How are carbon fiber composites made?
Carbon fiber composites are made by combining carbon fibers, epoxy resin or other materials. How they are manufactured depends largely on the desired properties and intended use. They can be manufactured as unidirectional, bidirectional or quasi-isotropic, and in different shapes and sizes as required. Manufacturing processes for carbon fiber composites include filament winding, pultrusion, kitting tooling, resin transfer, and autoclave processing.
What are carbon fiber composites?
Carbon fiber is essentially a stranded material. It is a lightweight and extremely durable material. Carbon fiber composites are about 60 percent stronger and stiffer than steel (20 percent denser) and about 1.7 times stronger and stiffer than aluminum (56 percent denser), making them an excellent manufacturing material for many components. Engineers and designers will choose carbon fiber composites for demanding applications because of their high stiffness and weight strength, and because they allow physical properties to be tailored at specific locations and orientations within the part.
Benefits of Carbon Fiber
Carbon fiber composites offer several advantages. One benefit is that they are more durable than other materials. Some other benefits of carbon fiber include:
high tensile strength
high stiffness weight
low thermal expansion
high chemical resistance
X-ray translucency
How Carbon Fiber is Made
Carbon fiber is a composite material formed by a combination of chemical and mechanical processes. The process starts by drawing long fibers, which are then heated to very high temperatures, not allowing contact with oxygen to prevent them from burning. This causes carbonization, which drives off most of the non-carbon atoms.
The fibers are then heated to high temperatures in various specialized environments, causing a chemical reaction between the molecules and converting them into carbides, which enhance the fiber's conductivity and make it stronger. The details of the process vary depending on the desired properties and uses of the product. Once the process is complete, the fibers can be used in everything from sporting goods to equipment and auto parts.
Carbon fiber composite manufacturing process
There are many different manufacturing processes for carbon composites including: filament winding, pultrusion, wet layup, vacuum bagging, resin transfer and tooling The process chosen depends on the application.
Winding
In filament winding, carbon fibers are wound on a rotating mandrel. This process is ideal for making structural parts with smooth curved surfaces, such as racing car bodies and kayaks. It also allows engineers to easily control where rebar is placed in the finished product. Therefore, the details of carbon fiber composite filament winding depend on the desired product.
Pultrusion process
The pultrusion process creates carbon fiber composites by pulling resin-impregnated rovings through heated resin to form them into specific sizes and shapes. How to manufacture carbon fiber composites produced in this way depends largely on the properties and uses of the desired product.
Wet layup, vacuum bagging and resin transfer
During these processes, carbon fiber cloth and/or unidirectional material, wetted with epoxy, is placed over a tool shaped like the desired part. For wet layup, excess resin is removed mechanically, usually with a flexible scraper or scraper. With vacuum bagging, a bag or film is placed over the part and a vacuum is used to remove excess resin. With resin transfer, after the carbon fiber cloth and bag are assembled on the tool, the resin is transferred to the part by vacuum.
Conclusion
Carbon fiber composites are excellent manufacturing materials for many components because of their ability to provide different physical properties depending on where the carbon fibers are located in the finished product. How each component is manufactured will depend on how much stiffness or reinforcement it needs, and ultimately, the process boils down to the use of the desired product.