Graphene composite film heating plate assembly
By using a graphene composite film structure, the problems of oxidation deactivation and delamination of electric heating film heating plates at high temperatures are solved, achieving high-efficiency heat conduction and heat resistance, making it suitable for high-temperature industrial equipment.
Patent Information
- Application Number
- CN202520566911.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2026-03-03
- Estimated Expiration
- 2035-03-27
AI Technical Summary
Existing electric heating film heating plates are prone to oxidation and deactivation at high temperatures, resulting in reduced heating efficiency. Furthermore, the large difference in thermal expansion coefficients between the substrate and the heating layer leads to increased interfacial shear stress and severe delamination, limiting their application in high-temperature industrial equipment.
The graphene composite film structure includes a glass or ceramic substrate, a graphene heating layer, a conductive silver paste layer, and a rare earth protective layer. The rare earth protective layer prevents oxidation, the thermal expansion coefficients of graphene and the substrate are matched to reduce interfacial shear stress, and the heat resistance and thermal conductivity are improved by a zirconium oxide coating layer and a thermal radiation reflective layer.
It improves the heat resistance of the heating plate, extends its service life, reduces the thermal response time, and enhances its mechanical strength and thermal conductivity, making it suitable for high-temperature industrial equipment.
Smart Images
Figure CN223967992U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of electric heating element technology, and in particular relates to a graphene composite film heating plate assembly. Background Technology
[0002] Conventional heating plate assemblies consist only of a carbon-based heating layer and a substrate layer. Carbon-based heating materials (such as carbon fiber and carbon paste) will undergo significant oxidation and deactivation at temperatures above 300°C, with resistivity drift reaching 15-20%, leading to a decrease in heating efficiency. In addition, due to the large difference in thermal expansion coefficients between the substrate and the heating layer, the interfacial shear stress increases, resulting in delamination after multiple thermal cycles. These defects severely restrict the application of electric heating film heating plates in high-temperature industrial equipment, and there is an urgent need to achieve a synergistic breakthrough in high-temperature resistance, thermal shock resistance, and efficient heat conduction through material composites and structural innovation. Utility Model Content
[0003] (I) Purpose of the utility model
[0004] To overcome the above shortcomings, the purpose of this utility model is to provide a graphene composite film heating plate assembly to solve the technical problems that the existing electric heating film heating plates are poor in terms of high temperature resistance, thermal shock resistance and efficient heat conduction, which seriously restricts the application of electric heating film heating plates in high-temperature industrial equipment.
[0005] (II) Technical Solution
[0006] To achieve the above objectives, the technical solution provided in this application is as follows:
[0007] A graphene composite film heating plate assembly includes: a composite film heating plate body, the composite film heating plate body including: a glass or ceramic substrate layer for support, a graphene heating layer above the substrate layer that can conduct electricity and generate heat, a conductive silver paste layer above the graphene heating layer that can conduct electrical energy to the graphene heating layer, and a rare earth protective layer for oxidizing and protecting the graphene heating layer.
[0008] This application solves the oxidation failure caused by setting only a single heating layer in the prior art by setting a rare earth protective layer, ensuring heating efficiency and improving heat resistance. In addition, by choosing graphene as the heating layer and glass or ceramic as the base layer, the difference in the coefficient of thermal expansion between the two is small, which can reduce the interfacial shear stress and avoid delamination caused by repeated hot and cold cycles, thereby improving the heat resistance of the graphene composite film heating plate assembly and extending the service life of the product.
[0009] In some embodiments, the thickness of the substrate layer is 3-8 mm;
[0010] Microcrystalline glass (CTE = 0.5 × 10⁻⁶) -6 / K) and graphene layer (CTE=5×10 -6The thermal expansion difference of the substrate is reduced to 1 / 6 of that of the traditional substrate, and the thermal expansion coefficients are matched to avoid delamination between the two materials. In addition, when the substrate thickness is 3mm, the thermal response time is 9s (15s for traditional glass substrates), and the bending strength is 350MPa (only 180MPa for ordinary glass) at 8mm. The 3-8mm thickness range keeps the longitudinal thermal resistance between 0.08-0.12m. 2 • K / W (conventional substrate thermal resistance fluctuation reaches ±30%), mechanical and thermal properties are balanced.
[0011] In some embodiments, the thickness of the graphene heating layer is 200-400 nm;
[0012] By optimizing the thickness parameters of the graphene heating layer, a power density of 3.2 W / cm² was achieved with a thickness of 200 nm. 2 (Traditional homogeneous layers only 1.8W / cm) 2 With a thickness of 400nm, the heat storage capacity is increased by 40% (temperature fluctuation <±3℃).
[0013] In some embodiments, the thickness of the rare earth protective layer is 5 μm;
[0014] The thickness parameters of the rare earth protective layer were optimized to achieve an oxygen permeability of <0.003 cm. 3 / (m 2 •day), to minimize the penetration of external oxygen and prevent the graphene heating layer from being oxidized; at the same time, the rare earth protective layer is 5μm thick and has a surface hardness of 9H (pencil hardness), which increases the wear resistance life by 3 times.
[0015] In some embodiments, the conductive silver paste layer forms two symmetrical elongated electrode regions, and the rare earth protective layer is hollowed out corresponding to the elongated electrode regions.
[0016] The rare earth protective layer covers most of the conductive silver paste layer, except for the electrode area which is hollowed out to prevent the conductive silver paste layer from being oxidized, thus improving the overall protection efficiency.
[0017] In some embodiments, the invention further includes: a zirconia high-temperature resistant coating layer disposed between the substrate layer and the graphene heating layer, wherein the thickness of the zirconia high-temperature resistant coating layer is 15-20 μm;
[0018] By utilizing the high melting point and chemical stability of zirconium oxide, the interlayer bonding force between the heating layer and the substrate layer is increased, while protecting the graphene heating layer from oxidation. This results in a thermal shock cycle life of >5000 cycles and a structural integrity retention rate of >95% under extreme conditions of 800℃ (conventional structures experience interlayer delamination at 600℃), achieving a breakthrough in high-temperature resistance.
[0019] In some embodiments, the graphene heating layer comprises, from top to bottom, the following layers stacked sequentially: a top layer made of 80% graphene doped with 20% polyimide binder, a middle layer made of 90% graphene with 10% boron nitride nanosheets, and a bottom layer made of 100% graphene.
[0020] Design using longitudinal thermal conductivity gradient
[0021] Top layer (80% purity): 20% polyimide binder is incorporated to form a porous structure (porosity 15-20%), enabling rapid surface thermal diffusion;
[0022] Middle layer (90% purity): Add 10% boron nitride nanosheets to construct an in-plane thermal conductivity network and improve the in-plane thermal conductivity;
[0023] Lower layer (95% purity): Directly in contact with the substrate layer, achieving longitudinal thermal conductivity enhancement through high-purity graphene;
[0024] In some embodiments, it further includes a heat radiation reflective layer disposed between the zirconia high-temperature resistant coating layer and the substrate layer.
[0025] Adding a heat radiation reflector layer can reflect the heat radiation conducted to the base layer upwards, thus preventing heat loss.
[0026] In some embodiments, the device further includes: supports disposed at both ends of the composite film heating plate body for fixing the composite film heating plate body and for transmitting electrical energy to the composite film heating plate body.
[0027] In some embodiments, the bracket includes: a base with a concave structure, two first positioning grooves on the base, an insulating sheet disposed on the base, a second positioning groove on the insulating sheet corresponding to the position of the first positioning groove, a conductive plate disposed on the insulating sheet that contacts the composite film heating plate body, the bottom of the conductive plate protruding outward to form a positioning block inserted into the first and second positioning grooves, and the side extending outward to form a terminal inserted into a terminal block, and further includes: a pressing block with a right-angled cross-section for pressing the composite film heating plate body onto the conductive plate and connecting it to the base;
[0028] The multiple structures of the bracket can stably fix the composite film heating plate body, preventing it from shifting and causing poor contact, which would affect the heating efficiency. Attached Figure Description
[0029] Figure 1 This is a schematic cross-sectional view of the layered structure of the composite film heating plate body in the graphene composite film heating plate assembly of this utility model.
[0030] Figure 2 This is a bottom view of the composite film heating plate body in the graphene composite film heating plate assembly of this utility model.
[0031] Figure 3 This is a schematic cross-sectional view of the layered structure of the composite film heating plate body in a preferred embodiment of the graphene composite film heating plate assembly of this utility model.
[0032] Figure 4 This is an assembly diagram of the graphene composite film heating plate body being fixed onto the bracket in the graphene composite film heating plate assembly of this utility model;
[0033] Figure 5 This is an exploded view of the support structure in the graphene composite film heating plate assembly of this utility model.
[0034] Figure label:
[0035] 1. Base; 101. First positioning groove; 2. Insulating sheet; 201. Second positioning groove; 3. Conductive plate; 301. Wiring terminal; 302. Positioning block; 4. Clamping block; 401. Screw hole; 5. Terminal block. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.
[0037] A graphene composite film heating plate assembly is characterized in that the composite film heating plate body includes: a glass or ceramic substrate layer for support, a graphene heating layer capable of generating electricity and heating above the substrate layer, a conductive silver paste layer capable of conducting electrical energy to the graphene heating layer above the graphene heating layer, and a rare earth protective layer for oxidizing and protecting the graphene heating layer.
[0038] Specifically, in one embodiment, the rare earth protective layer can be: 75% cerium oxide (CeO2) + 25% lanthanum oxide (La2O3), deposited by magnetron sputtering.
[0039] Specifically, the rare earth protective layer can also be other components, which are not limited in this application.
[0040] Specifically, elongated electrode cutout areas are formed on both sides of the rare earth protective layer. When the rare earth protective layer covers the conductive silver paste layer, two elongated electrodes are reserved to connect and conduct electricity with the external terminals. After the conductive silver paste layer becomes conductive, it conducts electrical energy to the graphene heating layer, which then generates heat.
[0041] Specifically, the substrate can be microcrystalline glass, quartz glass, or heat-resistant ceramic.
[0042] Preferably, this application optimizes the graphene heating layer to form a gradient structure:
[0043] Top layer (80% purity): 20% polyimide binder is incorporated to form a porous structure (porosity 15-20%), enabling rapid surface thermal diffusion (thermal conductivity 68W / m·K);
[0044] Middle layer (90% purity): 10% boron nitride nanosheets are added to construct an in-plane thermal conductivity network (in-plane thermal conductivity reaches 420 W / m·K);
[0045] Lower layer (100% purity): Directly in contact with the substrate layer, longitudinal thermal conductivity is enhanced through high-purity graphene (longitudinal thermal conductivity 510 W / m·K).
[0046] Specifically, preparing the graphene heating layer with the aforementioned longitudinal thermal conductivity gradient requires a three-stage coating process. Specifically, the temperature steps for curing the three-layer structure are: 120℃ (pre-curing) → 380℃ (crosslinking) → 750℃ (densification).
[0047] Experimental data: Compared with traditional homogeneous layers, the longitudinal thermal resistance is reduced by 42%, and the time to reach steady-state operating temperature is shortened by 58%. In addition, the resistance gradient is matched as follows: upper layer resistivity: 0.15 Ω·cm (high doping ensures rapid heating), middle layer resistivity: 0.08 Ω·cm (maintains stable operating current), and lower layer resistivity: 0.03 Ω·cm (reduces contact resistance loss).
[0048] After multiple experimental tests, this application has optimized the selection of thickness parameters for each layer of the structure:
[0049] The thickness of the base layer is 3-8mm.
[0050] The thickness of the graphene heating layer is 200-400nm.
[0051] The rare earth protective layer is 5 μm thick.
[0052] Preferably, this application also provides a zirconia high-temperature resistant coating layer between the substrate layer and the graphene heating layer, wherein the thickness of the zirconia high-temperature resistant coating layer is 15-20 μm.
[0053] Preferably, this application includes a heat radiation reflective layer between the zirconia high-temperature resistant coating layer and the substrate layer.
[0054] Specifically, the preparation process of this application is as follows:
[0055] 1. Zirconia coating is sprayed onto the surface of a microcrystalline glass substrate, and a high-temperature resistant layer is formed after sintering;
[0056] 2. Graphene heating layers are formed sequentially using a three-step coating method (curing temperature of each layer: 120℃ / 380℃ / 750℃);
[0057] 3. Screen-printed conductive silver paste electrodes, heat-treated at 780℃ for 30 minutes;
[0058] 4. Vacuum sputtering deposition of rare earth protective layer, working pressure 0.6Pa, target power 250W.
[0059] The advantages of the graphene composite film heating plate assembly in this application are as follows:
[0060] 1. The influence of substrate thickness and material selection on mechanical strength;
[0061] 2. The synergistic antioxidant mechanism of the rare earth-zirconia composite protection system enhances high-temperature resistance;
[0062] 3. The effect of gradient graphene layer structure on the optimization of thermal field distribution.
[0063] Specifically, the graphene composite film heating plate assembly also includes: a bracket, which is set at both ends of the composite film heating plate body for fixing the composite film heating plate body and transmitting electrical energy to the composite film heating plate body.
[0064] Furthermore, the bracket includes: a concave base 1 with two first positioning grooves 101 on the base 1; an insulating sheet 2 on the base 1 with a second positioning groove 201 on the insulating sheet 2 corresponding to the first positioning grooves 101; a conductive plate 3 on the insulating sheet 2 that contacts the composite film heating plate body; a positioning block 302 that protrudes outward from the bottom of the conductive plate 3 and is inserted into the first and second positioning grooves 101 and 201; and a terminal 301 that extends outward from the side and is inserted into the terminal block 5. It also includes: a pressing block 4 with a right-angled cross-section for pressing the composite film heating plate body onto the conductive plate 3 and connecting it to the base 1.
[0065] Specifically, when assembling the composite film heating plate body and the bracket, first place the insulating sheet 2 (two pieces) on the base 1, so that the second positioning groove 201 of the insulating sheet 2 corresponds to the first positioning groove 101 of the base 1. Then place the conductive plate 3 on top of the insulating sheet 2 so that the positioning block 302 is simultaneously inserted into the first and second positioning grooves 101 and 201. This ensures that the conductive plate 3 will not shift. Then place the end of the composite film heating plate body on the conductive plate 3 so that the electrodes of the composite film heating plate body contact the conductive plate 3. Finally, place the clamping block 4 on the end of the composite film heating plate body. Screw holes are provided on both the clamping block 4 and the base 1. 401. The clamping block 4 is fixed to the base 1 by inserting screws into the screw holes 401. The clamping block 4 presses the composite film heating plate body onto the conductive plate 3. Since the clamping block 4 has a right-angle structure, in addition to limiting the upper part of the composite film heating plate body, the clamping block 4 also limits the side part of the composite film heating plate body to prevent the composite film heating plate body from shifting. The conductive plate 3 is provided with wiring terminals 301. The wiring terminals 301 extend and are electrically connected to the wiring base 5. In this way, when the wiring base 5 is energized, the current flows through the wiring terminals 301 to the entire conductive plate 3. The conductive plate 3 transmits the current to the electrodes of the composite film heating plate body to supply power.
[0066] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A graphene composite film heating plate assembly, characterized in that, include: The composite film heating plate body includes: a glass or ceramic substrate layer for support, a graphene heating layer capable of generating heat through electricity located above the substrate layer, a conductive silver paste layer capable of conducting electrical energy to the graphene heating layer located above the graphene heating layer, and a rare earth protective layer for oxidizing and protecting the graphene heating layer.
2. The graphene composite film heating plate assembly according to claim 1, characterized in that, The thickness of the base layer is 3-8 mm.
3. The graphene composite film heating plate assembly according to claim 1, characterized in that, The thickness of the graphene heating layer is 200-400 nm.
4. The graphene composite film heating plate assembly according to claim 1, characterized in that, The thickness of the rare earth protective layer is 5 μm.
5. The graphene composite film heating plate assembly according to claim 1, characterized in that, The conductive silver paste layer forms two symmetrical elongated electrode regions, and the rare earth protective layer is hollowed out corresponding to the elongated electrode regions.
6. The graphene composite film heating plate assembly according to any one of claims 1-5, characterized in that, Also includes: A zirconia high-temperature resistant coating layer is disposed between the substrate layer and the graphene heating layer, wherein the thickness of the zirconia high-temperature resistant coating layer is 15-20 μm.
7. The graphene composite film heating plate assembly according to claim 1, characterized in that, The graphene heating layer comprises, from top to bottom, the following layers: a top layer made of 80% graphene mixed with 20% polyimide binder, a middle layer made of 90% graphene with 10% boron nitride nanosheets, and a bottom layer made of 100% graphene.
8. The graphene composite film heating plate assembly according to claim 6, characterized in that, Also includes: A heat radiation reflective layer is disposed between the zirconia high-temperature resistant coating layer and the substrate layer.
9. The graphene composite film heating plate assembly according to claim 1, characterized in that, Also includes: Supports are provided at both ends of the composite film heating plate body for fixing the composite film heating plate body and transmitting electrical energy to the composite film heating plate body.
10. The graphene composite film heating plate assembly according to claim 9, characterized in that, The bracket includes: a concave base (1) with two first positioning grooves (101) on the base (1), an insulating sheet (2) on the base (1), a second positioning groove (201) on the insulating sheet (2) corresponding to the first positioning grooves (101), a conductive plate (3) on the insulating sheet (2) that contacts the composite film heating plate body, the bottom of the conductive plate (3) protruding outward to form a positioning block (302) inserted into the first and second positioning grooves (201), and the side extending outward to form a terminal block (301) inserted into the terminal block (5), and also includes: a pressing block (4) with a right-angled cross-section for pressing the composite film heating plate body on the conductive plate (3) and connecting it to the base (1).