Mold heat radiation management system and method

Abstract

The application discloses a mold heat radiation management system and method. The system comprises a mold body and a heat-reflecting lining, and a radiation recycling cavity is formed between the heat-reflecting lining and the mold body. The inner surface of the heat-reflecting lining is provided with an array of spherical concave microstructures. The curvature radius of each spherical concave microstructure is configured to reflect and concentrate the diffuse thermal radiation emitted by the mold body near the outer surface of the mold body; and the array of spherical concave microstructures is non-uniformly spatially distributed on the inner surface of the heat-reflecting lining, and the distribution density or concentration efficiency of the spherical concave microstructures is locally enhanced at positions corresponding to high heat dissipation areas of the mold body. The application precisely compensates the high heat dissipation areas by forming a customized non-uniform reflected thermal radiation flux matching the inherent thermal gradient of the mold, solves the problem of uneven mold temperature, and improves product quality.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology, and more specifically, to a radiative thermal management system and method for molds, particularly suitable for injection molds. Background Technology

[0002] In injection molding and other mold processing technologies, mold temperature control is one of the key factors determining the final product quality, molding cycle, and process stability. Precise and uniform mold temperature control directly affects the fluidity, filling effect, crystallinity, shrinkage rate of molten plastic, as well as the surface finish, dimensional accuracy, and mechanical properties of the final product.

[0003] However, in actual production, the temperature field of the mold naturally exhibits non-uniformity. Due to the mold's geometry (such as corners, ribs, and thin-walled areas) and its contact with the external environment, the heat dissipation rate varies significantly across different parts. Typically, the corners and edges of the mold, due to their larger surface area to volume ratio, become high-heat-dissipation areas with relatively lower temperatures; while the center or thick-walled areas of the mold dissipate heat more slowly and have relatively higher temperatures. This inherent, non-uniform temperature gradient leads to inconsistent cooling and shrinkage of the plastic within the mold cavity, resulting in serious defects such as warping, shrinkage marks, and internal stress concentration, directly reducing the product yield.

[0004] To solve the above problems, existing technologies mainly adopt the following solutions:

[0005] 1. A method is to create straight cooling / heating channels inside the mold and circulate temperature-controlled fluids such as water or oil. While this method is common, for molds with complex geometries, straight channels cannot reach every corner of the mold cavity, and it is particularly ineffective in addressing localized heat loss in areas such as edges and corners, resulting in limited uniformity of temperature control.

[0006] 2. Adopting conformal cooling / heating technology, as an improvement over conventional solutions, allows conformal channels to better conform to the contours of the mold cavity, improving the uniformity of temperature distribution to some extent. However, the design and manufacturing costs of conformal channels are high, and their adjustment capability and response speed are still limited for some extremely complex structures or transient heat fluctuations, making it impossible to completely eliminate the thermal gradient of the mold.

[0007] 3. Employ external heating or insulation measures, such as installing electric heating tubes or heating plates on the outside of the mold for auxiliary heating, or wrapping it with insulation materials such as thermal insulation cotton. Active methods such as electric heating are energy-intensive and complex to control; while simple passive insulation methods such as thermal insulation cotton can only slow down heat loss as a whole and cannot distinguish the heat dissipation differences between different areas. Therefore, they have little effect on improving the problem of uneven temperature inside the mold.

[0008] In summary, current technologies still lack an effective means to intelligently and specifically compensate for localized high heat loss in molds, thereby achieving high-precision thermal field control. Therefore, there is an urgent need to develop a novel thermal management technology that is simple in structure, low in cost, and can effectively improve the uniformity of the mold temperature field. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art, such as uneven temperature control of the mold, especially the local high heat loss in areas such as the corners, which leads to product defects.

[0010] To solve the above-mentioned technical problems, the present invention provides a thermal radiation management system for a mold, comprising: a mold body and at least one heat-reflective lining;

[0011] The heat-reflective liner is configured to cover at least a portion of the outer surface of the mold body and form a radiation recovery cavity between the liner and the mold body.

[0012] The heat-reflective lining has an inner surface facing the mold body, and a spherical concave microstructure array is provided on the inner surface of the heat-reflective lining. The radius of curvature of each spherical concave microstructure in the spherical concave microstructure array is configured such that the focal point of heat-diffusing radiation emitted from the outer surface of the mold body is located at or near the outer surface of the mold body after being reflected by the spherical concave microstructure.

[0013] Furthermore, the array of spherical concave microstructures is spatially distributed non-uniformly on the inner surface of the heat-reflective lining. In the location corresponding to the predetermined high heat loss area of ​​the mold body, the distribution density or convergence efficiency of the spherical concave microstructures is locally enhanced. Thus, the heat radiation management system is configured to form a customized non-uniform reflective heat radiation flux distribution on the outer surface of the mold body that matches the inherent thermal gradient of the mold body, in order to compensate for the heat loss in the high heat loss area of ​​the mold body.

[0014] The thermal radiation management system also includes a set of high-temperature actuators disposed between a support structure and the heat-reflective lining, and a control unit configured to instruct the high-temperature actuators to displace based on temperature feedback signals from the mold body, so as to dynamically adjust the geometry of the radiation recovery cavity.

[0015] Preferably, the heat-reflective liner is made of aluminum.

[0016] Preferably, the heat-reflective liner is a dynamically controllable liner that includes an electrochromic layer;

[0017] The thermal radiation management system further includes at least one temperature sensor disposed on the mold body, and a control unit configured to apply a voltage to the electrochromic layer based on the signal from the temperature sensor to actively adjust its infrared reflectivity.

[0018] Preferably, the heat-reflective lining includes a thermochromic layer whose infrared reflectivity changes with its own temperature, thereby forming an adaptive thermal feedback regulation loop.

[0019] Preferably, the inner surface of the heat-reflective lining is constructed as a gradient thermal metasurface, which is composed of subwavelength unit structures. The geometric parameters of the subwavelength unit structures are spatially gradually distributed on the inner surface of the heat-reflective lining to generate a customized non-uniform reflected thermal radiation flux distribution on the outer surface of the mold body.

[0020] The present invention also provides a method for managing the heat radiation of a mold, comprising the following steps:

[0021] Heat dissipation radiation is emitted from the outer surface of the mold body;

[0022] The thermal radiation is intercepted using the inner surface of a heat-reflective liner, wherein the heat-reflective liner covers at least a portion of the outer surface of the mold body and forms a radiation recovery cavity; and

[0023] The array of spherical concave microstructures disposed on the inner surface of the heat-reflective lining will concentrate the heat radiation and reflect it back to the outer surface of the mold body.

[0024] The thermal radiation management method further includes:

[0025] Configure the radius of curvature of each spherical concave microstructure in the array of spherical concave microstructures such that the focal point of the reflected thermal radiation is located at or near the outer surface of the mold body; and

[0026] The spherical concave microstructure array is arranged in a non-uniform spatial distribution manner, wherein the distribution density or convergence efficiency of the spherical concave microstructure is locally enhanced at the position corresponding to the predetermined high heat dissipation area of ​​the mold body, so as to form a customized non-uniform reflected heat radiation flux distribution on the outer surface of the mold body that matches the inherent thermal gradient of the mold body.

[0027] The aforementioned thermal radiation management method further includes the following steps:

[0028] By using a set of high-temperature actuators and based on temperature feedback signals from the mold body, the geometry of the radiation recovery cavity is actively adjusted to dynamically regulate the intensity of radiation reflected back to the mold body.

[0029] Preferably, the thermal radiation management method further includes the following steps:

[0030] A temperature signal is received from the mold body via a control unit; and

[0031] Based on the temperature signal, a control voltage is applied to the electrochromic layer contained within the heat-reflective lining to actively adjust the infrared reflectivity of the inner surface of the heat-reflective lining.

[0032] Preferably, the step of focusing the heat radiation and reflecting it back to the outer surface of the mold body is achieved by constructing the inner surface of the heat-reflective lining as a gradient thermal metasurface, which is composed of subwavelength unit structures, and the geometric parameters of the subwavelength unit structures are spatially gradually distributed on the inner surface of the heat-reflective lining.

[0033] One or more technical solutions provided in this invention have at least the following technical effects or advantages:

[0034] This invention abandons the traditional approach of uniform heat preservation or heating. By non-uniformly arranging spherical concave microstructures with specific radii of curvature, this invention can reflect heat passively and diffusely radiated from the mold surface back into the mold in a concentrated and enhanced manner, distributing it on demand. That is, in areas with rapid heat dissipation, the reflected heat radiation flux is stronger; in areas with slow heat dissipation, the reflected flux is relatively weaker. This intelligent heat redistribution mechanism achieves precise and targeted compensation for areas of high heat loss in the mold, and its thermal field control precision is far superior to that of traditional heat preservation or cooling technologies.

[0035] Furthermore, by creating a customized reflective thermal field that matches the inherent thermal gradient of the mold, this invention can actively smooth out peaks and fill valleys, effectively suppressing temperature differences on the mold surface and achieving high temperature uniformity. Uniform mold temperature ensures synchronous and uniform shrinkage of plastic products during the cooling process, thereby fundamentally reducing defects such as warping, dimensional deviations, internal stress concentration, and surface shrinkage caused by uneven cooling, and greatly improving the dimensional accuracy, mechanical properties, and appearance quality of the final product.

[0036] Moreover, the core system of this invention is a completely passive physical system. It cleverly utilizes the heat radiated by the mold itself as an energy source, achieving heat recovery and intelligent redistribution through sophisticated microstructural design. The entire process requires no external energy input and generates no additional energy consumption. Compared to active temperature control solutions such as electric heating, this invention is a green, energy-saving, and highly efficient thermal management solution.

[0037] Moreover, the main component of this invention is a heat-reflective liner with a special surface treatment, which is simple in structure and durable. This heat-reflective liner can be easily integrated into the design of new molds or added to the outside of existing molds in a modular manner. It has low implementation cost, low modification difficulty, and extremely high industrial application value and promotion prospects. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram showing a partial magnification of the heat-reflective lining and its core working principle in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram illustrating the non-uniform distribution of spherical concave microstructures on the inner surface of the heat-reflective lining in an embodiment of the present invention.

[0041] Figure 4 This is a partial structural schematic diagram of an embodiment of the present invention employing active optical modulation (electrochromic) method;

[0042] Figure 5 for Figure 4 The control principle block diagram of the embodiment shown;

[0043] Figure 6 This is a partial structural schematic diagram of another embodiment of the present invention employing adaptive optics control (thermochromic) method;

[0044] Figure 7 This is a schematic diagram of the overall structure of another embodiment of the present invention employing an active mechanical control method;

[0045] Figure 8 for Figure 7 The control principle block diagram of the embodiment shown.

[0046] Explanation of reference numerals in the attached drawings: 100, mold body; 110, heat-reflective lining; 111, electrochromic layer; 112, thermochromic layer; 113, substrate; 120, radiation recovery chamber; 130, spherical concave microstructure; 140, temperature sensor; 150, control unit; 160, high-temperature actuator; 200, support structure. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Example

[0048] Reference Figures 1 to 3The present invention provides a thermal radiation management system for a mold. The system includes a mold body 100 and at least one heat-reflective liner 110.

[0049] Specifically, such as Figure 1 As shown, the heat-reflective liner 110 is configured to cover at least a portion of the outer surface of the mold body 100. In a preferred embodiment, for example, for a typical injection mold, its left and right sides need to be connected to the injection molding machine; therefore, the heat-reflective liner 110 can be disposed on the front and rear outer surfaces of the mold body 100. A radiation recovery cavity 120 with a predetermined gap is formed between the heat-reflective liner 110 and the mold body 100. In this embodiment, the heat-reflective liner 110 is preferably made of aluminum because it has high reflectivity in the infrared band and is relatively inexpensive.

[0050] Regarding the fixing method of the heat-reflective liner 110, in this embodiment, a static fixing method can be adopted. A specific fixing structure is as follows: the heat-reflective liner 110 is installed on the outside of the mold body 100 using multiple thermally insulating connectors (not shown). The thermally insulating connectors can be pads or supports made of materials with low thermal conductivity, such as ceramics or high-temperature engineering plastics. During installation, one end of the thermally insulating connector is connected to the outer surface of the mold body 100, and the other end is connected to the back of the heat-reflective liner 110, thereby establishing a precise and stable gap, i.e., the radiation recovery chamber 120, between the mold body 100 and the heat-reflective liner 110. This connection can be achieved using mechanical fasteners (e.g., bolts, clips, etc.), for example, by using bolts to pass through the heat-reflective liner 110 and the thermally insulating connectors and fastening them in pre-set threaded holes on the mold body 100. The function of the thermally insulating connectors is to minimize direct heat conduction between the heat-reflective liner 110 and the mold body 100 while ensuring structural stability. Alternatively, the heat-reflective lining 110 can be fixed to an external support frame independent of the mold body 100.

[0051] Reference Figure 2 The heat-reflective liner 110 has an inner surface facing the mold body 100, on which a spherical concave microstructure array is disposed. The spherical concave microstructure array is composed of a plurality of spherical concave microstructures 130.

[0052] A core technical concept of this invention lies in the precise optical design of these microstructures. For example... Figure 2As shown, the radius of curvature of each spherical concave microstructure 130 in the array of spherical concave microstructures is specially configured so that the heat radiation emitted from the outer surface of the mold body 100 (as indicated by the dashed arrow in the figure), after being reflected by the spherical concave microstructure 130, can be refocused at a focal point located on or near the outer surface of the mold body 100. This design ensures that the thermal radiation energy can be returned to the mold surface with the highest flux density, solving the problem of low recovery efficiency caused by energy divergence in ordinary reflective surfaces. This design requires a precise match between the radius of curvature of the spherical concave microstructure 130 and the thickness of the radiation recovery cavity 120. According to the principles of geometric optics, for approximately perpendicularly incident radiation, the focal distance of the spherical concave microstructure 130 is approximately half of its radius of curvature; therefore, the radius of curvature should be designed to be approximately twice the thickness of the radiation recovery cavity 120.

[0053] Another core technical concept of this invention lies in the functional design of the macroscopic arrangement of the spherical concave microstructure array. (Refer to...) Figure 3 The array of spherical concave microstructures is spatially distributed non-uniformly on the inner surface of the heat-reflective lining 110. Specifically, at locations corresponding to predetermined high heat dissipation areas of the mold body 100 (e.g., corners, edges, etc. of the mold), the distribution density of the spherical concave microstructures 130 is locally enhanced (e.g., ...). Figure 3 (As shown in the dense region at the edge); while in regions corresponding to slower heat dissipation (e.g., the central region of the mold), the distribution density is relatively sparse. Alternatively, the convergence efficiency can be locally enhanced by changing the geometry or shape of each spherical concave microstructure 130.

[0054] Through the aforementioned dual design of precise focusing and non-uniform distribution, this system can transform passively and uniformly dissipated heat radiation into a customized non-uniform reflected heat radiation flux distribution that matches the inherent thermal gradient of the mold body 100. That is, in the areas most in need of heat compensation, the most heat is returned and the energy density is highest, thus achieving precise compensation for heat loss in high-heat-dissipation areas and significantly improving the overall temperature uniformity of the mold. Example

[0055] This embodiment provides an active optical control scheme based on Embodiment 1.

[0056] Reference Figure 4 and Figure 5 In this embodiment, the heat-reflective liner 110 is a dynamically controllable liner, the structure of which may include a substrate 113 (e.g., an aluminum substrate) and an electrochromic layer 111 covering the inner surface of the spherical concave microstructure 130. The system also includes at least one temperature sensor 140 disposed on the mold body 100, and a control unit 150.

[0057] like Figure 5 The control principle illustrated involves the temperature sensor 140 monitoring the temperature of one or more key points on the mold body 100 in real time during operation and sending the temperature signal to the control unit 150. The control unit 150 applies a precise control voltage to the electrochromic layer 111 based on preset process parameters or a control algorithm (e.g., a PID algorithm). Under the influence of an electric field, the infrared reflectivity of the electrochromic layer 111 undergoes a reversible change. For example, when the mold temperature is below a set value, the control unit 150 can apply a voltage to put the electrochromic layer 111 in a high reflectivity state to enhance heat recovery; when the mold temperature is above the set value or rapid cooling is required, a reverse voltage can be applied or the voltage removed to put the electrochromic layer 111 in a low reflectivity state to reduce heat recovery. Through this closed-loop feedback control, the system achieves real-time, proactive, and precise adjustment of the amount of heat radiation recovered. Example

[0058] This embodiment provides an adaptive optics control scheme.

[0059] Reference Figure 6 In this embodiment, the structure of the heat-reflective lining 110 is similar to that of Embodiment 2. It includes a substrate 113, and the inner surface of its spherical concave microstructure 130 is covered with a thermochromic layer 112, such as a vanadium dioxide (VO2)-based material. This material is characterized by a significant change in infrared reflectivity as its temperature increases. When the temperature of the mold body 100 rises, the heat-reflective lining 110 is heated by thermal radiation. When the temperature of the thermochromic layer 112 reaches a certain phase transition point, its infrared reflectivity automatically changes from a lower value to a higher value, thereby enhancing the heat recovery effect; conversely, when the temperature decreases, its reflectivity automatically decreases. This design constitutes an adaptive thermal feedback regulation loop that requires no external sensors or control units, enabling passive and intelligent stabilization of the mold temperature. Example

[0060] This embodiment provides an active mechanical control scheme.

[0061] Reference Figure 7 and Figure 8 In this embodiment, the system further includes a set of high-temperature actuators 160 disposed between a support structure 200 and a heat-reflective liner 110. The high-temperature actuators 160 may be high-temperature resistant piezoelectric actuators or shape memory alloy actuators.

[0062] like Figure 8The control principle illustrated also includes a temperature sensor 140 and a control unit 150. The temperature sensor 140 monitors the temperature of one or more key points on the mold body 100 in real time and sends the temperature signal to the control unit 150. During operation, the control unit 150 calculates and instructs the high-temperature actuator 160 to produce a small displacement based on the temperature feedback signal from the temperature sensor 140. The displacement of the high-temperature actuator 160 pushes or pulls the heat-reflective liner 110, thereby dynamically adjusting the geometry of the radiation recovery cavity 120, such as changing its thickness. Since the focal position of the spherical concave microstructure 130 is closely related to the cavity thickness, changing the cavity thickness can directly control the radiation flux density and intensity reflected back to the mold body 100. This constitutes another closed-loop active thermal control system that is completely different from the optical control principle.

[0063] The present invention also provides a method for managing the radiative heat of a mold, which can be executed by the system of any of the above embodiments. The method mainly includes:

[0064] Heat dissipation radiation is emitted from the outer surface of a mold body 100;

[0065] The thermal radiation is intercepted using the inner surface of a heat-reflective lining 110;

[0066] The array of spherical concave microstructures disposed on the inner surface of the heat-reflective lining 110 will focus the heat radiation and reflect it back to the outer surface of the mold body 100.

[0067] The core of this method lies in the pre-configuration of the parameters of the spherical concave microstructure array through design and manufacturing steps before execution. Specifically, this includes: configuring the radius of curvature of each spherical concave microstructure 130 so that the focal point of reflected heat radiation is located at or near the outer surface of the mold body 100; and setting the spherical concave microstructure array in a non-uniform spatial distribution manner to locally enhance its distribution density or convergence efficiency at locations corresponding to predetermined high heat dissipation areas of the mold.

[0068] In some preferred embodiments, the method may also include an active control step, such as actively adjusting the infrared reflectivity of the electrochromic layer 111 by the control unit 150 based on the signal from the temperature sensor 140, or actively adjusting the displacement of the high-temperature actuator 160 to change the geometry of the radiation recovery cavity 120.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or equivalent substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thermal radiation management system for a mold, characterized in that, include: A mold body (100) and at least one heat-reflective liner (110); The heat-reflective liner (110) is configured to cover at least a portion of the outer surface of the mold body (100) and form a radiation recovery cavity (120) between the mold body (100) and the mold body (100). The heat-reflective liner (110) has an inner surface facing the mold body (100), and a spherical concave microstructure array is provided on the inner surface of the heat-reflective liner (110). The radius of curvature of each spherical concave microstructure (130) in the spherical concave microstructure array is configured such that the focal point of heat-diffusing radiation emitted from the outer surface of the mold body (100) after being reflected by the spherical concave microstructure (130) is located at or near the outer surface of the mold body (100). Furthermore, the array of spherical concave microstructures is spatially distributed non-uniformly on the inner surface of the heat-reflective lining (110), wherein the distribution density or convergence efficiency of the spherical concave microstructures (130) is locally enhanced at locations corresponding to predetermined high heat loss areas of the mold body (100), thereby the heat radiation management system is configured to form a customized non-uniform reflective heat radiation flux distribution on the outer surface of the mold body (100) that matches the inherent thermal gradient of the mold body (100) to compensate for heat loss in high heat loss areas of the mold body (100); The thermal radiation management system also includes a set of high-temperature actuators (160) disposed between a support structure (200) and the heat-reflective lining (110), and a control unit (150) configured to instruct the high-temperature actuators (160) to displace based on a temperature feedback signal from the mold body (100) to dynamically adjust the geometry of the radiation recovery cavity (120).

2. The thermal radiation management system according to claim 1, characterized in that, The heat-reflective lining (110) is made of aluminum.

3. The thermal radiation management system according to claim 1, characterized in that, The heat-reflective lining (110) is a dynamically controllable lining that includes an electrochromic layer (111). The thermal radiation management system further includes at least one temperature sensor (140) disposed on the mold body (100), and a control unit (150) configured to apply a voltage to the electrochromic layer (111) according to the signal of the temperature sensor (140) to actively adjust its infrared reflectivity.

4. The thermal radiation management system according to claim 1, characterized in that, The heat-reflective lining (110) includes a thermochromic layer (112) whose infrared reflectivity changes with its own temperature, thereby forming an adaptive thermal feedback regulation loop.

5. The thermal radiation management system according to claim 1, characterized in that, The inner surface of the heat-reflective lining (110) is constructed as a gradient thermal metasurface, which is composed of subwavelength unit structures. The geometric parameters of the subwavelength unit structures are spatially gradually distributed on the inner surface of the heat-reflective lining (110) to generate a customized non-uniform reflected thermal radiation flux distribution on the outer surface of the mold body (100).

6. A method for managing the thermal radiation of a mold, characterized in that, Includes the following steps: Heat dissipation radiation is emitted from the outer surface of a mold body (100); The thermal radiation is intercepted using the inner surface of a heat-reflective liner (110), wherein the heat-reflective liner (110) covers at least a portion of the outer surface of the mold body (100) and forms a radiation recovery cavity (120); and The array of spherical concave microstructures disposed on the inner surface of the heat-reflective lining (110) will focus the heat radiation and reflect it back to the outer surface of the mold body (100). The thermal radiation management method further includes: Configure the radius of curvature of each spherical concave microstructure (130) in the array of spherical concave microstructures such that the focal point of the reflected thermal radiation is located at or near the outer surface of the mold body (100); and The array of spherical concave microstructures is arranged in a non-uniform spatial distribution. At locations corresponding to predetermined high heat dissipation areas of the mold body (100), the distribution density or convergence efficiency of the spherical concave microstructures (130) is locally enhanced to form a customized non-uniform reflected thermal radiation flux distribution on the outer surface of the mold body (100) that matches the inherent thermal gradient of the mold body (100). The thermal radiation management method further includes the following steps: By using a set of high-temperature actuators (160) and based on the temperature feedback signal from the mold body (100), the geometry of the radiation recovery cavity (120) is actively adjusted to dynamically regulate the intensity of radiation reflected back to the mold body (100).

7. The thermal radiation management method according to claim 6, characterized in that, It also includes the following steps: A temperature signal is received from the mold body (100) via a control unit (150); and According to the temperature signal, a control voltage is applied to the electrochromic layer (111) contained in the heat-reflective lining (110) to actively adjust the infrared reflectivity of the inner surface of the heat-reflective lining (110).

8. The thermal radiation management method according to claim 6, characterized in that, The step of focusing the heat radiation and reflecting it back to the outer surface of the mold body (100) is achieved by constructing the inner surface of the heat-reflective lining (110) as a gradient thermal metasurface, which is composed of subwavelength unit structures, and the geometric parameters of the subwavelength unit structures are spatially gradually distributed on the inner surface of the heat-reflective lining (110).

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