阅读说明：本技术 石墨烯导热膜的压膜装置及制备方法 (Film pressing device and preparation method of graphene heat-conducting film ) 是由 周仁杰 周步存 周玉峰 于 2021-09-27 设计创作，主要内容包括：本发明提供石墨烯导热膜的压膜装置,包括抽真空设备、真空腔室、上压头和下压头,所述上压头和下压头在真空腔室内,抽真空设备对真空腔室抽真空,多层石墨烯泡沫膜放置在下压头上,上压头或/和下压头对多层石墨烯泡沫膜进行压膜获得石墨烯导热膜。本发明还提供制备石墨烯导热膜的方法。本发明能够通过压延制备高密度的无气泡的石墨烯导热膜。(The invention provides a film pressing device for a graphene heat-conducting film, which comprises vacuumizing equipment, a vacuum chamber, an upper pressing head and a lower pressing head, wherein the upper pressing head and the lower pressing head are arranged in the vacuum chamber, the vacuumizing equipment vacuumizes the vacuum chamber, a multi-layer graphene foam film is placed on the lower pressing head, and the upper pressing head or/and the lower pressing head press the multi-layer graphene foam film to obtain the graphene heat-conducting film. The invention also provides a method for preparing the graphene heat-conducting film. The high-density bubble-free graphene heat-conducting film can be prepared by rolling.)

1. The utility model provides a film pressing device of graphite alkene heat conduction membrane, its characterized in that, includes evacuation equipment, vacuum chamber, goes up pressure head and pressure head down, go up the pressure head and in the vacuum chamber with pressure head down, evacuation equipment is to the vacuum chamber evacuation, and multilayer graphite alkene foamed film is placed under on the pressure head, goes up pressure head or/and pressure head down and carries out the film pressing to multilayer graphite alkene foamed film and obtain graphite alkene heat conduction membrane.

2. A film pressing device for a graphene heat conduction film according to claim 1, further comprising a mold, wherein the mold is detachably connected with the upper pressing head or/and the lower pressing head, the mold comprises a pressing head and a pressing sleeve, the pressing sleeve surrounds the pressing head, the pressing sleeve is used for surrounding the multilayer graphene foam film, and the pressing head is used for calendering the multilayer graphene foam film;

preferably, the vacuum chamber further comprises a chamber frame, the chamber frame surrounds the vacuum chamber, the chamber frame comprises an upper cross beam, a lower cross beam and a plurality of support columns between the upper cross beam and the lower cross beam, the lower pressure head is fixed on the lower cross beam, and the upper pressure head is fixed on the upper cross beam;

further preferably, the vacuum chamber further comprises a viewing window, wherein the viewing window is arranged in the vacuum chamber;

further preferably, the die further comprises an upper connecting piece and a lower connecting piece, wherein the upper connecting piece is connected with the upper pressing head and the die, the lower connecting piece is connected with the die and the lower pressing head, and the upper connecting piece and the lower connecting piece are flanges.

3. A film pressing device for a graphene thermal conduction film according to claim 1, wherein the vacuum pumping device comprises one or more vacuum pumps; preferably, the vacuum cleaner further comprises an air switch, wherein the air switch is automatically opened when vacuum is pumped and automatically closed when vacuum is not pumped.

4. A film pressing device for a graphene heat conduction film according to claim 1, further comprising a hydraulic system for independently pressurizing the upper pressing head and the lower pressing head;

preferably, the hydraulic system comprises an electric driving device, a hydraulic cylinder, a pressure sensor and a hydraulic station, the hydraulic station is used for storing hydraulic oil, the electric driving device is used for driving the hydraulic oil of the hydraulic station into the hydraulic cylinder, and the pressure sensor detects the pressure reached by the hydraulic cylinder; preferably, the hydraulic station further comprises a contactor which is used as a switch for controlling the hydraulic station electric driving device; preferably, the system further comprises a relay, wherein the relay is used for controlling the oil transportation direction, and the oil transportation direction comprises an oil transportation direction of the oil transportation with the upper pressure head and an oil transportation direction of the oil transportation with the lower pressure head;

further preferably, the hydraulic system further comprises a proportional valve pressure regulator which regulates the rate of hydraulic oil entering the hydraulic cylinder, thereby regulating the rate of pressure increase.

5. A film pressing device for a graphene thermal conductive film according to claim 1, further comprising a grating ruler, wherein the grating ruler is fixedly connected with the upper pressing head and used for measuring a moving distance of the upper pressing head.

6. A film pressing device for graphene heat conduction films according to claim 1, further comprising a control system, wherein the control system is configured to set a vacuum degree, send a signal to a vacuum pumping device so that the vacuum chamber reaches the set vacuum degree, and send a signal to the upper pressing head or/and the lower pressing head to control a film pressing mode, and the film pressing mode includes one-way upward pressing, one-way downward pressing, and two-way pressing.

7. A film pressing device for a graphene heat conduction film according to claim 6, wherein the control system comprises a touch screen and a controller, the touch screen is used for inputting and displaying a vacuum degree and a film pressing mode, the controller is used for sending signals to the vacuum pumping equipment, the upper pressing head or/and the lower pressing head according to the input of the touch screen, preferably, the film pressing device further comprises a control cabinet, the touch screen is arranged on the control cabinet, the controller is arranged in the control cabinet, and further preferably, the controller is a PLC.

8. A film pressing device for a graphene thermal conductive film according to claim 7, wherein the touch screen is used for inputting instructions of a client, the instructions include dimensions of the graphene thermal conductive film, the controller stores a plurality of process recipes and a plurality of corresponding process curves of pressure changing with time, the controller calls the corresponding process recipes according to the instructions input by the touch screen, calls the process curves corresponding to the process recipes, and sends signals to the upper pressing head or/and the lower pressing head; preferably, the system further comprises an alarm, wherein the alarm is used for sending an alarm signal when the real-time upper pressure head or/and the real-time lower pressure head exceeds the set range of the pressure value corresponding to the process curve; preferably, an emergency switch is further included for power-off protection in the event of a fault.

9. A method for preparing a graphene heat conduction film by using the film pressing device of claim 1, which comprises the following steps:

constructing a vacuum chamber, and placing an upper pressure head and a lower pressure head in the vacuum chamber;

vacuumizing the vacuum cavity by using vacuumizing equipment;

and (3) rolling the multilayer graphene foam film through an upper pressure head and a lower pressure head in a vacuum chamber reaching a set vacuum degree.

10. The method according to claim 9, wherein the step of calendering the graphene thermal conductive film by an upper pressure head and a lower pressure head in the vacuum chamber reaching the set vacuum degree comprises:

storing a plurality of groups of process formulas;

calling a process formula corresponding to the client instruction;

sending a signal to a vacuumizing device, an upper pressure head or/and a lower pressure head according to a process curve corresponding to a process formula, wherein the process curve comprises a curve of pressure changing along with time;

and recording, storing and displaying the vacuum degree and the pressure in real time.

Technical Field

The invention belongs to the technical field of graphene heat-conducting films, and particularly relates to a film pressing device and a preparation method of a graphene heat-conducting film.

Background

The existing compaction process equipment realizes compaction by a flat plate stamping mode. Mass production cannot be achieved because the flat sheet stamping process can only be a single sheet or a few sheets of stamping. In the continuous stamping process, because the flat plate is deformed under stress, the thickness of the stamped graphite film can not be controlled within a smaller tolerance range all the time, and the thickness consistency is poor. Because the ratio of pressure to pressure of the whole plane stressed monolithic graphite film is not large, the density of the punched graphite film is not high.

The existing rolling equipment adopts a rolling mode, has no vacuumizing process, needs rolling for many times, has bubbles on the surface and is difficult to expel the bubbles.

Disclosure of Invention

The invention provides a film pressing device for a graphene heat-conducting film, which aims at solving one or more problems in the prior art and comprises vacuumizing equipment, a vacuum chamber, an upper pressing head and a lower pressing head, wherein the upper pressing head and the lower pressing head are arranged in the vacuum chamber, the vacuumizing equipment vacuumizes the vacuum chamber, a multi-layer graphene foam film is placed on the lower pressing head, and the upper pressing head or/and the lower pressing head press the multi-layer graphene foam film to obtain the graphene heat-conducting film.

Optionally, the film pressing device still includes the mould, the mould can be dismantled with last pressure head or/and lower pressure head and be connected, the mould includes the pressure head and presses the cover, press the cover to surround outward the pressure head, press the cover to be used for surrounding multilayer graphite alkene foamed film outward, the pressure head is used for calendering multilayer graphite alkene foamed film.

Optionally, the film pressing device further comprises a chamber frame, the chamber frame surrounds the vacuum chamber, the chamber frame comprises an upper cross beam, a lower cross beam and a plurality of support columns between the upper cross beam and the lower cross beam, the lower pressing head is fixed on the lower cross beam, and the upper pressing head is fixed on the upper cross beam.

Optionally, the film pressing device further comprises an observation window, and the observation window is arranged in the vacuum chamber.

Optionally, the film pressing device further comprises an upper connecting piece and a lower connecting piece, the upper connecting piece connects the upper pressing head and the die, and the lower connecting piece connects the die and the lower pressing head.

Optionally, the upper and lower connectors are flanges.

Optionally, the evacuation device comprises one or more vacuum pumps.

Optionally, the film pressing device further comprises an air switch, wherein the air switch is automatically turned on when vacuumized and is automatically turned off when not vacuumized.

Optionally, the film pressing device further comprises a hydraulic system for independently pressurizing the upper pressing head and the lower pressing head.

Optionally, the hydraulic system includes an electric drive device, a hydraulic cylinder, a pressure sensor, and a hydraulic station, the hydraulic station is configured to store hydraulic oil, the electric drive device is configured to drive hydraulic oil of the hydraulic station into the hydraulic cylinder, and the pressure sensor detects a pressure reached by the hydraulic cylinder.

Optionally, a contactor is further included as a switch for controlling the hydraulic station electric drive.

Optionally, the system further comprises a relay, wherein the relay is used for controlling the oil transportation direction, and the oil transportation direction comprises an oil transportation direction of the oil transportation with the upper pressure head and an oil transportation direction of the oil transportation with the lower pressure head.

Optionally, the hydraulic system further comprises a proportional valve pressure regulator which regulates the rate of hydraulic oil entering the hydraulic cylinder, thereby regulating the rate of pressure increase.

Optionally, the film pressing device further comprises a grating ruler, and the grating ruler is fixedly connected with the upper pressure head and used for measuring the moving distance of the upper pressure head.

Optionally, the film pressing device further comprises a control system, wherein the control system is used for setting a vacuum degree, sending a signal to the vacuumizing device, enabling the vacuum chamber to reach the set vacuum degree and sending a signal to the upper pressing head or/and the lower pressing head to control the film pressing mode, and the film pressing mode comprises one-way upper pressing, one-way lower pressing and two-way pressing.

Optionally, the control system includes a touch screen and a controller, the touch screen is used for inputting and displaying the vacuum degree and the squeeze film mode, and the controller is used for sending a signal to the vacuum pumping device, the upper pressure head or/and the lower pressure head according to the input of the touch screen.

Optionally, the film pressing device further comprises a control cabinet, the touch screen is arranged on the control cabinet, and the controller is arranged in the control cabinet.

Optionally, the controller is a PLC.

Optionally, the touch screen is configured to input an instruction of a client, the instruction includes a size of the graphene thermal conductive film, the controller stores a plurality of process recipes and a plurality of corresponding process curves of which the pressure changes with time, and the controller calls the corresponding process recipe according to the touch screen input instruction, calls the process curve corresponding to the process recipe, and sends a signal to the upper pressure head or/and the lower pressure head.

Optionally, the film pressing device further comprises an alarm, and the alarm is used for sending an alarm signal when the real-time upper pressing head or/and the real-time lower pressing head exceed the set range of the pressure value corresponding to the process curve.

Optionally, the film pressing device further comprises an emergency switch for power-off protection in case of a fault.

Optionally, a paper spacer is disposed between adjacent graphene foam films.

Optionally, the separation paper is coated paper or/and steel plate.

According to another aspect of the invention, there is also provided a method for preparing a graphene heat conduction film by using the film pressing device, including:

constructing a vacuum chamber, and placing an upper pressure head and a lower pressure head in the vacuum chamber;

vacuumizing the vacuum cavity by using vacuumizing equipment;

and (3) rolling the multilayer graphene foam film through an upper pressure head and a lower pressure head in a vacuum chamber reaching a set vacuum degree.

Optionally, the step of rolling the graphene heat conduction film through an upper pressure head and a lower pressure head in the vacuum chamber reaching the set vacuum degree includes:

storing a plurality of groups of process formulas;

calling a process formula corresponding to the client instruction;

sending a signal to a vacuumizing device, an upper pressure head or/and a lower pressure head according to a process curve corresponding to a process formula, wherein the process curve comprises a curve of pressure changing along with time;

and recording, storing and displaying the vacuum degree and the pressure in real time.

Optionally, the method further comprises:

and when the real-time upper pressure head or/and the real-time lower pressure head exceed the set range of the pressure values corresponding to the process curve, sending an alarm signal.

Optionally, the method further comprises:

and arranging a piece of separation paper between the adjacent graphene foam films, preferably, the separation paper is coated paper or/and a steel plate.

The film pressing device for the graphene heat-conducting film disclosed by the invention realizes vacuum flat pressing so as to obtain the high-density graphene heat-conducting film, and the appearance, the rolling thickness and the production efficiency of the graphene heat-conducting film are ensured without bubbles.

The film pressing method for the graphene heat-conducting film is a vacuum rolling method for the high-density graphene heat-conducting film, the preparation of the high-density graphene can be realized, the output and the utilization rate of the graphene heat-conducting film are effectively improved, the vacuum flat pressing can be realized, and the pressed graphite has good appearance and cannot generate bubbles.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic diagram of a front view of a film pressing device for a graphene thermal conductive film according to the present invention;

fig. 2 is a schematic diagram of a top view of a film pressing device for a graphene thermal conductive film according to the present invention;

fig. 3 is a schematic diagram of a right side view of a film pressing device for a graphene thermal conductive film according to the present invention.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

Fig. 1 is a schematic front view of a film pressing device for a graphene thermal conductive film according to the present invention, fig. 2 is a schematic top view of the film pressing device for the graphene thermal conductive film according to the present invention, and fig. 3 is a schematic right view of the film pressing device for the graphene thermal conductive film according to the present invention, and as shown in fig. 1 to 3, the film pressing device for the graphene thermal conductive film includes a vacuum chamber 1, and an upper pressing head 2 and a lower pressing head 3 disposed in the vacuum chamber.

As shown in fig. 1-3, the film pressing device further comprises:

the chamber frame 4 is of a double-beam four-column type, namely an upper cross beam 41, a lower cross beam 42 and a plurality of support columns 43 between the upper cross beam and the lower cross beam 42, a vacuum pumping connection hole 44 is formed in the chamber frame, an observation window 11 is formed in the vacuum chamber, a top beam 12 of the vacuum chamber is provided with a stainless steel upper pressure head hole (preferably phi 400mm), and the stainless steel upper pressure head hole and the 304 stainless steel upper pressure head 2 are welded into a whole through a reinforcing rib 13; the bottom beam 14 of the vacuum chamber is provided with a lower pressure head hole, and is integrated with a lower pressure head made of 304 stainless steel and welded into a whole through a reinforcing rib 13, and the lower pressure head or/and an upper pressure head are/is provided with a high-precision displacement sensor, for example, an upper pressure head is used for distance measurement by adopting a grating electronic ruler (the distance measurement precision is 0.05 mm).

A hydraulic system: adopts an electric input mode and two-way pressurization. The hydraulic station 5 is provided with an inlet proportional valve pressure regulator 52, a pressure sensor, a hydraulic cylinder 51 and other related hydraulic devices. The concentricity of the central mounting holes of the upper cross beam and the lower cross beam is in a set error valve through strict processing and adjustment, and the connecting mode of the stainless steel upper pressure head on the vacuum chamber and the hydraulic cylinder is flange connection, so that the parallelism of the upper pressure head and the lower pressure head is ensured. The hydraulic system has the functions of pressure relief and pressure maintaining, is used for driving the oil cylinder and has the function of automatically setting pressure.

The vacuum pumping equipment adopts a two-machine pump configuration, namely two vacuum pumps 61 are adopted, the two vacuum pumps comprise an H-150 sliding valve pump and a ZJP-600 roots pump, the vacuum pumping equipment further comprises a valve 62 (preferably a pneumatic vacuum butterfly valve) and a vacuum pressure gauge 63, a vacuum pipeline is connected with the vacuum pumps through metal corrugated pipes 64, the vacuum pressure gauge measures the vacuum degree of a vacuum cavity, and preferably, the vacuum pressure gauge is a digital display vacuum gauge.

The control system comprises: and a control cabinet 7 is adopted, and a ventilation system is integrated. The control cabinet is provided with a touch screen (such as a liquid crystal touch screen) and a controller (such as a PLC), and after the control cabinet can set the pumping to the designated vacuum degree through the input of the touch screen and the control of the controller, a pressurization program is automatically executed until the pressurization process is finished; and selecting three film pressing modes of one-way upward pressing, one-way downward pressing or two-way pressing.

Preferably, the film laminating device further comprises components such as an air switch, a contactor, a relay and an indicator light, and the logic control of a mechanical mechanism of the film laminating equipment is realized through signals of various sensors. The vacuum degree and the pressure are recorded, stored, displayed in real time and set with process curves, and the device has the functions of storing and calling a plurality of groups of process formulas. All working condition actions are provided with safety interlocking protection, such as an arranged sound-light alarm and a protection emergency switch.

In one embodiment, the film pressing device further comprises a mold 8 detachably connected with the upper pressing head, the mold comprises a pressing head 81 and a pressing sleeve 82, the pressing sleeve surrounds the pressing head, the pressing sleeve is used for surrounding the multilayer graphene foamed film, the pressing head is used for calendering the multilayer graphene foamed film, and the pressing head is used for calendering the multilayer graphene foamed film between the pressing head and the lower pressing head.

In one embodiment, the lamination device further comprises an upper connecting member 21 connecting the upper press head and the die and a lower connecting member 31 connecting the die and the lower press head.

Preferably, the upper and lower connectors are flanges.

The method for pressing the film by using the film pressing device comprises the following steps:

and (3) turning on a power supply on the control cabinet, modifying the touch screen according to a required process formula, wherein the process formula comprises pressure rise time, pressure maintaining time and pressure, placing a product to be calendered in a mold of the vacuum cavity, and locking the product by using a hand wheel 9 after closing the cavity door. And opening a plunger pump (vacuum pump) on the control cabinet, vacuumizing and descending the pressure head of the mold. And after the process time is finished, deflating, opening the plunger pump, and raising the pressure head of the mold.

In a specific embodiment, the film pressing device of the present invention is used to prepare graphene thermal conductive films on steel plate paper and/or as a separation paper according to the following process formula in table 1:

TABLE 1

Specifically, the thickness is 500-600 microns, and the density is 0.18g/cm³The graphene foam films are prepared by taking coated paper and graphene foam films as a group, stacking 300 groups of the coated paper and the graphene foam films, pressing films in a 300 x 345mm mold, pressing films according to the process formula in the table 1 under the condition that the vacuum degree is less than 500pa, stacking a 0.2mm steel plate (the surface roughness Ra is less than or equal to 0.4) and the pressed graphene foam films again according to the process formula in the table 1, and finally pressing the films to obtain the graphene foam films with the film thickness of 50um and the density of 2.03g/cm³The graphene thermal conductive film of (2).

The density can be 1.4g/cm under the condition of not adopting a vacuum rolling device, being capable of rolling for multiple times and ensuring no air bubbles³The density of the graphene heat-conducting film is much smaller than that of the graphene heat-conducting film obtained by the invention, and the theoretical limit density of graphite is 2.26g/cm³The invention approaches the limit density, the higher the density, the less the pores.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.