reduce the surface temperature of the thermoplastic layer to below the peak value of the cold crystallization temperature to inhibit spherulite growth; Step S1042, in the isothermal relaxation stage, the solenoid valve of the forced water cooling microcirculation pipeline is closed to maintain the temperature of the laminated assembly in the range of 60°C to 80°C to release internal stress and induce microcrystal formation; Step S1043, in the natural convection stage, the laminated assembly is cooled to the ambient temperature by air convection.

[0012] Preferably, the real-time calculation of the equivalent thermal conductivity coefficient of the laminated assembly over time in step S102 includes the following sub-steps: Step S1021, separating the upper surface temperature value of the adjacent upper pressure plate and the lower surface temperature value of the adjacent lower pressure plate from the temperature data; Step S1022, dividing the real-time heat flux value in the heat flux data by the difference between the upper surface temperature value and the lower surface temperature value to calculate the real-time equivalent thermal conductivity coefficient of the laminated assembly in the current control cycle; Step S1023, differentiating and calculating the first derivative of the real-time equivalent thermal conductivity coefficient with respect to time to generate the equivalent thermal conductivity coefficient over time.

[0013] Preferably, step S101, controlling the upper and lower pressure plates of the independent dual-drive temperature control assembly to perform asymmetric steady-state heat conduction heating on the laminated assembly, includes the following sub-steps: Step S1011, controlling the independent dual-drive temperature control assembly to set the heating temperature of the upper pressure plate in the range of 175°C to 190°C, and setting the heating temperature of the lower pressure plate in the independent dual-drive temperature control assembly in the range of 60°C to 80°C, thereby constructing an asymmetric temperature gradient field in the thickness direction of the laminated assembly; Step S1012, controlling the upper and lower pressure plates to simultaneously heat up at a heating rate of 2°C / min to 5°C / min, so that the thermoplastic layer melts and flows on the side adjacent to the upper pressure plate, while the porous substrate layer maintains a solid skeleton topology on the side adjacent to the lower pressure plate.

[0014] Preferably, the wetting phase change threshold in step S102 is determined by the following sub-steps: Step S1024, in the initial heating stage where the laminated assembly is heated in step S101 and the thermoplastic layer has not yet melted, the initial heat flux characteristic sequence is collected by a matrix heat flux meter; Step S1025, the variance of the initial heat flux characteristic sequence within a 10s time window is calculated, and the reciprocal of the variance is set as the filtering weight coefficient; Step S1026, the filtering weight coefficient is multiplied by the time change rate of the equivalent heat conduction coefficient for smoothing, and three times the fluctuation amplitude of the smoothed background noise is used as the numerical boundary and assigned to the wetting phase change threshold.

[0015] Preferably, step S103, which utilizes the residual heat inside the laminated assembly to drive the thermoplastic melt to fill the porous substrate layer to complete the final micro-topological interlocking, includes the following sub-steps: Step S1031, while the surface temperature of the upper platen drops to 145°C within 3 seconds, the independent dual-drive temperature control component applies mechanical pressure to the laminated assembly and linearly increases the mechanical pressure from 1.0 MPa to 2.5 MPa to provide an auxiliary power source to drive the thermoplastic melt to overcome mass transfer resistance and cut into the porous substrate layer; Step S1032: The mechanical pressure is kept constant at 2.5 MPa for 15 to 30 seconds, so that the thermoplastic melt completely fills the porous mesh of the porous substrate layer and solidifies under the constraint of the forced water-cooled micro-circulation pipeline solenoid valve removing heat, locking the interfacial topological interlocking state between the thermoplastic layer and the porous substrate layer.

[0016] Preferably, the thermoplastic layer is composed of a thermoplastic polymer resin, the melt index of which is 2.0 g / 10 min to 5.0 g / 10 min at 190 °C and 2.16 kg load, the thickness of the thermoplastic layer is 20 μm to 50 μm, and the shear viscosity of the thermoplastic melt at the heating temperature in step S101 is 100 Pa·s to 300 Pa·s.

[0017] Preferably, the porous substrate layer is composed of a porous fiber skeleton layer, the unit area mass of the porous substrate layer is 15g / m² to 35g / m², the internal average pore size is 5μm to 15μm, and the porosity of the porous substrate layer is 65% to 80%.

[0018] Preferably, the cooling medium flow rate of the forced water-cooled micro-circulation pipeline solenoid valve in step S104 includes the following sub-steps: Step S1044: In the rapid cooling section, the cooling medium flow rate of the forced water-cooled micro-circulation pipeline solenoid valve is adjusted to be set within the range of 0.5 m / s to 1.2 m / s, and the cooling rate of the laminated assembly is controlled to be no less than 15℃ / s; Step S1045: When entering the isothermal relaxation section, the cooling medium flow rate is reduced to 0 m / s to terminate the active cooling heat exchange.

[0019] Preferably, after completing the multi-stage nonlinear cooling, the following sub-steps are further included to implement continuous tracking of molding quality: Step S105, record the immersion duration time from the start of heating to reaching the immersion phase change threshold for each cycle in 100 consecutive processing cycles, and construct an immersion time evolution sequence; Step S106, calculate the monotonic trend slip rate of the immersion time evolution sequence with respect to the number of processing cycles; Step S107, when the monotonic trend slip rate exceeds the determined attenuation limit threshold, output a warning signal indicating that there is a risk of heat transfer performance degradation in the solenoid valve of the forced water-cooled micro-circulation pipeline or the electric heating tube of the upper pressure plate.

[0020] Compared with existing technologies, the temperature gradient control process for biological base membrane processing of the present invention has the following advantages:

[0021] 1. In the processing of biofilm, by real-time acquisition of transient temperature difference at the lamination interface and transient heat flux penetrating the composite layer during the flow of multiphase materials under pressure and heat, the transient equivalent thermal resistance characterizing the thermal conduction hindrance state of the composite layer is calculated in real time, and the rate of change of the transient equivalent thermal resistance with respect to time is tracked to accurately capture the physical property distortion node of thermoplastic resin melting and displacing air inside the porous fiber skeleton; when the rate of change shows a negative abrupt change and the absolute value exceeds the preset wetting threshold, the heating source on the high-temperature side is turned off and the forced cooling circuit is turned on to reduce the surface temperature of the upper hot pressing surface. Relying on the residual thermal inertia inside the material, the resin melt is driven to complete the final state micro-wetting, eliminating the risk of thermal degradation of the bottom heat-sensitive fiber caused by continuous external heat input accumulation, and realizing the physical control of deep resin wetting and fiber structure integrity maintenance during the multiphase composite interface molding process.

[0022] 2. By utilizing the interfacial heat flow blocking procedure constructed based on the objective law of transient heat transfer coefficient mutation in multiphase material composite layers, the thermoplastic resin phase obtains sufficient flow dynamics under high-temperature activation, enabling the polymer macromolecular chain segments to rapidly penetrate the micropores and interlacing nodes of the heat-sensitive fiber phase. Combined with the thermal boundary reshaping brought about by active cooling intervention, the melt front edge locks in position when it reaches the predetermined wetting depth. Under the condition of not introducing exogenous chemical modification components, a dense micro-mechanical interlocking structure is formed, which overcomes the curing limitations of insufficient resin fluidity, poor wetting, and lack of interfacial mechanical anchoring caused by blindly reducing the hot pressing temperature under traditional fixed process parameter settings, thereby improving the ultimate tensile strength of the composite mulch film.

[0023] 3. The multi-stage nonlinear cooling sequence after composite lamination molding controls the rate at which the cooling medium removes heat. In the rapid cooling stage, the cooling rate is controlled to quickly push the surface temperature of the resin layer above the peak of the cold crystallization temperature, freezing the rheological morphology and inhibiting excessive spherulite growth. In the isothermal relaxation stage, active cooling is terminated and the temperature is maintained within a preset range above the glass transition temperature, providing a relaxed environment for molecular chain conformation rearrangement and internal stress release, inducing the formation of interfacial microcrystalline regions with specific orientations on the porous fiber surface. In the natural convection stage, air convection cooling to ambient temperature completes the curing process, eliminating microscopic cracking at the interface caused by the difference in thermal expansion coefficients between the two phases. This allows the mulch film to exhibit a barrier effect that delays the initial invasion of water and microorganisms in actual field applications, meeting the physical shaping requirements of matching the degradation cycle with the crop growth cycle. Attached Figure Description

[0024] Figure 1 This is a flowchart of the execution steps for temperature gradient control in the biofilm processing of the present invention;

[0025] Figure 2 This is a state diagram of temperature gradient control during the processing of biological base membranes in this invention. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] A temperature gradient control process for biofilm processing includes the following steps:

[0028] Step S101: Control the upper and lower pressure plates in the independent dual-drive temperature control assembly to implement asymmetric steady-state heat conduction heating on the laminated assembly. The laminated assembly includes a thermoplastic plastic layer and a porous substrate layer. The heat flux data and temperature data characterizing the internal heat transfer state of the laminated assembly are obtained in real time by a matrix heat flow meter and thermocouple embedded inside the laminated assembly.

[0029] Step S102: Calculate the time change rate of the equivalent thermal conductivity coefficient of the laminated assembly in real time based on the heat flux data and temperature data. When the time change rate of the equivalent thermal conductivity coefficient exceeds the wetting phase change threshold determined by variance smoothing of the initial heat flux characteristic sequence of the initial heating stage, it is determined that the front edge of the thermoplastic melt generated by the melting of the thermoplastic layer has squeezed out the pore air of the porous substrate layer and cut into the porous substrate layer.

[0030] In step S103, at the instant when the change rate of the equivalent thermal conductivity coefficient generated in step S102 exceeds the threshold of the wetting phase change, the current input of the electric heating tube of the upper platen in the independent dual-drive temperature control assembly is cut off, and the solenoid valve of the forced water cooling micro-circulation pipeline built into the upper platen is opened simultaneously to control the surface temperature of the upper platen to drop back to 145°C within 3 seconds. The residual heat inside the laminated assembly body drives the thermoplastic melt to fill the porous substrate layer to complete the final state micro-topological interlocking.

[0031] Step S104: Adjust the cooling medium flow rate of the solenoid valve in the forced water-cooled micro-circulation pipeline to implement multi-stage nonlinear cooling, including a rapid cooling section, an isothermal relaxation section, and a natural convection section, on the laminated assembly that has completed the final state micro-topological interlocking.

[0032] Preferably, step S104 includes the following sub-steps: Step S1041, in the rapid cooling stage, the solenoid valve of the forced water cooling microcirculation pipeline is adjusted to reduce the surface temperature of the thermoplastic layer to below the peak value of the cold crystallization temperature to inhibit spherulite growth; Step S1042, in the isothermal relaxation stage, the solenoid valve of the forced water cooling microcirculation pipeline is closed to maintain the temperature of the laminated assembly in the range of 60°C to 80°C to release internal stress and induce microcrystal formation; Step S1043, in the natural convection stage, the laminated assembly is cooled to the ambient temperature by air convection.

[0033] Preferably, the real-time calculation of the equivalent thermal conductivity coefficient of the laminated assembly over time in step S102 includes the following sub-steps: Step S1021, separating the upper surface temperature value of the adjacent upper pressure plate and the lower surface temperature value of the adjacent lower pressure plate from the temperature data; Step S1022, dividing the real-time heat flux value in the heat flux data by the difference between the upper surface temperature value and the lower surface temperature value to calculate the real-time equivalent thermal conductivity coefficient of the laminated assembly in the current control cycle; Step S1023, differentiating and calculating the first derivative of the real-time equivalent thermal conductivity coefficient with respect to time to generate the equivalent thermal conductivity coefficient over time.

[0034] Preferably, step S101, controlling the upper and lower pressure plates of the independent dual-drive temperature control assembly to perform asymmetric steady-state heat conduction heating on the laminated assembly, includes the following sub-steps: Step S1011, controlling the independent dual-drive temperature control assembly to set the heating temperature of the upper pressure plate in the range of 175°C to 190°C, and setting the heating temperature of the lower pressure plate in the independent dual-drive temperature control assembly in the range of 60°C to 80°C, thereby constructing an asymmetric temperature gradient field in the thickness direction of the laminated assembly; Step S1012, controlling the upper and lower pressure plates to simultaneously heat up at a heating rate of 2°C / min to 5°C / min, so that the thermoplastic layer melts and flows on the side adjacent to the upper pressure plate, while the porous substrate layer maintains a solid skeleton topology on the side adjacent to the lower pressure plate.

[0035] Preferably, the wetting phase change threshold in step S102 is determined by the following sub-steps: Step S1024, in the initial heating stage where the laminated assembly is heated in step S101 and the thermoplastic layer has not yet melted, the initial heat flux characteristic sequence is collected by a matrix heat flux meter; Step S1025, the variance of the initial heat flux characteristic sequence within a 10s time window is calculated, and the reciprocal of the variance is set as the filtering weight coefficient; Step S1026, the filtering weight coefficient is multiplied by the time change rate of the equivalent heat conduction coefficient for smoothing, and three times the fluctuation amplitude of the smoothed background noise is used as the numerical boundary and assigned to the wetting phase change threshold.

[0036] Preferably, step S103, which utilizes the residual heat inside the laminated assembly to drive the thermoplastic melt to fill the porous substrate layer to complete the final micro-topological interlocking, includes the following sub-steps: Step S1031, while the surface temperature of the upper platen drops to 145°C within 3 seconds, the independent dual-drive temperature control component applies mechanical pressure to the laminated assembly and linearly increases the mechanical pressure from 1.0 MPa to 2.5 MPa to provide an auxiliary power source to drive the thermoplastic melt to overcome mass transfer resistance and cut into the porous substrate layer; Step S1032, the mechanical pressure is kept constant at 2.5 MPa for 15 to 30 seconds, so that the thermoplastic melt completely fills the porous mesh of the porous substrate layer and solidifies under the constraint of the forced water-cooled micro-circulation pipeline solenoid valve removing heat, locking the interfacial topological interlocking state between the thermoplastic layer and the porous substrate layer.

[0037] Preferably, the thermoplastic layer is composed of a thermoplastic polymer resin, the melt index of which is 2.0 g / 10 min to 5.0 g / 10 min at 190 °C and 2.16 kg load, the thickness of the thermoplastic layer is 20 μm to 50 μm, and the shear viscosity of the thermoplastic melt at the heating temperature in step S101 is 100 Pa·s to 300 Pa·s.

[0038] Preferably, the porous substrate layer is composed of a porous fiber skeleton layer, the unit area mass of the porous substrate layer is 15g / m² to 35g / m², the internal average pore size is 5μm to 15μm, and the porosity of the porous substrate layer is 65% to 80%.

[0039] Preferably, the cooling medium flow rate of the forced water-cooled micro-circulation pipeline solenoid valve in step S104 includes the following sub-steps: Step S1044: In the rapid cooling section, the cooling medium flow rate of the forced water-cooled micro-circulation pipeline solenoid valve is adjusted to be set within the range of 0.5 m / s to 1.2 m / s, and the cooling rate of the laminated assembly is controlled to be no less than 15℃ / s; Step S1045: When entering the isothermal relaxation section, the cooling medium flow rate is reduced to 0 m / s to terminate the active cooling heat exchange.

[0040] Preferably, after completing the multi-stage nonlinear cooling, the following sub-steps are further included to implement continuous tracking of molding quality: Step S105, record the immersion duration time from the start of heating to reaching the immersion phase change threshold for each cycle in 100 consecutive processing cycles, and construct an immersion time evolution sequence; Step S106, calculate the monotonic trend slip rate of the immersion time evolution sequence with respect to the number of processing cycles; Step S107, when the monotonic trend slip rate exceeds the determined attenuation limit threshold, output a warning signal indicating that there is a risk of heat transfer performance degradation in the solenoid valve of the forced water-cooled micro-circulation pipeline or the electric heating tube of the upper pressure plate.

[0041] Example 1: In a continuous hot-pressing composite production line, a laminated assembly consisting of a thermoplastic layer made of polylactic acid resin film and a porous substrate layer made of jute fiber needle-punched felt is manufactured. When the laminated assembly faces a transient step decay of thermal resistance caused by the coupling of material phase change heat transfer inside the closed heated cavity, if the preset static asymmetric temperature field is maintained for heating, after the polymer melt displaces the air in the fiber pores and fills the gaps densely in the later stages of processing, the equivalent thermal conductivity resistance of the system suddenly collapses. This causes the continuously input external heat energy to surge towards the underlying heat-sensitive skeleton fiber in the form of a significant increase in heat flux, thereby triggering irreversible thermal degradation of the hemicellulose in the porous fiber. To address the issue that the ultimate tensile strength of the laminated assembly may be reduced in practical applications due to damage to the skeletal fiber strength, during the initial stage of the laminated composite shaping process, the heating temperature of the upper platen in the independent dual-drive temperature control assembly is set within the range of 175℃ to 190℃, and the heating temperature of the lower platen is set within the range of 60℃ to 80℃. This creates an asymmetric temperature gradient field along the thickness direction of the laminated assembly. The upper and lower platens are controlled to heat synchronously at a heating rate of 2℃ / min to 5℃ / min, resulting in a thickness of 20μm to 50μm and a melt index of 2.0g / 10min to 5 at 190℃ and a load of 2.16kg.The thermoplastic layer with a density of 0 g / 10 min undergoes melt rheology on the side adjacent to the upper pressure plate, maintaining its shear viscosity at the heating temperature within the range of 100 Pa·s to 300 Pa·s. Meanwhile, a porous substrate layer with a unit area mass of 15 g / m² to 35 g / m², an average internal pore size of 5 μm to 15 μm, and a porosity of 65% to 80% maintains a solid-state skeletal topology on the side adjacent to the lower pressure plate. During this process, matrix heat flow meters and surface thermocouples embedded beneath each pressure-bearing bonding surface are used to acquire real-time heat flux and temperature data characterizing the internal heat transfer state of the laminated assembly at a data sampling frequency greater than 100 Hz. The upper surface temperature value adjacent to the upper pressure plate and the lower surface temperature value adjacent to the lower pressure plate are then separated from these data. The matrix heat flow meters and surface thermocouples are countersunk in the grooves of the upper and lower pressure plates, with their sensing ends aligned with the pressure-bearing bonding surfaces. By extending the interface contact into the thermal conductivity boundary domain of the laminated assembly, internal heat transfer state parameters are obtained. Based on the Fourier one-dimensional steady-state thermal conductivity model, the equivalent thermal conductivity across the thickness of the laminated assembly is proportional to the product of the penetration heat flux and the instantaneous thickness, and inversely proportional to the temperature difference. In the calculation process, the real-time heat flux value is divided by the difference between the upper and lower surface temperatures and multiplied by the instantaneous total thickness of the laminated assembly. The instantaneous total thickness is determined by reading the instantaneous displacement of the laminator spindle grating ruler and subtracting the mechanical zero-point gap value when the hard contacts of the upper and lower pressure plates are closed. A geometric dimension of compression due to pressure variation is introduced during the calculation. The real-time heat flux value is divided by the difference between the upper and lower surface temperatures and multiplied by this instantaneous total thickness to calculate the real-time equivalent thermal conductivity for the current control cycle. The first derivative of the real-time equivalent thermal conductivity with respect to time is then calculated to generate the time-varying rate of change of the equivalent thermal conductivity.

[0042] To implement boundary control of the rheological phase change process of the laminated assembly in a closed space, during the initial heating stage when the laminated assembly is heated but the thermoplastic layer has not yet melted, an initial heat flux characteristic sequence is collected using a matrix heat flux meter. The variance of the initial heat flux characteristic sequence within a 10-second time window is calculated, and its reciprocal is set as a filter weight coefficient. Smoothing is achieved by multiplying the filter weight coefficient by the time change rate of the equivalent thermal conductivity coefficient. Three times the amplitude of the smoothed background noise fluctuation is used as the numerical boundary to assign to the wetting phase change threshold. When the component controller detects a sudden change in the time change rate of the equivalent thermal conductivity coefficient due to the penetration of molten material into the internal voids of the skeleton, and the absolute value of this negative change exceeds the wetting phase change threshold, it indicates that the thermoplastic melt front generated by the melting of the thermoplastic layer has displaced the air with low thermal conductivity inside the porous fiber layer and cut into the core interwoven network of the porous substrate layer. The independent dual-drive temperature control component triggers boundary heat flux blocking the instant the change rate exceeds the threshold. The current input to the electric heating tube of the upper pressure plate in the independent dual-drive temperature control component is cut off, and the solenoid valve of the forced water-cooled micro-circulation pipeline built into the upper pressure plate is opened simultaneously. The condensing medium with a pressure of 0.6MPa to 0.8MPa flows through the staggered microchannel heat dissipation array inside the upper pressure plate, 2mm away from the pressure-bearing contact surface. The hydraulic diameter of the heat dissipation array is 0.8mm and the wall thickness is 0.5mm. This forces the surface temperature of the upper pressure plate to drop from a high temperature to 145℃ within 3 seconds, preventing the accumulation of heat in the porous layer skeleton due to the decrease in thermal resistance. The external heat flux is controlled by an independent dual-drive temperature control component, which linearly increases the mechanical pressure applied to the laminated assembly from 1.0 MPa to 2.5 MPa to provide an auxiliary power source. This suppresses the polymer macromolecular chain segments to overcome local flow mass transfer resistance and maintains a constant pressure of 2.5 MPa for 15 to 30 seconds. This allows the high-activation-energy thermoplastic melt to solidify under the constraint of heat removal by the solenoid valve in the forced water-cooled microcirculation pipeline, locking the interfacial topological interlocking state between the thermoplastic layer and the porous substrate layer.

[0043] After deep physical anchoring of the multiphase material interface is achieved by relying on the inherent residual heat and mechanical pressure within the laminated assembly, multi-stage nonlinear cooling is initiated by regulating the cooling medium flow rate of the solenoid valve in the forced water-cooled micro-circulation pipeline. In the rapid cooling stage, the cooling medium flow rate is set within the range of 0.5 m / s to 1.2 m / s to ensure that the cooling rate of the laminated assembly is not less than 15℃ / s. This allows the surface temperature of the thermoplastic layer to rapidly cross the peak of the cold crystallization temperature, completing the isotropic freezing of the high-temperature rheological morphology and inhibiting the excessive growth of large-sized spherulites within the amorphous matrix. In the isothermal relaxation stage, the cooling medium flow rate is reduced to 0 m / s to terminate the active cooling heat exchange, maintaining the temperature of the laminated assembly at a constant temperature within the range of 60℃ to 80℃. This provides a low thermal stress environment for molecular chain conformational rearrangement and multi-level relaxation, inducing the formation of high-density molecules at the interface interaction nodes. A directional crystalline layer is formed, thereby eliminating the potential risk of local cracking caused by the heterogeneity of the thermal expansion coefficients of the two-phase materials. After cutting off the active insulation constraint and implementing natural convection, the laminated assembly is cooled to the ambient temperature by room temperature air convection to complete the curing and shaping, so that the molded laminated assembly obtains improved interfacial bonding strength and structural stability. According to the least squares linear regression model, the heat transfer degradation monitoring includes the following steps: The storage module records the time duration from the start of heating to reaching the wetting phase change threshold within 100 consecutive processing cycles, generating a discrete time series containing 100 data points. The processor reads the discrete time series, uses the number of processing cycles as the independent variable and the duration as the dependent variable, and calculates the slope of the first-order linear equation using the least squares method as the monotonic trend slip rate; the expression of the first-order linear equation is constructed as follows: ,in, This refers to the number of processing cycles. This corresponds to the infiltration duration. The intercept constant of the equation is used to calculate the slope, which characterizes the rate of overall axial monotonic drift of the dependent variable as a function of the number of processing cycles, by substituting a discrete sequence of 100 consecutive processing cycles into the standard least squares regression matrix formula. and the slope of the deterministic first-order linear equation The absolute value is directly mapped and assigned as the monotonically changing trend slip ratio; this slip ratio calculation model can effectively eliminate the burr noise interference from occasional local material deviations or sensor contact fluctuations in a single processing cycle, accurately extract the deep-seated gradual performance degradation trend of the heat transfer system, and the processor compares the monotonically changing trend slip ratio with the preset attenuation limit threshold. When the value exceeds the attenuation limit threshold, the hardware output port outputs a 24V high-level signal to the external alarm circuit, driving the external buzzer to sound, indicating that there is a risk of thermal conductivity degradation in the electric heating tube or forced water cooling micro-circulation pipeline of the upper pressure plate.

[0044] Example 2:

[0045]

[0046] In a rheological testing platform consisting of a double-sided calendering composite machine, a matrix-type pressure fine-tuning mechanism, and an independent dual-drive temperature control component, a 35μm thick polylactic acid resin film and jute fiber needle-punched felt with a unit area mass of 25g / m² and a defined pore size are combined to form a laminated assembly. In order to simulate the background interference caused by electromagnetic environment and mechanical periodic reciprocating vibration in a closed heat transfer cavity under set environmental conditions, the signal conditioning module of the rheological testing platform introduces common-mode oscillation noise with an amplitude of 1.5kW / m² into the acquisition channel. At the same time, the power grid harmonic amplitude of the electric heating element induces a temperature fluctuation disturbance with a frequency of 50Hz and a first-order amplitude peak value of 0.8℃ on the surface of the upper pressure plate. The rheological testing platform uses a detection sensor array to acquire the original heat flux signal sequence and the original surface temperature signal sequence containing common-mode oscillation noise and temperature fluctuation disturbance at a rated sampling frequency of 200Hz as input source processing.

[0047] To determine the control boundary of thermoplastic phase change rheology, the heating temperature of the upper platen was controlled at temperature gradient points of 170℃, 175℃, 182℃, 190℃, and 195℃ in the process settings, while the heating temperature of the lower platen was kept constant at 70℃. The data processing unit in the controller extracted the original heat flux signal sequence within a 10-second time window during the initial heating period and calculated its statistical variance. Count it backwards The dimensionless filter weighting coefficient is multiplied by the rate of change of the equivalent thermal conductivity calculated according to the heat transfer balance equation. ,in The variance of the initial heat flux signal within a preset time window. These are the corresponding filter weight coefficients. The smoothed equivalent thermal conductivity over time rate, after smoothing to eliminate the amplitude interference of common-mode oscillation noise, is calculated as follows: When the heating temperature is set to 170℃, the polymer material remains solid because the material temperature has not reached the melt flow transition temperature of polylactic acid. The curve remained in the zero-value axis region during the pressing cycle, and the cooling process was not triggered. When the heating temperature was set within the range of 175℃, 182℃, and 190℃, the thermoplastic layer underwent a rheological phase transformation. Under pressure, the melt penetrated the interwoven network of the porous substrate layer and displaced the air in the voids, resulting in a decrease in the system's thermal resistance and an increase in the rate of change. The abrupt change exhibits a negative trend, with the absolute values ​​of its negative first derivative reaching 3.4, 5.2, and 4.8 calibration units, respectively. These values ​​all exceed the wetting phase transition threshold determined by three times the background noise amplitude, instantly triggering the boundary heat flow blocking procedure. This causes the surface temperature of the upper pressure plate to drop from its set temperature point to 145°C within 3 seconds. When the heating temperature increases to 195°C, the polylactic acid melt, due to excessive heating, experiences a shear viscosity below 10 Pa·s. The excessively rapid flow rate causes moisture in the jute fiber skeleton to vaporize and accumulate into high-pressure bubbles. These bubbles remain at the lamination interface, forming a discontinuous gaseous insulating layer. This gaseous insulating layer blocks downward heat transfer, leading to a decrease in the rate of change. The inability to generate a negative abrupt change signal exceeding the wetting phase transition threshold leads to a continuous input of external heat and thermal degradation of the skeletal fibers.

[0048] After the molding and shaping process was completed, the performance of each group of mulch film samples was tested using mechanical testing instruments. The test data showed that the test groups processed using the process method of this invention within the range of 175℃, 182℃, and 190℃ had stable ultimate tensile strengths of 38.4MPa, 45.2MPa, and 41.1MPa, respectively, and interlayer peel strengths of 2.8N / mm, 3.4N / mm, and 3.1N / mm, respectively. The polylactic acid melt and the porous fiber skeleton formed an interwoven physical interlocking morphology at the interface, and a high-density oriented crystalline structure phase was detected. In contrast, the low-end control group set at 170℃ had an ultimate tensile strength of only 18.2MPa and an interlayer peel strength of less than 0.5N / mm due to insufficient flow of the polymer melt. The high-end control group set at 195℃ had an ultimate tensile strength reduced to 15.6MPa due to carbonization of the fiber skeleton and bubble defects. The test group using a constant heating temperature of 182℃ and without equivalent thermal conductivity time change rate... In the conventional process control group of the feedback control loop, the average ultimate tensile strength of the mulch film was only 22.3 MPa, and the interlayer peel strength was 1.2 N / mm. The comparison results of the above quantitative data gradients confirm that the heating temperature control range established from 175℃ to 190℃, combined with the blocking control based on the transient thermal resistance derivative, can reduce the thermal damage of jute fibers, so that the final laminated assembly can obtain improved mechanical interlocking quality and overall mechanical component stability.

[0049] Example 3: When a multi-calendering composite shaping mechanism processes an ultra-thin laminate assembly consisting of a thermoplastic plastic layer composed of a 20μm thick polylactic acid resin film and a porous substrate layer composed of jute fiber needle-punched felt with a porosity of 80%, the total melt volume of the thermoplastic plastic layer after hot melting reaches the lower limit of the preset thickness range, and the internal free space of the porous substrate layer reaches the upper limit of the preset porosity range. The flow wetting cycle of the molten polylactic acid fluid filling the porous layer voids under capillary pressure is shortened to less than 500ms. This causes the bonding gap fluctuation caused by mechanical vibration inside the shaping cavity to induce non-stationary local burr noise in the signal collected by the matrix heat flow meter. If a fixed value judgment threshold is used, it will cause premature false triggering or delayed response of the cooling shaping control. This will cause the ultra-thin resin layer to break or the porous layer skeleton fiber to overload and decompose due to interfacial short-circuit heat transfer in the later stage of processing.

[0050] In the initial heating stage, before the thermoplastic layer has melted, the upper platen of the independent dual-drive temperature control assembly is heated from 60°C to 100°C. During this period, the initial heat flux signal sequence is continuously acquired through a matrix heat flux meter, and the statistical variance of the initial heat flux signal within a sliding data window consisting of 50 consecutive sampling points is calculated. The filter weight coefficient for the corresponding operating condition is determined based on its reciprocal. Its formula is as follows: ,in, Let V be the variance of the initial heat flux signal within the sliding data window. These are the corresponding filter weight coefficients; through the filter weight coefficients Multiplying by the heat transfer response characteristic value calculated by the matrix heat flux meter and surface thermocouples, a smoothing process is performed to eliminate the amplitude interference of burr noise. Three times the smoothed background noise fluctuation amplitude is then assigned to the wetting phase change threshold. When the corrected equivalent thermal conductivity time change rate is detected... When a sudden change occurs and the absolute value of the negative change rate exceeds the wetting phase change threshold, the driving pressure regulating mechanism linearly increases the mechanical pressure applied to the laminated assembly from 1.0MPa to 2.5MPa within 100ms, and simultaneously cuts off the electric heating circuit to drive the rapid cooling water circuit to regulate the temperature of the upper pressure plate.

[0051] In the filter weight coefficient The time-varying rate of change of the smoothed equivalent thermal conductivity coefficient under high porosity conditions, while suppressing signal glitches. The curve penetrates the dynamically constructed wetting phase transition threshold at 320ms during the flow wetting process, causing the pressure regulation mechanism and the rapid cooling water circuit to have a millisecond-level linkage response at the initial node where the melt contacts the interwoven fiber skeleton network. Through rapid cooling, the surface temperature of the upper pressure plate is rapidly reduced to 145℃ within 3s to suppress the heat flux enriched to the interface of the laminated assembly. Relying on the latent heat released by local consolidation and the constant mechanical stress of 2.5MPa, the polylactic acid melt is driven to solidify and shape under the constant temperature constraint of 70℃ on the lower pressure plate. According to the structural characterization data output by the testing equipment, the molded laminated assembly achieves an average ultimate tensile strength of 44.5MPa and an interlaminar peel strength of 3.2N / mm when the polylactic acid resin layer thickness is reduced to 20μm. This suppresses the propagation of interlaminar peel cracks at the interface and slows down the thermal decomposition of the porous layer skeleton fibers, so that the final molded laminated assembly achieves structural compactness and component stability.

[0052] Example 4: The heating temperature of the upper pressure plate in the independent dual-drive temperature control assembly is controlled at 50℃, and an initial contact pressure of 0.1MPa is applied. When the heat transfer baseline deviates nonlinearly due to a change in material batch, the average value of the reference heat flux sequence output by the matrix heat flux meter in the sensor array is detected to be 4.2kW / m². The environmental compensation gain coefficient is calculated by dividing the standard heat flux value of 4.0kW / m² by the average value of the reference heat flux sequence. The value is 0.95, which is a dimensionless constant; in subsequent suppression cycles, the system utilizes the environmental compensation gain coefficient. Multiplying the original heat flux signal to reshape the heat transfer baseline reduces the variance of the initial sampling signal from 0.35 to 0.02, filtering out burr noise caused by local roughness variations on the material surface.

[0053] As the heat transfer baseline of the laminated assembly aligns and enters the melting phase transition stage, the gain coefficient is compensated by the environment. Corrected rate of change of equivalent thermal conductivity over time The curve penetrates the wetting phase transition threshold at 350ms of the phase transition. The independent dual-drive temperature control component cuts off the power supply to the electric heating tube and opens the rapid cooling water circuit the instant the rate of change exceeds the threshold, causing the surface temperature of the upper platen to drop from 182℃ to 145℃ within 3s. At the same time, the pressure regulating mechanism increases the surface pressure applied to the laminated assembly from 1.0MPa to 2.5MPa to expel the air inside the porous substrate layer skeleton. The macromolecular chain segments cool and solidify under a constant pressure of 2.5MPa. The shaped laminated assembly obtains an average ultimate tensile strength of 43.8MPa and an interlaminar peel strength of 3.1N / mm, and mitigates local bonding defects and thermal degradation of the skeleton layer fibers caused by thermal overload due to batch changes in materials.

[0054] Example 5:

[0055]

[0056] In the independent dual-drive temperature control assembly, the heating temperature of the upper platen is controlled at 182℃ and the heating temperature of the lower platen at 70℃. When the continuous hot-pressing composite production line faces the condition that the thermal inertia of the heating element causes nonlinear drift due to changes in the external ambient temperature, a thermoplastic plastic layer composed of polylactic acid with a thickness of 35μm and a porous substrate layer composed of jute fiber needle-punched felt with a unit area mass of 25g / m² enter the cavity of the independent dual-drive temperature control assembly. The surface thermocouples embedded under each bonding surface measure that the initial wall temperature of the cavity deviates from the preset thermal field reference. The matrix heat flow meter under the bonding surface of the two phase materials collects the initial heat transfer data stream with background thermal interference. The data processing unit extracts the differential fluctuation parameters of the initial heat transfer data stream within the calibration period to reconstruct the dynamic zero point. By calculating the root mean square value of the differential fluctuation parameters within a 5s sliding time window, the adaptive gain operator is determined according to the formula. satisfy: ,in, The reference constant for calibration has a value of 1.0 W / m². The root mean square value of the difference parameter within a preset time window. The system utilizes a dimensionless adaptive gain operator. Multiplying by the time change rate of the original equivalent thermal conductivity coefficient to smooth out thermal interference and reshape the heat transfer baseline, thereby eliminating the thermal field interference of external environmental temperature drift on the determination of melt penetration endpoint in the pre-test stage. The calibration reference constant here is set to 1.0W / m², which is the ideal unit heat flux disturbance reference value based on the system being in static thermal equilibrium at standard ambient temperature, and is used as a molecular reference reference for dimensionless scaling. When the continuous hot pressing composite production line faces large-scale and drastic changes in external ambient temperature or nonlinear drift caused by the overall thermal inertia of the heating element, the deviation of the initial wall temperature of the cavity will induce noise fluctuations in the heat flow data in the signal channel. By calculating the root mean square value of its differential parameter within a 5s sliding time window, the actual noise power intensity caused by temperature drift interference can be quantified in real time. The adaptive gain operator obtained by comparing it with the fixed calibration reference constant has the characteristic of being inversely proportional to the actual thermal interference intensity, thereby dynamically compressing or amplifying the signal amplitude in subsequent multiplication operations, and realizing the digital calibration and alignment of the heat transfer baseline under different temperature drift environmental backgrounds to a unified calibration state.

[0057] In the adaptive gain operator Adjusting the rate of change of equivalent heat transfer coefficient over time In this state, as the thermoplastic layer crosses the melting rheological temperature, the melt front expands into the porous substrate layer's voids under capillary network hydrodynamic stress, resulting in unsteady wetting and filling. This process is then controlled by an adaptive gain operator. Corrected rate of change At a filling time of 400 ms, the penetration wetting phase transition threshold was reached. The independent dual-drive temperature control component cut off the power supply to the electric heating element and activated the built-in water-cooling micro-circulation loop the instant the rate of change exceeded the threshold. This caused the surface temperature of the upper pressure plate to rapidly decrease from 182°C to 145°C within 3 seconds to cut off the overload heat flux. Simultaneously, the matrix-type pressure fine-tuning mechanism linearly adjusted the mechanical pressure on the laminated assembly from 1.0 MPa to 2.5 MPa to offset melt flow resistance losses. This allowed the macromolecular chain segments to be tightly bonded to the porous framework and solidified under a constant shear stress of 2.5 MPa. The resulting laminated assembly sample exhibited a stable average ultimate tensile strength of 42.6 MPa and an interlaminar peel strength of 3.3 N / mm in mechanical tensile testing. The interfacial bonding network showed no phase separation voids and a uniformly distributed oriented crystalline structure, confirming the adaptive gain operator. The environmental fault-tolerant circuit maintains the physical and chemical stability of the plastic molding interface under thermal field deviation conditions.

[0058] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A temperature gradient control process for biofilm processing, characterized in that, Includes the following steps: Step S101: Control the upper and lower pressure plates in the independent dual-drive temperature control assembly to implement asymmetric steady-state heat conduction heating on the laminated assembly. The laminated assembly includes a thermoplastic plastic layer and a porous substrate layer. The heat flux data and temperature data characterizing the internal heat transfer state of the laminated assembly are obtained in real time by a matrix heat flow meter and thermocouple embedded inside the laminated assembly. Step S102: Calculate the time change rate of the equivalent thermal conductivity coefficient of the laminated assembly in real time based on the heat flux data and temperature data. When the time change rate of the equivalent thermal conductivity coefficient exceeds the wetting phase change threshold determined by variance smoothing of the initial heat flux characteristic sequence of the initial heating stage, it is determined that the front edge of the thermoplastic melt generated by the melting of the thermoplastic layer has squeezed out the pore air of the porous substrate layer and cut into the porous substrate layer. In step S103, at the instant when the change rate of the equivalent thermal conductivity coefficient generated in step S102 exceeds the threshold of the wetting phase change, the current input of the electric heating tube of the upper platen in the independent dual-drive temperature control assembly is cut off, and the solenoid valve of the forced water cooling micro-circulation pipeline built into the upper platen is opened simultaneously to control the surface temperature of the upper platen to drop back to 145°C within 3 seconds. The residual heat inside the laminated assembly body drives the thermoplastic melt to fill the porous substrate layer to complete the final state micro-topological interlocking. Step S104: Adjust the cooling medium flow rate of the solenoid valve of the forced water-cooled micro-circulation pipeline to implement multi-stage nonlinear cooling, including a rapid cooling section, an isothermal relaxation section, and a natural convection section, on the laminated assembly that has completed the final state micro-topological interlocking. The step S102, which calculates the time-varying rate of change of the equivalent thermal conductivity coefficient of the laminated assembly in real time, includes the following sub-steps: Step S1021, separating the upper surface temperature value of the adjacent upper platen and the lower surface temperature value of the adjacent lower platen from the temperature data; Step S1022, determining the instantaneous total thickness by reading the instantaneous displacement of the laminator spindle grating ruler and subtracting the mechanical zero-point gap value when the hard contacts of the upper and lower platens are closed, dividing the real-time heat flux value in the heat flux data by the difference between the upper surface temperature value and the lower surface temperature value, and multiplying by the instantaneous total thickness to calculate the real-time equivalent thermal conductivity coefficient of the laminated assembly in the current control cycle; Step S1023, calculating the first derivative of the real-time equivalent thermal conductivity coefficient with respect to time to generate the time-varying rate of change of the equivalent thermal conductivity coefficient.

2. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, Step S104 includes the following sub-steps: Step S1041, in the rapid cooling stage, the solenoid valve of the forced water cooling microcirculation pipeline is adjusted to reduce the surface temperature of the thermoplastic layer to below the peak value of the cold crystallization temperature to inhibit spherulite growth; Step S1042, in the isothermal relaxation stage, the solenoid valve of the forced water cooling microcirculation pipeline is closed to maintain the temperature of the laminated assembly in the range of 60°C to 80°C to release internal stress and induce microcrystal formation; Step S1043, in the natural convection stage, the laminated assembly is cooled to the ambient temperature by air convection.

3. The temperature gradient control process in the processing of a biofilm according to claim 1, characterized in that, Step S101 involves controlling the upper and lower pressure plates in the independent dual-drive temperature control assembly to perform asymmetric steady-state heat conduction heating on the laminated assembly, including the following sub-steps: Step S1011: Control the independent dual-drive temperature control assembly to set the heating temperature of the upper pressure plate within the range of 175°C to 190°C, and set the heating temperature of the lower pressure plate within the independent dual-drive temperature control assembly within the range of 60°C to 80°C, thereby constructing an asymmetric temperature gradient field in the thickness direction of the laminated assembly; Step S1012: Control the upper and lower pressure plates to simultaneously heat up at a heating rate of 2°C / min to 5°C / min, so that the thermoplastic layer melts and flows on the side adjacent to the upper pressure plate, while the porous substrate layer maintains a solid skeleton topology on the side adjacent to the lower pressure plate.

4. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, The wetting phase change threshold in step S102 is determined through the following sub-steps: Step S1024, in the initial heating stage where the laminated assembly is heated in step S101 and the thermoplastic layer has not yet melted, the initial heat flux characteristic sequence is collected by a matrix heat flux meter; Step S1025, the variance of the initial heat flux characteristic sequence within a 10s time window is calculated, and the reciprocal of the variance is set as the filtering weight coefficient; Step S1026, the filtering weight coefficient is multiplied by the time change rate of the equivalent heat conduction coefficient for smoothing, and three times the fluctuation amplitude of the smoothed background noise is used as the numerical boundary and assigned to the wetting phase change threshold.

5. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, Step S103 utilizes the residual heat inside the laminated assembly to drive the thermoplastic melt to fill the porous substrate layer to complete the final state micro-topological interlocking, including the following sub-steps: Step S1031, while the surface temperature of the upper platen drops to 145°C within 3 seconds, the independent dual-drive temperature control component applies mechanical pressure to the laminated assembly and linearly increases the mechanical pressure from 1.0 MPa to 2.5 MPa to provide an auxiliary power source to drive the thermoplastic melt to overcome mass transfer resistance and cut into the porous substrate layer; Step S1032, the mechanical pressure is kept constant at 2.5 MPa for 15 to 30 seconds, so that the thermoplastic melt completely fills the porous mesh of the porous substrate layer and solidifies under the constraint of the forced water-cooled micro-circulation pipeline solenoid valve removing heat, locking the interface topological interlocking state between the thermoplastic layer and the porous substrate layer.

6. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, The thermoplastic layer is composed of thermoplastic polymer resin, the melt index of which is 2.0 g / 10 min to 5.0 g / 10 min at 190 °C and 2.16 kg load, the thickness of the thermoplastic layer is 20 μm to 50 μm, and the shear viscosity of the thermoplastic melt at the heating temperature in step S101 is 100 Pa·s to 300 Pa·s.

7. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, The porous substrate layer is composed of a porous fiber skeleton layer. The unit area mass of the porous substrate layer is 15 g / m² to 35 g / m², the average pore size is 5 μm to 15 μm, and the porosity of the porous substrate layer is 65% to 80%.

8. The temperature gradient control process in the processing of biological base membranes according to claim 1, characterized in that, The step S104 of regulating the cooling medium flow rate of the forced water-cooled micro-circulation pipeline solenoid valve includes the following sub-steps: Step S1044, in the rapid cooling section, the forced water-cooled micro-circulation pipeline solenoid valve is regulated to set the cooling medium flow rate within the range of 0.5 m / s to 1.2 m / s, controlling the cooling rate of the laminated assembly to be no less than 15℃ / s; Step S1045, when entering the isothermal relaxation section, the cooling medium flow rate is reduced to 0 m / s to terminate the active cooling heat exchange.

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