Solid waste comprehensive utilization pp hollow plate and its preparation method

Abstract

This invention provides a PP hollow board based on the comprehensive utilization of solid waste, the raw material of which includes solid waste; wherein, the solid waste includes waste carbon fiber wind turbine blades and fly ash. A method for preparing the aforementioned PP hollow board is also provided, comprising crushing and calcining the solid waste before using it in the preparation of the PP hollow board. The PP hollow board of this invention has excellent performance, and the use of solid waste as raw material is beneficial for the comprehensive utilization of solid waste; the preparation method of the PP hollow board of this invention is simple and easy to operate, comprehensively utilizing solid waste and realizing resource recycling.

Description

Technical Field

[0001] This invention belongs to the field of solid waste comprehensive utilization technology, specifically relating to PP hollow boards for the comprehensive utilization of solid waste and their preparation method. Background Technology

[0002] Currently, based on resource needs, a comprehensive conservation strategy is being implemented to promote the conservation and intensive use of various resources and accelerate the construction of a waste recycling system. Based on environmental protection needs, the burning, landfilling, discarding, and stockpiling of solid waste are prohibited, and enterprises are encouraged to develop comprehensive waste utilization and centralized treatment technologies to turn waste into treasure.

[0003] Wind turbines typically have a lifespan of 20 to 25 years. With the upgrading and transformation of wind farms and the end of the lifespan of first-generation wind turbines, the period from 2025 to 2029 will see a concentrated decommissioning of wind turbine blades, generating a large number of waste wind turbine blades. The challenges of how to handle and environmentally reuse these waste wind turbine blades have gradually come to the forefront with the development of the wind power industry. Fly ash is a major solid waste discharged from coal-fired power plants, primarily composed of SiO2, Al2O3, CaO, Fe2O3, carbon, and other metal and non-metal oxides. With the development of the power industry, the amount of fly ash emitted by coal-fired power plants has increased year by year, becoming one of the largest industrial wastes in my country. Large amounts of untreated fly ash will generate dust, polluting the atmosphere; if discharged into waterways, it will cause river siltation; and the toxic chemicals in it will harm human health and other organisms, placing enormous pressure on my country's ecological environment. Comprehensive utilization of fly ash, turning waste into treasure and harm into benefit, is a bottleneck problem that must be addressed and solved in the development of coal-based energy in the new era.

[0004] In summary, how to comprehensively utilize solid waste is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The first objective of this invention is to provide a PP hollow board that utilizes solid waste as its raw material, which is beneficial for realizing the comprehensive utilization of solid waste.

[0006] The second objective of this invention is to provide a method for preparing the aforementioned PP hollow board. This method is simple and easy to operate, makes comprehensive use of solid waste, realizes the recycling of resources, solves the problem of solid waste disposal and reuse, obtains high-performance PP hollow boards, and improves the value of resource utilization.

[0007] To achieve the first objective of this invention, the following technical solution is adopted:

[0008] A PP hollow board utilizing solid waste, wherein the raw material for the PP hollow board includes solid waste; wherein,

[0009] The solid waste includes waste carbon fiber wind turbine blades and fly ash.

[0010] In this invention, the waste carbon fiber wind turbine blades are made from waste carbon fiber wind turbine blades from wind turbine units and are composed of carbon fiber and resin; the fly ash comes from thermal power plants.

[0011] The PP hollow board of this invention, which utilizes solid waste, has excellent performance. Its raw material is solid waste, which is conducive to the comprehensive utilization of solid waste, realizes the recycling of resources, solves the problem of solid waste disposal and reuse, and improves the utilization value of resources.

[0012] In one embodiment, the raw materials for the PP hollow board further include any one or more of thermoplastic resin, coupling agent, antioxidant, and lubricant.

[0013] In one embodiment, the thermoplastic resin includes PP (polypropylene) and / or PE (polyethylene). That is, the thermoplastic resin includes PP (polypropylene), PE (polyethylene), or a mixture of the two.

[0014] In one embodiment, the coupling agent comprises a silane coupling agent, preferably comprising vinyltrimethoxysilane and / or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0015] Those skilled in the art will understand that the silane coupling agent vinyltrimethoxysilane is abbreviated as A-171; the silane coupling agent 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane is abbreviated as A-186.

[0016] In one embodiment, the antioxidant comprises any one or a combination of triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 2,6-di-tert-butyl-p-cresol, and tris[2,4-di-tert-butylphenyl]phosphite.

[0017] Those skilled in the art will understand that triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], abbreviated as Antioxidant 245; 2,6- Di-tert-butyl-p-cresol Abbreviated as Antioxidant 264; Tris[2,4-di-tert-butylphenyl]phosphite, abbreviated as Antioxidant 168.

[0018] In one embodiment, the lubricant comprises any one or a combination of methyl stearate, butyl stearate, glass fiber dispersant, and zinc stearate.

[0019] Those skilled in the art will understand that glass fiber dispersant is abbreviated as TAF.

[0020] To achieve the second objective of this invention, the following technical solution is adopted:

[0021] A method for preparing the aforementioned PP hollow board is provided, comprising crushing and calcining the solid waste and then using it for the preparation of the PP hollow board.

[0022] The preparation method of this invention is simple and easy to operate, makes comprehensive use of solid waste, realizes the recycling of resources, and solves the problem of solid waste disposal and reuse.

[0023] In one embodiment, the preparation method includes the following steps:

[0024] (1) Crush the waste carbon fiber wind turbine blades to obtain scrap A for later use; for example, crush it to 60-100 mesh;

[0025] (2) Screen the fly ash to obtain screened fly ash for later use; for example, screen to 1200-1500 mesh;

[0026] (3) A portion of the calcined material A obtained in step (1) is calcined once, and the calcined product is crushed to obtain calcined material B; for example, crushed to 500-700 mesh.

[0027] (4) After mixing the crushed material B obtained in step (3) with the sieved fly ash obtained in step (2), the mixture is calcined for a second time, and the resulting secondary calcination product is crushed to obtain crushed material C; for example, crushed to 1200-1500 mesh.

[0028] (5) Mix the remaining fragments A obtained in step (1), thermoplastic resin and coupling agent to obtain material D;

[0029] (6) Mix the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant and the lubricant to obtain mixture E;

[0030] (7) Extrude the mixture E obtained in step (6) to obtain a PP hollow board.

[0031] The preparation method of this invention obtains high-performance PP hollow boards by comprehensively utilizing solid waste, thereby improving the value of resource utilization.

[0032] In this invention, after the waste carbon fiber wind turbine blades are crushed, a portion of the resulting fragments A are calcined and crushed twice in steps (3) and (4) to obtain fragments C with a fineness of 1200-1500 mesh. This solves the problem of high energy consumption and difficulty when directly crushing waste carbon fiber wind turbine blades to obtain high-fineness powder. In step (4), the obtained fragments B are mixed with the sieved fly ash obtained by sieving and calcined to maintain the internal temperature of the secondary calcination reaction and effectively avoid resin coking in the fragments. In step (5), the premixing of the remaining fragments A, thermoplastic resin and coupling agent can fully realize the combination of fragments A and thermoplastic resin, and improve the mechanical properties of the PP hollow board.

[0033] In this invention, the particle size of the crushed material A obtained in step (1) is relatively large, and one-step calcination cannot be used to fully calcine it. Moreover, the calcination temperature is too high, and local overheating may lead to coking risk. At the same time, the calcination energy consumption and grinding energy consumption of one-step calcination are both high. Therefore, this application adopts a two-step calcination process.

[0034] In one embodiment, in step (3), the first calcination is carried out under an inert atmosphere, such as a nitrogen atmosphere; and / or the first calcination temperature is 400-480 ℃, such as 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃, 450 ℃, 460 ℃, 470 ℃ and 480 ℃ and any value and range within this range; and / or the first calcination time is 20-35 min, such as 20 min, 25 min, 30 min and 35 min and any value and range within this range.

[0035] The present invention can obtain finer-mesh fragments B through a single calcination in step (3). The fragments A obtained in step (1) have a larger particle size, and a single calcination is not sufficient to calcine them completely. Therefore, a second calcination in step (4) is also provided.

[0036] In one embodiment, in step (4), the secondary calcination is carried out under an inert atmosphere, such as a nitrogen atmosphere; and / or the secondary calcination temperature is 550-700 ℃, such as 550 ℃, 560 ℃, 570 ℃, 580 ℃, 590 ℃, 600 ℃, 610 ℃, 620 ℃, 630 ℃, 640 ℃, 650 ℃, 660 ℃, 670 ℃, 680 ℃, 690 ℃ and 700 ℃ and any value and range within this range; and / or the secondary calcination time is 60-90 min, such as 60 min, 65 min, 70 min, 75 min, 80 min, 85 min and 90 min and any value and range within this range.

[0037] In order to improve the uniformity of the mixing of the coupling agent, in one embodiment, in step (5), the coupling agent is mixed in by spraying; preferably the spraying speed is 20-50 g / min, such as 20 g / min, 25 g / min, 30 g / min, 35 g / min, 40 g / min, 45 g / min and 50 g / min and any value and range within this range.

[0038] In order to improve the uniformity of material mixing, in one embodiment, in step (5), the coupling agent is mixed in by spraying during the mixing of the crushed material A and the thermoplastic resin PP, thereby promoting the combination of the three materials and improving the mechanical properties of the PP hollow board.

[0039] In order to improve the mixing uniformity and bonding uniformity of the granulated material A and the thermoplastic resin, in a preferred embodiment, in step (5), when the granulated material A and the thermoplastic resin are stirred and mixed, the stirring speed is 150-200 r / min, such as 150 r / min, 160 r / min, 170 r / min, 180 r / min, 190 r / min and 200 r / min and any value and range within this range; and / or the stirring time is 20-40 min, such as 20 min, 25 min, 30 min, 35 min and 40 min and any value and range within this range, so that the granulated material A and the thermoplastic resin are fully mixed.

[0040] In one embodiment, in step (4), the mass ratio of the crushed material B to the screened fly ash is (15-40):1, such as 15:1, 20:1, 25:1, 30:1, 35:1 and 40:1, and any value and range within this range.

[0041] To improve the coupling effect, in one embodiment, in step (5), the mass ratio of the scrap A, the thermoplastic resin and the coupling agent is (15-25):(45-60):(0.6-1.5), for example (15, 18, 20, 22 and 25 and any value and range within the range of 15-25):(45, 48, 50, 52, 55 and 60 and any value and range within the range of 45-60):(0.6, 0.8, 1.0, 1.2 and 1.5 and any value and range within the range of 0.6-1.5), for example 20:50:1.2, 25:48:0.8, 18:55:1.5, 15:45:0.6, 20:60:1.0, etc.

[0042] In order to improve the uniformity of material mixing, in one embodiment, the mixing temperature in step (6) is 102-105 ℃, such as 102 ℃, 103 ℃, 104 ℃ and 105 ℃ and any value and range within this range, so as to prevent the temperature from being too low and thus failing to mix effectively, and the temperature from being too high and thus causing agglomeration, so that the resulting mixture E has uniform quality.

[0043] In one embodiment, in step (6), the mixing speed is 1300-1450 r / min, such as 1300 r / min, 1350 r / min, 1400 r / min and 1450 r / min, and any value and range within that range.

[0044] In one embodiment, in step (6), the crushed material C, the material D, the antioxidant, and the lubricant are mixed using a high-speed mixer; preferably, the rotation speed of the high-speed mixer is 1300-1450 r / min, such as 1300 r / min, 1350 r / min, 1400 r / min, and 1450 r / min, and any value and range within this range; and / or the high-speed mixer stops mixing when it is heated to 102-105 ℃, such as 102 ℃, 103 ℃, 104 ℃, and 105 ℃, and any value and range within this range.

[0045] To improve the overall performance of the manufactured PP hollow board, in one embodiment, in step (6), the mass ratio of the crushed material C, the material D, the antioxidant, and the lubricant is (23-30):(60-70):(0.3-0.6):(2-5), for example (23, 25, 27, and 30, and any value and range within the range of 23-30):(60, 65, 68, and 70, and any value and range within the range of 60-70). Any value and range within the range): (0.3, 0.4, 0.5 and 0.6, and any value and range within the range of 0.3-0.6): (2, 3, 4, 4.5 and 5, and any value and range within the range of 2-5), such as 27:68:0.5:4.5, 30:65:0.3:4, 30:65:0.3:4, 23:60:0.6:2, 25:70:0.4:3, etc.

[0046] Those skilled in the art will understand that in step (7), the material is extruded through a co-extruder.

[0047] To improve the extrusion effect, in one embodiment, the extrusion parameters in step (7) include: a barrel temperature of 165-210 ℃, such as 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, 190 ℃, 195 ℃, 200 ℃, 205 ℃ and 210 ℃, and any value and range within this range; and / or a confluence core temperature of 150-170 ℃, such as 150 ℃, 155 ℃, 158 ℃, 160 ℃, 165 ℃ and 170 ℃, and any value and range within this range; and / or a die temperature of 165-185 ℃, such as 165 ℃, 170 ℃, 172 ℃, 175 ℃, 180 ℃ and 185 ℃, and any value and range within this range.

[0048] The present invention also provides a PP hollow board prepared by the aforementioned preparation method.

[0049] In one embodiment, the static bending strength of the PP hollow board is ≥27.4 MPa, such as 27.5 MPa, 28 MPa, 30 MPa, 32 MPa, 33 MPa, etc.

[0050] In one embodiment, the elastic modulus of the PP hollow board is ≥2200 MPa, such as 2209 MPa, 2400 MPa, 2500 MPa, etc.

[0051] In one embodiment, the impact strength of the PP hollow board is ≥15 kJ / m. 2 For example, 15 kJ / m 2 15.5kJ / m 2 16 kJ / m 2 wait.

[0052] The beneficial effects of this invention are as follows:

[0053] (1) The PP hollow board of the present invention, which utilizes solid waste, has excellent performance. Its raw material is solid waste, which is conducive to the comprehensive utilization of solid waste, realizes the recycling of resources, solves the problem of solid waste disposal and reuse, and improves the utilization value of resources.

[0054] (2) The method for preparing PP hollow board of the present invention is simple and easy to operate, makes comprehensive use of solid waste, successfully solves the problem of disposal and reuse of solid waste such as waste carbon fiber wind turbine blades and fly ash, realizes the comprehensive utilization of solid waste such as waste carbon fiber wind turbine blades and fly ash, and prepares PP hollow board with excellent performance. The preparation cost is low, improves the value of resource utilization, and has good industrial application prospects. Detailed Implementation

[0055] The technical solution and its effects of the present invention will be further described below with reference to specific embodiments / examples. The following embodiments / examples are only for illustrating the content of the present invention, and the invention is not limited to the following embodiments or examples. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0056] The raw materials used in the following examples and comparative examples are as follows:

[0057] Waste carbon fiber wind turbine blades, specifically waste carbon fiber wind turbine blades from wind turbine generators;

[0058] Fly ash comes from thermal power plants;

[0059] All other raw materials were commercially available and of analytical grade.

[0060] Test method:

[0061] 1. Static bending strength, obtained by testing the prepared PP hollow board according to the method of standard GB / T 17657-2013 "Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels";

[0062] The modulus of elasticity was obtained by testing the prepared PP hollow board according to the method of standard GB / T 17657-2013 "Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels".

[0063] Impact strength was determined by testing the prepared PP hollow board according to standard GB / T 1043.1-2008 "Determination of impact properties of simply supported plastic beams - Part 1: Non-instrumental impact test".

[0064] Example 1

[0065] Prepare PP hollow board A1 for comprehensive utilization of solid waste according to the following steps:

[0066] (1) Crush the waste carbon fiber wind turbine blades to 60-100 mesh to obtain scrap A for later use;

[0067] (2) Screen the fly ash to 1200-1500 mesh to obtain screened fly ash for later use;

[0068] (3) A portion of the crushed material A obtained in step (1) is calcined once in a heating furnace, and the resulting calcined product is crushed to 500-700 mesh to obtain crushed material B; wherein,

[0069] The first calcination was carried out under a nitrogen atmosphere; the first calcination temperature was 450 ℃ and the first calcination time was 25 min.

[0070] (4) The crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) at a mass ratio of 20:1 and then subjected to secondary calcination. The resulting secondary calcination product is then crushed to 1200-1500 mesh to obtain crushed material C; wherein,

[0071] The secondary calcination was carried out under a nitrogen atmosphere; the secondary calcination temperature was 600 ℃ and the secondary calcination time was 70 min.

[0072] (5) Mix the remaining scrap A obtained in step (1), thermoplastic resin PP, and coupling agent A-171 in a mass ratio of 20:50:1.2 to obtain material D; wherein,

[0073] The coupling agent A-171 is mixed in by spraying during the process of stirring and mixing the crushed material A and the thermoplastic resin PP (stirring speed 180 r / min, stirring time 30 min).

[0074] (6) Mix the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant, and the lubricant in a mass ratio of 27:68:0.5:4.5 to obtain mixture E; wherein,

[0075] The antioxidants were prepared by mixing 245 and 168 in a mass ratio of 1:1.

[0076] The lubricant is a mixture of zinc stearate and TAF in a mass ratio of 3:2.

[0077] The mixture was mixed using a high-speed mixer at a speed of 1400 r / min, and the mixing was stopped when the high-speed mixer reached a temperature of 105 °C.

[0078] (7) The mixture E obtained in step (6) is extruded through an extruder to obtain a PP hollow board; wherein,

[0079] The extrusion parameters include: barrel temperature of 190 ℃, sprue temperature of 165 ℃, and die temperature of 175 ℃.

[0080] Example 2

[0081] PP hollow board A2 for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, the only difference from Example 1 is the following:

[0082] In step (3), the calcination temperature is 420 ℃ and the calcination time is 30 min;

[0083] In step (4), the crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) at a mass ratio of 35:1; the secondary calcination temperature is 650 ℃ and the secondary calcination time is 60 min;

[0084] In step (5), the remaining scrap A obtained in step (1), thermoplastic resin PP, and coupling agent A-186 are mixed in a mass ratio of 25:48:0.8 to obtain material D; wherein,

[0085] The coupling agent A-186 is mixed in by spraying during the process of stirring and mixing the crushed material A and the thermoplastic resin PP (stirring speed 195 r / min, stirring time 20 min).

[0086] In step (6), the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant, and the lubricant are mixed in a mass ratio of 30:65:0.3:4 to obtain mixture E; wherein,

[0087] The antioxidants were prepared by mixing 264 and 168 in a mass ratio of 1:1.

[0088] The lubricant is TAF;

[0089] The mixture was mixed using a high-speed mixer at a speed of 1320 r / min, and the mixing was stopped when the high-speed mixer reached a temperature of 103 °C.

[0090] (7) Extrusion parameters include: barrel temperature of 200 ℃, confluence core temperature of 170 ℃, and die temperature of 185 ℃.

[0091] Example 3

[0092] PP hollow board A3 for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, the only difference from Example 1 is the following:

[0093] In step (3), the calcination temperature is 470 ℃ and the calcination time is 22 min;

[0094] In step (4), the crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) at a mass ratio of 30:1; the secondary calcination temperature is 560 ℃ and the secondary calcination time is 85 min.

[0095] In step (5), the remaining scrap A obtained in step (1), thermoplastic resin (a mixture of PP and PE mixed at a mass ratio of 1:1), and coupling agent A-171 are mixed at a mass ratio of 18:55:1.5 to obtain material D; wherein,

[0096] The coupling agent A-171 is mixed in by spraying during the process of stirring and mixing the crushed material A and the thermoplastic resin PP (stirring speed 160 r / min, stirring time 35 min).

[0097] In step (6), the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant, and the lubricant are mixed in a mass ratio of 30:65:0.3:4 to obtain mixture E; wherein,

[0098] The antioxidant content is 245;

[0099] The lubricant is a mixture of zinc stearate and methyl stearate in a mass ratio of 2:1.

[0100] The mixture was mixed using a high-speed mixer at a speed of 1440 r / min, and the mixing was stopped when the high-speed mixer reached a temperature of 102 ℃.

[0101] (7) Extrusion parameters include: barrel temperature of 185 ℃, confluence core temperature of 158 ℃, and die temperature of 172 ℃.

[0102] Example 4

[0103] PP hollow board A4 for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, the only difference from Example 1 is the following:

[0104] In step (3), the calcination temperature is 400 ℃ and the calcination time is 35 min;

[0105] In step (4), the crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) at a mass ratio of 15:1; the secondary calcination temperature is 700 ℃ and the secondary calcination time is 65 min.

[0106] In step (5), the remaining scrap A obtained in step (1), thermoplastic resin PP, and coupling agent A-171 are mixed in a mass ratio of 15:45:0.6 to obtain material D; wherein,

[0107] The coupling agent A-171 is mixed in by spraying during the process of stirring and mixing the crushed material A and the thermoplastic resin PP (stirring speed 150 r / min, stirring time 40 min).

[0108] In step (6), the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant, and the lubricant are mixed in a mass ratio of 23:60:0.6:2 to obtain mixture E; wherein,

[0109] The antioxidant content is 168;

[0110] The lubricant is butyl stearate;

[0111] (7) Extrusion parameters include: barrel temperature of 165 ℃, confluence core temperature of 150 ℃, and die temperature of 165 ℃.

[0112] Example 5

[0113] PP hollow board A5 for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, the only difference from Example 1 is the following:

[0114] In step (4), the crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) at a mass ratio of 40:1; the secondary calcination temperature is 550 ℃ and the secondary calcination time is 90 min;

[0115] In step (5), the remaining fragments A obtained in step (1), thermoplastic resin PP, and coupling agent A-171 are mixed in a mass ratio of 20:60:1.0 to obtain material D;

[0116] In step (6), the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant and the lubricant are mixed in a mass ratio of 25:70:0.4:3 to obtain mixture E;

[0117] (7) Extrusion parameters include: barrel temperature of 210 ℃, confluence core temperature of 160 ℃, and die temperature of 180 ℃.

[0118] Comparative Example 1

[0119] PP hollow board A1' for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, it differs from Example 1 only in the following aspects:

[0120] When obtaining mixture E, the stepwise mixing steps (5) and (6) were not performed. Instead, the remaining fragments A obtained in step (1), thermoplastic resin, coupling agent, fragments C obtained in step (4), antioxidant and lubricant were directly mixed by a high-speed mixer to obtain mixture E.

[0121] Comparative Example 2

[0122] PP hollow board A2' for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, it differs from Example 1 only in the following aspects:

[0123] In step (5), the scrap A is changed to scrap C.

[0124] Comparative Example 3

[0125] PP hollow board A3' for comprehensive utilization of solid waste was prepared according to the preparation method of Example 1; wherein, it differs from Example 1 only in the following aspects:

[0126] In step (6), the mass ratio of the fragments C obtained in step (4), the material D obtained in step (5), the antioxidant and the lubricant are changed to 7:88:0.5:4.5.

[0127] Performance testing

[0128] The static bending strength, elastic modulus and impact strength of the obtained PP hollow boards A1-5 and A1'-3' were tested. The test results are shown in Table 1.

[0129] Table 1 Performance test results of PP hollow boards A1-5 and A1'-3'

[0130]

[0131] As can be seen from the results in Table 1, the PP hollow board and its preparation method of the present invention can successfully solve the problem of disposal and reuse of waste carbon fiber wind turbine blades, realize the comprehensive utilization of waste carbon fiber wind turbine blades and fly ash, and the prepared PP hollow board has excellent mechanical properties, low cost, and good industrial application prospects.

[0132] According to the comparison between Example 1 and Comparative Example 1, Comparative Example 1 obtained mixture E by mixing all the materials, including the scrap A obtained in step (1), thermoplastic resin and coupling agent, and the scrap C obtained in step (4), antioxidant and lubricant, in one step. Compared with the stepwise mixing (steps (5) and (6)) used in Example 1 of this application, that is, mixing the remaining scrap A, thermoplastic resin and coupling agent obtained in step (1) to obtain material D, and then mixing the scrap C obtained in step (4), the material D obtained in step (5), antioxidant and lubricant to obtain mixture E, the performance of the obtained PP hollow board is significantly reduced. The reason may be that: In this application, by mixing scrap A, thermoplastic resin and coupling agent in step (5) of the stepwise mixing, the combination of scrap A and thermoplastic resin can be fully realized, thereby improving the mechanical properties of the obtained PP hollow board; In this application, by mixing in steps, the consumption of coupling agent is avoided due to mixing coupling agent and scrap C, thus avoiding waste of coupling agent.

[0133] A comparison between Example 1 and Comparative Example 2 reveals that in Comparative Example 2, the scrap material used in step (6) is scrap C, which, compared to scrap A used in Example 1 of this application, results in a significant decrease in the performance of the obtained PP hollow board. The possible reason is that in Comparative Example 2, the scrap C used in step (6) has a particle size of 1200-1500 mesh; while in Example 1 of this application, the scrap A used in step (6) has a particle size of 60-100 mesh. The particle size of scrap A is more suitable and has a positive effect on improving the performance of the board.

[0134] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A PP hollow board for comprehensive utilization of solid waste, characterized in that, The raw materials for the PP hollow board include solid waste; wherein, The solid waste includes waste carbon fiber wind turbine blades and fly ash; The method for preparing the PP hollow board includes crushing and calcining the solid waste and then using it for the preparation of the PP hollow board; specifically, it includes the following steps: (1) Crush the waste carbon fiber wind turbine blades to 60-100 mesh to obtain scrap A for later use; (2) Screen the fly ash to 1200-1500 mesh to obtain screened fly ash for later use; (3) A portion of the scrap A obtained in step (1) is calcined once, and the calcined product is crushed to 500-700 mesh to obtain scrap B; (4) The crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) and then calcined for a second time. The resulting secondary calcined product is crushed to 1200-1500 mesh to obtain crushed material C. The mass ratio of the crushed material B to the sieved fly ash is (15-40):

1. (5) Mix the remaining fragments A, thermoplastic resin and coupling agent obtained in step (1) to obtain material D; the mass ratio of the fragments A, the thermoplastic resin and the coupling agent is (15-25):(45-60):(0.6-1.5). (6) Mix the fragments C obtained in step (4), the material D obtained in step (5), the antioxidant and the lubricant to obtain mixture E; the mass ratio of the fragments C, the material D, the antioxidant and the lubricant is (23-30):(60-70):(0.3-0.6):(2-5). (7) Extrude the mixture E obtained in step (6) to obtain a PP hollow board.

2. The PP hollow board according to claim 1, characterized in that, The coupling agent includes a silane coupling agent; The antioxidant comprises any one or more combinations of triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 2,6-di-tert-butyl-p-cresol, and tris[2,4-di-tert-butylphenyl]phosphite; and / or, The lubricant includes any one or a combination of methyl stearate, butyl stearate, glass fiber dispersant, and zinc stearate.

3. The PP hollow board according to claim 2, characterized in that, The silane coupling agent includes vinyltrimethoxysilane and / or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

4. A method for preparing a PP hollow board as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) The waste carbon fiber wind turbine blades are crushed to obtain scrap A for later use; (2) Screen the fly ash to obtain screened fly ash for later use; (3) A portion of the fragments A obtained in step (1) is calcined once, and the resulting calcined product is crushed to obtain fragments B; (4) The crushed material B obtained in step (3) is mixed with the sieved fly ash obtained in step (2) and then calcined for a second time. The resulting secondary calcination product is crushed to obtain crushed material C. (5) Mix the remaining fragments A obtained in step (1), thermoplastic resin and coupling agent to obtain material D; (6) Mix the crushed material C obtained in step (4), the material D obtained in step (5), the antioxidant and the lubricant to obtain mixture E; (7) Extrude the mixture E obtained in step (6) to obtain a PP hollow board.

5. The preparation method according to claim 4, characterized in that, In step (3), the first calcination is carried out under an inert atmosphere, and / or the first calcination temperature is 400-480 ℃, and / or the first calcination time is 20-35 min; and / or, In step (4), the secondary calcination is carried out under an inert atmosphere, and / or the secondary calcination temperature is 550-700 ℃, and / or the secondary calcination time is 60-90 min.

6. The preparation method according to claim 4, characterized in that, In step (5), the coupling agent is mixed in by spraying.

7. The preparation method according to claim 4, characterized in that, In step (6), the mixing temperature is 102-105 ℃.

8. The preparation method according to any one of claims 4-7, characterized in that, Its features are, In step (7), the extrusion parameters include: barrel temperature of 165-210 ℃, and / or merging core temperature of 150-170 ℃, and / or die temperature of 165-185 ℃.

9. A PP hollow board prepared by any one of claims 4-8.

10. The PP hollow board according to claim 9, characterized in that, The static bending strength of the PP hollow board is ≥27.4 MPa; and / or The elastic modulus of the PP hollow board is ≥2200 MPa; and / or The impact strength of the PP hollow board is ≥15 kJ / m 2 .

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