In the design and manufacture of carbon fiber rod composite drones, the elastic and stiffness distribution of the structure is often achieved by adjusting the laying angle and the number of material layers.
Carbon fiber rod composites are currently one of the most reinforced materials used by drones. The use of carbon fiber rod composites to make drones generally involves the following three types of molding processes:
Heat pressure tank molding process
Thermopressure tank molding is one of the high performance molding processes of composite materials. For drones with high speed requirements, composite components and main load-bearing components are often manufactured using this process.
The internal quality of the carbon fiber rod composite member formed by the heat pressure tank is better and the content of the resin is more uniform, and the mechanical properties are also better.
However, there are some shortcomings in the hot pressure tank molding technology. The technology has higher requirements for equipment, and the pre-production and processing costs are relatively high, and the economy is relatively poor. From the cost point of view, low temperature and low pressure molding technology is often chosen instead when the budget is limited.
In addition, the flow, heat transfer, chemical crosslinking, and voids of carbon fiber rod composites will interact and interact with each other during the formation of thermal pressure tanks, which will increase the difficulty of process control. Once the error is grasped, There will be poor glue, high porosity and other processing defects.
In order to ensure the quality of the unbuilt parts of carbon fiber rod composite, we can control the pressure and temperature curve of the heat pressure tank process by simulating the dynamics change, resin flow and heat transfer during the heat pressure tank forming process.
Vacuum bag forming process
Compared with the hot pressure tank process, the vacuum bag molding process is relatively simple, and there is no need for excessive input in the early stages, and the operation difficulty is moderate. However, this molding method has a small pressure and is only suitable for composite members that do not require high quality standards. It is mostly used to manufacture Honeycomb sandwich structures and laminate structures that do not exceed 1.5 mm.
Because of the obvious cost advantage, this process method is used more often in the manufacture of low-speed drones, because in the manufacture of small low-speed drones, vacuum bag molding technology can meet the production requirements of most parts.
In practice, because vacuum bag molding requires the use of preimpregnation paving, wet paving and other processes, and the wet method operation is affected by human factors, it is easy to lead to uneven adhesive coating, which is particularly evident in the sandwich structure molding.
In addition, the unreasonable direction of the brush can easily lead to the bending and change of the fiber direction, threatening the stability of the carbon fiber rod composite manufacturing parts. Our new materials technology is the use of preprepreg pasting, can effectively avoid the above problems, improve the stability of the parts.
Modular molding process
The molding process is more suitable for the manufacturing of foam sandwich composite members. It integrates the advantages of hot press tank molding technology and vacuum bag molding technology, with high production efficiency and large molding pressure, moderate equipment input and cost, and good economy.
Most parts of the drone rudder surface that use foam sandwich structure use this kind of molding process. In the manufacture of carbon fiber rod unmanned Airfoil, the use of molding technology can also ensure the appearance quality and Airfoil accuracy of the drone wing. Improve the overall manufacturing quality of the drone.
But pressure control is the key process of the process. Our new material can determine the pressure control parameters more accurately and guarantee the performance level of the structure by analyzing the structure of the product and summarizing the long-term experience.
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