Multi-layer composite wear-resistant squeezing papermaking felt and preparation method thereof

Abstract

The invention relates to a multi-layer composite wear-resistant squeezing papermaking felt and a preparation method thereof.The multi-layer composite wear-resistant squeezing papermaking felt comprises a papermaking felt body and a wear-resistant layer, the papermaking felt body is prepared from polyester fibers, and the wear-resistant layer is formed by coating the surface of the papermaking felt body with a wear-resistant agent; the wear-resistant agent is prepared from the following raw materials in parts by mass: 40 to 60 parts of epoxy resin, 10 to 30 parts of isocyanate-terminated liquid rubber, 15 to 25 parts of inorganic filler, 5 to 10 parts of curing agent, 20 to 25 parts of xylene and 0.1 to 0.5 part of defoaming agent. The wear-resistant agent has the effect of improving the wear resistance of the papermaking felt.

Description

Technical Field

[0001] The present application relates to the field of papermaking felts, and in particular to a multi-layer composite wear-resistant press papermaking felt and a preparation method thereof. Background Art

[0002] In the papermaking industry, press section felts are key components of paper machines, and their performance directly impacts paper dewatering efficiency, surface quality, and equipment operational stability. Traditional papermaking felts are typically woven from synthetic fibers such as polyester and polyamide.

[0003] Traditional fiber materials (such as polyester and polyamide) have low surface hardness. Long-term mechanical friction (such as squeeze rolls and friction from vacuum suction boxes) can easily lead to fiber breakage, felt surface fuzzing, and even damage. This is especially true when processing highly filled pulp or using chemical additives (such as bleach and sizing agents). Felt wear is significantly accelerated, significantly shortening its service life. Summary of the Invention

[0004] In order to improve the wear resistance of papermaking felts and extend the service life of papermaking felts, the present application provides a multi-layer composite wear-resistant pressing papermaking felt and a preparation method thereof.

[0005] In the first aspect, the present application provides a multi-layer composite wear-resistant pressing papermaking felt, which adopts the following technical solution: a multi-layer composite wear-resistant pressing papermaking felt, comprising a papermaking felt body and a wear-resistant layer, wherein the papermaking felt body is made of polyester fiber, and the wear-resistant layer is formed by coating a wear-resistant agent on the surface of the papermaking felt body, and the wear-resistant layer comprises the following raw materials in parts by mass: 40-60 parts of epoxy resin, 10-30 parts of terminal isocyanate liquid rubber, 15-25 parts of inorganic filler, 5-10 parts of curing agent, 20-25 parts of xylene, and 0.1-0.5 parts of defoaming agent.

[0006] By adopting the above technical solution, the isocyanate groups in the isocyanate-terminated liquid rubber react chemically with the hydroxyl groups in the epoxy resin to generate a block polymer, which forms a three-dimensional network structure after curing; and the inorganic filler has the function of increasing the hardness of the coating and reducing friction loss. Therefore, the inorganic filler is added to the wear-resistant agent, and the inorganic filler particles are embedded in the three-dimensional network structure, playing a "pinning" role, effectively improving the internal bonding force of the three-dimensional network structure, thereby improving the wear resistance of the wear-resistant layer formed by curing the wear-resistant agent, and then forming a continuous protective film on the surface of the papermaking felt body, effectively dispersing the friction stress and enhancing the wear resistance of the papermaking felt.

[0007] Preferably, the inorganic filler is silicon carbide.

[0008] By adopting the above technical solution, silicon carbide has hydrophobic properties. Therefore, when the wear-resistant layer formed by silicon carbide acts on the papermaking felt, it can effectively improve the hydrophobicity of the surface layer of the papermaking felt, thereby improving the air permeability of the papermaking felt. Furthermore, when the papermaking felt is used in the papermaking process, it is beneficial to the dehydration of wet paper sheets.

[0009] Preferably, the modification preparation method of silicon carbide comprises the following steps: S1. Adding silicon carbide to a nitric acid aqueous solution, ultrasonically treating, and then washing and drying in sequence to obtain pretreated silicon carbide; S2. Dopamine and Tris-HCl buffer are mixed, ultrasonically dispersed, and pretreated silicon carbide is added. After sufficient stirring, the mixture is filtered, washed, and dried in sequence to obtain modified silicon carbide.

[0010] By adopting the above technical solution, silicon carbide is treated with nitric acid, so that the surface of silicon carbide can be hydroxylated, and dopamine reacts to form polydopamine. Therefore, the hydroxyl groups on the surface of silicon carbide form hydrogen bonds with the hydroxyl groups and amino groups on the polydopamine, so that polydopamine is grafted onto the surface of silicon carbide. The hydrogen bonding between polydopamine and epoxy resin is used to improve the bonding strength between silicon carbide and epoxy resin, thereby improving the bonding strength of silicon carbide within the three-dimensional network structure, and further improving the wear resistance of the wear-resistant layer.

[0011] Preferably, the mass ratio of silicon carbide to dopamine is 1:(0.2-0.6).

[0012] By adopting the above technical solution and controlling the mass ratio between silicon carbide and dopamine within the above range, the stability of polydopamine grafted on the surface of silicon carbide can be effectively improved.

[0013] Preferably, the modification preparation method of the polyester fiber comprises the following steps: The polyester fiber is added to a nitric acid aqueous solution, and then cerium ammonium nitrate and acrylamide are added, and after a water bath reaction, the fibers are washed and dried in sequence; the dried polyester fiber is then added to a sodium hydroxide aqueous solution, and after sufficient reaction, the fibers are washed and dried in sequence to obtain a modified polyester fiber.

[0014] By adopting the above technical solution, acrylamide is grafted onto polyester fibers using ammonium cerium nitrate, and then hydrolyzed using sodium hydroxide to obtain carboxyl groups, thereby forming covalent bonds with the epoxy resin in the wear-resistant layer, thereby improving the bonding force between the wear-resistant layer and the fibers, effectively improving the stability of the wear-resistant layer on the polyester fibers, and having a positive effect on improving the wear resistance of papermaking felts.

[0015] In addition, sodium hydroxide also corrodes the polyester fibers, thereby increasing the roughness of the polyester fiber surface and the surface roughness of the papermaking felt body formed by the polyester fibers, thereby increasing the stability of the wear-resistant layer on the papermaking felt body.

[0016] Preferably, the mass ratio of the polyester fiber to acrylamide is 1:(0.5-0.9).

[0017] By adopting the above technical solution, the mass ratio of polyester fiber to acrylamide is controlled within the above range, which can effectively improve the bonding strength between the wear-resistant layer and the polyester fiber.

[0018] Preferably, the anti-wear agent further comprises 1-5 parts of modified carbon nanotubes, and the modification preparation method of the modified carbon nanotubes comprises the following steps: S10, adding carbon nanotubes to a nitric acid aqueous solution, ultrasonically treating, performing a reflux reaction, and then sequentially filtering, washing, and drying to obtain pretreated carbon nanotubes; S20. Add the pretreated carbon nanotubes to an aqueous solution of sodium dodecyl sulfate, and after ultrasonic treatment, obtain a carbon nanotube dispersion. Then, add pyrrole monomer, stir thoroughly, add an aqueous solution of ferric chloride under an ice bath, and then react in a water bath. After the reaction is completed, filter, wash, and dry in sequence to obtain modified carbon nanotubes.

[0019] By adopting the above technical solution, carbon nanotubes have extremely high hardness and excellent wear resistance, which promotes the improvement of the wear resistance of the wear-resistant layer. In addition, carbon nanotubes are conductive, which can improve the antistatic effect of the wear-resistant layer, effectively reduce the abrasive wear caused by dust adsorption on the papermaking felt, and improve the wear resistance of the papermaking felt.

[0020] The carbon nanotubes are reacted with nitric acid to introduce carboxyl groups on the surface of the carbon nanotubes, thereby increasing the surface active sites of the carbon nanotubes and promoting the uniform wrapping of the carbon nanotubes by polypyrrole. Thus, the stability of the carbon nanotubes in the wear-resistant layer is enhanced through the reaction of polypyrrole with the terminal isocyanate liquid rubber, which effectively improves the wear resistance of the wear-resistant layer and has a positive effect on improving the wear resistance of papermaking felts.

[0021] Preferably, the mass ratio of the carbon nanotubes to the pyrrole monomers is 1:(3-5).

[0022] By adopting the above technical solution and controlling the mass ratio of carbon nanotubes to polypyrrole within the above range, the stability of the polypyrrole-coated carbon nanotubes can be effectively improved.

[0023] Preferably, the isocyanate-terminated liquid rubber is isocyanate-terminated polybutadiene liquid rubber, and the curing agent is tetraethylenepentamine.

[0024] In a second aspect, the present application provides a method for preparing a multi-layer composite wear-resistant press papermaking felt as in the first aspect, using the following technical solution: A method for preparing a multi-layer composite wear-resistant press papermaking felt comprises the following steps: S100, after vacuum dehydration of epoxy resin, add isocyanate-terminated liquid rubber, after sufficient reaction, add inorganic filler, stir thoroughly, add curing agent, xylene, and defoaming agent to prepare wear-resistant agent; S200, applying a wear-resistant agent to the surface of the papermaking felt, heating to dry the surface, then raising the temperature to solidify, cooling and then standing to obtain a wear-resistant papermaking felt.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The isocyanate groups in the isocyanate-terminated liquid rubber react chemically with the hydroxyl groups in the epoxy resin to form a block polymer, which forms a three-dimensional network structure after curing. Inorganic fillers have the function of increasing the hardness of the coating and reducing friction loss. Therefore, inorganic fillers are added to the wear-resistant agent. The inorganic filler particles are embedded in the three-dimensional network structure, playing a "pinning" role, effectively improving the internal binding force of the three-dimensional network structure, thereby improving the wear resistance of the wear-resistant layer formed by curing the wear-resistant agent. Furthermore, by forming a continuous protective film on the surface of the papermaking felt body, the friction stress is effectively dispersed, thereby enhancing the wear resistance of the papermaking felt.

[0026] 2. Silicon carbide has hydrophobic properties. Therefore, when the wear-resistant layer formed by silicon carbide acts on the papermaking felt, it can effectively improve the hydrophobicity of the surface of the papermaking felt, thereby improving the air permeability of the papermaking felt. When the papermaking felt is used in the papermaking process, it is beneficial to the dehydration of wet paper sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the overall structure of a multi-layer composite wear-resistant press papermaking felt of the present application.

[0028] Description of reference numerals: 1. Papermaking felt body; 2. Wear-resistant layer DETAILED DESCRIPTION

[0029] The following is combined with Figure 1 The present application is further described in detail. The present application embodiment discloses a multi-layer composite wear-resistant press papermaking felt and its preparation method. Figure 1 The papermaking felt comprises a papermaking felt body 1 and a wear-resistant layer 2. The papermaking felt body 1 is made of polyester fiber, and the wear-resistant layer 2 is formed by coating a wear-resistant agent on the surface of the papermaking felt body.

[0030] Unless otherwise specified, the raw materials used in this application can be obtained from commercially available raw materials. The following is a further detailed description of this application in conjunction with the examples: Raw materials: Epoxy resin (E-51 epoxy resin) was provided by Baling Petrochemical Company, isocyanate-terminated polybutadiene liquid rubber was provided by Tianyuan Aviation Materials (Yingkou) Technology Co., Ltd., tetraethylenepentamine (CAS No.: 112-57-2) was provided by Jinan Liyang Chemical Co., Ltd., silicon carbide (CAS No.: 409-21-2) was provided by Ningbo Luofei Nanotechnology Co., Ltd., dopamine (CAS No.: 51-61-6) was provided by Henan Puhui Tiancheng Biotechnology Co., Ltd., Tris-HCl buffer (1 M, pH 6.8) was provided by Shanghai MacLean Biochemical Technology Co., Ltd., acrylamide (CAS No.: 79-06-1) was provided by Shanghai Aladdin Biochemical Technology Co., Ltd., carbon nanotubes (CAS No.: 308068-56-6) was provided by Shanghai Liantian Materials Technology Co., Ltd., and pyrrole monomer (CAS No.: 109-97-7) was provided by Shanghai Bangcheng Chemical Co., Ltd.

[0031] Example 1 The anti-wear agent includes the following raw materials by weight: 40g of epoxy resin, 10g of isocyanate-terminated liquid rubber, 15g of inorganic filler, 5g of curing agent, 20g of xylene, and 0.1g of defoaming agent.

[0032] The isocyanate-terminated liquid rubber is isocyanate-terminated polybutadiene liquid rubber, the curing agent is tetraethylenepentamine, and the defoaming agent is polydimethylsiloxane.

[0033] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100°C and removing water in a vacuum for 30 minutes, cooling to 60°C, adding the isocyanate-terminated liquid rubber, then heating to 90°C, reacting at a constant temperature for 4 hours, cooling to 60°C, adding the inorganic filler, dispersing at a speed of 3000 rpm for 30 minutes, adding the curing agent, xylene, and defoaming agent, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in an oven at 60°C for 30 minutes, transferring to a constant temperature of 80°C for curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt.

[0034] Example 2 The anti-wear agent includes the following raw materials by weight: 60g of epoxy resin, 30g of isocyanate-terminated liquid rubber, 25g of inorganic filler, 10g of curing agent, 25g of xylene, and 0.5g of defoaming agent.

[0035] The isocyanate-terminated liquid rubber is isocyanate-terminated polybutadiene liquid rubber, the curing agent is tetraethylenepentamine, and the defoaming agent is polydimethylsiloxane.

[0036] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100°C and removing water in a vacuum for 30 minutes, cooling to 60°C, adding the isocyanate-terminated liquid rubber, then heating to 90°C, reacting at a constant temperature for 4 hours, cooling to 60°C, adding the inorganic filler, dispersing at a speed of 3000 rpm for 30 minutes, adding the curing agent, xylene, and defoaming agent, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in an oven at 60°C for 30 minutes, transferring to a constant temperature of 80°C for curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt.

[0037] Example 3 The anti-wear agent includes the following raw materials by weight: 50g of epoxy resin, 20g of isocyanate-terminated liquid rubber, 20g of inorganic filler, 8g of curing agent, 23g of xylene, and 0.3g of defoaming agent.

[0038] The isocyanate-terminated liquid rubber is isocyanate-terminated polybutadiene liquid rubber, the curing agent is tetraethylenepentamine, and the defoaming agent is polydimethylsiloxane.

[0039] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100°C and removing water in a vacuum for 30 minutes, cooling to 60°C, adding the isocyanate-terminated liquid rubber, then heating to 90°C, reacting at a constant temperature for 4 hours, cooling to 60°C, adding the inorganic filler, dispersing at a speed of 3000 rpm for 30 minutes, adding the curing agent, xylene, and defoaming agent, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in an oven at 60°C for 30 minutes, transferring to a constant temperature of 80°C for curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt.

[0040] Example 4 The difference between Example 4 and Example 3 is that the modification preparation method of silicon carbide includes the following steps: S1. Add 10 g of silicon carbide to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treat at 60° C. for 120 min, separate the solid by filtration, wash with deionized water until neutral, and finally vacuum dry at 60° C. for 12 h to obtain pretreated silicon carbide; S2. After mixing 2 g of dopamine and 100 mL of Tris-HCl buffer, ultrasonically disperse the mixture for 10 min, add pretreated silicon carbide, and magnetically stir the mixture at room temperature for 24 h. Then, filter and collect the solid, wash it three times with deionized water, and vacuum dry it at 60°C for 24 h to obtain modified silicon carbide.

[0041] Example 5 The difference between Example 5 and Example 3 is that the modification preparation method of silicon carbide includes the following steps: S1. Add 10 g of silicon carbide to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treat at 60° C. for 120 min, separate the solid by filtration, wash with deionized water until neutral, and finally vacuum dry at 60° C. for 12 h to obtain pretreated silicon carbide; S2. After mixing 6 g of dopamine and 100 mL of Tris-HCl buffer, ultrasonically disperse the mixture for 10 min, add pretreated silicon carbide, and magnetically stir the mixture at room temperature for 24 h. Then, filter and collect the solid, wash it three times with deionized water, and vacuum dry it at 60°C for 24 h to obtain modified silicon carbide.

[0042] Example 6 The difference between Example 6 and Example 3 is that the modification preparation method of silicon carbide includes the following steps: S1. Add 10 g of silicon carbide to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treat at 60° C. for 120 min, separate the solid by filtration, wash with deionized water until neutral, and finally vacuum dry at 60° C. for 12 h to obtain pretreated silicon carbide; S2. 4 g of dopamine and 100 mL of Tris-HCl buffer were mixed, ultrasonically dispersed for 10 min, and pretreated silicon carbide was added. After magnetic stirring at room temperature for 24 h, the solid was collected by filtration, washed three times with deionized water, and vacuum dried at 60°C for 24 h to obtain modified silicon carbide.

[0043] Example 7 The difference between Example 7 and Example 6 is that the mass ratio of silicon carbide to dopamine is 1:0.1.

[0044] Example 8 The difference between Example 8 and Example 6 is that the mass ratio of silicon carbide to dopamine is 1:0.7.

[0045] Example 9 The difference between Example 9 and Example 6 is that the modification preparation method of polyester fiber includes the following steps: 10 g of polyester fiber was added to 1000 mL of nitric acid aqueous solution (the mass concentration of the nitric acid aqueous solution was 5%), and then 0.2 g of ceric ammonium nitrate and 5 g of acrylamide were added, and the mixture was reacted in a 60° C. water bath for 2 h, with continuous nitrogen flow. The mixture was then washed with deionized water until neutral, and then vacuum dried at 60° C. for 12 hours. The dried polyester fiber was then added to 1000 mL of sodium hydroxide aqueous solution (the mass concentration of the sodium hydroxide aqueous solution was 5%) heated to 80° C., and reacted for 60 minutes. The residual alkali was neutralized with dilute hydrochloric acid, the mixture was washed with water until neutral, and then vacuum dried at 60° C. for 12 hours to obtain a modified polyester fiber.

[0046] Example 10 The difference between Example 10 and Example 6 is that the modification preparation method of polyester fiber includes the following steps: 10 g of polyester fiber was added to 1000 mL of nitric acid aqueous solution (the mass concentration of the nitric acid aqueous solution was 5%), and then 0.2 g of ceric ammonium nitrate and 9 g of acrylamide were added. The mixture was reacted in a 60° C. water bath for 2 h with continuous nitrogen flow. The mixture was then washed with deionized water until neutral and vacuum dried at 60° C. for 12 h. The dried polyester fiber was then added to 1000 mL of sodium hydroxide aqueous solution (the mass concentration of the sodium hydroxide aqueous solution was 5%) heated to 80° C., reacted for 60 min, and then the residual alkali was neutralized with dilute hydrochloric acid. The mixture was washed with water until neutral and vacuum dried at 60° C. for 12 h to obtain a modified polyester fiber.

[0047] Example 11 The difference between Example 11 and Example 6 is that the modification preparation method of polyester fiber includes the following steps: 10 g of polyester fiber was added to 1000 mL of nitric acid aqueous solution (the mass concentration of the nitric acid aqueous solution was 5%), and then 0.2 g of ceric ammonium nitrate and 7 g of acrylamide were added. The mixture was reacted in a 60° C. water bath for 2 h with continuous nitrogen flow. The mixture was then washed with deionized water until neutral and vacuum dried at 60° C. for 12 h. The dried polyester fiber was then added to 1000 mL of sodium hydroxide aqueous solution (the mass concentration of the sodium hydroxide aqueous solution was 5%) heated to 80° C., reacted for 60 min, and then the residual alkali was neutralized with dilute hydrochloric acid. The mixture was washed with water until neutral and vacuum dried at 60° C. for 12 h to obtain a modified polyester fiber.

[0048] Example 12 The difference between Example 12 and Example 11 is that the mass ratio of polyester fiber to acrylamide is 1:0.3.

[0049] Example 13 The difference between Example 13 and Example 11 is that the mass ratio of polyester fiber to acrylamide is 1:1.1.

[0050] Example 14 The difference between Example 14 and Example 11 is that 1 g of modified carbon nanotubes is further added to the anti-wear agent, and the preparation method of the modified carbon nanotubes includes the following steps: S10, adding 1 g of carbon nanotubes to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treating for 45 min, and then refluxing in an oil bath at 140° C. for 2.5 h. After the reaction is completed, cooling to room temperature, filtering and washing with deionized water until the filtrate is neutral, and drying the product in an oven at 110° C. for 12 h to obtain pretreated carbon nanotubes; S20. The pretreated carbon nanotubes were added to 100 mL of a 1% (w / v) sodium dodecyl sulfate aqueous solution, and ultrasonically treated for 60 min to obtain a carbon nanotube dispersion. 3 g of pyrrole monomer was then added, and magnetic stirring was performed for 15 minutes under nitrogen protection. 20 mL of a 1 mol / L ferric chloride aqueous solution was slowly added dropwise at 2°C, and the mixture was reacted in a water bath at 25°C for 12 minutes. The product was then filtered and washed with deionized water and ethanol, and finally dried in vacuo at 60°C for 6 hours to obtain modified carbon nanotubes.

[0051] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100° C. and removing water in a vacuum for 30 minutes, cooling to 60° C., adding the isocyanate-terminated liquid rubber, then heating to 90° C. and reacting at a constant temperature for 4 hours, cooling to 60° C., adding the inorganic filler, and dispersing at a speed of 3000 rpm for 30 minutes, then adding the curing agent, xylene, defoaming agent, and modified carbon nanotubes, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in an oven at 60°C for 30 minutes, transferring to a constant temperature of 80°C for curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt.

[0052] Example 15 The difference between Example 15 and Example 11 is that 5 g of modified carbon nanotubes are further added to the anti-wear agent, and the preparation method of the modified carbon nanotubes includes the following steps: S10, adding 1 g of carbon nanotubes to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treating for 45 min, and then refluxing in an oil bath at 140° C. for 2.5 h. After the reaction is completed, cooling to room temperature, filtering and washing with deionized water until the filtrate is neutral, and drying the product in an oven at 110° C. for 12 h to obtain pretreated carbon nanotubes; S20. The pretreated carbon nanotubes were added to 100 mL of a 1% (w / v) aqueous solution of sodium dodecyl sulfate, and ultrasonically treated for 60 min to obtain a carbon nanotube dispersion. 5 g of pyrrole monomer was then added, and magnetic stirring was performed for 15 minutes under nitrogen protection. 20 mL of a 1 mol / L aqueous solution of ferric chloride was slowly added dropwise at 2°C, and the mixture was reacted in a water bath at 25°C for 12 minutes. The product was then filtered and washed with deionized water and ethanol, and finally dried in vacuo at 60°C for 6 hours to obtain modified carbon nanotubes.

[0053] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100° C. and removing water in a vacuum for 30 minutes, cooling to 60° C., adding the isocyanate-terminated liquid rubber, then heating to 90° C. and reacting at a constant temperature for 4 hours, cooling to 60° C., adding the inorganic filler, and dispersing at a speed of 3000 rpm for 30 minutes, then adding the curing agent, xylene, defoaming agent, and modified carbon nanotubes, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in a 60°C oven for 30 minutes, transferring to 80°C constant temperature curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt Example 16 The difference between Example 16 and Example 11 is that 3 g of modified carbon nanotubes are further added to the anti-wear agent, and the preparation method of the modified carbon nanotubes includes the following steps: S10, adding 1 g of carbon nanotubes to 100 mL of nitric acid aqueous solution (mass concentration of nitric acid aqueous solution is 65%), ultrasonically treating for 45 min, and then refluxing in an oil bath at 140° C. for 2.5 h. After the reaction is completed, cooling to room temperature, filtering and washing with deionized water until the filtrate is neutral, and drying the product in an oven at 110° C. for 12 h to obtain pretreated carbon nanotubes; S20. The pretreated carbon nanotubes were added to 100 mL of a 1% (w / v) aqueous solution of sodium dodecyl sulfate, and ultrasonically treated for 60 min to obtain a carbon nanotube dispersion. 4 g of pyrrole monomer was then added, and magnetic stirring was performed for 15 min under nitrogen protection. 20 mL of a 1 mol / L aqueous solution of ferric chloride was slowly added dropwise at 2°C, and the mixture was reacted in a water bath at 25°C for 12 h. The product was then filtered and washed with deionized water and ethanol, and finally dried in vacuo at 60°C for 6 h to obtain modified carbon nanotubes.

[0054] A method for preparing a wear-resistant papermaking felt comprises the following steps: S100, heating the epoxy resin to 100° C. and removing water in a vacuum for 30 minutes, cooling to 60° C., adding the isocyanate-terminated liquid rubber, then heating to 90° C. and reacting at a constant temperature for 4 hours, cooling to 60° C., adding the inorganic filler, and dispersing at a speed of 3000 rpm for 30 minutes, then adding the curing agent, xylene, defoaming agent, and modified carbon nanotubes, and stirring at a speed of 1000 rpm for 10 minutes to prepare the wear-resistant agent; S200, applying the wear-resistant agent to the surface of the papermaking felt by roller coating, drying in a 60°C oven for 30 minutes, transferring to 80°C constant temperature curing for 2 hours, cooling and standing for 24 hours to obtain a wear-resistant papermaking felt Example 17 The difference between Example 17 and Example 16 is that the mass ratio of carbon nanotubes to pyrrole monomers is 1:2.

[0055] Example 18 The difference between Example 18 and Example 16 is that the mass ratio of carbon nanotubes to pyrrole monomers is 1:6.

[0056] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that the anti-wear agent does not contain silicon carbide.

[0057] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that the inorganic filler is alumina.

[0058] Performance testing: GB / T 1768-2006 Paints and varnishes - Determination of abrasion resistance - Rotating rubber grinding wheel method was selected as the standard. Three samples with a size of 100 mm × 100 mm were cut from the test specimen. A wear test was conducted using a Taber abrasion tester at 5000 revolutions. The mass changes of the samples in their initial state and after 30 washes were measured before and after the test to obtain the wear loss. The average value was taken after measurement and the results are recorded in Table 1.

[0059] Table 1 Data Analysis Specifically combining Example 6 and Example 3: The initial wear amount of Example 6 is lower than that of Example 3. The difference between Example 6 and Example 3 is that polydopamine is grafted onto the surface of silicon carbide, and the bonding force between silicon carbide and epoxy resin is improved by polydopamine, thereby improving the stability of silicon carbide in the wear-resistant layer, thereby improving the wear resistance of the papermaking felt.

[0060] Specifically combining Example 11 and Example 6: The initial state wear amount and the increase in the initial state wear amount after washing 30 times in Example 11 are both lower than those in Example 6. The difference between Example 11 and Example 6 is that: carboxyl groups are formed on the polyester fibers, and covalent bonds are formed with the epoxy resin in the wear-resistant layer, thereby improving the bonding force between the wear-resistant layer and the polyester fibers, effectively improving the stability of the wear-resistant layer on the papermaking felt, thereby improving the wear resistance of the papermaking felt in the initial state, and making the papermaking felt still have excellent wear resistance after multiple washings.

[0061] Specifically combining Example 16 and Example 11: The initial wear amount of Example 16 is lower than that of Example 11. The difference between Example 16 and Example 11 is that modified carbon nanotubes are also added to the wear-resistant agent. The carbon nanotubes have the functions of wear resistance and conductivity, and the carbon nanotubes are uniformly wrapped by polypyrrole to enhance the adhesion between the carbon nanotubes and the epoxy resin, thereby improving the wear resistance of the wear-resistant layer and further improving the wear resistance of the papermaking felt.

[0062] Specifically combining Example 3 and Comparative Example 1: The initial wear amount of Example 3 is lower than that of Comparative Example 1. The difference between Example 3 and Comparative Example 1 is that silicon carbide is added to the wear-resistant agent. Silicon carbide has the effects of high hardness and wear resistance, so it has the effect of increasing the hardness of the coating and reducing friction loss, thereby improving the wear resistance of the wear-resistant layer, and further improving the wear resistance of the papermaking felt.

[0063] Specifically in combination with Example 3 and Comparative Example 2: After washing 30 times, the increase in the wear amount of Example 3 compared to the initial state is lower than that of Comparative Example 2. The difference between Example 3 and Comparative Example 2 is that the inorganic filler is silicon carbide, which has hydrophobic properties, while aluminum oxide has hydrophilic properties. Therefore, silicon carbide can effectively improve the hydrophobicity of the surface layer of the papermaking felt, so that the papermaking felt still has excellent wear resistance after multiple washings.

[0064] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A multi-layer composite wear-resistant paper press felt, characterized by: The invention comprises a papermaking felt body (1) and a wear-resistant layer (2), wherein the papermaking felt body (1) is made of polyester fiber, and the wear-resistant layer (2) is formed by coating a wear-resistant agent on the surface of the papermaking felt body, wherein the wear-resistant agent comprises the following raw materials in parts by mass: 40-60 parts of epoxy resin, 10-30 parts of terminal isocyanate liquid rubber, 15-25 parts of inorganic filler, 5-10 parts of curing agent, 20-25 parts of xylene, and 0.1-0.5 parts of defoaming agent.

2. The multi-layer composite wear-resistant paper press felt according to claim 1, characterized in that: The inorganic filler is silicon carbide.

3. The multi-layer composite wear-resistant paper press felt according to claim 2, characterized in that: The modification preparation method of silicon carbide comprises the following steps: S1. Adding silicon carbide to a nitric acid aqueous solution, ultrasonically treating, and then washing and drying in sequence to obtain pretreated silicon carbide; S2. Dopamine and Tris-HCl buffer are mixed, ultrasonically dispersed, and pretreated silicon carbide is added. After sufficient stirring, the mixture is filtered, washed, and dried in sequence to obtain modified silicon carbide.

4. The multi-layer composite wear-resistant paper press felt according to claim 3, characterized in that: The mass ratio of the silicon carbide to dopamine is 1:(0.2-0.6).

5. The multi-layer composite wear-resistant paper press felt according to claim 1, characterized in that: The modification preparation method of the polyester fiber comprises the following steps: The polyester fiber is added to a nitric acid aqueous solution, and then cerium ammonium nitrate and acrylamide are added, and after a water bath reaction, the fibers are washed and dried in sequence; the dried polyester fiber is then added to a sodium hydroxide aqueous solution, and after sufficient reaction, the fibers are washed and dried in sequence to obtain a modified polyester fiber.

6. The multi-layer composite wear-resistant paper press felt according to claim 5, characterized in that: The mass ratio of the polyester fiber to acrylamide is 1:(0.5-0.9).

7. The multi-layer composite wear-resistant paper press felt according to claim 1, characterized in that: The anti-wear agent further comprises 1-5 parts of modified carbon nanotubes. The modification preparation method of the modified carbon nanotubes comprises the following steps: S10, adding carbon nanotubes to a nitric acid aqueous solution, ultrasonically treating, performing a reflux reaction, and then sequentially filtering, washing, and drying to obtain pretreated carbon nanotubes; S20. Add the pretreated carbon nanotubes to an aqueous solution of sodium dodecyl sulfate, and after ultrasonic treatment, obtain a carbon nanotube dispersion. Then, add pyrrole monomer, stir thoroughly, add an aqueous solution of ferric chloride under an ice bath, and then react in a water bath. After the reaction is completed, filter, wash, and dry in sequence to obtain modified carbon nanotubes.

8. The multi-layer composite wear-resistant paper press felt according to claim 7, characterized in that: The mass ratio of the carbon nanotubes to the pyrrole monomers is 1:(3-5).

9. The multi-layer composite wear-resistant paper press felt according to claim 1, characterized in that: The isocyanate-terminated liquid rubber is isocyanate-terminated polybutadiene liquid rubber, and the curing agent is tetraethylenepentamine.

10. A felt for preparing the multi-layer composite wear-resistant press papermaking felt according to claim 1, characterized in that: The steps include: S100, after vacuum dehydration of epoxy resin, add isocyanate-terminated liquid rubber, after sufficient reaction, add inorganic filler, stir thoroughly, add curing agent, xylene, and defoaming agent to prepare wear-resistant agent; S200, applying a wear-resistant agent to the surface of the papermaking felt body, heating to dry the surface, then raising the temperature to solidify, cooling and then standing to obtain a wear-resistant papermaking felt.

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