Graphene heating pad and preparation method and application thereof

Abstract

The invention relates to a graphene heating pad and a preparation method and application thereof, and belongs to the technical field of graphene automobile heating seat pads. The graphene heating pad comprises a graphene heating film layer, the graphene heating film layer comprises a graphene heating body with two free ends, a plurality of ventilation holes are formed in the periphery of the graphene heating body, the graphene heating body is arranged in a snake shape to form a snake-shaped heating wire, and the snake-shaped heating wire is arranged to avoid the ventilation holes. Porous rivets are arranged at the two free ends of the graphene heating body, the wiring harness is electrically connected with the graphene heating body, and the wiring harness is led out through the porous rivets and is communicated with a power supply. The heating area of the graphene heating body is large and uniform, the graphene heating body is coated with the upper protective film layer and the lower protective film layer, dust prevention, water prevention, friction prevention, external force prevention and the like can be achieved, and the service life is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of graphene automobile heated seat pads, and in particular to a graphene heating pad and a preparation method and application thereof. Background Art

[0002] With the continuous improvement of living standards, in order to improve the comfort of car seats, many car seats are now equipped with heating functions. Based on performance and health concepts, many graphene heating pads have emerged, but traditional graphene heating pads have the following disadvantages: A. Printed graphene heating pads: Use graphene slurry to screen print the graphene heating layer and silver paste electrode layer on the PET or PI film, and lead out the wires. The disadvantages are as follows: 1. The graphene heating layer has poor resistance uniformity due to the printing method, resulting in uneven heating; 2. After long-term use, due to mechanical effects, the graphene layer cracks, the resistance increases, and the power decays; 3. The silver paste electrode needs to carry a large current, which requires the silver paste line width to increase, reducing the heating area and increasing the material cost. And the existence of silver paste resistance leads to increased tail resistance, increased voltage drop, and lower heating temperature; 4. Since the silver paste is printed, there is heating and attenuation at the wire lead-out point; 5. The heating pad is subjected to greater force at the ribs, and long-term mechanical friction causes the silver paste wire to break; 6. The printing scrap rate is high, the process is complex, and the cost is high. B. PU film graphene heating pad: Use a planar PU film, a rectangular structure, conductive copper foil is arranged on both sides, a protective layer is pasted, and then the wire is led out. It has the following disadvantages: 1. Because it is a planar structure and the electrode strips are arranged in parallel, the heating shape can only be a regular shape and cannot completely match the structure on the seat; 2. The electrode is a conductive copper strip, and the conductive glue and graphene contact surface have contact resistance, which produces heating phenomenon, and after long-term use, the conductive glue hardens and decays, and finally the contact fails; 3. After pasting the conductive copper strip, in order to facilitate the lead-out of the wire, the electrode strip needs to be close, so the copper strip needs to be turned and then close, and the connection is poor at the turn, and problems often occur; 4. The conductive copper strip has poor resistance; 5. The cost of the conductive copper strip is high. C. Laminated graphene heating pad: Graphene powder is used, adhesive is added, laminated to form a graphene heating element, a protective layer is pasted, and then the wires are led out. It has the following disadvantages: 1. The cost is extremely high; 2. The resistance uniformity is poor; 3. After long-term use, due to mechanical effects, the graphene is layered, the resistance increases, and the power decays; 4. The heating pad is subjected to greater force at the ribs, and long-term mechanical friction causes the graphene wire to break.

[0003] In view of the above situation, there is an urgent need to design a graphene heating pad with stable performance, low material cost, simple process and high production efficiency. Summary of the invention

[0004] In view of this, the present application provides a graphene heating pad and a preparation method and application thereof to solve the technical problems raised by the background technology.

[0005] The first aspect of the present application provides a graphene heating pad, the graphene heating pad includes a graphene heating film layer, the graphene heating film layer includes a graphene heating body with two free ends, a plurality of ventilation holes are arranged around the graphene heating body, the graphene heating body is arranged in a serpentine shape to form a serpentine heating line, the serpentine heating line avoids the ventilation holes, and porous rivets are arranged on both free ends of the graphene heating body, a wire bundle is electrically connected to the graphene heating body, and the wire bundle is led out through the porous rivets and connected to a power source. Specifically, the porous rivet is made of metal.

[0006] Preferably, the two free ends of the graphene heating body are respectively a wire outlet head end and a wire outlet tail end, a slit is left between the wire outlet head end and the wire outlet tail end to form a wire connection port, and the wire connection port and the rivet are bonded and protected with a rubber block. Specifically, the rubber block is a low-pressure injection molding rubber block to protect the exposed rivet and wire bundle.

[0007] Preferably, the graphene heating pad also includes an upper protective film layer and a lower protective film layer, the upper protective film layer is arranged on the upper surface of the graphene heating film layer, the lower protective film layer is arranged on the lower surface of the graphene heating film layer, and the upper protective film layer, the graphene heating film layer and the lower protective film layer are sequentially connected and fixed from top to bottom.

[0008] Preferably, the upper protective film layer and the lower protective film layer are respectively connected and fixed to the graphene heating film layer by means of glue spraying and hot pressing, high-frequency welding or lamination and hot pressing.

[0009] Preferably, the graphene heating pad also includes an upper glue film layer and a lower glue film layer, the upper glue film layer is arranged between the upper protective film layer and the graphene heating film layer, the lower glue film layer is arranged between the graphene heating film layer and the lower protective film layer, and the upper protective film layer, the upper glue film layer, the graphene heating film layer, the lower glue film layer and the lower protective film layer are glued and fixed in sequence from top to bottom.

[0010] Preferably, the inclination angle of the curved section of the serpentine heating wire relative to the horizontal plane is set to 45°, and the turning point of the curved section is rounded.

[0011] Preferably, the multi-hole rivet is a three-hole rivet or a four-hole rivet, wherein the three-hole rivet is composed of a bottom rivet with a stretching protrusion and a top rivet with a connecting hole, and the bottom rivet with a stretching protrusion and the top rivet with a connecting hole are riveted and formed.

[0012] Preferably, the graphene heating body of the graphene heating film layer is made of a graphene-polyurethane mixed material.

[0013] The second aspect of the present application also provides a method for preparing the above-mentioned graphene heating pad, comprising the following steps:

[0014] S1, stirring, mixing, grinding and negative pressure defoaming of polyurethane resin, graphene powder, carbon black powder, dispersant, plasticizer and defoamer in proportion to obtain a graphene polyurethane mixed material, and the graphene polyurethane mixed material is coated, cast and dried in turn to obtain a graphene heating body;

[0015] S2. Designing the shape of the graphene heater according to the shape of the car seat, the layout of the ventilation holes and the heating power parameters, stamping the rolled graphene heater film to form a single-piece graphene heater, and cutting the single-piece graphene heater by laser cutting or die cutting to form a serpentine heating line, thereby obtaining a graphene heating layer;

[0016] S3, the bottom rivet is made into three convex points by a stretching process, and the outer edge of the convex point is contoured and deburred to obtain a stretched convex point bottom rivet; the top rivet is reserved with holes that match the bottom convex points to obtain a connection hole top rivet; the convex points of the stretched convex point bottom rivet are inserted into the connection holes reserved in the graphene heating layer, and the connection hole terminals of the connection hole top rivet are used to press down and fix, so as to form the head end and the tail end of the wire lead-out port for electrical lead-out, and obtain a graphene heating body with three-hole rivets at two free ends;

[0017] S4. Determine the specifications and dimensions of the wire harness according to the data requirements of the car seat, crimp the wire harness and the three-hole rivet to make the wire harness rivet; rivet the bottom rivet of the stretched convex point, the graphene heating layer and the top rivet of the connecting hole, and control the rivet width, height, profile and pull-off force parameters through the riveting die;

[0018] S5. Connect and fix the upper protective film layer, the upper glue film layer, the graphene heating film layer, the lower glue film layer and the lower protective film layer in sequence from top to bottom, reserve a wire connection port, and use low-pressure injection molding to bond and protect the wire connection port with a glue block to obtain a graphene heating pad.

[0019] The third aspect of the present application also provides a use of the graphene heating pad as described above in the preparation of a heated seat pad for an automobile.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] (1) The processing technology of the graphene heating pad of the present application is simple: cutting of the graphene heating layer, compounding of the protective layer, riveting of the wires, and protection by injection of glue; the material cost of the graphene heating pad of the present application is low: a single graphene heating layer; the performance of the graphene heating pad of the present application is stable: folding resistance, firm rivet joints, and uniform and stable heating.

[0022] (2) The graphene heating body of the present application has a large and uniform heating area, and is covered with an upper protective film layer and a lower protective film layer, which can prevent dust, water, friction, and external forces, thereby enhancing the service life; three-hole rivets are provided on the two free ends of the graphene heating body for riveting, and at the same time, low-pressure injection molding rubber blocks are used for protection. The rivets have a large contact area and high strength, which can eliminate contact heating, and the rubber block protection can effectively alleviate damage caused by external forces; since graphene is used for heating, the graphene heating pad of the present application also has the advantages of fast heating, low energy consumption, bending resistance, thin thickness, large heating area, and uniform heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the description of the present application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic diagram of the structure of the graphene heating pad in this application;

[0025] Figure 2 A schematic diagram illustrating the graphene arrangement of the graphene heating pad in the present application;

[0026] Figure 3 This is a schematic diagram of the graphene wire lead-out port of the graphene heating pad in this application;

[0027] Figure 4 This is a schematic diagram of the bottom layer of porous rivets of the graphene heating pad in this application;

[0028] Figure 5 Schematic diagram of the porous rivet upper layer of the graphene heating pad in this application.

[0029] Description of reference numerals:

[0030] 1. Upper protective layer; 2. Upper rubber layer; 3. Graphene heating layer; 4. Lower rubber layer; 5. Lower protective layer; 6. Ventilation holes; 7. Wire connection port; 8. Rubber block; 9. Wire bundle; 10. Serpentine heating wire; 11. Starting end of wire outlet; 12. End of wire outlet. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0033] Secondly, it should be noted that in the description of the present application, terms such as "up", "down", "left", "right", "front", "back", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present application.

[0034] Example 1

[0035] like Figure 1-5 As shown, an embodiment of the present application provides a graphene heating pad, which is applied to a heated seat pad for a car. The graphene heating pad includes a graphene heating film layer 3. The graphene heating film layer 3 includes a graphene heating body with two free ends. A plurality of ventilation holes 6 are arranged around the graphene heating body. The graphene heating body is arranged in a serpentine shape to form a serpentine heating wire 10. The serpentine heating wire 10 is arranged to avoid the ventilation holes 6. Three-hole rivets are arranged on both free ends of the graphene heating body. A wire harness 9 is electrically connected to the graphene heating body. The wire harness 9 is led out through the three-hole rivets and connected to a power source.

[0036] The three-hole rivet is composed of a bottom rivet with a stretched convex point and a top rivet with a connecting hole, and the bottom rivet with a stretched convex point and the top rivet with a connecting hole are riveted and formed. In order to achieve the strength and life of the junction between the wire bundle 9 and the graphene heating film layer 3, the first end 11 of the wire lead-out port and the tail end 12 of the wire lead-out port are both three-hole rivet structures.

[0037] When arranging the serpentine heating wire 10 , the positions of the ventilation holes 6 can be reserved and matched according to the actual setting requirements of the ventilation holes 6 .

[0038] Specifically, the two free ends of the graphene heating body are respectively a wire outlet head end 11 and a wire outlet tail end 12, a slit is left between the wire outlet head end 11 and the wire outlet tail end 12 to form a wire connection port 7, the wire connection port 7 and the rivet are bonded and protected with a rubber block 8, more specifically, the rubber block 8 is a low-pressure injection molding rubber block, which serves to protect the exposed three-hole rivet and the wire bundle 9.

[0039] In a specific implementation, in order to protect the strength and waterproof performance of the crimping point, a TPR rubber block is used for protection at the wire connection port 7 and the three-hole rivet. The material of the rubber block 8 can also be selected from other forms of protective glue such as silicone, rubber, hot melt adhesive, etc., and is implemented by low-pressure injection molding, which is not limited in this embodiment.

[0040] Specifically, the inclination angle of the curved section of the serpentine heating wire 10 relative to the horizontal plane is set to 45°, and the turning point of the curved section is rounded.

[0041] In a specific embodiment, the graphene heating film layer 3 is a whole sheet structure, adopts a serpentine design structure, constitutes a wide-line serpentine heating wire 10, and the heating area efficiency is above 90%; and the inclination angle of the bending section of the serpentine heating wire 10 relative to the horizontal plane is set to 45°, and the turning part of the bending section is chamfered, which can effectively alleviate the influence of mechanical aspects on the performance of the graphene heating film layer 3.

[0042] Specifically, the graphene heating body of the graphene heating film layer 3 is made of a graphene-polyurethane mixed material.

[0043] In a specific embodiment, the graphene heating film layer 3 is made of a coiled graphene polyurethane film, and the heating shape is achieved by laser cutting or die cutting, and the process is simple. It should be noted that a small amount of laser cutting is used, and a large amount of die cutting tooling is made and die cutting machine is used for stamping, which has precise alignment and high yield rate; this embodiment of the application is not limited to this.

[0044] Example 2

[0045] This embodiment can refer to Embodiment 1, the difference is that the graphene heating pad also includes an upper protective film layer 1 and a lower protective film layer 5, the upper protective film layer 1 is arranged on the upper surface of the graphene heating film layer 3, the lower protective film layer 5 is arranged on the lower surface of the graphene heating film layer 3, and the upper protective film layer 1, the graphene heating film layer 3 and the lower protective film layer 5 are connected and fixed in sequence from top to bottom.

[0046] In a specific embodiment, the upper protective film layer 1 and the lower protective film layer 5 can be made of different materials such as cloth, fabric, non-woven fabric, etc. The upper protective film layer 1 and the lower protective film layer 5 are hot pressed by spraying glue, welded by high frequency welding, or hot pressed by protective layer lamination to integrate the graphene heating film layer 3 for protection.

[0047] Example 3

[0048] This embodiment can refer to Embodiment 2, the difference is that the graphene heating pad also includes an upper glue film layer 2 and a lower glue film layer 4, the upper glue film layer 2 is arranged between the upper protective film layer 1 and the graphene heating film layer 3, the lower glue film layer 4 is arranged between the graphene heating film layer 3 and the lower protective film layer 5, and the upper protective film layer 1, the upper glue film layer 2, the graphene heating film layer 3, the lower glue film layer 4 and the lower protective film layer 5 are glued and fixed in sequence from top to bottom.

[0049] Exemplarily, the material of the upper adhesive film layer 2 and the lower adhesive film layer 4 may be adhesive materials such as hot melt adhesive, double-sided adhesive, thermoplastic adhesive or thermosetting adhesive.

[0050] Example 4

[0051] This embodiment can refer to the embodiment 1, except that the three-hole rivet is replaced by a four-hole rivet. In order to achieve the strength and life of the connection between the wire bundle 9 and the graphene heating film layer 3, the wire outlet head end 11 and the wire outlet tail end 12 are both four-hole rivet structures.

[0052] Example 5

[0053] The present application embodiment provides a method for preparing the graphene heating pad of embodiment 3, comprising the following steps:

[0054] S1, stirring, mixing, grinding, and negative pressure defoaming polyurethane resin, graphene powder, carbon black powder, dispersant, plasticizer, and defoamer in proportion to obtain a graphene polyurethane mixed material, and the graphene polyurethane mixed material is coated, cast, and dried to obtain a graphene heating body;

[0055] Among them, the graphene heating film layer 3 is made of a graphene polyurethane mixed material by adding graphene powder, carbon black powder, dispersant, plasticizer, and defoamer to polyurethane resin, stirring, mixing, grinding, and negative pressure defoaming in sequence. The graphene heating film is made by coating, casting, and drying. The square resistance of the graphene heating film layer 3 is adjusted according to the ratio of graphene powder and carbon black powder, and graphene heating film layers 3 with different resistivity specifications can be made. At the same time, according to the parameter control of casting, graphene heating film layers 3 with different thicknesses can be made. The addition of dispersant can effectively ensure the uniformity of square resistance, plasticizer can improve the tensile properties of graphene heating film layer 3, and defoamer and negative pressure defoaming process can ensure the appearance performance of graphene heating film layer 3.

[0056] S2, designing the shape of the graphene heating body according to the shape of the car seat, the layout of the ventilation holes 6 and the heating power parameters, stamping the rolled graphene heating body film to form a single-piece graphene heating body, and the single-piece graphene heating body is cut by laser or die-cut to form a serpentine heating line 10, so as to obtain the graphene heating layer 3;

[0057] S3, the bottom rivet is made into three convex points by a stretching process, and the outer edge of the convex point is contoured and deburred to obtain a stretched convex bottom rivet; the top rivet is reserved with a hole that matches the bottom convex point, and a wire pressing port is reserved at the same time, one end is riveted with the bottom rivet convex point, and the other end is crimped with the wire through a terminal crimping machine to obtain a connection hole top rivet; the convex point of the stretched convex bottom rivet is inserted into the connection hole reserved by the graphene heating layer 3, and the connection hole terminal of the connection hole top rivet is used to press down and fix it, so as to form the wire lead-out head end 11 and the wire lead-out tail end 12 for electrical lead-out, and obtain a graphene heating body with three-hole rivets at two free ends;

[0058] S4. According to the requirements of the car seat data, the size of the wire harness 9 is determined, and the wire harness 9 and the three-hole rivet are pressed to make the wire harness rivet; the bottom rivet of the stretched convex point, the graphene heating layer 3 and the top rivet of the connecting hole are riveted, and the riveting width, height, profile and pull-off force parameters are controlled by the riveting mold;

[0059] S5. Connect and fix the upper protective film layer 1, the upper glue film layer 2, the graphene heating film layer 3, the lower glue film layer 4 and the lower protective film layer 5 in sequence from top to bottom, reserve a wire connection port 7, and use low-pressure injection molding to bond and protect the wire connection port 7 with a glue block 8 to obtain a graphene heating pad.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 application.

Claims

1. A graphene heating pad, characterized in that: The graphene heating pad comprises a graphene heating film layer (3), the graphene heating film layer (3) comprises a graphene heating body with two free ends, a plurality of ventilation holes (6) are arranged around the graphene heating body, the graphene heating body is arranged in a serpentine shape to form a serpentine heating wire (10), the serpentine heating wire (10) is arranged to avoid the ventilation holes (6), and porous rivets are arranged on the two free ends of the graphene heating body, a wire bundle (9) is electrically connected to the graphene heating body, and the wire bundle (9) is led out through the porous rivets and connected to a power source.

2. The graphene heating pad according to claim 1, characterized in that: The two free ends of the graphene heating body are respectively a wire lead-out port head end (11) and a wire lead-out port tail end (12), a slit is left between the wire lead-out port head end (11) and the wire lead-out port tail end (12) to form a wire connection port (7), and the wire connection port (7) and the rivet are bonded and protected with a glue block (8).

3. The graphene heating pad according to claim 2, characterized in that: The graphene heating pad further comprises an upper protective film layer (1) and a lower protective film layer (5), wherein the upper protective film layer (1) is arranged on the upper surface of the graphene heating film layer (3), and the lower protective film layer (5) is arranged on the lower surface of the graphene heating film layer (3), and the upper protective film layer (1), the graphene heating film layer (3) and the lower protective film layer (5) are sequentially connected and fixed from top to bottom.

4. The graphene heating pad according to claim 3, characterized in that: The upper protective film layer (1) and the lower protective film layer (5) are respectively connected and fixed to the graphene heating film layer (3) by means of glue spraying and hot pressing, high-frequency welding or laminating and hot pressing.

5. The graphene heating pad according to claim 3, characterized in that: The graphene heating pad further comprises an upper glue film layer (2) and a lower glue film layer (4), wherein the upper glue film layer (2) is arranged between the upper protective film layer (1) and the graphene heating film layer (3), and the lower glue film layer (4) is arranged between the graphene heating film layer (3) and the lower protective film layer (5), and the upper protective film layer (1), the upper glue film layer (2), the graphene heating film layer (3), the lower glue film layer (4) and the lower protective film layer (5) are glued and fixed in sequence from top to bottom.

6. The graphene heating pad according to claim 1, characterized in that: The inclination angle of the curved section of the serpentine heating wire (10) relative to the horizontal plane is set to 45°, and the turning point of the curved section is rounded.

7. The graphene heating pad according to claim 5, characterized in that: The multi-hole rivet is a three-hole rivet or a four-hole rivet, wherein the three-hole rivet is composed of a bottom rivet with a stretching protrusion and a top rivet with a connecting hole, and the bottom rivet with a stretching protrusion and the top rivet with a connecting hole are riveted and formed.

8. The graphene heating pad according to claim 1, characterized in that: The graphene heating body of the graphene heating film layer (3) is made of a graphene-polyurethane mixed material.

9. A method for preparing the graphene heating pad according to claim 7, characterized in that: The following steps are involved: S1, stirring, mixing, grinding and negative pressure defoaming of polyurethane resin, graphene powder, carbon black powder, dispersant, plasticizer and defoamer in proportion to obtain a graphene polyurethane mixed material, and the graphene polyurethane mixed material is coated, cast and dried in turn to obtain a graphene heating body; S2, designing the shape of the graphene heating body according to the shape of the car seat, the layout of the ventilation holes (6) and the heating power parameters, stamping the rolled graphene heating body film to form a single-piece graphene heating body, and the single-piece graphene heating body is cut by laser or die-cut to form a serpentine heating line (10), so as to obtain a graphene heating layer (3); S3, the bottom rivet is made into three convex points by a stretching process, and the outer edge of the convex point is contoured and deburred to obtain a stretched convex point bottom rivet; the top rivet is reserved with holes that match the bottom convex points to obtain a connection hole top rivet; the convex points of the stretched convex point bottom rivet are inserted into the connection holes reserved in the graphene heating layer (3), and the connection hole terminals of the connection hole top rivet are used to press down and fix, so as to form the wire lead-out head end (11) and the wire lead-out tail end (12) for electrical lead-out, and obtain a graphene heating body with three-hole rivets at two free ends; S4. Determine the size of the wire harness (9) according to the data requirements of the automobile seat, crimp the wire harness (9) and the three-hole rivet to make the wire harness rivet; perform riveting on the bottom rivet of the stretched convex point, the graphene heating layer (3) and the top rivet of the connecting hole, and control the riveting width, height, profile and pull-off force parameters through the riveting die; S5. The upper protective film layer (1), the upper adhesive film layer (2), the graphene heating film layer (3), the lower adhesive film layer (4) and the lower protective film layer (5) are connected and fixed in sequence from top to bottom, and a wire connection port (7) is reserved. The wire connection port (7) is bonded and protected with an adhesive block (8) by low-pressure injection molding to obtain a graphene heating pad.

10. Use of the graphene heating pad according to any one of claims 1 to 8 in preparing a heated seat pad for an automobile.

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