Composite plate for fan blades and production process thereof

Abstract

The present invention belongs to the technical field of fan blade board materials, and discloses a composite board material for fan blades and its production process, wherein the middle layer material of the board material is a cross-grained board core layer; the second layer material is an adhesive layer, which is located on the upper and lower sides of the cross-grained board core layer to form a primary layer; the third layer material is a modified technical wood layer, which is located on the upper and lower sides of the primary layer to form a symmetrical structure. The present application uses technical wood to replace the common plastic, aluminum or thickened plywood materials in the preparation process of large-sized fan blades, thereby improving the utilization rate of miscellaneous wood and broken wood, thereby greatly reducing the felling and use of trees, and the modification treatment of technical wood by the present invention can make the surface of the board smoother and the internal structure more stable, not easy to deform, and the material has excellent bending resistance, which greatly reduces the board thickness requirements and motor power requirements, making the fan blades prepared by the present invention thin and durable, and having a long service life.

Description

Technical Field

[0001] The invention belongs to the technical field of fan blade plates and provides a composite plate for fan blades and a production process thereof. Background Art

[0002] Fan blades are an important component of fans. The quality of fan blades greatly affects the quality of fans. In the past, plastic, aluminum or thickened plywood were often used. Although metal fan blades are durable, they are heavy, which causes the fan to consume more electricity. Moreover, the fan noise of metal blades is very loud. Now with the development of the plastic industry, fan blades are mostly made of plastic. Fans made of plastic are light, quiet, easy to mold, and low in cost. However, plastic fan blades are weak in strength and often cause damage to the fan blades after long-term use, especially the fan blade mounting holes are easily damaged, causing damage to the fan. Now the injection molding method is used to produce fan blades. Uneven mold temperature will also cause the strength of the fan blade mounting holes to decrease.

[0003] Boards are the main materials in furniture and construction industries. Compared with single-layer boards, multi-layer boards have good structural strength and stability. They are light, strong, elastic, tough, resistant to impact and vibration, easy to process and paint, and insulated. They have become a common material in boards. The wooden boards used for fan blades on the market currently have high requirements for wood due to the influence of production technology, and the source of wood is limited. At the same time, they do not meet the energy-saving and environmental protection requirements called for by the state. Wooden boards are prone to thermal expansion and contraction during use. When exposed to moisture or heat, they are prone to deformation and mildew, as well as delamination, cracking, sagging, bending and other problems. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a composite board material for fan blades and a production process thereof. The present invention utilizes modified technical wood to replace the whole vertical grain board as the second and third layers, and uses the horizontal grain board as the core layer in the middle layer, thereby successfully producing a composite board material for fan blades.

[0005] To achieve the above purpose, the specific technical solution of the present invention is as follows:

[0006] A production process of a composite plate for fan blades, comprising the following steps:

[0007] S1. Add 65 to 80 parts of 3,4-epoxycyclohexyl methacrylate, 3 to 5 parts of lignin coupling agent, 6 to 9 parts of toughening agent, and 10 to 12 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 60 to 70 ° C, and remove after it is completely dissolved to obtain an adhesive;

[0008] S2. Disperse the adhesive into fine droplets within 10 microns, and plant them on the front and back sides of the core layer of the cross-grained board by atomization and uniform distribution, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0009] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment so that each layer of material is tightly combined to form a composite sheet;

[0010] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0011] Preferably, in S1, the preparation of modified nano magnesium oxide comprises the following steps:

[0012] S101. 15 to 20 parts of methyl hexahydrophthalic anhydride, 12 to 14 parts of nano-magnesium oxide, and 14 to 19 parts of silicone resin are added to 31 to 34 parts of deionized water and stirred at a stirring speed of 400 to 600 r / min for 15 to 20 minutes to obtain a preliminary mixed solution;

[0013] S102. Ultrasonic dispersion is performed on the preliminary mixed solution at an ultrasonic dispersion power of 170 to 220 W to obtain a modified nano-magnesium oxide solution.

[0014] Preferably, in S2, the preparation of the modified technical wood comprises the following steps:

[0015] S201. Select the waste wood without insect eyes and dry it for later use;

[0016] S202. The dried wood is immersed in an ethanol solution for 1 to 3 hours, and vacuum treatment is performed during the ethanol immersion time. After the immersion is completed, the wood is taken out and immersed in deionized water for 1 to 2 hours to obtain the primary processed wood;

[0017] S203. The primary processed wood is placed in a low eutectic solvent for reaction for 15 to 20 minutes and then subjected to microwave treatment at a power of 300 to 500 W for 20 to 30 minutes to obtain a secondary processed wood;

[0018] S204. placing the secondary processed wood in a low eutectic solvent for reaction at a temperature of 80° C. for a reaction time of 15 to 20 min;

[0019] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1 to 2 hours to obtain modified technical wood.

[0020] Preferably, the low eutectic solvent is a quaternary ammonium sodium-carboxylic acid mixture with a mass ratio of 1:2.

[0021] Preferably, in S1, the toughening agent is one of synthetic rubber and acetal resin.

[0022] Preferably, in S3, the temperature of the heating and pressurizing treatment is 80 to 90°C and the pressure is 11 to 15 MPa.

[0023] Preferably, the cutting process in S4 is performed using a high-precision CNC machine tool to ensure the dimensional accuracy and shape consistency of the composite board; the surface treatment in S4 is to use 3,4-epoxycyclohexyl methacrylate and phenolic resin as primers and polyurethane topcoat for coating.

[0024] Preferably, a composite sheet material for fan blades produced by a production process for a composite sheet material for fan blades comprises:

[0025] The middle layer material is the core layer of the cross-grained board;

[0026] The second layer of material is the adhesive layer, which is located on the upper and lower sides of the cross-grained board core layer to form the primary layer;

[0027] The third layer is a modified technical wood layer, which is located on the upper and lower sides of the primary layer to form a symmetrical structure.

[0028] Preferably, the core layer of the cross-grained board is made of a lightweight and high-strength material, which is an aluminum honeycomb panel, an aramid paper honeycomb material or a lightweight wood cross-grained board.

[0029] Preferably, the core layer thickness of the cross-grained board is 1.06-1.42 mm, the single layer thickness of the adhesive layer is 0.5-0.92 mm, the single layer thickness of the modified technical wood layer is 1.62-1.92 mm, and the total thickness of the board is 5.3-7.1 mm.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] Using modified technology wood (i.e. artificial wood) instead of wood can improve the utilization rate of miscellaneous wood and wood chips, thereby greatly reducing the felling of large trees, which reflects the environmental protection of the material. The use of modified technology wood makes the surface of the board smoother and the internal structure more stable, less prone to deformation, and has a significant improvement in static bending strength and elastic modulus compared to ordinary materials. Subsequent board processing is more efficient and saves manpower. Using cross-grained board as the core layer in the middle layer of the board can increase the overall strength of the plywood and prevent it from sagging and bending.

[0032] The second adhesive layer formed by the adhesive modified by modified nano-magnesium oxide solution can not only make the upper and lower layers more firmly bonded, but also enhance the static bending strength and elastic modulus of the overall composite board. The third layer of modified technical wood does not need to be repaired and the surface after veneer is very smooth, and the symmetry and balance fully meet the requirements, thereby enhancing the bending strength and deformation degree of the plywood blades.

[0033] The material of the process of the present invention has good bending resistance and reduces the thickness requirement of the board. Its static bending strength and elastic modulus are twice that of conventional fan blade plywood. For large-sized fans, plastic, aluminum or thickened plywood materials were previously used, but now modified technological wood is used instead and the thickness is controlled within the range of 5.3 to 7.1 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A process flow chart for manufacturing the composite sheet material for fan blades of the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the composite plate material for fan blades of the present invention;

[0036] In the above drawings, 100: core layer of the cross-grained board; 201: front adhesive layer; 202: back adhesive layer; 301: front modified technical wood layer; 302: back modified technical wood layer. DETAILED DESCRIPTION

[0037] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The modified technological wood layer with vertical grain texture in the present invention simulates the texture and feel of natural wood through modern scientific and technological means, and at the same time has good physical properties and processing performance. The symmetrical structure formed can enhance the overall strength and stability of the board. The corresponding material layer does not need to be repaired and the surface after veneer is very smooth. Its symmetry and balance fully meet the requirements, thereby enhancing the bending strength and deformation degree of the plywood fan blades.

[0039] The core layer of the cross-grained board adopts a cross-grained design to enhance the transverse shear resistance and structural stability of the board. The production process provided by the present invention has the advantages of high strength, good impact resistance and molding consistency, and is particularly suitable for the manufacture of fan blades.

[0040] The modified technological wood layer in the invention is formed by combining wood fibers with a resin matrix through high temperature and high pressure treatment. Its texture and color can be customized according to needs, while maintaining the natural texture and environmental friendliness of the wood.

[0041] See also Figure 1-2 , the present invention provides a technical solution:

[0042] The structure of the composite plate for fan blades of the present invention is as follows:

[0043] The middle layer material is 100 cross-grained board core layer;

[0044] The second layer of material is a front adhesive layer 201 located on the upper side of the 100 cross-grained board core layer and a back adhesive layer 202 located on the lower side, forming a primary layer;

[0045] The third layer of material is a front modified technical wood layer 301 located on the upper side of the front adhesive layer 201 and a back modified technical wood layer 302 located on the lower side of the back adhesive layer 202 to form a symmetrical structure.

[0046] Example 1

[0047] S1. Add 65 parts of 3,4-epoxycyclohexyl methacrylate, 3 parts of lignin coupling agent, 6 parts of synthetic rubber, and 10 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 60°C, and remove after it is completely dissolved to obtain an adhesive;

[0048] S2. Disperse the adhesive into fine droplets within 10 microns, and plant them on the front and back sides of the core layer of the cross-grained board by atomization and uniform distribution, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood layers on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0049] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 80°C and a pressure of 11MPa, so that each layer of material is tightly combined to form a composite sheet;

[0050] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0051] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0052] S101. 15 parts of methyl hexahydrophthalic anhydride, 12 parts of nano magnesium oxide, and 14 parts of skin-feel UV resin (brand: Y3507) were added to 31 parts of deionized water and stirred at a stirring speed of 400 r / min for 15 minutes to obtain a preliminary mixed solution;

[0053] S102. Ultrasonic dispersion is performed on the preliminary mixed solution at an ultrasonic dispersion power of 170 W to obtain a modified nano-magnesium oxide solution.

[0054] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0055] S201. Select the waste wood without insect eyes and dry it for later use;

[0056] S202. The dried wood was immersed in an ethanol solution for 1 hour, and the ethanol immersion time was vacuum treated. After the immersion, the wood was removed and immersed in deionized water for 1 hour to obtain the first processed wood;

[0057] S203. The primary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 and reacted for 15 min, and then subjected to microwave treatment at a power of 300 W for 20 min to obtain a secondary processed wood;

[0058] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 15 min;

[0059] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1 hour to obtain modified technical wood.

[0060] Example 2

[0061] S1. 80 parts of 3,4-epoxycyclohexyl methacrylate, 5 parts of lignin coupling agent, 9 parts of synthetic rubber, and 12 parts of modified nano-magnesium oxide solution were added to a reactor, stirred continuously and heated to 70°C, and removed after it was completely dissolved to obtain an adhesive;

[0062] S2. Disperse the adhesive into fine droplets within 10 microns, and plant them on the front and back sides of the core layer of the cross-grained board by atomization and uniform distribution, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood layers on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0063] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 90°C and a pressure of 15MPa, so that each layer of material is tightly combined to form a composite sheet;

[0064] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0065] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0066] S101. 20 parts of methyl hexahydrophthalic anhydride, 14 parts of nano magnesium oxide, and 19 parts of skin-feel UV resin (brand: Y3507) were added to 34 parts of deionized water and stirred at a stirring speed of 600 r / min for 20 minutes to obtain a preliminary mixed solution;

[0067] S102. Ultrasonic dispersion is performed on the preliminary mixed solution at an ultrasonic dispersion power of 220 W to obtain a modified nano-magnesium oxide solution.

[0068] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0069] S201. Select the waste wood without insect eyes and dry it for later use;

[0070] S202. The dried wood was immersed in an ethanol solution for 3 h, and vacuum treatment was performed during the ethanol immersion time. After the immersion, the wood was removed and immersed in deionized water for 2 h to obtain the first processed wood;

[0071] S203. The primary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 and reacted for 20 minutes, and then subjected to microwave treatment at a power of 500 W for 30 minutes to obtain a secondary processed wood;

[0072] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 20 min;

[0073] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 2 h. After drying, the modified technical wood is obtained.

[0074] Example 3

[0075] S1. Add 70 parts of 3,4-epoxycyclohexyl methacrylate, 4 parts of lignin coupling agent, 7 parts of acetal resin, and 11 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 63°C, and remove after it is completely dissolved to obtain an adhesive;

[0076] S2. Disperse the adhesive into fine droplets within 10 microns, and plant them on the front and back sides of the core layer of the cross-grained board by atomization and uniform distribution, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood layers on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0077] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 83°C and a pressure of 12MPa, so that each layer of material is tightly combined to form a composite sheet;

[0078] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0079] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0080] S101. 17 parts of methyl hexahydrophthalic anhydride, 13 parts of nano magnesium oxide, 16 parts of skin-feel UV resin (brand: Y3507) were added to 32 parts of deionized water and stirred at a stirring speed of 500r / min for 17 minutes to obtain a preliminary mixed solution;

[0081] S102. Ultrasonic dispersion is performed on the preliminary mixed solution at an ultrasonic dispersion power of 190 W to obtain a modified nano-magnesium oxide solution.

[0082] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0083] S201. Select the waste wood without insect eyes and dry it for later use;

[0084] S202. The dried wood was immersed in an ethanol solution for 2 h, and vacuum treatment was performed during the ethanol immersion time. After the immersion, the wood was removed and immersed in deionized water for 1.5 h to obtain the first processed wood;

[0085] S203. The primary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 and reacted for 17 minutes, and then subjected to microwave treatment at a power of 400 W for 15 minutes to obtain a secondary processed wood;

[0086] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 17 min;

[0087] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1.5 h to obtain modified technical wood.

[0088] Example 4

[0089] S1. 75 parts of 3,4-epoxycyclohexyl methacrylate, 4 parts of lignin coupling agent, 8 parts of acetal resin, and 11 parts of modified nano-magnesium oxide solution were added to the reaction kettle, stirred continuously and heated to 68°C, and removed after it was completely dissolved to obtain an adhesive;

[0090] S2. Disperse the adhesive into fine droplets within 10 microns, and plant them on the front and back sides of the core layer of the cross-grained board by atomization and uniform distribution, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood layers on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0091] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 88°C and a pressure of 14MPa, so that each layer of material is tightly combined to form a composite sheet;

[0092] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0093] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0094] S101. 19 parts of methyl hexahydrophthalic anhydride, 13 parts of nano magnesium oxide, and 18 parts of skin-feel UV resin (brand: Y3507) were added to 33 parts of deionized water and stirred at a stirring speed of 550r / min for 19 minutes to obtain a preliminary mixed solution;

[0095] S102. The preliminary mixed solution is ultrasonically dispersed at an ultrasonic dispersion power of 210 W to obtain a modified nano-magnesium oxide solution.

[0096] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0097] S201. Select the waste wood without insect eyes and dry it for later use;

[0098] S202. The dried wood was immersed in an ethanol solution for 2 h, and vacuum treatment was performed during the ethanol immersion time. After the immersion, the wood was removed and immersed in deionized water for 1.7 h to obtain the first processed wood;

[0099] S203. The primary processed wood was placed in a mixture of sodium quaternary ammonium and carboxylic acid in a mass ratio of 1:2 and reacted for 19 minutes, and then subjected to microwave treatment at a power of 400 W for 28 minutes to obtain a secondary processed wood;

[0100] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 19 min;

[0101] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1.8 hours to obtain modified technical wood.

[0102] Comparative Example 1

[0103] S1. Add 65 parts of 3,4-epoxycyclohexyl methacrylate, 3 parts of lignin coupling agent, 6 parts of synthetic rubber, and 10 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 60°C, and remove after it is completely dissolved to obtain an adhesive;

[0104] S2. The adhesive is dispersed into fine droplets of less than 10 microns, and is evenly distributed by atomization on the front and back sides of the core layer of the horizontally ribbed board, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the horizontally ribbed board to form a meshing structure, forming a "sandwich" structure, and then two layers of vertically ribbed bamboo fiber reinforced composite materials are placed on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0105] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 80°C and a pressure of 11MPa, so that each layer of material is tightly combined to form a composite sheet;

[0106] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0107] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0108] S101. 15 parts of methyl hexahydrophthalic anhydride, 12 parts of nano magnesium oxide, and 14 parts of skin-feel UV resin (brand: Y3507) were added to 31 parts of deionized water and stirred at a stirring speed of 400 r / min for 15 minutes to obtain a preliminary mixed solution;

[0109] S102. Ultrasonic dispersion is performed on the preliminary mixed solution at an ultrasonic dispersion power of 170 W to obtain a modified nano-magnesium oxide solution.

[0110] Comparative Example 2

[0111] S1. Disperse HJ-732 high-strength single-component silicone sealant into fine droplets within 10 microns, and evenly distribute them on the front and back sides of the core layer of the cross-grained board by atomization, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then place two layers of modified technical wood layers on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0112] S2. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 80°C and a pressure of 11MPa, so that each layer of material is tightly combined to form a composite sheet;

[0113] S3. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0114] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0115] S201. Select the waste wood without insect eyes and dry it for later use;

[0116] S202. The dried wood was immersed in an ethanol solution for 1 hour, and the ethanol immersion time was vacuum treated. After the immersion, the wood was removed and immersed in deionized water for 1 hour to obtain the first processed wood;

[0117] S203. The primary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 and reacted for 15 min, and then subjected to microwave treatment at a power of 300 W for 20 min to obtain a secondary processed wood;

[0118] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 15 min;

[0119] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1 hour to obtain modified technical wood.

[0120] Comparative Example 3

[0121] S1. Add 65 parts of 3,4-epoxycyclohexyl methacrylate, 3 parts of lignin coupling agent, 6 parts of synthetic rubber, and 10 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 60°C, and remove after it is completely dissolved to obtain an adhesive;

[0122] S2. The adhesive is dispersed into fine droplets within 10 microns, and is evenly distributed by atomization and planted on one side of the modified technology wood layer, so that the adhesive particles and the modified technology wood layer have a layer of adhesive cross-linked to form a meshing structure;

[0123] S3. The meshing structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 80°C and a pressure of 11MPa, so that each layer of material is tightly combined to form a composite sheet;

[0124] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0125] In the above step S1, the preparation of modified nano magnesium oxide includes the following steps:

[0126] S101. 15 parts of methyl hexahydrophthalic anhydride, 12 parts of nano magnesium oxide, and 14 parts of skin-feel UV resin (brand: Y3507) were added to 31 parts of deionized water and stirred at a stirring speed of 400 r / min for 15 minutes to obtain a preliminary mixed solution;

[0127] S102. The preliminary mixed solution is ultrasonically dispersed at an ultrasonic dispersion power of 170 W to obtain a modified nano-magnesium oxide solution.

[0128] In the above step S2, the preparation of the modified technical wood includes the following steps:

[0129] S201. Select the waste wood without insect eyes and dry it for later use;

[0130] S202. The dried wood was immersed in an ethanol solution for 1 hour, and the ethanol immersion time was vacuum treated. After the immersion, the wood was removed and immersed in deionized water for 1 hour to obtain the first processed wood;

[0131] S203. The primary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 and reacted for 15 min, and then subjected to microwave treatment at a power of 300 W for 20 min to obtain a secondary processed wood;

[0132] S204. The secondary processed wood is placed in a mixture of quaternary ammonium sodium and carboxylic acid in a mass ratio of 1:2 for reaction at a temperature of 80° C. for a reaction time of 15 min;

[0133] S205. Rinse the wood obtained in step S204 with deionized water and dry it at 80° C. for 1 hour to obtain modified technical wood.

[0134] Comparative Example 4

[0135] S1. 65 parts of 3,4-epoxycyclohexyl methacrylate, 3 parts of lignin coupling agent, and 6 parts of synthetic rubber were added to a reaction kettle, and the temperature was raised to 60°C with constant stirring, and the mixture was removed after being completely dissolved to obtain an adhesive;

[0136] S2. The adhesive is dispersed into fine droplets of less than 10 microns, and is evenly distributed by atomization on the front and back sides of the core layer of the horizontally ribbed board, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the horizontally ribbed board to form a meshing structure, forming a "sandwich" structure, and then two layers of vertically ribbed bamboo fiber reinforced composite materials are placed on the upper and lower layers of the "sandwich" structure to form a composite structure;

[0137] S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment at a temperature of 80°C and a pressure of 11MPa, so that each layer of material is tightly combined to form a composite sheet;

[0138] S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade.

[0139] Performance Test:

[0140] Bending strength and elastic modulus test:

[0141] The static bending strength and elastic modulus of four-point bending are measured by applying the same load to the specimen supported at two points, at one-third of the distance from the support. The static bending strength is the ratio of the bending moment and the bending section modulus of the specimen when the maximum load is applied; the elastic modulus is the ratio of the stress and strain generated by the load within the elastic limit of the material. Examples 1 to 4 and Comparative Examples 1 to 3 were tested according to GB / T17657-2013 "Test Methods for Physical and Chemical Properties of Artificial Boards and Faced Artificial Boards". The calculation formulas for the static bending strength and elastic modulus of the material are as follows:

[0142]

[0143] Where:

[0144] σ b ——static bending strength of the specimen, in megapascals (MPa);

[0145] F max ——The maximum load when the specimen is destroyed, in Newton (N);

[0146] l——The distance between two supports. The unit is millimeter (mm);

[0147] b——Vertical loading specimen width (specimen thickness when parallel loading), in millimeters (mm);

[0148] t is the thickness of the specimen when vertically loaded (the width of the specimen when parallel loaded), in millimeters (mm).

[0149]

[0150] E b ——elastic modulus of the specimen, in megapascals (MPa);

[0151] l——the distance between two supports, in millimeters (mm);

[0152] b——Vertical loading specimen width (specimen thickness when parallel loading), in millimeters (mm);

[0153] t——vertically loaded specimen thickness (specimen width when parallel loaded), in millimeters (mm);

[0154] F2-F1——the increase in load in the straight line segment of the load-deflection curve, in Newton (N);

[0155] a2-a1——the increase in deformation in the middle of the specimen, that is, the deformation of the specimen in the force range of F2 to F1, in millimeters (mm).

[0156] The measured results are shown in Table 1:

[0157] Table 1 Test of static bending strength and elastic modulus

[0158] Group Static bending strength / (MPa) Elastic modulus / (MPa) Example 1 23.5 2950 Example 2 23.3 2930 Example 3 23.2 2870 Example 4 22.9 2890 Comparative Example 1 12.3 1520 Comparative Example 2 14.5 1830 Comparative Example 3 15.1 1850 Comparative Example 4 13.8 1750

[0159] The results obtained from the static bending strength and elastic modulus tests of Examples 1 to 4 and Comparative Examples 1 to 4 above can prove that while meeting the national fan blade quality standards, the static bending strength and elastic modulus of the present invention are twice that of conventional fan blade plywood. Using ordinary adhesives instead of the adhesive prepared in this application cannot achieve the same technical effect, and stacking the material layers in an asymmetric manner significantly reduces the bending strength and deformation of the plywood fan blades. This strongly proves that the composite sheet material for fan blades prepared according to the process described in this application is reliable; by comparing the test data of Examples 1 to 4 and Comparative Examples 1 to 4, it can be seen that the method described in this application has successfully invented a composite sheet material for fan blades by designing a new material structure. Compared with Comparative Examples 1 to 4, the composite sheet material for fan blades invented by the scheme described in this application has been significantly improved in environmental protection, thickness, static bending strength and elastic modulus compared to the prior art, and has broad application prospects.

[0160] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A production process for a composite sheet material for fan blades, characterized in that: The following steps are involved: S1. Add 65 to 80 parts of 3,4-epoxycyclohexyl methacrylate, 3 to 5 parts of lignin coupling agent, 6 to 9 parts of toughening agent, and 10 to 12 parts of modified nano-magnesium oxide solution into a reaction kettle, stir continuously and heat to 60 to 70 ° C, and remove after it is completely dissolved to obtain an adhesive; S2. The adhesive is dispersed into fine droplets within 10 microns, and is evenly distributed by atomization on the front and back sides of the core layer of the cross-grained board, so that the adhesive particles are cross-linked with the front and back sides of the core layer of the cross-grained board to form a meshing structure, forming a "sandwich" structure, and then two layers of modified technical wood are placed on the upper and lower layers of the "sandwich" structure to form a composite structure; S3. The composite structure formed in S2 is placed in a hot pressing mold and subjected to heating and pressurization treatment so that each layer of material is tightly combined to form a composite sheet; S4. Post-processing the composite sheet in S3, including cutting, grinding, and surface treatment, to meet specific requirements of the fan blade; Wherein, the preparation of modified nano magnesium oxide comprises the following steps: S101. 15 to 20 parts of methyl hexahydrophthalic anhydride, 12 to 14 parts of nano-magnesium oxide, and 14 to 19 parts of silicone resin are added to 31 to 34 parts of deionized water and stirred at a stirring speed of 400 to 600 r / min for 15 to 20 minutes to obtain a preliminary mixed solution; S102. The preliminary mixed solution is ultrasonically dispersed at an ultrasonic dispersion power of 170 to 220 W to obtain a modified nano-magnesium oxide solution; The preparation of modified technical wood includes the following steps: S201. Select the waste wood without insect eyes and dry it for later use; S202. The dried wood is immersed in an ethanol solution for 1 to 3 hours, and vacuum treatment is performed during the ethanol immersion time. After the immersion is completed, the wood is taken out and immersed in deionized water for 1 to 2 hours to obtain the primary processed wood; S203. The primary processed wood is placed in a low eutectic solvent for reaction for 15 to 20 minutes and then subjected to microwave treatment at a power of 300 to 500 W for 20 to 30 minutes to obtain a secondary processed wood; S204. placing the secondary processed wood in a low eutectic solvent for reaction at a temperature of 80° C. for a reaction time of 15 to 20 min; S205. The wood obtained in step S204 is rinsed with deionized water and dried at 80° C. for 1 to 2 hours to obtain modified technical wood; Wherein, during the preparation of the modified technical wood, the low eutectic solvent is a mixture of sodium quaternary ammonium and carboxylic acid in a mass ratio of 1:

2.

2. The production process of a composite plate material for fan blades according to claim 1, characterized in that: In S1, the toughening agent is one of synthetic rubber and acetal resin.

3. The production process of a composite plate material for fan blades according to claim 1, characterized in that: In S3, the temperature of the heating and pressurizing treatment is 80 to 90°C and the pressure is 11 to 15 MPa.

4. The production process of a composite plate material for fan blades according to claim 1, characterized in that: The cutting process in S4 is carried out by high-precision CNC machine tools to ensure the dimensional accuracy and shape consistency of the composite board; the surface treatment in S4 is to use 3,4-epoxycyclohexyl methacrylate and phenolic resin as primers and polyurethane topcoat for coating.

5. A composite sheet material for fan blades produced based on the production process of the composite sheet material for fan blades according to any one of claims 1 to 4, characterized in that: include: The middle layer material is the core layer of the cross-grained board; The second layer of material is the adhesive layer, which is located on the upper and lower sides of the cross-grained board core layer to form the primary layer; The third layer is a modified technical wood layer, which is located on the upper and lower sides of the primary layer to form a symmetrical structure.

6. The composite plate material for fan blades according to claim 5, characterized in that: The core layer of the cross-grained board is made of a light and high-strength material and is a light wood cross-grained board.

7. The composite plate material for fan blades according to claim 5, characterized in that: The core layer thickness of the cross-grained board is 1.06-1.42 mm, the single layer thickness of the adhesive layer is 0.5-0.92 mm, the single layer thickness of the modified technical wood layer is 1.62-1.92 mm, and the total thickness of the board is 5.3-7.1 mm.

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