Can thermoplastic composites be used for fan blades
the manufacturing of wind turbine blades has been based on thermosetting composite technology. But thermoplastic composites can give recyclability and other advantages. When reinforced thermoplastics are used to produce wind turbine blades, they can provide significant advantages over thermosetting plastics. First, thermoplastics are plastic when heated and remain plastic, unlike thermosetting plastics, which are permanently hard. Therefore, at the end of its service life, thermoplastic blades can be recycled by heating and forming some things. Assuming that the blade manufacturing now uses hundreds of thousands of tons of composite materials every year, this will also cause a part of waste materials, which will form an increasingly important market benefit
1. Advantages and disadvantages
advantage 1: recyclable due to the bumpy journey
at the end of its service life, thermoplastic blades can be recycled by heating some things
advantage 2: short curing cycle
thermoplastic can also solve the obstacle of curing cycle, which now slows down the production speed of thermosetting blades. The formed blades can be demoulded under heating to further accelerate the production process. Components can be co cured or connected by heating local interfaces and welding. Small parts can be injection molded with granular materials
advantage 3: higher strength and stiffness
reinforced thermoplastics can have higher strength than thermosetting plastics under the same weight, which can form a lighter structure. The blade design optimization of these plastics can form different structures. For example, by designing a blade to make it more like an aircraft wing and strengthening it with ribs and beams, designers can eliminate many structural cores currently used in blades. Foam and other core materials absorb resin, which increases weight and cost, and must be processed and formed
in use, its resistance to rain, snow and other erosion is better than thermosetting plastics, and it usually has a higher damage tolerance and slower crack growth. Because it is more elongated, the impact strength of thermoplastic is better, and the damage is often shown as visible dents, unlike thermosetting composites, which are hidden in the laminate, and no defects can be seen on the surface
disadvantage 1: poor fatigue resistance
the fatigue performance of reinforced thermoplastic is quite poor, because of the weak connection between fiber and plastic matrix. The connection between the two is mechanical, which is formed by the shrinkage of the matrix resin around the fiber during the curing process, rather than chemical connection. Common coupling agents are used to improve the adhesion of glass fiber, carbon fiber and thermosetting resin, but they have little effect on thermoplastic resin
disadvantage 2: the thermal/wet performance is generally worse than that of thermosetting resin
the thermal/wet performance is generally worse than that of thermosetting resin, because hot moisture will expand the matrix, loosen the mechanical connection, and make the matrix molecular chain slide along the fiber. In addition, most thermoplastic resins are difficult to process, and their high viscosity in the molten state means that higher processing temperature and curing pressure are required to ensure that the resin can completely penetrate into long fiber continuous fibers. Due to the need for metal molds and high energy consumption, the cost rises
2. Research status at home and abroad
abroad: the greenblade project of eircomposites
in Ireland, the composite research unit of Galway National University, the research team of Limerick University and the commercial company eircomposites have further studied this latest technology. Aplc-12 composites have been extensively studied by the two universities, while eirecomposites has actively developed liquid forming technology for the production of thermoplastic composite wind turbine blades and nacelle covers. In the project of green blade (g, the current development status of the domestic plastic machinery industry is that there is a reenblade with low independent innovation ability and few advanced and personalized special varieties), eircomposites is leading a cooperation (through its subsidiary eircomposite Teo), which includes Mitsubishi Heavy Industry, Ahlstrom glass fiber company and cycles company to jointly develop and manufacture a 12.6-meter-long blade sample and test it. This work will naturally lead to the development and certification of full-size thermoplastic composite blades in the future
abroad: Danish LM company's new blade technology development project blade King
among the major blade manufacturers, Danish LM company, which is the world's largest wind turbine blade manufacturer, pays close attention to this work. Under normal circumstances, the company can hardly produce blades fast enough to meet the requirements, so it wants to shorten the current production cycle by half as part of its latest blade technology development project, blade king. The company has been attracted by the fact that thermoplastics can reduce the production cycle. It can be used as a possible key to bring new varieties of plastics to the market by 2015. In order to produce super large blades for future offshore wind turbines, a high level of automation is also required. This is another focus of the blade King project: the use of automated fiber layering or tape, although their role is very important, to speed up the layering of fibers in the mold. Riso DTU and Aalborg University, together with LM company, carried out the research work of blade King project, which was partially sponsored by the Danish national advanced technology fund
domestic: Zhongke Hengyuan cooperates with RTP company to develop long fiber reinforced thermoplastic blades
Hunan Zhongke Hengyuan wind power industry technology Co., Ltd. has designed and manufactured small wind turbines suitable for areas not powered by electricity. The company uses long glass fiber reinforced thermoplastic from RTP company of the United States to inject and mold wind turbine blades. It is reported that the company cooperates with RTP to develop products reinforced with long fibers because they have the highest strength/weight ratio in injection molding materials. Long glass fiber reinforced materials provide high modulus and impact resistance, and can maintain the blade shape regardless of environmental conditions. Excellent dimensional stability can effectively prevent the blade from changing the windward angle, thus greatly improving the efficiency of the turbine, especially in very wet and dry conditions
3. Summarize the accelerated development of the global wind power market, so that blade suppliers should not only expand capacity, but also look for technologies to speed up the production process to meet future needs. Thermoplastic resin has potential advantages to help them do this. At the same time, it also strengthens the structural feasibility of super large blades and solves the renewable problem of blades after retirement. For the field of wind energy, due to its increasing demand, these real plastics can prove to be a revolutionary technology
note: the reprinted content is indicated with the source. The reprint is for the purpose of transmitting more information, and does not mean to agree with its views or confirm the authenticity of its content
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