A method for preparing a profiled mica piece based on a pre-pressing process and a profiled mica piece

Abstract

The application belongs to the technical field of mica part preparation, and particularly relates to a method for preparing a special-shaped mica part based on a pre-pressing process and the special-shaped mica part. The method comprises the following steps: S1, obtaining mica paper and glass fiber cloth, stacking the mica paper to obtain a mica plate, and placing one piece of the glass fiber cloth on the upper and lower surfaces of the mica plate to obtain a composite mica plate; S2, pre-pressing the composite mica plate to obtain a pre-pressed mica plate, and hot-pressing the pre-pressed mica plate to obtain a hot-pressed mica plate; and S3, machining the hot-pressed mica plate to obtain a special-shaped mica part. The application introduces a pre-pressing process step before formal hot pressing, effectively removes residual air between mica paper layers, and significantly improves the bonding tightness between layers of materials. After pre-pressing, hot pressing can effectively avoid defects such as bubbles, delamination and rupture in the final product.

Description

Technical Field

[0001] This application belongs to the field of mica component preparation technology, specifically relating to a method for preparing irregularly shaped mica components based on a pre-pressing process and the irregularly shaped mica components themselves. Background Technology

[0002] The core power system of widely used new energy electric vehicles is primarily composed of lithium-ion battery packs. During vehicle operation, lithium-ion batteries generate significant heat during charging and discharging. Especially under extreme conditions such as high load, fast charging, or high temperatures, the internal temperature of the battery can rise sharply, potentially leading to thermal runaway. This poses a serious threat to the structural safety of the vehicle and the safety of its occupants. To effectively address this risk and ensure the stability and reliability of the battery system, specialized heat insulation and thermal insulation components are typically integrated within the battery pack. Mica, due to its excellent high-temperature resistance, electrical insulation, and chemical stability, has become the preferred material for such protective components.

[0003] The current industry standard for manufacturing mica-shaped protective components uses mica paper as the basic raw material. A custom-designed hot-press mold is created based on the specific product's geometry and functional requirements. The mica paper is then placed directly into the mold and pressed into shape in one step using a high-temperature, high-pressure hot-pressing process. However, this traditional one-step hot-pressing method has several technical drawbacks: Firstly, during the pressing process, the gas inside the mica paper is difficult to completely escape, easily leading to air bubbles, delamination, and even structural defects such as cracking or breakage on the surface or between layers of the finished product. This severely affects the product's mechanical strength and insulation performance, resulting in a low overall pass rate. Secondly, the hot-pressing cycle required by this process is long, which not only limits the production line's cycle time and reduces overall production efficiency but also consumes a large amount of energy due to prolonged high-temperature heating, causing unnecessary resource waste and increased costs.

[0004] Therefore, in order to address the above problems, there is an urgent need for an improved mica paper pre-pressing method to improve product quality and production efficiency by optimizing the process flow. Summary of the Invention

[0005] To solve the above-mentioned technical problems, this application provides a method for preparing irregular mica parts based on a pre-pressing process, comprising the following steps: S1, obtaining mica paper and fiberglass cloth, stacking the mica paper to obtain a mica board, and placing a fiberglass cloth on each of the upper and lower surfaces of the mica board to obtain a composite mica board; S2, pre-pressing the composite mica board to obtain a pre-pressed mica board, and hot-pressing the pre-pressed mica board to obtain a hot-pressed mica board; S3, machining the hot-pressed mica board to obtain irregular mica parts.

[0006] As a preferred embodiment of the method for preparing irregular mica parts based on a pre-pressing process described in this application, in step S1, the size of the mica paper is reserved with a margin of more than 10 mm for subsequent machining.

[0007] As a preferred embodiment of the method for preparing irregular mica parts based on a pre-pressing process described in this application, in step S1, the length and width dimensions of the fiberglass cloth are the same as those of the mica paper.

[0008] As a preferred embodiment of the method for preparing irregularly shaped mica parts based on a pre-pressing process described in this application, in step S2, when the number of mica sheets in the mica board is ≥8 PCS and <500 PCS, the pre-pressing temperature is ≥60℃ and <70℃, the pre-pressing pressure is ≥3MPa and <4MPa, and the pre-pressing time is ≥0.1h and <0.3h; the hot-pressing temperature is ≥220℃ and <230℃, the hot-pressing pressure is ≥10MPa and <11MPa, and the hot-pressing time is ≥0.35h and <0.4h.

[0009] As a preferred embodiment of the method for preparing irregularly shaped mica parts based on a pre-pressing process described in this application, in step S2, when the number of mica sheets in the mica board is ≥500PCS and <1000PCS, the pre-pressing temperature is ≥70℃ and <80℃, the pre-pressing pressure is ≥4MPa and <5MPa, and the pre-pressing time is ≥0.3h and <0.6h; the hot-pressing temperature is ≥230℃ and <240℃, the hot-pressing pressure is ≥11MPa and <12MPa, and the hot-pressing time is ≥0.4h and <0.45h.

[0010] As a preferred embodiment of the method for preparing irregularly shaped mica parts based on a pre-pressing process described in this application, in step S2, when the number of mica sheets in the mica board is ≥1000PCS and <1500PCS, the pre-pressing temperature is ≥80℃ and <90℃, the pre-pressing pressure is ≥5MPa and <6MPa, and the pre-pressing time is ≥0.6h and <1h; the hot-pressing temperature is ≥240℃ and <250℃, the hot-pressing pressure is ≥12MPa and <13MPa, and the hot-pressing time is ≥0.45h and <0.5h.

[0011] As a preferred embodiment of the method for preparing irregular mica parts based on pre-pressing process described in this application, in step S2, the pre-pressing mold is a planar mold, and the hot-pressing mold is an irregular mold.

[0012] As a preferred embodiment of the method for preparing irregular mica parts based on a pre-pressing process described in this application, the qualification rate of the irregular mica parts is ≥90%, and the production efficiency of the irregular mica parts is ≥90%.

[0013] This application also provides a shaped mica part, which is prepared by the above-described method for preparing shaped mica parts based on pre-pressing process.

[0014] As a preferred embodiment of the irregular mica component described in this application, the irregular mica component has a bending strength ≥120MPa and a bending modulus ≥7GPa.

[0015] The beneficial effects of this application are as follows: To address the common technical defects in the direct hot-pressing process of mica paper, such as blistering, delamination, and even cracking caused by uneven heating or ineffective gas removal, this application innovatively proposes a method for preparing irregularly shaped mica parts based on a pre-pressing process. This method introduces a pre-pressing step before the formal hot pressing, effectively eliminating residual air between the mica paper layers, thereby significantly improving the bonding tightness between the material layers. Pre-pressing before hot pressing effectively avoids defects such as bubbles, delamination, and cracking in the final product, shortening the total hot pressing time, improving overall production efficiency, and ensuring stable and reliable product performance. Currently, many irregularly shaped structural parts often have multiple rounded corners and a certain stretching depth. However, mica paper itself has poor ductility; if directly hot-pressed, blistering, delamination, and even cracking are easily generated at the corners or stretching areas. Once these defects occur, they will seriously affect the insulation performance and high-voltage resistance of the product, causing it to fail to meet usage requirements.

[0016] When the number of mica sheets is within a certain range, if the pre-pressing time is too short, the adhesive between the mica sheets cannot soften, resulting in an excessively long subsequent hot-pressing time. This is equivalent to directly hot-pressing the mica sheets, easily leading to defects such as delamination, bubbling, and breakage, resulting in a low product qualification rate. If the pre-pressing time is too long, although the adhesive between the mica sheets softens, the continuous pre-pressing prevents further curing and molding, taking up too much time and reducing production efficiency. Given that mica materials are widely used in scenarios with extremely high safety requirements, such as power battery packs, the high-quality mica components produced by this method can provide battery packs with more reliable and durable thermal protection and electrical insulation barriers, thereby effectively reducing safety hazards such as short circuits and thermal runaway caused by insulation failure, and significantly improving the overall system safety and reliability.

[0017] The mica paper pre-pressing method proposed in this application not only has significant advantages in technical effects, but also demonstrates high practicality and economy in actual production applications. The process flow design is simple and reasonable, with clear and explicit operation steps. It requires no complex equipment or harsh environmental conditions, making it easy to implement and promote on existing production lines. Depending on actual production needs and equipment specifications, the number of pressing layers can be flexibly adjusted to achieve simultaneous pre-pressing of multiple layers of mica paper, greatly improving production efficiency per unit time. Furthermore, the auxiliary materials used in the pre-pressing process (such as fiberglass cloth) possess good heat resistance and structural stability, maintaining good performance even after multiple uses. Therefore, they can be recycled and reused, significantly reducing raw material consumption and auxiliary material costs. In summary, this method combines multiple advantages such as simple process, high efficiency, low cost, and stable quality, making it very suitable for large-scale industrial mass production and able to efficiently respond to the growing market demand for high-performance mica insulation components.

[0018] This application boasts significant advantages such as simple operation, reliable process, and ease of implementation. Its core process flow is as follows: first, mica paper and fiberglass cloth are stacked to obtain a composite mica board; then, the multi-layer composite mica board is placed in a pre-press machine for preliminary pre-pressing treatment, making its structure more compact and uniform; subsequently, the pre-pressed mica board is placed in the lower cavity of a hot press mold and hot-pressed to shape it. Finally, combined with precision machining, the overall quality and consistency of the final mica board product are effectively improved. This process route of pre-pressing, hot pressing, and machining not only significantly improves the physical properties and dimensional stability of mica products but also makes the entire production process easier to standardize and automate. In practical applications, this technical solution greatly improves production efficiency and product yield while reducing manual intervention and material waste, making it particularly suitable for large-scale industrial production scenarios with high requirements for capacity and quality stability.

[0019] Compared to the production method of directly hot-pressing mica paper using a hot press, the mica products produced by this application have a 20% higher yield, a 15% higher production efficiency, and a 10% higher product bending performance, while also saving production costs. The resulting mica boards are lower in cost and have better performance, making them more competitive in the market.

[0020] The mica products produced in this application can effectively eliminate air between mica paper layers and improve the interlayer bonding tightness, thereby significantly reducing structural defects in the finished product. This not only greatly enhances the overall density and mechanical strength of the mica components, but also reliably ensures their excellent insulation performance and high-voltage resistance, providing good fire protection, insulation, and flame retardancy for lithium battery packs. In the event of thermal runaway, it can also provide more reliable protection for lithium battery packs, meeting the growing demands of the new energy electric vehicle market. Detailed Implementation

[0021] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] This application provides a method for preparing irregularly shaped mica parts based on a pre-compression process, including the following steps: S1. Obtain mica paper and fiberglass cloth, stack the mica paper to obtain a mica board, and place a fiberglass cloth on each of the upper and lower surfaces of the mica board to obtain a composite mica board. The dimensions of the mica paper are reserved with a margin of more than 10mm for subsequent machining; the length and width dimensions of the fiberglass cloth are the same as those of the mica paper. S2. The composite mica board is pre-pressed to obtain a pre-pressed mica board, and the pre-pressed mica board is hot-pressed to obtain a hot-pressed mica board. When the number of mica paper sheets in the mica board is ≥8 PCS and <500 PCS, the pre-pressing temperature is ≥60℃ and <70℃, the pre-pressing pressure is ≥3MPa and <4MPa, and the pre-pressing time is ≥0.1h and <0.3h; the hot-pressing temperature is ≥220℃ and <230℃, the hot-pressing pressure is ≥10MPa and <11MPa, and the hot-pressing time is ≥0.35h and <0.4h. When the number of mica paper sheets in the mica board is ≥500PCS and <1000PCS, the pre-pressing temperature is ≥70℃ and <80℃, the pre-pressing pressure is ≥4MPa and <5MPa, and the pre-pressing time is ≥0.3h and <0.6h; the hot-pressing temperature is ≥230℃ and <240℃, the hot-pressing pressure is ≥11MPa and <12MPa, and the hot-pressing time is ≥0.4h and <0.45h. When the number of mica paper sheets in the mica board is ≥1000PCS and <1500PCS, the pre-pressing temperature is ≥80℃ and <90℃, the pre-pressing pressure is ≥5MPa and <6MPa, and the pre-pressing time is ≥0.6h and <1h; the hot-pressing temperature is ≥240℃ and <250℃, the hot-pressing pressure is ≥12MPa and <13MPa, and the hot-pressing time is ≥0.45h and <0.5h. The pre-pressing mold is a flat mold, and the hot-pressing mold is a non-circular mold; S3. The hot-pressed mica plate is machined to obtain irregularly shaped mica parts; The pass rate of the irregular mica component is ≥90%, and the production efficiency of the irregular mica component is ≥90%.

[0023] This application also provides a shaped mica component, comprising: the flexural strength of the shaped mica component ≥120MPa, and the flexural modulus of the shaped mica component ≥7GPa.

[0024] The technical solution of this application will be further described below with reference to specific embodiments.

[0025] Example 1

[0026] A method for preparing irregularly shaped mica parts based on a pre-compression process includes the following steps: S1. Obtain mica paper and fiberglass cloth, stack the mica paper to obtain a mica board, and place a fiberglass cloth on the top and bottom surfaces of the mica board to obtain a composite mica board. The mica paper is 1000mm long and 300mm wide; a margin of at least 10mm is reserved for subsequent machining of the mica paper; the length and width of the fiberglass cloth are the same as those of the mica paper. S2. Pre-press the composite mica sheet to obtain a pre-pressed mica sheet, and then hot-press the pre-pressed mica sheet to obtain a hot-pressed mica sheet. The number of mica paper sheets in the mica board is 250 PCS. The pre-pressing temperature is 65℃, the pre-pressing pressure is 3.5MPa, and the pre-pressing time is 0.2h. The hot-pressing temperature is 225℃, the hot-pressing pressure is 10.5MPa, and the hot-pressing time is 0.38h. The pre-pressing mold is a flat mold, while the hot-pressing mold is a special-shaped mold; S3. The hot-pressed mica sheet is machined to obtain irregularly shaped mica parts; The pass rate for irregularly shaped mica parts is 90%, and the production efficiency for irregularly shaped mica parts is 92%.

[0027] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 120 MPa and the bending modulus was 7 GPa.

[0028] Example 2

[0029] A method for preparing irregularly shaped mica parts based on a pre-compression process includes the following steps: S1. Obtain mica paper and fiberglass cloth, stack the mica paper to obtain a mica board, and place a fiberglass cloth on the top and bottom surfaces of the mica board to obtain a composite mica board. The mica paper is 1000mm long and 300mm wide; a margin of at least 10mm is reserved for subsequent machining of the mica paper; the length and width of the fiberglass cloth are the same as those of the mica paper. S2. Pre-press the composite mica sheet to obtain a pre-pressed mica sheet, and then hot-press the pre-pressed mica sheet to obtain a hot-pressed mica sheet. The number of mica paper sheets in the mica board is 750 PCS, the pre-pressing temperature is 75℃, the pre-pressing pressure is 4.5MPa, and the pre-pressing time is 0.45h; the hot-pressing temperature is 235℃, the hot-pressing pressure is 11.5MPa, and the hot-pressing time is 0.42h. The pre-pressing mold is a flat mold, while the hot-pressing mold is a special-shaped mold; S3. The hot-pressed mica sheet is machined to obtain irregularly shaped mica parts; The pass rate for irregularly shaped mica parts is 92%, and the production efficiency for irregularly shaped mica parts is 91%.

[0030] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 130 MPa and the bending modulus was 10 GPa.

[0031] Example 3

[0032] A method for preparing irregularly shaped mica parts based on a pre-compression process includes the following steps: S1. Obtain mica paper and fiberglass cloth, stack the mica paper to obtain a mica board, and place a fiberglass cloth on the top and bottom surfaces of the mica board to obtain a composite mica board. The mica paper is 1000mm long and 300mm wide; a margin of at least 10mm is reserved for subsequent machining of the mica paper; the length and width of the fiberglass cloth are the same as those of the mica paper. S2. Pre-press the composite mica sheet to obtain a pre-pressed mica sheet, and then hot-press the pre-pressed mica sheet to obtain a hot-pressed mica sheet. The mica board contains 1250 sheets of mica paper. The pre-pressing temperature is 85℃, the pre-pressing pressure is 5.5MPa, and the pre-pressing time is 0.8h. The hot-pressing temperature is 245℃, the hot-pressing pressure is 12.5MPa, and the hot-pressing time is 0.48h. The pre-pressing mold is a flat mold, while the hot-pressing mold is a special-shaped mold; S3. The hot-pressed mica sheet is machined to obtain irregularly shaped mica parts; The pass rate for irregularly shaped mica parts is 95%, and the production efficiency for irregularly shaped mica parts is 90%.

[0033] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 140 MPa and the bending modulus was 12 GPa.

[0034] Comparative Example 1 The difference between this comparative example and Example 1 is that pre-compression is not performed; the remaining steps are the same as in Example 1.

[0035] The pass rate for irregularly shaped mica parts is 75%, and the production efficiency for irregularly shaped mica parts is 91%.

[0036] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 90 MPa and the bending modulus was 5 GPa.

[0037] Comparative Example 2 The difference between this comparative example and Example 1 is that the pre-pressing temperature is 75°C, the pre-pressing pressure is 4.5 MPa, and the pre-pressing time is 0.45 h; the hot-pressing temperature is 235°C, the hot-pressing pressure is 11.5 MPa, and the hot-pressing time is 0.42 h. The remaining steps are the same as in Example 1.

[0038] The pass rate for irregularly shaped mica parts is 85%, and the production efficiency for irregularly shaped mica parts is 80%.

[0039] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 115 MPa and the bending modulus was 6.5 GPa.

[0040] Comparative Example 3 The difference between this comparative example and Example 2 is that the pre-pressing temperature is 85°C, the pre-pressing pressure is 5.5 MPa, and the pre-pressing time is 0.8 h; the hot-pressing temperature is 245°C, the hot-pressing pressure is 12.5 MPa, and the hot-pressing time is 0.48 h. The remaining steps are the same as in Example 2.

[0041] The pass rate for irregularly shaped mica parts is 88%, and the production efficiency for irregularly shaped mica parts is 78%.

[0042] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 118 MPa and the bending modulus was 6.7 GPa.

[0043] Comparative Example 4 The difference between this comparative example and Example 3 is that the pre-pressing temperature is 65°C, the pre-pressing pressure is 3.5 MPa, and the pre-pressing time is 0.2 h; the hot-pressing temperature is 225°C, the hot-pressing pressure is 10.5 MPa, and the hot-pressing time is 0.38 h. The remaining steps are the same as in Example 3.

[0044] The pass rate for irregularly shaped mica parts is 78%, and the production efficiency for irregularly shaped mica parts is 88%.

[0045] The prepared irregular mica parts were tested, and the results showed that the bending strength of the irregular mica parts was 93 MPa and the bending modulus was 5.2 GPa.

[0046] As can be seen from the above examples and comparative examples: Example 1 combined with Comparative Example 1 shows that pre-pressing can initially cure the adhesive between the mica papers, improving the product hot-pressing pass rate; Example 1 combined with Comparative Example 2 and Example 2 combined with Comparative Example 3 show that the overall process parameters are too large, and continuous pre-pressing causes the mica paper to be unable to continue to cure and form, the product performance no longer improves or even slightly decreases, and the production efficiency is reduced due to the excessive process time; Example 3 combined with Comparative Example 4 shows that the overall process parameters are too small, the adhesive between the mica papers is not sufficiently softened, and the product pass rate and product performance decrease; Combining Examples 1-3 and Comparative Examples 1-4, it can be seen that a certain number of sheets of coated paper, under appropriate pre-pressing and hot-pressing conditions, is beneficial to improving the product pass rate, performance and production efficiency.

[0047] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the inventive concept of this application and using the content of this application specification, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for preparing irregularly shaped mica parts based on a pre-pressing process, characterized in that, Includes the following steps: S1. Obtain mica paper and fiberglass cloth, stack the mica paper to obtain a mica board, and place a fiberglass cloth on each of the upper and lower surfaces of the mica board to obtain a composite mica board. S2. The composite mica board is pre-pressed to obtain a pre-pressed mica board, and the pre-pressed mica board is hot-pressed to obtain a hot-pressed mica board. S3. The hot-pressed mica plate is machined to obtain irregularly shaped mica parts.

2. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S1, the size of the mica paper is reserved with a margin of more than 10mm for subsequent machining.

3. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S1, the length and width dimensions of the fiberglass cloth are the same as those of the mica paper.

4. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S2, when the number of mica sheets in the mica board is ≥8 PCS and <500 PCS, the pre-pressing temperature is ≥60℃ and <70℃, the pre-pressing pressure is ≥3MPa and <4MPa, and the pre-pressing time is ≥0.1h and <0.3h; the hot-pressing temperature is ≥220℃ and <230℃, the hot-pressing pressure is ≥10MPa and <11MPa, and the hot-pressing time is ≥0.35h and <0.4h.

5. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S2, when the number of mica sheets in the mica board is ≥500PCS and <1000PCS, the pre-pressing temperature is ≥70℃ and <80℃, the pre-pressing pressure is ≥4MPa and <5MPa, and the pre-pressing time is ≥0.3h and <0.6h; the hot-pressing temperature is ≥230℃ and <240℃, the hot-pressing pressure is ≥11MPa and <12MPa, and the hot-pressing time is ≥0.4h and <0.45h.

6. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S2, when the number of mica sheets in the mica board is ≥1000PCS and <1500PCS, the pre-pressing temperature is ≥80℃ and <90℃, the pre-pressing pressure is ≥5MPa and <6MPa, and the pre-pressing time is ≥0.6h and <1h; the hot-pressing temperature is ≥240℃ and <250℃, the hot-pressing pressure is ≥12MPa and <13MPa, and the hot-pressing time is ≥0.45h and <0.5h.

7. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, In step S2, the pre-pressing mold is a flat mold, and the hot-pressing mold is a non-circular mold.

8. The method for preparing irregularly shaped mica parts based on a pre-pressing process according to claim 1, characterized in that, The pass rate of the irregular mica component is ≥90%, and the production efficiency of the irregular mica component is ≥90%.

9. A type of irregularly shaped mica component, characterized in that, The mica part was prepared using a method based on a pre-pressing process as described in any one of claims 1-8.

10. A shaped mica component according to claim 9, characterized in that, The flexural strength of the irregular mica component is ≥120MPa, and the flexural modulus of the irregular mica component is ≥7GPa.