Multi-layer composite component, preparation method thereof and wind power blade

Abstract

The invention discloses a multi-layer composite component and a preparation method thereof and a wind power blade, the multi-layer composite component comprises the following layers: a) a PE film at least containing ultra-high molecular weight polyethylene, b) a fiber layer and c) an elastic layer, the fiber layer is arranged between the PE film and the elastic layer, and the fiber layer is at least partially embedded in the PE film and / or the elastic layer; the PE film and the fibrous layer are joined in a first process to form a laminated composite, and the elastic layer is joined to the other side of the fibrous layer opposite the PE film in a second process to form the multilayer composite member. The multi-layer composite component has comprehensive performance such as high interlayer bonding strength and overall mechanical strength and excellent fatigue resistance, and the wind power blade manufactured through the multi-layer composite component is simple in manufacturing process, low in cost and capable of being safely applied to the severe environment for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blades, and in particular to a multi-layer composite component and a preparation method thereof, and a wind turbine blade. Background Art

[0002] Composite component technology in the field of wind turbine blades has developed rapidly in recent years. The operating environment of wind turbine blades is complex and changeable, including long-term exposure to harsh conditions such as wind pressure, rain, and ultraviolet radiation. Especially in tropical or coastal areas with high humidity and high temperature, blades need to have extremely high wear resistance, corrosion resistance, and fatigue resistance. To this end, the research and development of composite components for wind turbine blades focuses on improving the mechanical properties, environmental tolerance, and overall durability of the material to reduce maintenance costs caused by blade wear or corrosion and extend the service life of the blade.

[0003] Traditional wind turbine blades usually use fiber-reinforced composite materials, such as glass fiber or carbon fiber reinforced resin-based materials, to provide high strength and rigidity. However, with the development of technology, the composite performance of a single material is no longer sufficient to meet the comprehensive requirements of modern wind turbine blades for light weight, toughness and weather resistance. Therefore, multi-layer composite structure technology has become a current research hotspot, that is, by introducing different performance levels in the material to achieve the effect of each layer complementing each other, thereby achieving high strength, light weight and excellent environmental resistance.

[0004] Invention CN118082334A discloses a laminated material, which comprises at least two layers, wherein the first layer i) comprises at least one polyethylene polymer and the second layer ii) comprises at least one first elastomer (E1) and at least one thermoplastic second elastomer (E2). The laminated material of the invention aims to improve the corrosion resistance of laminated composite parts (especially rotor blades), and to prepare the laminated material and the laminated composite parts comprising the laminated material simply and as cost-effectively as possible. Invention CN108136716B discloses a multilayer composite component, which has the following layer structure: a) a first layer (11), which is at least partially composed of polyethylene, b) only one second layer (12), which is at least partially composed of polyurethane and / or elastomer, c) at least one third layer (13), which is at least partially composed of plastic reinforced by fibers (14), or the third layer is at least partially composed of adhesive material, wherein the second layer (12) is directly arranged between the first layer (11) and the third layer (13), wherein the first layer (11) and the second layer (12) are bonded into a laminated composite in a first process, and the third layer (13) is bonded to the laminated composite including the first layer (11) and the second layer (12) in a second process, wherein the laminated composite including the first layer (11) and the second layer (12) has been completely hardened, and the splicing of the third layer (13) and the laminated composite including the first layer (11) and the second layer (12) is carried out under the condition of hardening of the third layer (13). However, the above inventions only obtain laminated materials through polyethylene layers and elastomer layers, and the overall mechanical strength is insufficient, which is difficult to meet the use requirements in high-load and high-impact environments, and the simple lamination process directly bonding the two layers will also result in the interlayer bonding force being difficult to meet the stringent requirements of high peel strength in the use environment of wind turbine blades.

[0005] Therefore, how to provide a composite component for wind turbine blades that has high inter-layer bonding strength and overall mechanical strength, good fatigue resistance, and can adapt to harsh environments for a long time has become an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0006] In view of the defects existing in the above-mentioned prior art, the present invention provides a multi-layer composite component and a preparation method thereof and a wind turbine blade. The multi-layer composite component has comprehensive properties such as high bonding strength between high layers and overall mechanical strength, excellent fatigue resistance, etc. The wind turbine blade made of the multi-layer composite component has a simple manufacturing process and low cost, and can be safely used in harsh environments for a long time.

[0007] In a first aspect, the present invention provides a multilayer composite component, comprising the following layers:

[0008] d) a PE film comprising at least ultra-high molecular weight polyethylene,

[0009] e) a fiber layer,

[0010] f) an elastic layer,

[0011] The fiber layer is disposed between the PE film and the elastic layer, and the fiber layer is at least partially embedded in the PE film and / or the elastic layer;

[0012] The PE film and the fiber layer are bonded into a laminated composite in a first process, and the elastic layer is bonded to the other side of the fiber layer opposite to the PE film in a second process to form the multi-layer composite member.

[0013] The PE film layer containing ultra-high molecular weight polyethylene as the outer layer of the composite part can effectively resist the corrosion of wind turbine blades in high humidity and high salinity environments by virtue of the ultra-high molecular weight polyethylene's advantages such as super wear resistance, high strength, self-lubrication, chemical stability, and strong anti-aging, and prevent the material from aging due to long-term exposure to ultraviolet rays and bad weather. At the same time, the low friction coefficient of ultra-high molecular weight polyethylene material helps to reduce the wear on the surface of wind turbine blades and extend the service life of the blades.

[0014] The fiber layer is arranged between the PE film and the elastic layer. In the first process of bonding the laminated composite by isostatic pressing, the fiber layer is preferably at least partially embedded in the PE film. In the second process, the exposed part of the fiber layer that is not embedded in the PE film is preferably embedded and combined with the elastic layer. The fiber layer can play the role of bridging, supporting and dispersing stress, enhance the mechanical strength and impact resistance of the composite, and ensure that the wind turbine blade can maintain stability in high wind speeds and drastic airflow changes. The addition of the fiber layer enables the composite to have higher tensile strength and fatigue resistance, thereby extending the service life of the blade under harsh conditions.

[0015] The elastic layer plays a role of buffering and energy absorption in the composite part, which can effectively absorb the vibration and impact generated by the wind turbine blade during operation and reduce the damage to the composite structure caused by stress concentration. By setting the elastic layer, the toughness of the composite part is significantly improved, so that the blade can still maintain good structural integrity and stability under long-term and high-load conditions.

[0016] Based on the above-mentioned design and joining method of the PE film, the fiber layer and the elastic layer, the multilayer composite component provided by the present invention preferably has a tensile strength of more than 25MPa, a tensile modulus of more than 450MPa, and an elongation at break of less than 80%. From the composition of each layer, including the high-performance PE film outer layer containing ultra-high molecular polyethylene, the fiber layer embedded and bridged to enhance, and the elastic layer with excellent cushioning and external joining performance, as well as the performance parameters exhibited by the multilayer composite component, it can be seen that the multilayer composite component of the present invention has excellent comprehensive performance from both microscopic and macroscopic aspects, and can meet the complex and stringent requirements of wind turbine blades in various application environments.

[0017] Preferably, the multilayer composite component satisfies at least one of the following:

[0018] 1) The molecular weight of the ultra-high molecular weight polyethylene is greater than 1 million;

[0019] 2) The fiber layer comprises one or more of glass fiber, carbon fiber, polypropylene fiber, nylon fiber, aramid fiber, polyester fiber, viscose fiber, acrylic fiber, and ultra-high molecular weight polyethylene fiber;

[0020] 3) The elastic layer comprises one or more of EPDM rubber, EPDM rubber, ethylene acrylate rubber, fluorocarbon rubber, acrylate rubber, and nitrile rubber.

[0021] The ultra-high molecular weight polyethylene used in the present invention is an unbranched linear polyethylene with a molecular weight greater than 1 million, preferably greater than 1.5 million, and more preferably greater than 3 million.

[0022] Preferably, the surface density of the fiber layer is 50-200 g / m 2 The fiber temperature resistance is not less than 150°C, the fiber strength is greater than 30cN / dtex, and the fineness is 500-1000D.

[0023] Preferably, the fiber layer comprises glass fiber and / or ultra-high molecular weight polyethylene fiber;

[0024] The elastic layer comprises EPDM;

[0025] The interlayer peeling strength of the multilayer composite component is above 40N / cm.

[0026] Preferably, the molecular weight of the ultra-high molecular weight polyethylene fiber used to make the fiber layer is above 1 million, preferably above 1.5 million.

[0027] Preferably, the thickness difference of the multilayer composite component is less than 0.1 mm, and the thickness deviation ΔH≤5%.

[0028] Preferably, a peelable isolation film is provided on the outer side of the elastic layer away from the fiber layer. Providing the isolation film on the outer side of the elastic layer can prevent the elastic layer from sticking, contaminating and being damaged during winding, storage and transportation, etc., thereby ensuring the quality and performance of the multi-layer composite component.

[0029] In a second aspect, the present invention further provides a method for preparing the multilayer composite component, comprising the following steps:

[0030] The first step: manufacturing or providing a laminated composite comprising a PE film and a fiber layer;

[0031] The second step is to bond the laminated composite part and the elastic layer to obtain the multi-layer composite component.

[0032] Preferably, in the first step, the laminated composite part is manufactured by an isostatic pressing process, comprising the following steps:

[0033] S1.1, setting the pressing pressure of the isostatic press according to the initial thickness of the PE film, the initial thickness of the fiber cloth and the target thickness of the laminated composite;

[0034] S1.2, the static press is temperature controlled in sections;

[0035] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material;

[0036] S1.4, inputting the preheated material into the heating pressing section for isostatic pressing and compounding to obtain a laminated composite comprising a PE film and a fiber layer;

[0037] S1.5 The laminated composite is cooled and shaped.

[0038] Ultra-high molecular weight polyethylene has low surface energy and poor direct bonding effect. In the art, the molecular weight of ultra-high molecular weight polyethylene is usually reduced, that is, polyethylene is modified to enhance its bonding properties. However, the above means are likely to destroy the natural advantages of ultra-high molecular weight polyethylene. In the first process, the present invention uses an isostatic pressing composite process to composite the PE film and the fiber layer, and sets the pressing pressure, temperature and other process conditions of the isostatic press according to the performance and size requirements of the feeding and laminating composite parts, thereby obtaining a composite part with set size and tight interlayer bonding, which provides important guarantees for the second process and multi-layer composite component products.

[0039] Preferably, before entering the preheating section of the isostatic press, the ultra-high molecular weight polyethylene film and / or fiber cloth is subjected to a surface activation treatment, including but not limited to:

[0040] The surface of the ultra-high molecular weight polyethylene film to be composited is subjected to corona treatment to make the surface dyne value greater than 40, and the corona treatment conditions are: 20000-40000V / ㎡ voltage, speed 5-7m / min; and / or

[0041] The surface of the fiber cloth to be composited is subjected to plasma activation treatment, and the treatment conditions are: power 50-200W, oxygen flux 0.5-5L / min, pressure 10-30Pa, and treatment time 1-5min.

[0042] The corona treatment of the surface of the ultra-high molecular weight polyethylene film uses a (high frequency / medium frequency) high voltage power supply to produce a corona release phenomenon. Through the discharge process, the oxygen between the two electrodes is ionized to produce a strong oxidant ozone, which can immediately oxidize the surface molecules of the ultra-high molecular weight polyethylene, converting it from non-polar to polar, and increasing the surface wetting tension; and after the electron impact, micro-dense pits are generated on the surface, achieving the effect of roughening the surface to increase the surface activity. While the above surface treatment improves the bonding performance of the ultra-high molecular weight polyethylene film and the fiber cloth, it does not destroy the overall molecular weight and performance of the polyethylene, and does not reduce the protective effect of the ultra-high molecular weight polyethylene film on the wind turbine blades.

[0043] Plasma activation treatment is used on the surface of the fiber cloth to produce active groups such as hydroxyl and carboxyl groups on the surface to be composited, which significantly improves the external bonding performance of the fiber cloth and prepares for the subsequent isostatic pressing composite process with ultra-high molecular polyethylene film.

[0044] Preferably, the initial thickness H1 of the ultra-high molecular weight polyethylene film is 0.2-0.8 mm; the initial thickness H2 of the fiber cloth is 0.1-1 mm, preferably 0.1-0.8 mm, more preferably 0.15-0.5 mm;

[0045] The target thickness Hc after compounding satisfies the relationship: H1<Hc

[0046] The thickness of the composite part is less than the sum of the thicknesses of the PE film and the fiber layer input materials. The fiber layer is at least partially embedded in the PE film to form a mechanical anchor. That is, a chemical and physical interface bonding method is formed between the PE film and the fiber layer through the isostatic pressing composite process, thereby effectively enhancing the interface bonding ability.

[0047] In the present invention, it is difficult to combine ultra-high molecular weight polyethylene (UHMWPE) with the fiber layer, mainly because the UHMWPE material has low surface energy, resulting in poor adhesion to other materials, and it is difficult to achieve a stable combination of UHMWPE and fiber by traditional hot pressing process. The present invention overcomes this technical difficulty by adopting isostatic pressing process. Isostatic pressing uses high uniform pressure to tightly combine UHMWPE with the fiber layer, avoiding the common delamination problem in traditional hot pressing process.

[0048] ​This process can achieve good interface bonding effect at a lower temperature, ensure the structural stability of the material, and significantly improve the interlayer peeling force and overall adhesion. At the same time, cold isostatic pressing reduces the risk of thermal deformation of the material, improves production efficiency and product quality, and further enhances the durability and reliability of the composite component.

[0049] In addition, after the initial thickness and target thickness of the ultra-high molecular weight polyethylene film and the fiber cloth are determined, the depth of the fiber cloth embedded in the ultra-high molecular weight polyethylene film is adjusted by process parameters (including pressure, temperature and time, etc.) as needed, so as to obtain the target thickness of the desired laminated composite. Similarly, according to the needs of the pasting object and the use environment, the application thickness of the elastic layer, the target thickness of the multi-layer composite component and the corresponding process conditions of the second step are selected to finally obtain a multi-layer composite component of the desired thickness. The thickness of the multi-layer composite component product has a large adjustment space, for example, the thickness of the multi-layer composite component is 0.3-3.0 mm, preferably 0.5-2.5 mm, and more preferably 0.8-2.0 mm.

[0050] Preferably, the isostatic pressing composite process satisfies at least one of the following conditions:

[0051] 1) The pressing pressure of the isostatic press is 5-20 bar, preferably 8-16 bar;

[0052] 2) The pressing temperature T2 of the heating pressing section is 140-185°C, preferably 150-180°C, and the heating pressing time t2 is 30-120s, preferably 50-100s;

[0053] 3) The preheating temperature T1 of the preheating section satisfies: (25%-45%)×T2≤T1≤(50%-80%)×T2, and the preheating time t1 is 10-30s;

[0054] 4) The cooling and setting temperature T3 of the laminated composite is 10-50°C, and the cooling and setting time t3 is 15-45s.

[0055] The present invention has carried out detailed tests on various links such as pressing pressure, pressing temperature, pressing time, etc. through a large number of experiments, and has explored process parameters suitable for the composite of PE film containing ultra-high molecular polyethylene and fiber cloth. On this basis, the two can be effectively laminated into a composite part with a tight combination and controllable thickness.

[0056] Preferably, the PE film and the fiber cloth are fed discontinuously; or

[0057] The PE film and the fiber cloth are continuously fed at a uniform speed, and the length ratio of the preheating section, the heating pressing section and the cooling shaping section of the static isostatic press is (10-30): (60-100): (15-45).

[0058] In the actual molding process, non-continuous feeding is relatively simple and controllable, but the production efficiency is low, and it is suitable for small batch and high precision production. When large-scale continuous feeding production is adopted, since the pressure of the static isostatic press is consistent throughout the process, the temperature setting and time setting of each section need to be coordinated accordingly, so as to ensure the lamination quality of the composite parts while taking into account high production efficiency.

[0059] More preferably, the isostatic press is also provided with a thickness measurement and control unit, which is arranged downstream of the cooling and shaping section, to perform online detection of the thickness of the ultra-high molecular weight polyethylene / fiber cloth composite material, so that the thickness deviation ΔH of the composite material is ≤5%. The isostatic press production process can effectively control the product thickness. When the product thickness has a large deviation, on the one hand, it is necessary to check the pressurization and force of the press, and on the other hand, it can also preliminarily judge the lamination and bonding of the PE film and the fiber layer. When the lamination conditions are adapted to the feed and the product, the product layers are tightly bonded and have high dimensional stability. On the contrary, after cooling and shaping, due to the difference in shrinkage trend exceeding the interlayer bonding strength, delamination and bulging will occur. If necessary, the machine should be stopped and the process conditions readjusted.

[0060] Preferably, the second process comprises the following steps:

[0061] S2.1 Inducing vulcanization of the raw rubber material of the elastic layer;

[0062] S2.2 rolling and bonding the induced vulcanized elastic layer to the other side of the fiber layer opposite to the PE film;

[0063] S2.3: Fully vulcanize the induced vulcanization elastic layer through a constant temperature vulcanization oven to obtain the multilayer composite component.

[0064] Before the roll bonding in step S2.2, the surface of the laminated composite facing the elastic layer to be bonded may be subjected to surface corona treatment or plasma activation treatment, and the treatment conditions refer to the surface activation treatment conditions before the first step. Through the surface activation treatment, the surface to be bonded can be better infiltrated by the induced vulcanized elastic layer material, thereby improving the overall bonding performance.

[0065] The aforementioned full vulcanization generally refers to a vulcanization degree of 80-90%. Since the multi-layer composite component will also have a process of applying heat and force to the bonding material during the subsequent combination with the blade, the purpose of induced vulcanization and full vulcanization of the elastic layer here is mainly to compound and shape it with the fiber layer. Once it is fully vulcanized, there is a risk of over-vulcanization in the subsequent heating process, which may damage the comprehensive performance of the composite component.

[0066] In a third aspect, the present invention also provides a wind turbine blade, comprising a blade body, and the multilayer composite component joined to the surface of the blade body, wherein the elastic layer of the multilayer composite component is directly joined to the blade body, or is bonded by a structural adhesive layer. During the bonding process, the isolation film on the elastic layer side is peeled off, and then a structural adhesive is applied between the elastic layer and the blade. After the structural adhesive is cured into a structural adhesive layer, the composite component and the blade are bonded as one. This bonding method is simple to operate and is also suitable for the needs of regular replacement of composite components. Alternatively, during the blade molding process, the elastic layer side of the composite component with the isolation film peeled off is bonded to the blade material, and an integrated structure is directly formed through the curing process. This bonding method has a good integrated effect, but has high requirements on the blade molding process.

[0067] The present invention has at least the following beneficial effects:

[0068] (1) The present invention selects ultra-high molecular weight polyethylene (UHMWPE), a highly weather-resistant elastomer (such as EPDM rubber) and a fiber layer therebetween, and forms a high-performance multi-layer composite component through a lamination process adapted to the characteristics of the raw materials. The high-performance multi-layer composite component can still maintain good toughness and impact resistance under long-term and high-stress conditions, is suitable for long-term use in harsh environments such as wind turbine blades, and prolongs the service life of the blades and reduces maintenance costs.

[0069] (2) The first step of the present invention adopts an isostatic pressing composite process, which accurately controls process parameters such as preheating, heating pressing and cooling shaping, ensures that the materials are evenly combined during the lamination process, reduces the appearance of bubbles and uneven bonding areas, and realizes effective lamination of the PE film and the fiber layer in an embedded manner, greatly improving production efficiency and being suitable for mass production.

[0070] (3) The second process of the present invention adopts raw rubber induced vulcanization, roll-pressing bonding and full vulcanization shaping, and the elastic layer is tightly laminated on the other side of the fiber layer in an embedded manner, forming a multi-layer composite component product with a complete structure, excellent comprehensive performance and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic structural diagram of a multi-layer composite component of the present invention;

[0072] Figure 2 It is a schematic diagram of the process of the method for preparing a multi-layer composite component of the present invention;

[0073] Figure 3 This is a physical picture of the laminated composite obtained in the first process of the present invention;

[0074] Figure 4 This is a physical picture of the multi-layer composite component of the present invention.

[0075] Explanation of reference numerals: 1-PE film, 2-fiber layer, 3-elastic layer, 41-preheating section, 42-heating and pressing section, 43-cooling and shaping section, 44-four-roll calender, 45-vulcanization drying tunnel. DETAILED DESCRIPTION

[0076] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification and specific implementation methods. 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 making creative work are within the scope of protection of the present invention.

[0077] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0078] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0079] The multi-layer composite component and its preparation method and the technical solution of the wind turbine blade of the present invention will now be further explained in conjunction with the accompanying drawings.

[0080] like Figure 1 As shown, a multi-layer composite component comprises:

[0081] (1) The PE film 1 comprises at least ultra-high molecular weight polyethylene, wherein the molecular weight of the ultra-high molecular weight polyethylene is greater than 1 million, preferably greater than 1.5 million, and more preferably greater than 3 million.

[0082] (2) Fiber layer 2, comprising one or more of glass fiber, carbon fiber, polypropylene fiber, nylon fiber, aramid fiber, polyester fiber, viscose fiber, acrylic fiber, and ultra-high molecular weight polyethylene fiber; preferably comprising glass fiber and / or ultra-high molecular weight polyethylene fiber; the surface density of fiber layer 2 is 50-200 g / m 2 The fiber temperature resistance is not less than 150°C, the fiber strength is greater than 30cN / dtex, and the fineness is 500-1000D.

[0083] (3) The elastic layer 3 comprises one or more of EPDM rubber, EPDM rubber, ethylene acrylate rubber, fluorocarbon rubber, acrylate rubber, and nitrile rubber; the elastic layer 3 preferably comprises EPDM rubber.

[0084] (4) An optional isolation film is disposed on the outer side of the elastic layer 3 away from the fiber layer 2 in a removable manner.

[0085] The fiber layer 2 is disposed between the PE film 1 and the elastic layer 3, and the fiber layer 2 is at least partially embedded in the PE film 1 and / or the elastic layer 3. Figure 1 Preferably, the fiber layer 2 is embedded in the PE film 1 and the elastic layer 3, respectively, so that the inter-fiber pores of the fiber layer 2 are almost completely filled, so that the tensile strength of the multi-layer composite component is above 25 MPa, the tensile modulus is above 450 MPa, the elongation at break is below 80%, the interlayer peeling strength is above 40 N / cm, and the thickness difference of the multi-layer composite component is below 0.1 mm, and the thickness deviation ΔH≤5%.

[0086] like Figure 2 The method for preparing the multi-layer composite component comprises at least the following steps:

[0087] (1) First step: using an isostatic pressing process to manufacture or provide a laminated composite comprising a PE film 1 and a fiber layer 2 (see Figure 3 ):

[0088] S1.1, according to the initial thickness of the PE film 1, the initial thickness of the fiber cloth and the target thickness of the laminated composite, the pressing pressure of the isostatic press is set to 5-20 bar, preferably 8-16 bar;

[0089] S1.2, the isostatic press is divided into a preheating section 41, a heating and pressing section 42 and a cooling and shaping section 43, and temperature control is performed in sections;

[0090] S1.3, stacking the PE film 1 and the fiber cloth 2 and inputting them into the preheating section 41 of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section 41 satisfies: (25%-45%)×T2≤T1≤(50%-80%)×T2, the preheating time t1 is 10-30s, and T2 is the pressing temperature of the heating pressing section 42;

[0091] S1.4, inputting the preheated material into the heating and pressing section 42 for isostatic pressing to obtain a laminated composite comprising the PE film 1 and the fiber layer 2, wherein the pressing temperature T2 of the heating and pressing section 42 is 140-185°C, and the heating and pressing time t2 is 30-120s;

[0092] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 10-50° C., and the cooling and shaping time t3 is 15-45 s.

[0093] Optionally, in the steps S1.3-S1.5, the PE film 1 and the fiber cloth are fed discontinuously, and the control unit controls the PE film 1 and the fiber cloth to stay in each section for a corresponding time according to their sizes.

[0094] Optionally, in the steps S1.3-S1.5, the PE film 1 and the fiber cloth are fed continuously and uniformly. In order to ensure that the processing time of each section is implemented according to the set duration while feeding continuously and uniformly, the length ratio of the preheating section 41, the heating pressing section 42 and the cooling and forming section 43 of the static isostatic press is (10-30): (60-100): (15-45). It can be seen that the static isostatic press of the present invention has multiple independently temperature-controlled pressing units, and the length interval of each section can be set according to the process requirements of the laminated product.

[0095] (2) Second step: Joining the laminated composite member and the elastic layer 3 to obtain the multilayer composite member (see Figure 4 ):

[0096] S2.1, supplying the raw rubber material to a four-roll calender 44, and inducing vulcanization at 135-145° C. for 0.3-3 min;

[0097] S2.2: Roll-bonding the induced vulcanized elastic layer 3 to the other side of the fiber layer 2 opposite to the PE film 1 for roll-compounding to obtain a multi-layer composite component;

[0098] S2.3: The multilayer composite component is sent into a constant temperature vulcanization oven 45, and the rubber elastic layer 3 that has been induced to be vulcanized but not completely vulcanized is fully vulcanized in the vulcanization oven 45 (the degree of vulcanization is about 80-90%), and the vulcanization time is 5-10 minutes;

[0099] S2.4: The multi-layer composite component is cooled to room temperature by a cooling device to obtain a multi-layer composite component.

[0100] The wind turbine blade can be obtained by directly bonding the multi-layer composite component prepared above to the blade body, or bonding them through a structural adhesive layer.

[0101] Example 1

[0102] The multilayer composite component of Example 1, with a thickness of 1.5 mm, comprises in sequence:

[0103] (1) PE film, using ultra-high molecular weight polyethylene with a molecular weight of about 1.5 million;

[0104] (2) Fiber layer: glass fiber cloth;

[0105] (3) Elastic layer, made of EPDM rubber;

[0106] (4) A separation film is disposed on the outer side of the elastic layer away from the fiber layer in a removable manner.

[0107] The fiber layer is completely embedded in and arranged between the PE film and the elastic layer.

[0108] A method for preparing a non-continuous sample of a multi-layer composite component comprises the following steps:

[0109] (1) First process: manufacturing or providing a laminated composite comprising a PE film and a fiber layer by an isostatic pressing process:

[0110] S1.1, the initial thickness of PE film is 0.8mm, the initial thickness of glass fiber cloth is 0.5mm (surface density is about 150g / m 2 ) and the target thickness of the laminated composite is 1.1 mm, and the pressing pressure of the isostatic press is set to 8 bar;

[0111] S1.2, the isostatic press is divided into a preheating section, a heating and pressing section, and a cooling and shaping section, and temperature control is performed in sections;

[0112] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section is set to 100°C, and the preheating time t1 is 20s;

[0113] S1.4, inputting the preheated material into the heating and pressing section for isostatic pressing to obtain a laminated composite comprising a PE film and a fiber layer, wherein the pressing temperature T2 of the heating and pressing section is 150° C., and the heating and pressing time t2 is 70 s;

[0114] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 30° C. and the cooling and shaping time t3 is 30 s.

[0115] (2) Second step: joining the laminated composite member and the elastic layer to obtain the multilayer composite member:

[0116] S2.1. Supply the raw rubber material of EPDM rubber to a four-roll calender and induce vulcanization at 140°C for 1 minute.

[0117] S2.2: Roll-bonding the induced vulcanized rubber layer to the other side of the fiber layer, wherein the fiber layer is further embedded in the elastic layer to obtain a multi-layer composite component;

[0118] S2.3: The multi-layer composite component is sent into a 120°C constant temperature vulcanization oven, and the rubber elastic layer that has been induced to be vulcanized but not completely vulcanized is vulcanized in the vulcanization oven for 8 minutes to reach a vulcanization degree of 85%;

[0119] S2.4: The multilayer composite component is cooled to room temperature by a cooling device to obtain a multilayer composite component sample with an overall thickness of about 1.5 mm.

[0120] Example 2

[0121] The difference between this embodiment and embodiment 1 is that this embodiment uses ultra-high molecular weight polyethylene with a molecular weight greater than 3.5 million, and the parameters of the isostatic pressing composite process in the first step are changed:

[0122] First process: manufacturing or providing laminated composite parts including PE film and fiber layer by isostatic pressing process:

[0123] S1.1, the initial thickness of PE film is 0.8mm, the initial thickness of glass fiber cloth is 0.5mm (surface density is about 150g / m 2 ) and the target thickness of the laminated composite is 1.1 mm, and the pressing pressure of the isostatic press is set to 10 bar;

[0124] S1.2, the isostatic press is divided into a preheating section, a heating and pressing section, and a cooling and shaping section, and temperature control is performed in sections;

[0125] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section is set to 120°C, and the preheating time t1 is 20s;

[0126] S1.4, inputting the preheated material into the heating and pressing section for isostatic pressing to obtain a laminated composite comprising a PE film and a fiber layer, wherein the pressing temperature T2 of the heating and pressing section is 170° C., and the heating and pressing time t2 is 70 s;

[0127] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 35° C. and the cooling and shaping time t3 is 30 s.

[0128] The second step is carried out in the same manner as in Example 1 to obtain a multilayer composite component sample 2 with an overall thickness of about 1.5 mm.

[0129] Example 3

[0130] The difference between this embodiment and embodiment 2 is that in the first step, the pressing pressure of the isostatic press is set to 5 bar.

[0131] Example 4

[0132] The difference between this embodiment and Embodiment 2 is that the multilayer composite component adopts a continuous feeding preparation process, and under the same process conditions as in Embodiment 2, the length ratio of the preheating section, heating pressing section and cooling shaping section of the static press is 20:70:30.

[0133] Example 5

[0134] The difference between this embodiment and embodiment 2 is that the thickness of the PE layer, the thickness of the multilayer composite component sample and the parameters of the isostatic pressing composite process in the first step are changed:

[0135] First process: manufacturing or providing laminated composite parts including PE film and fiber layer by isostatic pressing process:

[0136] S1.1, the initial thickness of PE film is 0.5mm, the initial thickness of glass fiber cloth is 0.5mm (surface density is about 150g / m 2 ) and the target thickness of the laminated composite is 0.6 mm, and the pressing pressure of the isostatic press is set to 10 bar;

[0137] S1.2, the isostatic press is divided into a preheating section, a heating and pressing section, and a cooling and shaping section, and temperature control is performed in sections;

[0138] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section is set to 120°C, and the preheating time t1 is 20s;

[0139] S1.4, inputting the preheated material into the heating and pressing section for isostatic pressing to obtain a laminated composite comprising a PE film and a fiber layer, wherein the pressing temperature T2 of the heating and pressing section is 165° C., and the heating and pressing time t2 is 60 s;

[0140] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 35° C. and the cooling and shaping time t3 is 30 s.

[0141] The second step is carried out in the same manner as in Example 1 to obtain a multilayer composite component sample with an overall thickness of about 1.0 mm.

[0142] Example 6

[0143] The difference between this embodiment and embodiment 2 is that the thickness of the PE layer, the thickness of the multilayer composite component sample and the parameters of the isostatic pressing composite process in the first step are changed:

[0144] First process: manufacturing or providing laminated composite parts including PE film and fiber layer by isostatic pressing process:

[0145] S1.1, the initial thickness of PE film is 0.8mm, the initial thickness of glass fiber cloth is 0.3mm (surface density is about 140g / m 2 ) and the target thickness of the laminated composite is 0.9 mm, and the pressing pressure of the isostatic press is set to 12 bar;

[0146] S1.2, the isostatic press is divided into a preheating section, a heating and pressing section, and a cooling and shaping section, and temperature control is performed in sections;

[0147] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section is set to 120°C, and the preheating time t1 is 20s;

[0148] S1.4, inputting the preheated material into the heating and pressing section for isostatic pressing to obtain a laminated composite comprising a PE film and a fiber layer, wherein the pressing temperature T2 of the heating and pressing section is 175° C., and the heating and pressing time t2 is 80 s;

[0149] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 35° C. and the cooling and shaping time t3 is 30 s.

[0150] The second step was carried out in the same manner as in Example 1 to obtain a multilayer composite component sample with an overall thickness of about 1.2 mm.

[0151] Example 7

[0152] The difference between this embodiment and embodiment 2 is that the initial thickness of the fiber layer and the thickness of the multilayer composite component sample are different. The initial thickness of the PE film is 0.5 mm, the initial thickness of the glass fiber cloth is 0.5 mm (surface density is about 150 g / m 2 ) and the target thickness of the laminated composite is 0.8 mm, and the total thickness of the multilayer composite component laminated with the elastic layer is about 1.0 mm.

[0153] Example 8

[0154] The difference between this embodiment and embodiment 2 is that ultra-high molecular weight polyethylene fiber is used to replace glass fiber, and the following are sequentially included:

[0155] (1) PE film, ultra-high molecular weight polyethylene with a molecular weight greater than 3.5 million is selected;

[0156] (2) Fiber layer, which is an ultra-high molecular weight polyethylene fiber layer with a molecular weight of about 1.5 million;

[0157] (3) Elastic layer, made of EPDM rubber;

[0158] (4) A separation film is disposed on the outer side of the elastic layer away from the fiber layer in a removable manner.

[0159] And the parameters of the isostatic pressing composite process in the first step have changed:

[0160] First process: manufacturing or providing laminated composite parts including PE film and fiber layer by isostatic pressing process:

[0161] S1.1, the initial thickness of the PE film is 0.8 mm, the initial thickness of the ultra-high molecular weight polyethylene fiber layer is 0.4 mm (surface density is about 150 g / m 2 ) and the target thickness of the laminated composite is 1.0 mm, and the pressing pressure of the isostatic press is set to 14 bar;

[0162] S1.2, the isostatic press is divided into a preheating section, a heating and pressing section, and a cooling and shaping section, and temperature control is performed in sections;

[0163] S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material, wherein the preheating temperature T1 of the preheating section is set to 120°C, and the preheating time t1 is 20s;

[0164] S1.4, inputting the preheated material into the heating and pressing section for isostatic pressing to obtain a laminated composite comprising a PE film and a fiber layer, wherein the pressing temperature T2 of the heating and pressing section is 175° C., and the heating and pressing time t2 is 80 s;

[0165] S1.5 The laminated composite is cooled and shaped, wherein the cooling and shaping temperature T3 of the laminated composite is 35° C. and the cooling and shaping time t3 is 30 s.

[0166] The second step was carried out in the same manner as in Example 1 to obtain a multilayer composite component sample with an overall thickness of about 1.5 mm.

[0167] Example 9

[0168] The difference between this embodiment and embodiment 8 is that before entering the preheating section of the static isostatic press, the surface of the PE film to be composited is corona treated to make the surface dyne value greater than 40, and the corona treatment conditions are: 30000V / ㎡ voltage, speed 5m / min.

[0169] Comparative Example 1

[0170] The difference between this embodiment and embodiment 2 is that in the first step, the pressing pressure of the isostatic press is set to 4.8 bar.

[0171] Comparative Example 2

[0172] The difference between this embodiment and embodiment 2 is that in the first step, the pressing temperature T2 of the heating pressing section of the isostatic press is set to 135° C., and the pressing time t2 is set to 100 s.

[0173] Comparative Example 3

[0174] This embodiment refers to the invention CN114536799A, and the difference from Embodiment 2 is that no fiber layer and isostatic pressing are used, and the PE film with an initial thickness of 0.8 mm is directly compounded with the elastic layer to form a two-layer composite structure with a thickness of about 1.0 mm. Specifically, the EPDM rubber elastic layer is induced vulcanized at 140°C for 1 minute, directly roll-compounded with an ultra-high molecular weight polyethylene film with a molecular weight greater than 3.5 million, and vulcanized in a drying oven at 120°C for 8 minutes, and then cooled to set.

[0175] The main process parameters of Examples 1-8 and Comparative Examples 1-3 are shown in Table 1:

[0176] Table 1:

[0177]

[0178]

[0179] Performance Testing

[0180] (1) Mechanical properties test: Test standard, DIN 53530.

[0181] (2) Interlayer peel strength test: test standard, ASTM D3759.

[0182] The mechanical properties test and interlayer peel strength test results of Examples 1-9 and Comparative Examples 1-3 are shown in Table 2:

[0183] Table 2 Test results of Examples 1-9 and Comparative Examples 1-3

[0184]

[0185]

[0186] (3) Thickness detection

[0187] A rectangular sample with a length × width of 60 mm × 40 mm was selected, and the sample thickness was measured at the four midpoints of each side line (points A, B, C, and D) to obtain the average thickness, thickness difference, and thickness deviation.

[0188] Thickness difference = maximum measured thickness - minimum measured thickness;

[0189]

[0190] The test results of Examples 1-9 and Comparative Examples 1-3 are shown in Table 3:

[0191] Table 3 Test results of Examples 1-9 and Comparative Examples 1-3

[0192]

[0193]

[0194] The ultra-high molecular weight polyethylene film with a molecular weight of 1.5 million used in Example 1 is less difficult to press than the ultra-high molecular weight polyethylene with a molecular weight greater than 3.5 million used in Examples 2-9 and Comparative Examples 1-3. The pressing pressure and pressing temperature used are relatively low, and the overall performance of the multi-layer composite component is better, especially the thickness deviation performance is better.

[0195] In Examples 2-7, although the molecular weight of the PE film is greater than 3.5 million, through the adjustment and optimization of process parameters, the comprehensive performance of the above embodiments, such as thickness deviation, tensile strength / modulus, elongation at break and interlayer peeling force, are at a relatively good level.

[0196] Examples 8 and 9 use PE film and ultra-high molecular weight polyethylene fiber layer composites. Through the isostatic pressing composite process provided by the present invention, better mechanical properties, interlayer peeling strength and thickness uniformity can be obtained, effectively overcoming the problems of the prior art in the interlayer bonding between ultra-high molecular weight polyethylene and other materials and between ultra-high molecular weight polyethylene.

[0197] In general, the tensile strength of each embodiment is above 25MPa, the tensile modulus is above 450MPa, the elongation at break is below 80%, preferably 10-60%, and the interlayer peel strength is above 40N / cm. As for thickness uniformity, the thickness difference of each embodiment is below 0.1mm, preferably below 0.05mm, and the thickness deviation ΔH≤5%, preferably ΔH≤3%.

[0198] In contrast, due to the low pressing pressure, the interlayer peeling force of the prepared composite film in Comparative Example 1 is too low, and it can be easily peeled by hand, which cannot meet the use requirements. Due to the low pressing temperature, although the pressing time is long, the interlayer peeling force of the composite component in Comparative Example 2 is not up to standard. In addition, due to insufficient interlayer bonding, the thickness difference and thickness deviation of Comparative Examples 1 and 2 in thickness detection are much greater than those of the embodiments. In addition, in Comparative Example 3, the composite film obtained by direct pressing without using a fiber layer has a comprehensive performance such as mechanical properties and interlayer peeling strength lower than that of the embodiments.

[0199] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the present invention is intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims

1. A multi-layer composite component, characterized in that: Includes the following layers: a) a PE film comprising at least ultra-high molecular weight polyethylene, b) Fiber layer, c) an elastic layer, The fiber layer is disposed between the PE film and the elastic layer, and the fiber layer is at least partially embedded in the PE film and / or the elastic layer; The PE film and the fiber layer are bonded into a laminated composite in a first process, and the elastic layer is bonded to the other side of the fiber layer opposite to the PE film in a second process to form the multi-layer composite member.

2. The multilayer composite component according to claim 1, characterized in that: The multi-layer composite component satisfies at least one of the following: 1) The molecular weight of the ultra-high molecular weight polyethylene is greater than 1 million; 2) The fiber layer comprises one or more of glass fiber, carbon fiber, polypropylene fiber, nylon fiber, aramid fiber, polyester fiber, viscose fiber, acrylic fiber, and ultra-high molecular weight polyethylene fiber; 3) The elastic layer comprises one or more of EPDM rubber, EPDM rubber, ethylene acrylate rubber, fluorocarbon rubber, acrylate rubber, and nitrile rubber.

3. The multilayer composite component according to claim 1 or 2, characterized in that: The fiber layer comprises glass fiber and / or ultra-high molecular weight polyethylene fiber; The elastic layer comprises EPDM; The interlayer peeling strength of the multilayer composite component is above 40N / cm.

4. The multi-layer composite component according to claim 3, characterized in that: A peelable isolation film is also arranged on the outer side of the elastic layer away from the fiber layer.

5. A method for preparing a multilayer composite component according to any one of claims 1 to 4, characterized in that: Including the following processes: The first step: manufacturing or providing a laminated composite comprising a PE film and a fiber layer; The second step is to bond the laminated composite part and the elastic layer to obtain the multi-layer composite component.

6. The preparation method according to claim 5, characterized in that: In the first process, the laminated composite part is manufactured by an isostatic pressing process, which includes the following steps: S1.1, setting the pressing pressure of the isostatic press according to the initial thickness of the PE film, the initial thickness of the fiber cloth and the target thickness of the laminated composite; S1.2, the static press is temperature controlled in sections; S1.3, stacking the PE film and the fiber cloth and inputting them into the preheating section of the static isostatic press to obtain a preheated material; S1.4, inputting the preheated material into the heating pressing section for isostatic pressing and compounding to obtain a laminated composite comprising a PE film and a fiber layer; S1.5 The laminated composite is cooled and shaped.

7. The preparation method according to claim 6, characterized in that: The isostatic pressing composite process meets at least one of the following conditions: 1) The pressing pressure of the isostatic press is 5-20bar; 2) The pressing temperature T2 of the heating pressing section is 140-185°C, and the heating pressing time t2 is 30-120s; 3) The preheating temperature T1 of the preheating section satisfies: (25%-45%)×T2≤T1≤(50%-80%)×T2, and the preheating time t1 is 10-30s; 4) The cooling and setting temperature T3 of the laminated composite is 10-50°C, and the cooling and setting time t3 is 15-45s.

8. The preparation method according to claim 7, characterized in that: Discontinuous feeding of PE film and fiber cloth; or The PE film and the fiber cloth are continuously fed at a uniform speed, and the length ratio of the preheating section, the heating pressing section and the cooling shaping section of the static isostatic press is (10-30): (60-100): (15-45).

9. The preparation method according to any one of claims 5 to 8, characterized in that: The second process includes the following steps: S2.1 Inducing vulcanization of the raw rubber material of the elastic layer; S2.2 rolling and bonding the induced vulcanized elastic layer to the other side of the fiber layer opposite to the PE film; S2.3: Fully vulcanize the induced vulcanization elastic layer through a constant temperature vulcanization oven to obtain the multilayer composite component.

10. A wind turbine blade, characterized in that: The wind turbine blade comprises a blade body, and a multilayer composite component according to any one of claims 1 to 4 bonded to a surface of the blade body, wherein the elastic layer of the multilayer composite component is directly bonded to the blade body or bonded via a structural adhesive layer.

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