Automobile carbon fiber composite material (CFRP) can be said to be the star material in the development of automobile lightweight. In recent years, the application research of this "black gold" material in the industry is also developing constantly.https://www.gpmplus.fr/
With the debut of two domestic mass-produced carbon fiber composite component models, the independent brand has entered the era of mass production of carbon fiber applications!
At the same time, the application range of carbon fiber composite materials is also expanding.
Extend from body and exterior trim system to chassis and powertrain system;
Expand from outer covering material to structural or structural reinforcement material.
However, the high cost of carbon fiber is still an important factor limiting its development.
At present, commercial grade automotive carbon fiber is mainly PAN based carbon fiber, and its high cost problems mainly focus on the high production cost of PAN precursor and the long production process.
Therefore, the main way to reduce the cost of automotive CFRP is to reduce the cost of automotive carbon fiber raw wire, and to seek for low-cost fiber production technology and low-cost CFRP preparation technology.
Low-cost carbon fiber technology
1. Production process of large wire bundle
Generally, the carbon fiber with more than 48K is called large beam carbon fiber. The performance advantages of large beam carbon fiber are mainly in the following two aspects :(1) the quality requirement of large beam carbon fiber for PAN precursor is lower than that of small beam, so civil PAN fiber can be used.
(2) The manufacturing cost of carbon fiber in large tow is about 60% of that in small tow.
However, the production difficulties of large bundle carbon fiber lie in the following aspects: the large bundle fiber accumulates, the yarn spreading effect is not good, the yarn pieces are hard to infiltrate evenly, and the thickness and quality of the yarn pieces are difficult to meet the requirements of product structure design.
In the process of yarn spreading, yarn hairiness often occurs, resulting in tangled yarn and broken yarn, affecting production efficiency and product appearance, material performance cannot be effectively converted, and product performance is unstable.
2. Development of low-cost carbon fiber precursors
The price of PAN accounts for about 50% of the cost of carbon fiber production, according to the data.
As a result, domestic and foreign carbon fiber producers are also looking for lower-cost sources other than PAN to make carbon fiber.
Automobile carbon fiber manufacturing countries have developed low cost alternative materials including polyolefin polymers, lignin cellulose, electrospinning phenolic fiber, radiation acrylic textile and so on.
3. Hybrid carbon fiber technology
The hybrid of carbon fiber and other fibers can be complementary in performance and can effectively reduce the production cost.
For example, by mixing carbon fiber with glass fiber and aramid fiber, the production cost can be reduced on the basis of maintaining the original high performance of the material through reasonable structural design.
4. Pre-oxidation process
The long pre-oxidation time and long production cycle in carbon fiber production process is also an important reason for the high production cost of carbon fiber.
At present, studies have been carried out on PAN profilament by physical treatment such as ULTRAVIOLET ray and X-ray, or chemical treatment such as KMnO4 and C6H5COOH to reduce the cyclic temperature and shorten the pre-oxidation time.
Process parameters such as temperature, time and gas atmosphere can be changed to improve the performance of carbon fiber.
High efficiency molding resin and molding process
The manufacturing cost of carbon fiber composite material mainly consists of two aspects.
One is due to the high cost of forming equipment such as hot pressing tank and automatic laying-up, and the other is due to the consumption of manpower and material resources caused by the long forming time of composite materials.
Therefore, resin material based on efficient molding and new molding process will be an important way to optimize the low cost of carbon fiber composite materials.
Epoxy resins are preferred for carbon fiber composites due to their excellent bonding strength and modulus, creep resistance, high toughness and good fatigue resistance.
Carbon fibre recovery technology
The recovery and reuse of carbon fiber composites is an effective way to reduce the cost of carbon fiber and increase its economic added value.
At present, the research on carbon fiber recovery methods is also constantly updated, such as high temperature pyrolysis, fluidized bed oxidation, supercritical fluid technology, etc