Cylindrical high polymer thermal conductivity measuring system and measuring method thereof

Abstract

The invention discloses a cylindrical high polymer thermal conductivity measuring system and a measuring method thereof, and the system comprises a high polymer forming assembly, a heating controller and a data processing assembly; the high polymer forming assembly comprises a top cover, a base, an inner cylinder and an outer cylinder, the inner cylinder and the outer cylinder are arranged between the top cover and the base, the inner cylinder and the outer cylinder are different in diameter and are concentrically arranged, and a containing cavity used for injecting high polymer slurry is further formed between the inner cylinder and the outer cylinder. A hot plate unit is arranged on the inner wall of one side, close to the outer cylinder, of the accommodating cavity; a cold plate unit is arranged on the inner wall of the side, close to the inner cylinder, of the containing cavity. Corresponding temperature detectors are embedded in the hot plate unit and the cold plate unit; the temperature detectors, the hot plate unit and the cold plate unit are all in electric signal connection with the heating controller; and the heating controller is also in electric signal connection with the data processing assembly. The invention aims to improve the universality of measurement of the heat conductivity of the cylindrical high polymer.

Description

Technical Field

[0001] The invention relates to the technical field of polymer thermal conductivity measurement, in particular to a cylindrical polymer thermal conductivity measurement system and a measurement method thereof. Background Art

[0002] At present, the test methods of thermal conductivity are mainly divided into two categories: steady-state method and non-steady-state method. In the steady-state method, the guarded hot plate method is widely recognized as the standard method for measuring thermal conductivity. It is mainly used to measure thermal insulation materials with thermal conductivity below 1W / (m·K). Due to its high measurement accuracy, it is adopted by metrology institutes of various countries as a standard method for establishing thermal conductivity measurement reference devices. The specimen used in the guarded hot plate method for measuring thermal conductivity must be homogeneous. This is because when measuring the thermal resistance or thermal conductivity of non-homogeneous specimens, the heat flux density inside the specimen and on the surface of the measurement area may be neither unidirectional nor uniform, and there will be thermal field deformation in the specimen. If the specimen is uniform but anisotropic (that is, the thermal conductivity component measured in the direction parallel to the specimen surface is different from the thermal conductivity component measured in the direction perpendicular to the surface), serious errors (edge ​​heat loss error and imbalance error, etc.) will occur. As a result, the heat flow in the specimen deviates from the one-dimensional steady-state heat transfer mode, and this change cannot be accurately predicted. Most of the error calculations will limit the simplified boundary conditions and assume that the specimen is a radiant opaque body. Therefore, if the specimen is a translucent body, the error calculation will also be inaccurate. In addition, due to the influence of the indoor thermal environment, such as thermal reversible expansion and contraction or thermal irreversible expansion and contraction, the thickness of the specimen will change slightly, causing changes in the heat conduction process. The thickness of the specimen placed in the equipment determines the density of the material and the temperature gradient when testing thermal properties. Since the transfer coefficient is related to the thickness of the specimen, it does not meet the requirements of the definition of thermal conductivity and thermal resistance (both of which are inherent properties of the material).

[0003] Based on the provisions in ISO8302, the thickness of the test piece should be greater than the thickness at which the transfer coefficient of the material, product or system does not change by more than 2% when the thickness is further increased. The thinner the test piece and the lower the density, the more the thermal resistance is related to the heat transfer process other than conduction. The minimum thickness of the test piece is limited by the contact thermal resistance between the test piece and the hot plate and the cold plate, and the maximum thickness is restricted by the boundary conditions at the edge of the test piece. Therefore, the traditional protected hot plate method has limitations for measuring the thermal conductivity of polymers, and the existing utility model patent with patent publication number CN203236686U discloses a mold heat transfer coefficient measuring device, which can measure the heat transfer coefficient between ultra-thin parts and injection molds, but still cannot measure the thermal conductivity of the injection mold itself. Therefore, polymer materials need an effective, low-error, and low-cost method for measuring their thermal conductivity. Summary of the invention

[0004] The main purpose of the present invention is to provide a cylindrical polymer thermal conductivity measurement system and a measurement method thereof, aiming to solve the technical problem of the existing polymer thermal conductivity test being limited.

[0005] To achieve the above object, the present invention provides a cylindrical polymer thermal conductivity measurement system, the system comprising a polymer molding component, a heating controller and a data processing component;

[0006] The polymer molding assembly comprises a top cover, a base, and an inner cylinder and an outer cylinder arranged between the top cover and the base. The inner cylinder and the outer cylinder have different diameters and are arranged concentrically. A receiving cavity for injecting polymer slurry is also arranged between the inner cylinder and the outer cylinder.

[0007] A heat plate unit is arranged on the inner wall of the accommodating chamber near the outer cylinder, and the heat plate unit is used to heat the polymer after the polymer slurry in the accommodating chamber is solidified;

[0008] A cold plate unit is arranged on the inner wall of the accommodating chamber near the inner cylinder, and the cold plate unit is used to refrigerate the polymer after the polymer slurry in the accommodating chamber is solidified;

[0009] The hot plate unit and the cold plate unit are both embedded with corresponding temperature detectors;

[0010] Each temperature detector, hot plate unit, and cold plate unit are connected to the heating controller by electrical signals;

[0011] The heating control instrument is also connected to the data processing component by electrical signals.

[0012] Optionally, the side wall of the outer cylinder is provided with grouting holes, and the grouting holes are connected to the accommodating cavity.

[0013] Optionally, the inner cylinder is further provided with a detachable inner cylinder cover, and the bottom of the inner cylinder and the top of the inner cylinder cover are respectively snap-connected in the first snap-in grooves of the base and the top cover.

[0014] Optionally, corresponding heat-insulating gaskets are also arranged at the bottom and top of the accommodating cavity.

[0015] Optionally, the upper and lower ends of the outer cylinder are respectively arranged in the second slots of the top cover and the base with corresponding heat insulation gaskets.

[0016] Optionally, each second slot is further provided with a reinforcing gasket, and each reinforcing gasket is in contact with the outer wall of the outer tube.

[0017] Optionally, each second slot is further provided with a limiter, and each limiter is provided between the reinforcement gasket and the outer cylinder.

[0018] Optionally, the inner cylinder is formed by splicing a plurality of inner cylinder arc-shaped pieces, and the outer cylinder is formed by splicing a plurality of outer cylinder arc-shaped pieces.

[0019] Optionally, the heat plate unit comprises a heat plate block, a protective heater and a heat insulating shell, and the heat insulating shell is tightly fitted to the inner wall of the outer cylinder.

[0020] In addition, in order to achieve the above-mentioned results, the present invention also provides a measuring method of a cylindrical polymer thermal conductivity measuring system, characterized in that the method comprises the following steps:

[0021] Step 1, assembling a polymer molding component and injecting polymer slurry into the accommodating cavity for molding, wherein the radii of the inner cylinder and the outer cylinder are r1 and r2;

[0022] Step 2, after the polymer is molded and cooled to room temperature, the hot plate unit and the cold plate unit are started, and the energy input to the hot plate unit and the area of ​​the hot plate unit are obtained;

[0023] Step 3, obtaining the real-time temperatures t1 and t2 of the connection points between the inner tube, the outer tube and the polymer;

[0024] Step 4, the radii r1 and r2 of the inner cylinder and the outer cylinder, the real-time temperatures t1 and t2 of the connection between the inner cylinder and the outer cylinder and the polymer, and the energy input by the heat plate unit are calculated according to the thermal conductivity model to obtain the thermal conductivity coefficient λ of the polymer material;

[0025] The heat conduction model satisfies q is the heat flux density, Φ is equal to the energy supplied to the hot plate unit, and l is the height of the polymer molding component.

[0026] Beneficial effects:

[0027] The present invention adopts a measurement system that integrates molding and measurement, effectively avoiding the error caused by cutting polymer specimens in the traditional hot plate method, and can directly measure the apparent thermal conductivity of the polymer porous medium foam structure. The thickness of the cylindrical polymer used for measurement is adjustable, breaking through the limitation of material thickness in the traditional protective hot plate method and improving the versatility of polymer material measurement; and the polymer slurry is directly molded in the measuring device under room temperature, so that the thickness of the cylindrical polymer is no longer affected by the measurement environment temperature, thereby effectively reducing the cost investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0029] Figure 1It is a structural schematic diagram of an embodiment of a cylindrical polymer thermal conductivity measurement system of the present invention;

[0030] Figure 2 for Figure 1 Schematic diagram of polymer molding components in;

[0031] Figure 3 for Figure 1 Schematic diagram of the structure of the middle inner tube;

[0032] Figure 4 for Figure 1 Schematic diagram of the structure of the medium heat plate unit;

[0033] Figure 5 This is a schematic diagram of the linear distribution of heat flow from the hot plate unit to the cold plate unit during the actual measurement process;

[0034] Figure 6 for Figure 1 Schematic diagram of heat flux distribution inside the measurement cavity.

[0035] Description of Figure Numbers:

[0036] Label name Label name 1 Top cover 2 Base 3 Inner tube 4 outer cylinder 5 Hot plate unit 6 Cold plate unit 7 Thermal insulation gasket 8 Reinforcement gasket 9 Limiter 10 Cylindrical polymer 20 Heating controller 30 Data processing components 31 Inner cylinder cover 41 Grouting holes 51 Hot Plate 52 Protective heater 53 Insulated shell

[0037] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0041] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] See also Figure 1-Figure 6 According to the present invention, a cylindrical polymer thermal conductivity measurement system is provided, the system comprising a polymer molding component, a heating controller 20 and a data processing component 30. The polymer molding component is used to prepare a cylindrical polymer 10 that can be actually measured, and the heating controller 20 measures the cylindrical polymer and transmits the measured data to the data processing component 30 through a data transmission line for data processing and display on a corresponding screen. The mainboard of the heating controller 20 adopts a high-speed, high-performance 32-bit ARM microprocessor, which can simultaneously collect and record temperature data of 32 channels. The data sampling rate can be as fast as refreshing the record once every 100 milliseconds. The basic error of the high temperature record is ±0.5%+0.6℃, and the basic error of the low temperature record is 0.5%+1.5℃. Thus, molding and measurement are integrated, avoiding the error caused by the traditional hot plate method of polymer specimen cutting.

[0043] Furthermore, if Figure 2 As shown, the polymer molding component includes a top cover 1, a base 2, and an inner cylinder 3 and an outer cylinder 4 arranged between the top cover 1 and the base 2. The inner cylinder 3 and the outer cylinder 4 have different diameters and are concentrically arranged, and a receiving cavity for injecting polymer slurry is also arranged between the inner cylinder 3 and the outer cylinder 4. In actual application, the inner cylinder 3 is formed by splicing a plurality of inner cylinder arc pieces, and the outer cylinder 4 is formed by splicing a plurality of outer cylinder arc pieces. The size of the outer cylinder 4 is adjustable and can be adjusted accordingly according to the actual thickness of the cylindrical polymer 10, thereby solving the problem that the thermal conductivity of large-volume non-homogeneous polymer materials cannot be accurately measured.

[0044] Furthermore, a heat plate unit 5 is arranged on the inner wall of the accommodating chamber near the outer cylinder 4. The heat plate unit 5 is used to heat the cylindrical high polymer 10 after the high polymer slurry in the accommodating chamber is solidified, and the heat plate unit 5 is electrically connected to the heating controller 20, and the heat plate unit 5 can be controlled by the heating controller 20 to heat the cylindrical high polymer 10 in contact with the heat plate unit 5. The heat plate unit 5 is made of high-quality heat-conducting material, which can make the temperature of the heating plate surface more uniform.

[0045] Furthermore, a cold plate unit 6 is arranged on the inner wall of the accommodating chamber near the inner cylinder 3. The cold plate unit 6 is used to cool the cylindrical polymer 10 after the polymer slurry in the accommodating chamber is solidified. Preferably, the cold plate unit 6 is made of high-quality heat-conducting material and uses electronic refrigeration to control the temperature. The temperature can be controlled by the heating controller 20, and then the cold plate unit 6 can be controlled by the heating controller 20 to achieve cooling of the cylindrical polymer 10 in contact with the cold plate unit 6.

[0046] Furthermore, the hot plate unit 5 and the cold plate unit 6 are both embedded with corresponding temperature detectors, and each temperature detector is also electrically connected to the heating controller 20. The heating controller 20 includes a control module for the cold and hot plates, a high-precision DC power sensor module, a temperature acquisition card module, an analog / digital signal processing module, and a shell surface has a plurality of wiring ports. Preferably, it is also connected to the data processing component 30 via a USB-B line.

[0047] Furthermore, the side wall of the outer cylinder 4 is provided with a grouting hole 41, and the grouting hole 41 is connected to the accommodating chamber, and the bottom and the top of the accommodating chamber are also provided with corresponding thermal insulation gaskets 7, and then the required polymer slurry can be injected into the accommodating chamber through the grouting hole 41. The setting of the thermal insulation gasket 7 can ensure that the heat flow of the hot plate unit 5 completely acts on the cylindrical polymer 10.

[0048] Furthermore, in order to enhance the stabilization effect of polymer molding, such as Figure 3 As shown, the inner cylinder 3 is also arranged to be detachable, and further provided with a detachable inner cylinder cover 31, and the bottom of the inner cylinder 3 and the top of the inner cylinder cover 31 are respectively snap-connected in the first snap-in grooves of the base 2 and the top cover 1.

[0049] Furthermore, the upper and lower ends of the outer cylinder 4 are respectively arranged in the second slots of the top cover 1 and the base 2 with corresponding heat insulating gaskets 7, and the upper and lower ends of the outer cylinder 4 are effectively fixed by the heat insulating gaskets 7 to enhance the stability of polymer molding.

[0050] Further, the thickness of the cylindrical polymer 10 is adjusted by adjusting the diameter of the outer cylinder 4, that is, the position of the upper and lower ends of the outer cylinder 4 in the second slot needs to be adjusted. Therefore, a reinforcing gasket 8 can be arranged in the corresponding second slot, and each reinforcing gasket 8 is fitted with the outer wall of the outer cylinder 4, and then the outer cylinder 4 is fixed by the reinforcing gasket 8 and the heat insulating gasket 7 to enhance the stability of the polymer molding. Preferably, a stopper 9 can be arranged in each second slot, and each stopper 9 is arranged between the reinforcing gasket 8 and the outer cylinder 4. The setting of the stopper 10 can prevent the outer cylinder 4 from falling off.

[0051] Furthermore, if Figure 4As shown, the hot plate unit 5 includes a hot plate 51, a protective heater 52 and an insulating shell 53. The insulating shell 53 is tightly fitted with the inner wall of the outer tube 4. The protective heater 52 is arranged at the upper and lower ends of the hot plate 51, and the hot plate 51 and the protective heater 52 are separated from the inner wall of the outer tube 4 by the insulating shell 53. Then, in the actual measurement process, the energy input to the hot plate is set, and the measured temperature and temperature gradient between the heat source and the cold plate are adjusted by adjusting the heat transmitted to the cold plate. The protective heater and the insulating shell around the hot plate ensure that the heat flow from the hot plate to the cold plate is linear and one-dimensional. Figure 5 shown.

[0052] Furthermore, the schematic diagram of heat flow distribution inside the measurement cavity of the polymer molding mold is as follows: Figure 6 As shown, the outer cylinder 4 has a built-in annular hot plate 51, the hot plate 51 is wrapped by an insulating shell 53, the hot plate 51 is embedded with a K-type thermocouple temperature detector (the white circle on the surface of the hot plate 51 in the figure), and the inner cylinder 3 also has a built-in cold plate unit 6 and a K-type thermocouple temperature detector embedded in the surface of the cold plate unit 6 (the white circle on the surface of the cold plate unit 6 in the figure).

[0053] Furthermore, in order to better illustrate the measurement and molding-integrated configuration of the cylindrical polymer thermal conductivity measurement system of the present invention, the following is a detailed step-by-step description.

[0054] Step 1, assemble the polymer molding components, and inject polymer slurry into the accommodating cavity for molding, wherein the radius of the inner cylinder 3 and the outer cylinder 4 are r1 and r2; specifically, first insert the lower ends of the multiple inner cylinder arc pieces into the first slot of the base 2 one after another, and fix the inner cylinder cover 31 on the upper end of the inner cylinder arc piece, then place the thermal insulation gasket 7 in the second slot of the top cover 1 and the base 2, and successively put the outer cylinder arc piece into the second slot of the base 2 to fix it, finally put the top cover 1 on and press it, and fix it through the corresponding fixing holes on the edges of the top cover 1 and the base 2 by the anchor rod, and after the assembly is completed, inject the required polymer slurry into the accommodating cavity through the grouting hole 41. Among them, the outer cylinder 4 has a built-in hot plate unit 5 and a built-in K-type thermocouple temperature detector, and the inner cylinder arc piece and the inner cylinder cover 31 have a built-in cold plate unit 6 and a built-in K-type thermocouple temperature detector.

[0055] Preferably, the inner diameter of the inner cylinder 3 is 100 mm, the thickness of the cylindrical polymer is 10-100 mm, and the height is 300 mm.

[0056] Step 2: After the polymer is formed and cooled to room temperature, the hot plate unit 5 and the cold plate unit 6 are started, and the energy input to the hot plate unit and the area of ​​the hot plate unit are obtained through the heating controller 20.

[0057] Step 3, obtaining the real-time temperatures t1 and t2 of the connection between the inner tube, the outer tube and the polymer through a temperature detector;

[0058] Step 4, the radii r1 and r2 of the inner tube 3 and the outer tube 4, the real-time temperatures t1 and t2 of the connection between the inner tube and the outer tube and the polymer, and the energy input by the hot plate unit are calculated according to the thermal conductivity model to obtain the thermal conductivity λ of the polymer material.

[0059] Specifically, the constructed heat conduction model adopts a cylindrical coordinate system (r, ω, z), the purpose of which is to simplify the two-dimensional steady-state heat conduction problem into a one-dimensional heat conduction problem along the radial direction.

[0060] That is, assuming that the thermal conductivity λ of the material is equal to a constant, the thermal conduction differential equation and the corresponding boundary conditions are:

[0061]

[0062] r=r1,t=t1,(2);

[0063] r=r2,t=t2,(3);

[0064] Integrating equation (1) twice yields the general solution:

[0065] t=c1lnr+c2,(4);

[0066] In the above formula, c1 and c2 are determined by the boundary conditions. Among them, r1 and r2 are the inner and outer radii of the cylinder, and t1 and t2 are the inner and outer surface temperatures. Substituting the boundary conditions (2) and (3) into (4), we can get

[0067]

[0068] Substituting into equation (4), the temperature distribution is

[0069]

[0070] Taking the derivative of formula (7) we can get

[0071]

[0072] Substituting into Fourier's law we get

[0073]

[0074] Where q is the heat flux.

[0075] Furthermore, in the steady-state heat conduction through the cylinder wall, the heat flux density q at different radii is inversely proportional to the radius r, but the heat flux Φ through the entire cylinder wall is a constant and does not change with the radius. Then multiply both sides of equation (9) by 2πr l to obtain

[0076]

[0077] Where Ф is equal to the energy supplied to the hot plate unit, and l is the height of the polymer molding component. Therefore, the parameters such as the radius r1, r2, the temperature difference, the energy supplied to the hot plate unit, and the plate area of ​​the hot plate unit are transmitted to the data processing component 30, and the thermal conductivity λ of the polymer material can be calculated based on the above model.

[0078] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A cylindrical polymer thermal conductivity measurement system, characterized in that: The system comprises a polymer molding component, a heating controller (20) and a data processing component (30); The polymer molding assembly comprises a top cover (1), a base (2), and an inner cylinder (3) and an outer cylinder (4) arranged between the top cover (1) and the base (2); the inner cylinder (3) and the outer cylinder (4) have different diameters and are arranged concentrically; and a receiving cavity for injecting polymer slurry is also arranged between the inner cylinder (3) and the outer cylinder (4); A heat plate unit (5) is arranged on the inner wall of the accommodating chamber on one side close to the outer cylinder (4), and the heat plate unit (5) is used to heat the cylindrical high polymer (10) after the high polymer slurry in the accommodating chamber is solidified; A cold plate unit (6) is arranged on the inner wall of the accommodating chamber on one side close to the inner cylinder (3), and the cold plate unit (6) is used to cool the cylindrical polymer (10) after the polymer slurry in the accommodating chamber is solidified; The hot plate unit (5) and the cold plate unit (6) are both embedded with corresponding temperature detectors; Each temperature detector, the hot plate unit (5), and the cold plate unit (6) are all connected to the heating control device (20) by electrical signals; The heating control device (20) is also connected to the data processing component (30) via electrical signals.

2. The cylindrical polymer thermal conductivity measurement system according to claim 1, characterized in that: The side wall of the outer cylinder (4) is provided with grouting holes (41), and the grouting holes (41) are communicated with the accommodating cavity.

3. The cylindrical polymer thermal conductivity measurement system according to claim 1, characterized in that: The inner cylinder (3) is also provided with a detachable inner cylinder cover (31), and the bottom of the inner cylinder (3) and the top of the inner cylinder cover (31) are respectively snap-connected in the first snap-in grooves of the base (2) and the top cover (1).

4. The cylindrical polymer thermal conductivity measurement system according to claim 1, characterized in that: Corresponding heat-insulating gaskets (7) are also arranged at the bottom and top of the accommodating cavity.

5. The cylindrical polymer thermal conductivity measurement system according to claim 4, characterized in that: The upper and lower ends of the outer cylinder (4) are respectively arranged in the second slots of the top cover (1) and the base (2) with corresponding heat insulation gaskets (7).

6. The cylindrical polymer thermal conductivity measurement system according to claim 5, characterized in that: A reinforcing gasket (8) is also arranged in each second clamping groove, and each reinforcing gasket (8) is in contact with the outer wall of the outer cylinder (4).

7. The cylindrical polymer thermal conductivity measurement system according to claim 6, characterized in that: A stopper (9) is also arranged in each second clamping groove, and each stopper (9) is arranged between the reinforcing gasket (8) and the outer cylinder (4).

8. The cylindrical polymer thermal conductivity measurement system according to any one of claims 1 to 7, characterized in that: The inner cylinder (3) is formed by splicing a plurality of inner cylinder arc-shaped pieces, and the outer cylinder (4) is formed by splicing a plurality of outer cylinder arc-shaped pieces.

9. The cylindrical polymer thermal conductivity measurement system according to claim 8, characterized in that: The heat plate unit (5) comprises a heat plate block (51), a protective heater (52) and a heat-insulating outer shell (53), and the heat-insulating outer shell (53) is tightly fitted to the inner wall of the outer cylinder (4).

10. The measuring method of the cylindrical polymer thermal conductivity measuring system according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Step 1, assembling a polymer molding component and injecting polymer slurry into the accommodating cavity for molding, wherein the radii of the inner cylinder and the outer cylinder are r1 and r2; Step 2, after the polymer is molded and cooled to room temperature, the hot plate unit and the cold plate unit are started, and the energy input to the hot plate unit and the area of ​​the hot plate unit are obtained; Step 3, obtaining the real-time temperatures t1 and t2 of the connection points between the inner tube, the outer tube and the polymer; Step 4, the radii r1 and r2 of the inner cylinder and the outer cylinder, the real-time temperatures t1 and t2 of the connection between the inner cylinder and the outer cylinder and the polymer, and the energy input by the heat plate unit are calculated according to the thermal conductivity model to obtain the thermal conductivity coefficient λ of the polymer material; The heat conduction model satisfies q is the heat flux density, Φ is equal to the energy supplied to the hot plate unit, and l is the height of the polymer molding component.

Images