Graphite vulcanized paper board as well as preparation method and preparation system thereof

Abstract

The invention discloses a graphite vulcanized paper board and a preparation method and a preparation system thereof, the graphite vulcanized paper board comprises an upper graphite fiber layer and a lower graphite fiber layer, a polyester fiber layer is arranged between the two graphite fiber layers, the polyester fiber layer is formed by dispersing and pulping hydrophilic modified polyester fibers to form a wet paper sheet, and the graphite fiber layer is formed by dispersing and pulping hydrophilic modified graphite fibers to form a wet paper sheet. Mixing the slurry with the hydrophilic modified graphite powder dispersion liquid, then forming a wet paper sheet, and integrally pressing a polyester fiber wet paper sheet with an upper graphite fiber wet paper sheet and a lower graphite fiber wet paper sheet; the use amount of the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, the hydrophilic modified graphite powder and the dispersing agent is as follows in parts by weight: 20-30 parts of the hydrophilic modified polyester fiber, 40-50 parts of the hydrophilic modified graphite fiber and 40-20 parts of the hydrophilic modified graphite powder, and the use amount of the dispersing agent polyvinyl alcohol is 0.5-0.8% of the total weight of the three raw materials. The graphite steel paperboard produced by the invention is low in cost, and the main performance indexes of the product are superior to those of the existing product.

Description

Technical Field

[0001] The invention belongs to the technical field of graphite paper production, and in particular relates to graphite steel paper produced with chemical fiber, graphite fiber and graphite powder as raw materials, and a preparation method and a preparation system thereof. Background Art

[0002] Steel paper is a kind of deformed paper with good elasticity, wear resistance, corrosion resistance, heat resistance, mechanical strength, insulation performance and mechanical processing performance. The strength of steel paper is close to that of metal aluminum, and its specific gravity is 50% of aluminum. It is widely used in machinery, electrical, chemical, engine, textile and other fields to make various tool gaskets, insulation materials, sealing materials and other parts. Steel paper is also called steel paperboard. According to the national light industry product quality standard classification, steel paperboard is divided into hard steel paperboard (QB / T2199-1996) and soft steel paperboard (QB / T2200-1996). Hard steel paperboard is divided into three categories A, B and C according to its use: Category A is for aviation components; Category B is for machinery, electrical appliances, instrument components and insulating arc extinguishing materials; Category C is for textiles, railways, oxygen equipment and other mechanical components and electrical insulation arc extinguishing materials. Soft steel paperboard is divided into two categories A and B according to its use: Category A is for aircraft engine seals and other components; Category B is for automobile and tractor engines and various internal combustion engine seals and other components.

[0003] In the prior art, steel paper production usually uses high-quality 100% bleached cotton pulp as raw material. After pulping, it is made into base paper on a papermaking machine, and then the base paper is impregnated with a swelling agent (concentrated zinc chloride solution or cuprammonium solution) to swell and gelatinize the cellulose, and then bonded layer by layer on a gelatinizer, and then aged, desalted by water, and dried and shaped to make steel paper. The above production process is cumbersome, and many types of process equipment are used, and the process parameters are difficult to control. In addition, the price of high-quality bleached cotton pulp used as raw material in the existing preparation method has been rising all the way, and now it is as high as tens of thousands of yuan per ton, resulting in an extremely high price of steel paperboard. Affected by the above factors, the existing steel paperboard is limited in application in most other fields except for a few fields such as engines. In addition, its production process uses many types of chemicals, and the waste gas and wastewater generated are difficult to treat; defective products, scraps and products after expiration are difficult to recycle, which brings environmental pollution problems.

[0004] Graphite, as a non-metallic mineral, high-purity graphite with a carbon content of 99.9% or more has extremely high electrical conductivity, thermal conductivity and heat resistance, and is widely used in electronics, communications, aerospace, new materials, new energy and other fields; low-purity graphite with a carbon content of less than 99% is chemically stable, has good toughness, good color and temperature resistance, high mechanical strength and other characteristics, and is mainly used in lubrication and sealing, insulation, machine parts, friction and corrosion protection. Graphite products can be easily cut, bent and folded to meet the needs of various complex shapes and sizes. With the continuous improvement and maturity of graphite material preparation technology, its application areas are also continuously expanding and innovating, and the price is also continuously decreasing, bringing new opportunities for steel paperboard production. Summary of the invention

[0005] The present invention provides a graphite steel paperboard and a preparation method and a preparation system thereof. The preparation method has a simple process and low cost. The main performance indicators of the prepared graphite steel paperboard are better than those of existing products, and the product is environmentally friendly throughout its entire life cycle.

[0006] The object of the present invention is achieved in the following manner: a graphite steel paperboard comprises two upper and lower graphite fiber layers, a polyester fiber layer is disposed between the two graphite fiber layers, the polyester fiber layer is prepared by dispersing, beating and forming a wet paper sheet from hydrophilic modified polyester fibers, the graphite fiber layer is prepared by dispersing and beating the hydrophilic modified graphite fibers, the slurry is mixed with a hydrophilic modified graphite powder dispersion, and then a wet paper sheet is formed, and the polyester fiber wet paper sheet is pressed into one with the upper and lower graphite fiber wet paper sheets; the amounts of the hydrophilic modified polyester fibers, the hydrophilic modified graphite fibers, the hydrophilic modified graphite powder and the dispersant are as follows by weight: 20-30 parts by weight of the hydrophilic modified polyester fibers, 40-50 parts by weight of the hydrophilic modified graphite fibers and 40-20 parts by weight of the hydrophilic modified graphite powder, and the amount of the dispersant polyvinyl alcohol is 0.5-0.8% of the total weight of the three raw materials.

[0007] The hydrophilic modified polyester fiber has a length of 6-12 mm and a diameter of 0.04-0.08 mm.

[0008] The hydrophilic modified polyester fiber has a molecular weight of 18000-25000 and a melting point of 255-264°C.

[0009] The length of the hydrophilic modified graphite fiber is 5-10 mm, and the diameter is 0.08-0.15 mm; the particle size of the hydrophilic modified graphite powder is 120-150 meshes.

[0010] The carbon content of the hydrophilic modified graphite fiber and the hydrophilic modified graphite powder is 95-99%.

[0011] The polyvinyl alcohol has an alcoholysis degree of 88% and a polymerization degree of 2000.

[0012] The method for preparing the graphite steel paperboard comprises the following steps: (1) Prepare raw materials Weigh the raw materials and polyvinyl alcohol according to weight; (2) Preparation of polyester fiber, graphite fiber and graphite powder suspension The prepared polyvinyl alcohol solution is added to water in proportion, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are added respectively while stirring, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are completely dispersed into a suspension in the water containing the polyvinyl alcohol solution, and the concentration of the suspension is adjusted to 5wt%; (3) Production of polyester fiber slurry and graphite slurry The polyester fiber suspension and the graphite fiber suspension are pulped separately to make the average length of the hydrophilic modified polyester fiber and the hydrophilic modified graphite fiber reach 5-8 mm and 3-5 mm respectively, and the fiber surface is fluffed and the two ends are broomed. The wet weight and beating degree of the hydrophilic modified polyester fiber pulp are controlled at 4.5-5g and 30-32 0 SR, hydrophilic modified graphite fiber slurry wet weight and beating degree are controlled at 3.5-4g and 33 0 -35 0 SR, the two slurries are stored separately, and the graphite powder suspension prepared in step (2) is added to the graphite fiber and mixed evenly; (4) Molding The two kinds of pulp are sent to the forming part respectively and evenly distributed on the three-layer forming structure. In this process, water is added to adjust the pulp concentration to 1-1.2%. After forming, the dryness of each layer of wet paper is controlled at 11-15%. The three layers of paper are pressed into one, dehydrated to control the dryness of the paper at 45-50%, dried at 80-100℃ to a dryness of 90-93%, and then finished and finally rolled up to become the finished product.

[0013] The graphite steel paperboard preparation system comprises a polyester fiber slurry preparation part, a graphite fiber and graphite powder slurry preparation part and a papermaking part. The polyester fiber slurry preparation part comprises a first disperser (101), a first slurry pump (102), a first disc grinder (103), a first slurry tank (104) and a second slurry pump (105); the first disperser (101) is connected to the first disc grinder (103) through the first slurry pump 102; the graphite fiber and graphite powder slurry preparation part comprises a second disperser (201), a third slurry pump (202), a second disc grinder (203), a third disperser (204), a fourth slurry pump (205), a second slurry tank (206), a fifth slurry pump (207) ), the second disperser (201) is connected to the second disc grinder (203) via a third pulp pump (202), the third disperser (204) is connected to the second pulping pool (206) via a fourth pulp pump (205); the papermaking part comprises a headbox (301), a forming wire (302), a pressing part (303), a drying part (304), and a finishing winding part (305) which are connected in sequence, the headbox (301) comprises three heads connected in parallel, the forming wire (302) comprises three heads connected in parallel, the first pulping pool (104) is connected to the middle headbox via a second pulp pump (105), and the second pulping pool (206) is connected to the upper and lower headboxes via a fifth pulp pump (207).

[0014] Compared with the prior art, the present invention uses hydrophilic modified polyester fiber as reinforcing material, hydrophilic modified graphite fiber and hydrophilic modified graphite powder as functional materials, and polyvinyl alcohol is used to make three suspensions respectively, and then the two fiber suspensions are pulped to make slurries respectively, and the graphite powder suspension is mixed with the graphite fiber slurry to form wet paper sheets, and the polyester fiber slurry is formed into wet paper sheets separately, and a layer of polyester fiber wet paper sheets is sandwiched between two layers of graphite wet paper sheets, and the three layers of wet paper sheets are pressed into one body and dried into graphite steel paperboard. The above-mentioned wet papermaking technology is used to produce graphite steel paperboard. Compared with the existing steel plate production method, the process is simple and the cost is low, and the main performance indicators of the product are better than the existing products; because the raw materials and production process do not use volatile organic compounds, all wastewater in the production is reused in the production process, and waste products, scraps and products after expiration are recycled and crushed and added to the raw materials in proportion for continued use, so as to achieve environmental friendliness throughout the life cycle of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a production flow chart of the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the present invention.

[0017] A graphite steel paperboard comprises two upper and lower graphite fiber layers, a polyester fiber layer is disposed between the two graphite fiber layers, the polyester fiber layer is formed by dispersing, beating and sheeting hydrophilically modified polyester fibers, the graphite fiber layer is dispersed and beated hydrophilically modified graphite fibers, the slurry is mixed with a hydrophilically modified graphite powder dispersion, and then sheeted, and the formed polyester fiber layer and the graphite fiber layer are pressed into one body; the amounts of the hydrophilically modified polyester fibers, the hydrophilically modified graphite fibers, the hydrophilically modified graphite powder and the dispersant are as follows by weight: 20-30 parts of the hydrophilically modified polyester fibers, 40-50 parts of the hydrophilically modified graphite fibers and 40-20 parts of the hydrophilically modified graphite powder, and the amount of the dispersant polyvinyl alcohol is 0.5-0.8% of the total weight of the three raw materials.

[0018] The present invention selects chemical fiber - hydrophilic modified polyester fiber as the reinforcing material of wet paper sheets in the papermaking process of the paper machine, and preferably has a molecular weight of 18000-25000, a melting point of 255-264 ° C, a length of 6-12 mm, and a diameter of 0.04-0.08 mm. Polyester fiber itself has the characteristics of good heat resistance, light resistance and extremely high insulation, good resistance to organic solvents, oxidants and corrosion resistance, stability to weak acids and alkalis, etc. Compared with plant fibers, it has high tensile index and tear index. The hydrophilically modified polyester fiber has good hydrophilicity and can be evenly dispersed in the liquid. The density of the hydrophilically modified polyester fiber is 1.36g / cm 3 , tensile strength ≥500Mpa, elastic modulus ≥13500Mpa, elongation at break 15-25%.

[0019] The hydrophilic modified polyester fiber selected in the present invention obtains hydrophilic groups through modification. In addition to being easily dispersed in a solution, when formed at a concentration of 20% or less, chemical bonds with a connecting function are formed between the polyester fibers and between the polyester fibers and the graphite fibers, thereby increasing the bonding force between the fibers and allowing the papermaking process to proceed smoothly.

[0020] The present invention selects hydrophilic modified graphite fiber and hydrophilic modified graphite powder as functional materials, the carbon content of the hydrophilic modified graphite fiber and the hydrophilic modified graphite powder is 95-99%, and the hydrophilic modified graphite fiber with a length of 5-10 mm and a diameter of 0.08-0.15 mm and the hydrophilic modified graphite powder with a particle size of 120-150 mesh are preferred. The graphite fiber itself has the characteristics of high mechanical strength such as tensile strength and bending resistance, and good toughness. In the occasion of relative mechanical movement, it also has excellent lubricity and heat dissipation function. The graphite fiber has good hydrophilicity after modification and can be evenly dispersed when added to liquid. In addition to being used as a functional material, the hydrophilic modified graphite powder can also increase the product density and surface smoothness.

[0021] The hydrophilic modified graphite fiber and hydrophilic modified graphite powder selected by the present invention are modified to obtain oxygen-containing polar groups, such as hydroxyl and carboxyl groups, and have excellent hydrophilicity while ensuring that their mechanical properties are not affected.

[0022] The polyvinyl alcohol selected by the present invention preferably has a degree of alcoholysis of 88% and a degree of polymerization of 2000, and is used as a dispersant for hydrophilic modified polyester fibers, hydrophilic modified graphite fibers and hydrophilic modified graphite powder in a solution. At a slurry concentration of 8% or less, the raw materials have an excellent dispersing effect and are conducive to forming a uniform suspension. In addition to playing a dispersant role, polyvinyl alcohol also plays an adhesive role, and polyvinyl alcohol has the best bonding performance among all water-soluble adhesives. Polyvinyl alcohol is a polymer containing a large number of hydrophilic groups, and its hydrophilic groups react chemically with oxygen-containing polar groups such as hydrophilic hydroxyl groups of hydrophilic modified polyester fibers, hydrophilic modified graphite fibers, and hydrophilic modified graphite powders, thereby enhancing the bonding strength between hydrophilic modified polyester fibers, between hydrophilic modified graphite fibers, between hydrophilic modified graphite powders, and between hydrophilic modified graphite fibers and hydrophilic modified graphite powders.

[0023] A method for preparing graphite steel paperboard comprises the following steps: (1) Prepare raw materials Weigh the raw materials and polyvinyl alcohol according to weight; (2) Preparation of polyester fiber, graphite fiber and graphite powder suspension The prepared polyvinyl alcohol solution is added to water in proportion, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are added respectively while stirring, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are completely dispersed into a suspension in the water containing the polyvinyl alcohol solution, and the concentration of the suspension is adjusted to 5wt%; (3) Production of polyester fiber slurry and graphite slurry The polyester fiber suspension and the graphite fiber suspension are pulped separately to make the average length of the hydrophilic modified polyester fiber and the hydrophilic modified graphite fiber reach 5-8 mm and 3-5 mm respectively, and the fiber surface is fluffed and the two ends are broomed. The wet weight and beating degree of the hydrophilic modified polyester fiber pulp are controlled at 4.5-5g and 30-32 0 SR, hydrophilic modified graphite fiber slurry wet weight and beating degree are controlled at 3.5-4g and 33 0 -35 0 SR, the two slurries are stored separately, and the graphite powder suspension prepared in step (2) is added to the graphite fiber and mixed evenly; (4) Molding The two kinds of pulp are sent to the forming part respectively and evenly distributed on the three-layer forming structure. In this process, water is added to adjust the pulp concentration to 1-1.2%. After forming, the dryness of each layer of wet paper is controlled at 11-15%. The three layers of paper are pressed into one, dehydrated to control the dryness of the paper at 45-50%, and dried at 80-100℃ to a dryness of 90-93%. After finishing, the graphite steel paper is compacted to increase its density and make it have a smooth surface, and finally it is rolled into a finished product.

[0024] The graphite steel paperboard obtained by the above preparation method has the following performance indicators: thickness 0.3-1.5mm, density ≥1.35 g / cm³; cross-sectional tensile strength: longitudinal 15×10 4 KN / m 2 , horizontal 9.5×10 4 KN / m 2 , oil absorption ≤0.6%, water absorption ≤15%, elongation ≥15%, volume resistivity ≥10 12 Ω.cm, compressive strength ≥1600Mpa.

[0025] Compared with the standards of hard steel paperboard (QB / T2199-1996) and soft steel paperboard (QB / T2200-1996), the main indicators of the graphite steel paperboard produced by the present invention are better than the above standard requirements, and its application scope is not limited to the application scope of existing steel paperboard.

[0026] Example 1 A graphite steel paperboard (small test) is prepared according to the following steps: (1) Weigh 0.25 kg of hydrophilic modified polyester fiber, 0.45 kg of hydrophilic modified graphite fiber and 0.3 kg of hydrophilic modified graphite powder, and 0.006 kg of polyvinyl alcohol.

[0027] (2) Polyvinyl alcohol was prepared into a 5 wt% polyvinyl alcohol solution, which was added into three 23-liter experimental trough-type pulping machines in proportion to disperse the solution. During the dispersion process, the rotating upper roller was lifted and stirred while adding hydrophilic modified polyester fibers, hydrophilic modified graphite fibers, and hydrophilic modified graphite powder to form a uniformly dispersed suspension with a concentration of 5 wt%.

[0028] (3) The polyester fiber suspension and graphite fiber suspension after uniform dispersion were beaten by adjusting the gap between the upper roller blade and the bottom blade of a 23-liter experimental trough-type beating machine, so that the average length of the hydrophilic modified polyester fiber reached 5-8 mm, and the surface was fluffed and the ends were buffed to increase the mechanical connection strength between the fibers. The wet weight and beating degree of the pulp were controlled at 5 g and 32 g, respectively. 0SR; the average length of hydrophilic modified graphite fibers reaches 3-5 mm, and the surface is fluffed and the ends are broomed to increase the mechanical connection strength between the fibers. The wet weight and beating degree of pulp are controlled at 4g and 33 0 SR, the two slurry fiber slurries are respectively placed into respective storage containers through the pulping port of the pulping machine, and the hydrophilic modified graphite suspension prepared in step (2) is added to the graphite fiber slurry and mixed evenly to form graphite slurry.

[0029] (4) Take 86 ml of 1 polyester fiber slurry and 128 ml of 2 graphite mixed slurries, add water to each of them to adjust the concentration to 1.2%, and use a manual sheeter (Φ200 mm) to make polyester fiber wet paper sheets and graphite wet paper sheets. The wet paper sheets formed by sheeting have a dryness of 11%. The wet paper sheets peeled off from the sheeter net are placed on the bottom plate of a flat press. First, a graphite wet paper sheet is placed, then a polyester fiber wet paper sheet is placed, and finally a graphite paper sheet is placed. The three layers of paper sheets are pressed into one by a flat press. After pressing, the paper sheets have a dryness of 47%. After drying and shaping in a dryer at 90°C, they are calendered by manual three-roller finishing to become a finished product with a dryness of 93% - graphite steel paperboard.

[0030] The thickness of the finished product is 0.55 mm, the density is ≥1.36 g / cm³, and the tensile strength of the cross section is: 15×10 4 KN / m 2 , horizontal 9.5×10 4 KN / m 2 , oil absorption ≤0.6%, water absorption ≤15%, elongation ≥15%, volume resistivity ≥10 12 Ω.cm, compressive strength ≥1600Mpa.

[0031] Example 2 The difference between this embodiment and embodiment 1 is that 0.30 kg of hydrophilic modified polyester fiber, 0.50 kg of hydrophilic modified graphite fiber and 0.2 kg of hydrophilic modified graphite powder are used, and the amount of polyvinyl alcohol is 0.005 kg. The wet weight and beating degree of the hydrophilic modified polyester fiber are controlled at 4.5 g and 30 g, respectively. 0 The wet weight and beating degree of SR and hydrophilic modified graphite fibers were controlled at 3.5 g and 34 0 SR. The pulp concentration was adjusted to 1.0% before wet paper sheets were formed, the dryness of wet paper sheets formed by sheeting was 15%, the dryness of paper sheets after pressing was 45%, and the dryness of graphite steel paperboard after drying and shaping at 100℃ and calendering was 90%. Other process conditions were the same.

[0032] Example 3 The difference between this embodiment and embodiment 1 is that 0.20 kg of hydrophilic modified polyester fiber, 0.40 kg of hydrophilic modified graphite fiber and 0.4 kg of hydrophilic modified graphite powder are used, and the amount of polyvinyl alcohol is 0.008 kg. The wet weight and beating degree of the hydrophilic modified polyester fiber are controlled at 4.8 g and 31 respectively. 0 The wet weight and beating degree of SR and hydrophilic modified graphite fibers were controlled at 3.8 g and 35 0 SR. The pulp concentration was adjusted to 1.2% before wet paper sheets were formed. The dryness of wet paper sheets formed by sheeting was 13%. The dryness of the sheets after pressing was 50%. After drying and shaping at 80℃, the dryness of the graphite steel paperboard after calendering was 92%.

[0033] like Figure 1 As shown, a graphite steel paperboard preparation system includes a polyester fiber slurry preparation part, a graphite fiber and graphite powder slurry preparation part and a papermaking part. The polyester fiber slurry preparation part includes a first disperser 101, a first slurry pump 102, a first disc grinder 103, a first pulping tank 104 and a second slurry pump 105. The first disperser 101 is connected to the first disc grinder 103 through the first slurry pump 102; the graphite fiber and graphite powder slurry preparation part includes a second disperser 201, a third slurry pump 202, a second disc grinder 203, a third disperser 204, a fourth slurry pump 205, a second pulping tank 206, a fourth slurry pump 207, a fifth slurry pump 208, a fifth slurry pump 209, a fifth slurry pump 210, a fifth slurry pump 211, a fifth slurry pump 212, a fifth slurry pump 213, a fifth slurry pump 214, a fifth slurry pump 215, a fifth slurry pump 216, a fifth slurry pump 217, a fifth slurry pump 218, a fifth slurry pump 219, a fifth slurry pump 220 Five pulp pumps 207, the second disperser 201 is connected to the second disc refiner 203 through the third pulp pump 202, the third disperser 204 is connected to the second pulping pool 206 through the fourth pulp pump 205; the papermaking part includes a headbox 301, a forming wire 302, a pressing part 303, a drying part 304, and a finishing winding part 305 connected in sequence, the headbox 301 includes three upper, middle and lower headboxes connected in parallel, the forming wire 302 includes three upper, middle and lower headboxes connected in parallel, the first pulping pool 104 is connected to the middle headbox through the second pulp pump 105, and the second pulping pool 206 is connected to the upper and lower headboxes through the fifth pulp pump 207.

[0034] The prepared dispersant is added into the water of the first disperser 101 in proportion, and the polyester fiber is added into the first disperser 101 during the stirring process. The polyester fiber is completely dispersed into a suspension and pumped into the first disc mill 103 for beating through the first pulp pump 102. Through beating, the length of the polyester fiber reaches the required length of 5-8 mm, and the two ends of the polyester fiber are beating. The wet weight and beating degree of the polyester fiber pulp are controlled at 5g and 32°SR respectively. After meeting the pulping requirements, it is stored in the first pulping pool 104, and then pumped into the middle flow pulp box and the middle screen of the paper machine through the second pulp pump 105 for forming.

[0035] The prepared dispersant is added to the water of the second disperser 201 in proportion, and graphite fibers are added during the stirring process of the second disperser 201. The graphite fibers are completely dispersed into a suspension and pumped into the second disc mill 203 through the third slurry pump 202 for beating. Through beating, the length of the graphite fibers reaches the required length of 3-5 mm, and the two ends of the graphite fibers are broomed. The wet weight and beating degree of the graphite fibers are controlled at 4g and 33°SR respectively. After meeting the slurry requirements, they are stored in the second slurry tank 206; the prepared dispersant is added to the water of the third disperser 204 in proportion, and graphite powder is added during the stirring process of the third disperser 204. The graphite powder is completely dispersed into a suspension. The graphite powder suspension is pumped into the second slurry tank 206 through the fourth slurry pump 205, and mixed evenly with the graphite fiber slurry. Then, the mixed slurry in the second slurry tank 206 is pumped into the upper and lower headboxes and the upper and lower wires of the paper machine through the fifth slurry pump 207 for molding. The three-layer paper sheets peeled from the wire section are pressed into one piece by the pressing section 303 and further dehydrated, and then dried by the drying cylinder of the drying section 304, and then processed by the finishing winding section 5 to become a finished product.

[0036] The polyester fiber, graphite fiber and graphite powder are hydrophilically modified to make them easy to disperse in the solution, and chemical bonds with connecting function are formed between the fibers to increase the bonding force between the fibers; through the beating process, in addition to adjusting the fiber length, the fiber surface is fluffed and the two ends are buffed to increase the mechanical bonding force or bonding strength between the fibers. The above two points are the key to increasing the strength of the product.

[0037] The present invention uses hydrophilic modified polyester fiber as reinforcing material, hydrophilic modified graphite fiber and hydrophilic modified graphite powder as functional materials, and polyvinyl alcohol is used to prepare three suspensions respectively, and then the two fiber suspensions are pulped to prepare slurries respectively, and the graphite powder suspension is mixed with the graphite fiber slurry to form paper sheets, and the polyester fiber slurry is formed into paper sheets separately, and a layer of polyester fiber paper sheets is sandwiched between two layers of graphite paper sheets, and the three layers of paper sheets are pressed into one body and dried to form graphite steel paperboard. The above-mentioned wet papermaking technology is used to produce graphite steel paperboard. Compared with the existing steel plate production method, the process is simple and the cost is low, and the main performance indicators of the product are better than the existing products; because the raw materials and production process do not use volatile organic compounds, all the wastewater in the production is reused in the production process, and the waste products, scraps and products after the expiration of the service life are recycled and crushed and added to the raw materials in proportion for continued use, so as to achieve environmental friendliness throughout the life cycle of the product.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.

Claims

1. A graphite steel paperboard, characterized in that: The invention comprises an upper and lower graphite fiber layer, a polyester fiber layer is disposed between the two graphite fiber layers, the polyester fiber layer is prepared by dispersing, beating and forming a wet paper sheet from hydrophilic modified polyester fiber, the graphite fiber layer is prepared by dispersing and beating the hydrophilic modified graphite fiber, the slurry is mixed with a hydrophilic modified graphite powder dispersion, and then a wet paper sheet is formed, and the polyester fiber wet paper sheet and the upper and lower graphite fiber wet paper sheets are pressed into one body; the dosage of the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, the hydrophilic modified graphite powder and the dispersant is the following parts by weight: 20-30 parts of the hydrophilic modified polyester fiber, 40-50 parts of the hydrophilic modified graphite fiber and 40-20 parts of the hydrophilic modified graphite powder, and the dosage of the dispersant polyvinyl alcohol is 0.5-0.8% of the total weight of the three raw materials.

2. The graphite steel paperboard according to claim 1, characterized in that: The hydrophilic modified polyester fiber has a length of 6-12 mm and a diameter of 0.04-0.08 mm.

3. The graphite steel paperboard according to claim 1, characterized in that: The hydrophilic modified polyester fiber has a molecular weight of 18000-25000 and a melting point of 255-264°C.

4. The graphite steel paperboard according to claim 1, characterized in that: The length of the hydrophilic modified graphite fiber is 5-10 mm, and the diameter is 0.08-0.15 mm; the particle size of the hydrophilic modified graphite powder is 120-150 meshes.

5. The graphite steel paperboard according to claim 1, characterized in that: The carbon content of the hydrophilic modified graphite fiber and the hydrophilic modified graphite powder is 95-99%.

6. The graphite steel paperboard according to claim 1, characterized in that: The polyvinyl alcohol has an alcoholysis degree of 88% and a polymerization degree of 2000.

7. The method for preparing the graphite steel paperboard according to any one of claims 1 to 6, characterized in that: The following steps are included: (1) Prepare raw materials Weigh the raw materials and polyvinyl alcohol according to weight; (2) Preparation of polyester fiber, graphite fiber and graphite powder suspension The prepared polyvinyl alcohol solution is added to water in proportion, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are added respectively while stirring, and the hydrophilic modified polyester fiber, the hydrophilic modified graphite fiber, and the hydrophilic modified graphite powder are completely dispersed into a suspension in the water containing the polyvinyl alcohol solution, and the concentration of the suspension is adjusted to 5wt%; (3) Production of polyester fiber slurry and graphite slurry The polyester fiber suspension and the graphite fiber suspension are pulped separately to make the average length of the hydrophilic modified polyester fiber and the hydrophilic modified graphite fiber reach 5-8 mm and 3-5 mm respectively, and the fiber surface is fluffed and the two ends are broomed. The wet weight and beating degree of the hydrophilic modified polyester fiber pulp are controlled at 4.5-5g and 30-32 0 SR, hydrophilic modified graphite fiber slurry wet weight and beating degree are controlled at 3.5-4g and 33 0 -35 0 SR, the two slurries are stored separately, and the graphite powder suspension prepared in step (2) is added to the graphite fiber and mixed evenly; (4) Molding The two kinds of pulp are sent to the forming part respectively and evenly distributed on the three-layer forming structure. In this process, water is added to adjust the pulp concentration to 1-1.2%. After forming, the dryness of each layer of wet paper is controlled at 11-15%. The three layers of paper are pressed into one, dehydrated to control the dryness of the paper at 45-50%, dried at 80-100℃ to a dryness of 90-93%, and then finished and finally rolled up to become the finished product.

8. The system for preparing graphite steel paperboard according to claim 1, characterized in that: The invention comprises a polyester fiber slurry preparation part, a graphite fiber and graphite powder slurry preparation part and a papermaking part. The polyester fiber slurry preparation part comprises a first disperser (101), a first slurry pump (102), a first disc grinder (103), a first slurry tank (104) and a second slurry pump (105); the first disperser (101) is connected to the first disc grinder (103) via the first slurry pump 102; the graphite fiber and graphite powder slurry preparation part comprises a second disperser (201), a third slurry pump (202), a second disc grinder (203), a third disperser (204), a fourth slurry pump (205), a second slurry tank (206), a fifth slurry pump (207), and a second disperser (201). The disperser (201) is connected to the second disc grinding machine (203) via a third pulp pump (202), and the third disperser (204) is connected to the second pulping pool (206) via a fourth pulp pump (205); the papermaking part comprises a headbox (301), a forming wire (302), a pressing part (303), a drying part (304), and a finishing winding part (305) which are connected in sequence; the headbox (301) comprises three heads connected in parallel, namely, an upper headbox, a middle headbox, and a lower headbox; the forming wire (302) comprises three heads connected in parallel, namely, an upper headbox, a middle headbox, and a lower headbox; the first pulping pool (104) is connected to the middle headbox via a second pulp pump (105), and the second pulping pool (206) is connected to the upper and lower headboxes via a fifth pulp pump (207).

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