Wood-plastic composite material and preparation method thereof

Abstract

The invention provides a wood-plastic composite material preparation method, which comprises: S1, cutting and crushing a wind power blade recovered material to obtain a wind power blade powder material, and carrying out screening and surface treatment on the powder material; s2, uniformly mixing the wind power blade powdery material, wood flour and an auxiliary agent in proportion to obtain a mixed material; and S3, the mixed material is subjected to internal mixing treatment, the internally mixed material is subjected to hot press molding and cold press shaping, and the composite material is obtained. The WGFRP material in the retired wind power blade is used for preparing the wood-plastic composite material, so that the mechanical property and weather resistance of the composite material are remarkably improved, the service life of the material is prolonged, resource reutilization of wastes is realized, environmental pollution caused by landfill and incineration is reduced, the use amount of plastic in the production process is reduced, and the production cost is reduced. The carbon emission is reduced, and the influence on the environment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of wind turbine blade recycling, and in particular to a wood-plastic composite material and a preparation method thereof. Background Art

[0002] The development of the wind power industry has led to a rapid increase in the number of wind turbine blades, but it has also brought about a large number of wind turbine blade retirement issues. Wind turbine blades are usually made of glass fiber reinforced plastic (GFRP), which is widely used in the wind power industry due to its light weight, high strength, and corrosion resistance. However, these blades are difficult to handle and recycle after their life cycle, becoming an environmental burden. Traditional GFRP waste disposal methods such as landfill and incineration not only occupy a large amount of land resources, but also produce harmful gases and leachate, causing environmental pollution.

[0003] After the waste WGFRP of wind turbine blades is cut and crushed, the recycled glass fiber is similar to the short-cut glass fiber and still has a certain strength. With the improvement of people's environmental awareness, the recycling of resources has become one of the effective ways to solve the problem of GFRP waste.

[0004] At present, traditional wood-plastic composites are mainly made by mixing plastics such as polypropylene (PP) and polyethylene (PE) with wood powder. However, the mechanical properties of wood-plastic composites are low and it is difficult to meet the needs of certain high-strength applications; and ordinary wood-plastic composites are prone to aging and performance degradation in harsh environments such as ultraviolet rays, humidity and heat. Therefore, using WGFRP to prepare wood-plastic composites (WPC) is an effective way to reuse resources and help reduce the environmental burden.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a wood-plastic composite material and a preparation method thereof, which can achieve efficient utilization of wind turbine blade waste, improve the mechanical properties and weather resistance of the wood-plastic composite material, extend the service life of the material, and reduce the impact on the environment.

[0007] The first aspect of the present invention provides a method for preparing a wood-plastic composite material, comprising the following steps:

[0008] S1. Cutting and crushing the wind turbine blade recycling materials to obtain wind turbine blade powder materials, and then screening and surface treating the powder materials;

[0009] S2, mixing the wind turbine blade powder material, wood powder and additives in proportion to obtain a mixed material;

[0010] S3, subjecting the mixed material to banburying treatment, and subjecting the banburying material to hot pressing and cold pressing to shaping, so as to obtain the wood-plastic composite material.

[0011] Preferably, in step S1, the particle size of the wind turbine blade powder material after screening is 40-120 meshes.

[0012] Preferably, in step S1, the surface treatment includes: cleaning and drying treatment to ensure the purity and uniformity of the material.

[0013] Preferably, in step S2, the auxiliary agent includes: one or more of polypropylene (PP), calcium bicarbonate (CaCO3), polyolefin elastomer (POE) and maleic anhydride grafted polypropylene (MAPP).

[0014] Preferably, the mass ratio of the polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene is (80-120):(30-50):(10-30):(7-9), more preferably 100:40:20:8.

[0015] Preferably, in step S2, the mass ratio of the wind turbine blade powder material to the wood powder is (20-40):(30-50), more preferably 30:40.

[0016] Preferably, in step S2, the particle size of the wood powder is 100-200 mesh.

[0017] Preferably, in step S2, the wood powder is placed in a 60-100° C. environment for drying in advance.

[0018] Preferably, in step S3, the temperature of the banburying is 150-200°C (preferably 180°C), the temperature of the hot pressing molding is 150-200°C (preferably 180°C), and the pressure of the hot pressing molding does not exceed 5MP.

[0019] Preferably, the method further comprises the following steps:

[0020] S4, cutting the obtained wood-plastic composite material and conducting performance tests.

[0021] The second aspect of the present invention provides a wood-plastic composite material, which is prepared by the above-mentioned method for preparing the wood-plastic composite material.

[0022] Preferably, the thickness of the wood-plastic composite material is 3-5 mm, more preferably 4 mm; the density of the wood-plastic composite material is 1000-1200 kg / m 3 , more preferably 1100kg / m 3 .

[0023] Beneficial effects:

[0024] (1) The present invention significantly improves the static bending strength, elastic modulus and impact strength of the wood-plastic composite material by introducing WGFRP material. Test data show that the static bending strength reaches 36.1MPa (standard requirement ≥35MPa), the elastic modulus reaches 3943MPa (standard requirement ≥3500MPa), and the impact strength reaches 15.95kJ / m 2 (Standard requirement ≥12.0kJ / m 2 ), which significantly exceeded the standard requirements.

[0025] (2) The Vicat softening temperature of the wood-plastic composite material of the present invention reaches 155.2°C (the standard requires ≥75°C), which significantly improves the stability and durability of the material in a high temperature environment. In addition, the Shore hardness reaches 80.5, further enhancing the anti-aging ability of the material.

[0026] (3) The present invention utilizes WGFRP materials from retired wind turbine blades. On the one hand, it realizes the resource recycling of waste and reduces the environmental pollution caused by landfill and incineration. On the other hand, it reduces the use of plastics in the production process and reduces carbon emissions, which has a significant environmental protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The present invention provides a process flow chart of the method for preparing the wood-plastic composite material. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0032] Example

[0033] like Figure 1 As shown, this embodiment provides a method for preparing a wood-plastic composite material, comprising the following steps:

[0034] (1) Wind turbine blade recycled material (WGFRP) is cut and crushed to obtain powdered WGFRP, which is then sieved through three different mesh sizes of 40 mesh, 80 mesh, and 100 mesh to obtain large-particle powdered WGFRP of 40-80 mesh (L-WGFRP), medium-particle powdered WGFRP of 80-100 mesh (M-WGFRP), and small-particle powdered WGFRP of more than 100 mesh (S-WGFRP). The powdered WGFRP is then cleaned and dried to ensure the purity and uniformity of the material.

[0035] (2) First, place wood powder with a particle size of 150 mesh in an oven at 80° C. and dry for 24 hours for later use; then mix the powdered WGFRP, wood powder and additives in proportion to obtain a mixed material;

[0036] The additives include polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene; the mass ratio of powdered WGFRP, wood flour, polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene is 30:40:100:40:20:8.

[0037] (3) The mixed material is placed in a pressure mixer and mixed at a temperature of 180° C. The speed is set to 20 rad / min, and the total mixing time is 8 min. After the mixing is completed, the wood-plastic composite material is taken out for use;

[0038] The temperature of the hot press is set to 180℃, and the kneaded mixture is placed in the mold. When the temperature reaches 180℃, the mold and the raw materials are placed in the mold and hot pressing is started. The process is set as the initial pressure increases from 0 to 5MPa, and the pressure is maintained for 6 minutes, then the pressure is reduced to 3MPa, and the pressure is maintained for 30s before releasing the pressure and taking it out. After taking it out, the mold containing the raw materials is immediately placed in the cold press and cold pressed for 6 minutes. After cooling and shaping, it is demolded and sampled.

[0039] (4) Using a cutting machine to perform different tests and characterizations on the wood-plastic composite material, the prepared wood-plastic composite material board is cut to obtain test specimens, and performance tests are performed.

[0040] This embodiment also provides a wood-plastic composite material, which is prepared by the preparation method of the wood-plastic composite material of this embodiment. The thickness of the composite material is 4 mm, and the density of the composite material is 1100 kg / m 3 .

[0041] By introducing WGFRP material, this embodiment significantly improves the static bending strength, elastic modulus and impact strength of the composite material. The test data shows that the wood-plastic composite material of this embodiment performs well in various performance indicators, as follows: The static bending strength reaches 36.1MPa (standard requirement

[0042] ≥35MPa), elastic modulus reaches 3943MPa (standard requirement ≥3500MPa), impact strength reaches 15.95kJ / m 2 (Standard requirement ≥12.0kJ / m 2 ), which significantly exceeded the standard requirements.

[0043] In addition, the Vicat softening temperature of the wood-plastic composite material of this embodiment reaches 155.2° C. (the standard requires ≥75° C.), which significantly improves the stability and durability of the material in a high temperature environment; the Shore hardness reaches 80.5, further enhancing the material's anti-aging ability.

[0044] Comparative Example 1

[0045] This comparative example is basically the same as the embodiment, except that: in this comparative example, no wind turbine blade recycled material (WGFRP) is added.

[0046] The test data show that the material of this comparative example has a static bending strength of 28.4MPa, an elastic modulus of 3031MPa, and an impact strength of 6.5kJ / m 2 .

[0047] Comparative Example 2

[0048] This comparative example is basically the same as the embodiment, except that in this comparative example, the powdered WGFRP is sieved through a 40-mesh sieve.

[0049] The test data show that the material of this comparative example has a static bending strength of 31.2MPa, an elastic modulus of 3451MPa, and an impact strength of 11.35kJ / m 2 .

[0050] Comparative Example 3

[0051] This comparative example is basically the same as the embodiment, except that in this comparative example, the mass ratio of powdered WGFRP to wood powder is 40:40.

[0052] The test data show that the material of this comparative example has a static bending strength of 29.5MPa, an elastic modulus of 3127MPa, and an impact strength of 12.76kJ / m 2 .

[0053] Comparative Example 4

[0054] This comparative example is basically the same as the example, except that in this comparative example, the mass ratio of polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene is 100:40:20:4.

[0055] The test data show that the material of this comparative example has a static bending strength of 31.7MPa, an elastic modulus of 3396MPa, and an impact strength of 12.26kJ / m 2 .

[0056] Comparative Example 5

[0057] This comparative example is basically the same as the embodiment, except that: in this comparative example, wood powder with a particle size of 100 mesh is used.

[0058] The test data show that the material of this comparative example has a static bending strength of 34.8MPa, an elastic modulus of 3547MPa, and an impact strength of 13.26kJ / m 2 .

[0059] Comparative Example 6

[0060] This comparative example is basically the same as the embodiment, except that in this comparative example, the mixed material is put into a pressure mixer and the composite material is mixed at a temperature of 190°C.

[0061] The test data show that the material of this comparative example has a static bending strength of 33.97MPa, an elastic modulus of 3518MPa, and an impact strength of 13.78kJ / m 2 .

[0062] Comparative Example 7

[0063] This comparative example is basically the same as the embodiment, except that in this comparative example, the temperature of the hot press is set to 170°C.

[0064] The test data show that the material of this comparative example has a static bending strength of 35.4MPa, an elastic modulus of 3764MPa, and an impact strength of 14.51kJ / m 2 .

[0065] Comparative Example 8

[0066] This comparative example is basically the same as the embodiment, except that in this comparative example, the thickness of the material is 3 mm.

[0067] The test data show that the material of this comparative example has a static bending strength of 19.7MPa, an elastic modulus of 2056MPa, and an impact strength of 8.72kJ / m 2 .

[0068] Comparative Example 9

[0069] This comparative example is basically the same as the embodiment, except that: in this comparative example, the density of the material is 1000 kg / m 3 .

[0070] The test data show that the material of this comparative example has a static bending strength of 32.5MPa, an elastic modulus of 3663MPa, and an impact strength of 12.16kJ / m 2 .

[0071] In summary, through the environmental assessment of the production process and the product, it is proved that the wood-plastic composite material of the present invention has significant environmental advantages. First, the WGFRP material in the retired wind turbine blades is used to reduce the pollution caused by landfill and incineration of waste. Secondly, the amount of plastic used in the production process is reduced, and carbon emissions are reduced. The wood-plastic composite material with excellent performance, environmental protection and energy saving provided by the present invention has broad application prospects and is conducive to promoting the further development of wood-plastic composite materials.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a wood-plastic composite material, characterized in that: The steps include: S1. Cutting and crushing the wind turbine blade recycling materials to obtain wind turbine blade powder materials, and then screening and surface treating the powder materials; S2, mixing the wind turbine blade powder material, wood powder and additives in proportion to obtain a mixed material; S3, subjecting the mixed material to banburying treatment, and subjecting the banburying material to hot pressing and cold pressing to shaping, so as to obtain the wood-plastic composite material.

2. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: In step S1, the particle size of the wind turbine blade powder material after screening is 40-120 mesh; the surface treatment includes: cleaning and drying treatment.

3. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: In step S2, the auxiliary agent includes one or more of polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene.

4. The method for preparing the wood-plastic composite material according to claim 3, characterized in that: The mass ratio of the polypropylene, calcium bicarbonate, polyolefin elastomer and maleic anhydride grafted polypropylene is (80-120):(30-50):(10-30):(7-9).

5. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: In step S2, the mass ratio of the wind turbine blade powder material to the wood powder is (20-40):(30-50).

6. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: In step S2, the particle size of the wood powder is 100-200 meshes; the wood powder is placed in an environment of 60-100°C for drying in advance.

7. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: In step S3, the temperature of the banburying is 150-200°C, the temperature of the hot pressing molding is 150-200°C, and the pressure of the hot pressing molding does not exceed 5MP.

8. The method for preparing the wood-plastic composite material according to claim 1, characterized in that: The following steps are also included: S4, cutting the obtained wood-plastic composite material and conducting performance tests.

9. A wood-plastic composite material, characterized in that: The wood-plastic composite material is prepared by the preparation method of any one of claims 1 to 8.

10. The wood-plastic composite material according to claim 9, characterized in that: The thickness of the composite material is 3-5 mm, and the density of the wood-plastic composite material is 1000-1200 kg / m 3 .

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