Manufacturing method of extra-thick mica paper

Abstract

The invention provides a manufacturing method of super-thick mica paper. The manufacturing method comprises the steps of mica material selection, mica material screening, mica material crushing, mica material rotational flow, mica material screening and dewatering, mica material papermaking, drying and rolling. The mica paper produced by the invention is subjected to high-pressure and low-pressure two-time rotational flow, five-time screening and dewatering, and five-time sizing by adding a net wheel, so that impurities, unqualified mica phosphorus sheets and particles of mica slurry are all removed, the purity of the mica paper is improved, the quality stability of the mica paper is improved, and five-layer sizing and covering are performed, so that the mica paper is tighter and has no cracks; the tension and the tensile strength are higher. According to the mica paper produced by the method, the thickness and the compactness of the mica paper are increased, the structural stability and the quality stability of the mica paper are improved, the temperature resistance and the pressure resistance of the mica paper are improved, the production efficiency of applying downstream products of mica plates and mica tapes is improved, and the production cost is reduced. And the safety and the service life of new energy products, especially new energy automobile parts, are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mica insulation material production, and particularly relates to a manufacturing method of extra-thick mica paper. Background Art

[0002] Mica has complete chemical inertness and non-flammability. Most importantly, it has the characteristics of resisting high voltage, high temperature, corona and radiation, and has the characteristics of non-toxic, odorless, aging-resistant, corrosion-resistant, etc.

[0003] Mica paper products are widely used in industrial electrics, household appliances, aerospace, petrochemical, metallurgical subway, wind energy and nuclear power, high-speed locomotives and other fields. Some products have been used in aerospace projects such as the Shenzhou series and Chang'e-1.

[0004] With the development of the new energy industry, especially new energy vehicles, a large amount of high-quality mica insulation materials are required. These high-quality mica papers, mica boards and mica tapes are mainly used to wind the cables and conductors in new energy vehicle engines, and isolate and package important components. However, the quality of traditional mica insulation materials cannot meet the requirements of new energy product quality.

[0005] The main existing problem is that the thickness of the mica paper formed at one time cannot reach the required value. Increasing the thickness of the mica paper will inevitably cause unstable structure of the mica paper, uneven thickness of the paper surface, insufficient compaction, cracks on the paper surface, and insufficient softness of the mica paper, as well as unstable temperature and pressure resistance performance. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art, increase the thickness and tightness of the mica paper, improve the stability of the mica paper structure, the evenness of the paper surface thickness, the softness of the mica paper and the temperature and pressure resistance performance, improve the safety of new energy products, especially new energy vehicles, so as to reduce production costs and save resources.

[0007] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] A manufacturing method of extra-thick mica paper, characterized in that: the manufacturing method includes the following steps:

[0009] ① Mica material picking: Manually pick out stones, yellow materials, dead materials and weathered materials from the mica material;

[0010] ② Mica material screening: Use a filter screen to remove mud, sawdust and other impurities from the mica material;

[0011] ③ Mica material crushing: Crush the mica material with high-pressure water in a crusher;

[0012] ④Flat-pressure swirl: The crushed mica material is fed into a hydrocyclone with slow speed and low pressure to eliminate unqualified large-diameter flake mica and fine leaves, roots;

[0013] ⑤High-pressure swirl: The mica slurry after flat-pressure swirl is fed into a hydrocyclone with high speed and high pressure to eliminate mica material particles that are not completely crushed and residual sand grains in the mica material;

[0014] ⑥Mica material screening and dehydration: The mica slurry after high-pressure swirl is fed into a screening and dehydrator. The slurry is screened and dehydrated according to the mica flake diameters of 350 - 300um, 300 - 250um, 250 - 200um, 200 - 150um, and 150 - 100um, and stored, and further impurities in the slurry are removed;

[0015] ⑦Mica paper making: The mica paper is sized in 5 layers and laminated sequentially;

[0016] ⑧Drying: The mica paper after 5-layer lamination is dried on a dryer;

[0017] ⑨Rewinding: The dried mica paper is drawn to a rewinding frame and wound around a mica paper reel.

[0018] Preferably, in step ③, the mica material is crushed with water at a pressure of 6.5 - 7.5 MPa, and preferably the pressure for mica material crushing is 7.0 MPa.

[0019] Preferably, in step ④, the pressure of the flat-pressure swirl is 0.5 - 1 MPa, and preferably the pressure of the flat-pressure swirl is 7.5 MPa.

[0020] Preferably, in step ⑤, the pressure of the high-pressure swirl is 1 - 2 MPa, and preferably the pressure of the high-pressure swirl is 1.5 MPa.

[0021] Preferably, in step ⑥, the mica slurry is stored according to the mica flake diameters of 350 - 300um, 300 - 250um, 250 - 200um, 200 - 150um, and 150 - 100um, and preferably the mica flake diameters are 352um, 275um, 225um, 175um, and 125um respectively.

[0022] Preferably, in step ⑦, when making mica paper, it is sized in 5 layers. The first layer is the slurry with mica flake diameter of 350 - 300um, the second layer is the slurry with mica flake diameter of 300 - 250um, the third layer is the slurry with mica flake diameter of 250 - 200um, the fourth layer is the slurry with mica flake diameter of 150 - 100um, and the fifth layer is the slurry with mica flake diameter of 150 - 100um.

[0023] Beneficial effects: The mica paper produced by the present invention undergoes two-stage swirling of high and low pressures, five-stage screening and dehydration, and sizing is carried out five times with a net wheel, so that impurities in the mica slurry, unqualified mica scales and particles are all removed, the purity of the mica paper is improved, and the quality stability of the mica paper is improved. Sizing is carried out in five layers for covering, making the mica paper tighter, without cracks, and having greater tension and tensile strength.

[0024] The mica paper produced by this method not only increases the thickness and tightness of the mica paper, but also improves the structural stability and quality stability of the mica paper, improves the temperature and pressure resistance performance of the mica paper, improves the production efficiency of downstream application products such as mica boards and mica tapes, and improves the safety and service life of application new energy products, especially new energy vehicle parts. Detailed implementation mode

[0025] The present invention relates to a manufacturing method of extra-thick mica paper. In order to make the technical features, technical purposes and technical effects of the present invention easy to understand, the technical solutions of the present invention will be further described below through embodiments.

[0026] Example 1:

[0027] Mica material selection: First, manually select the mica material, and manually remove the existing stone materials, yellow materials, dead materials and weathered materials in the mica material;

[0028] Mica material screening: There are still some mud, sawdust and other impurities in the mica material after manual selection. A filter screen is used to remove these impurities in the mica material;

[0029] Mica material crushing: The mica material is crushed in a crusher with high-pressure water of 6.5 MPa;

[0030] Flat-pressure swirling: The crushed mica material is swirled by a cyclone with a small pressure of 0.5 MPa to eliminate unqualified large-diameter mica slurry and leaves and roots that have not been removed by the filter screen;

[0031] High-pressure swirling: The mica slurry after flat-pressure swirling is swirled by a cyclone with a large pressure of 2 MPa to eliminate mica material particles that have not been completely crushed and sand grains remaining in the mica material;

[0032] Mica material screening and dehydration: The mica material after high-pressure swirling is sent into a screening and dehydrating device. The slurry is stored according to the sizes of mica sheet diameters of 350 um, 300 um, 250 um, 200 um, and 150 um, and impurities in the slurry are further removed;

[0033] Mica paper manufacturing: The mica paper is sized in 5 layers and sequentially compounded. The mica material for sizing in the first layer has a flake diameter of 350um, the mica material for sizing in the second layer has a flake diameter of 300um, the mica material for sizing in the third layer has a flake diameter of 250um, the mica material for sizing in the fourth layer has a flake diameter of 200um, and the mica material for sizing in the fifth layer has a flake diameter of 150um;

[0034] Drying: The mica paper after compounding five layers is dried on a dryer;

[0035] Rewinding: The dried mica paper is drawn to a rewinding rack and wound into a mica paper reel for rewinding.

[0036] Under the technical conditions of this embodiment, the thickness of the mica paper obtained is 3.0mm, the grammage per square meter reaches 500 grams, the dielectric strength is 30.5kV / mm, the heat-resistant strength is 850 degrees, the tensile strength is 45.2N / cm, and the tensile strength ≥ 65Rm / MPa.

[0037] Example 2:

[0038] Mica material sorting: First, manually select the mica material and manually remove the existing stone materials, yellow materials, dead materials, and weathered materials in the mica material;

[0039] Mica material screening: There are still some mud, sawdust, and other impurities in the mica material after manual sorting. A filter screen is used to remove these impurities in the mica material;

[0040] Mica material crushing: The mica material is crushed in a crusher using 7MPa high-pressure water;

[0041] Flat pressure cyclone: The crushed mica material is passed through a cyclone with a small pressure of 0.75MPa to eliminate unqualified large-diameter flake mica slurries and leaves and roots that have not been removed by the filter screen;

[0042] High-pressure cyclone: The mica slurry after flat pressure cyclone is passed through a cyclone with a large pressure of 2.5MPa to eliminate mica material particles that have not been completely crushed and sand grains remaining in the mica material;

[0043] Mica material screening and dehydration: The mica material after high-pressure cyclone is fed into a screening and dehydrator. The slurry is stored according to the sizes of mica flake diameters of 325um, 275um, 225um, 175um, and 125um, and further impurities in the slurry are removed;

[0044] Mica paper manufacturing: The mica paper is sized in 5 layers and sequentially laminated. The mica material for sizing in the first layer has a flake diameter of 325um, the mica material for sizing in the second layer has a flake diameter of 275um, the mica material for sizing in the third layer has a flake diameter of 225um, the mica material for sizing in the fourth layer has a flake diameter of 175umum, and the mica material for sizing in the fifth layer has a flake diameter of 125umum;

[0045] Drying: The mica paper after laminating five layers is dried on a dryer;

[0046] Rewinding: The dried mica paper is drawn to a rewinding rack and wound into a mica paper reel for rewinding.

[0047] The mica paper prepared under the technical conditions of this embodiment has a thickness of 2.8mm, a grammage per square meter of 450 grams, a dielectric strength of 28.4kV / mm, a heat resistance strength of 835 degrees, a tensile strength of 42.2N / cm, and a tensile strength ≥ 62Rm / MPa.

[0048] Example 3:

[0049] Mica material selection: First, manually select the mica material and remove the existing stone materials, yellow materials, dead materials, and weathered materials in the mica material by hand;

[0050] Mica material screening: There are still some mud, sawdust, and other impurities in the mica material after manual selection. Use a filter screen to remove these impurities in the mica material;

[0051] Mica material crushing: Crush the mica material in a crusher with high-pressure water at 7MPa;

[0052] Flat pressure cyclone: Use a cyclone with a small pressure of 0.75MPa to eliminate unqualified large-diameter flake mica slurry and leaves that have not been removed by the filter screen from the crushed mica material; Roots;

[0053] High-pressure cyclone: Use a cyclone with a large pressure of 3MPa to eliminate mica material particles that have not been completely crushed and residual sand grains in the mica material from the mica slurry after flat pressure cyclone;

[0054] Mica material screening and dewatering: Feed the mica material after high-pressure cyclone into a screening and dewatering device. The slurry is stored according to the sizes of mica flake diameters of 300um, 250um, 200um, 150um, and 100um, and further remove impurities in the slurry;

[0055] Mica paper manufacturing: The mica paper is sized in 5 layers and sequentially compounded. The flake diameter of the mica material sized in the first layer is 300um, the flake diameter of the mica material sized in the second layer is 250um, the flake diameter of the mica material sized in the third layer is 200um, the flake diameter of the mica material sized in the fourth layer is 150um, and the flake diameter of the mica material sized in the fifth layer is 100um;

[0056] Drying: The mica paper after five - layer compounding is dried on a dryer;

[0057] Rewinding: The dried mica paper is drawn to a rewinding frame and wound into a mica paper reel for rewinding.

[0058] Under the technical conditions of this embodiment, the thickness of the mica paper obtained is 2.5mm, the grammage per square meter reaches 400 grams, the dielectric strength is 20.4kV / mm, the temperature - resistant strength is 800 degrees, the tensile strength is 35.1N / cm, and the tensile strength ≥ 55Rm / MPa.

Claims

1. A method for manufacturing extra thick mica paper, characterized in that: The manufacturing method comprises the following steps: ① Mica material picking: remove stone, yellow material, dead material and weathered material from mica material by manual picking; ② Screening of mica materials: Use a filter screen to remove mud, sand, wood chips and other impurities in the mica materials; ③ Crushing of mica: crush the mica in a crusher using high-pressure water; ④ Flat-pressure cyclone: ​​The crushed mica material is treated with a slow-speed, low-pressure cyclone to eliminate unqualified large-diameter mica slurry and small leaves, root; ⑤ High-pressure cyclone: ​​The mica slurry after flat-pressure cyclone is subjected to a cyclone with high speed and high pressure to eliminate the mica particles that are not completely broken and the remaining sand particles in the mica material; ⑥ Screening and dehydration of mica material: The mica material after high-pressure cyclone is sent to the screening dehydrator, and the slurry is stored according to the size of mica flakes with diameters of 350-300um, 300-250um, 250-200um, 200-150um, and 150-100um, and impurities in the slurry are further removed; ⑦ Mica papermaking: mica paper is sized in 5 layers using 5 sizes of mica slurry sieved and dehydrated according to step ⑥, and then compounded in turn; ⑧ Drying: Dry the mica paper after 5 layers of compounding in a dryer; ⑨Reeling: Pull the dried mica paper onto the reeling rack and reel it around the mica paper drum.

2. The method for manufacturing extra thick mica paper according to claim 1, characterized in that: In step ③, the mica material is crushed by water at a pressure of 6.5 to 7.5 MPa, and the pressure of crushing the mica material is preferably 7.0 MPa.

3. The method for manufacturing extra thick mica paper according to claim 1, characterized in that: The pressure of the flat-pressure cyclone used in step ④ is 0.5-1 MPa, and the preferred pressure of the flat-pressure cyclone is 0.75 MPa.

4. The method for manufacturing a super thick mica paper according to claim 1, characterized in that: The pressure of the high-pressure cyclone used in step ⑤ is 2-3 MPa, and preferably the pressure of the high-pressure cyclone is 2.5 MPa.

5. The method for manufacturing extra thick mica paper according to claim 1, characterized in that: In step ⑥, the mica slurry is stored in sizes of 350-300um, 300-250um, 250-200um, 200-150um, and 150-100um. The preferred mica sheet diameters are 325um, 275um, 225um, 175um, and 125um, respectively.

6. The method for manufacturing extra thick mica paper according to claim 1, characterized in that: Step 7: The mica paper is sized in 5 layers, the first layer is a slurry with a mica sheet diameter of 350-300um, the second layer is a slurry with a mica sheet diameter of 300-250um, the third layer is a slurry with a mica sheet diameter of 250-200um, the fourth layer is a slurry with a mica sheet diameter of 150-100um, and the fifth layer is a slurry with a mica sheet diameter of 150-100um.