What is CFRP?
CFRP (Carbon Fiber Reinforced Plastic) is an advanced lightweight composite material composed of carbon fibers and thermosetting resins.
Manufacture of carbon fibers for post processing
Carbon Fiber Fabrication – Post-treatment is the final stage and once complete, the CFRP part is ready for assembly. In post-processing, carbon fiber trimming removes excess material if necessary and carbon fiber cutting is used to feature machine parts in CFRP. Using Waterjet technology or robotic router technology – unrivaled accuracy and speed using robots for post CFRP trimming, laser software and guidance software technology can make all the difference carbon fiber sheet manufacturer.
Robotic carbon fiber trimming systems are easy to use and easy to maintain and recover. Learning Path Control (LPC), Learning Vibration Control (LVC) combined with Adaptive Process Control (APC) technologies increase the speed of automated trimming by up to 60% beyond what is possible out of the box. Accufind and iRCalibration are technologies that use IR vision technology and CCD to maintain selected path accuracy while maintaining CFRP cutting speed.
Waterjet, dry router and wet router technologies can all be suitable for carbon fiber cutting or carbon fiber cutting according to part characteristics and production requirements. A variety of studies and tests are available to find the best carbon fiber cutting solution for a specific carbon fiber reinforced carbon part.
Fiber in CFRP
CFRP begins as an acrylonitrile plastic powder that is mixed with another plastic, such as methyl acrylate or methyl methacrylate. Then, it is combined with a catalyst in a conventional suspension or solution polymerization reaction to form a polyacrylonitrile plastic.
The plastic is then spun into fibers using several different methods. In some methods, the plastic is mixed with certain chemicals and pumped through small jets into a chemical bath or combustion chamber where the plastic coagulates and turns into fibers. This is similar to the process used to form polyacrylic textile fibres. In other methods, the plastic mixture is heated and pumped through small jets into a chamber where the solvents evaporate leaving hard fibers. The spinning step is important because the internal atomic structure of the fibers is formed during this process.
Then the fibers are washed and stretched to the desired fiber diameter. Stretching helps align the molecules within the fibers and provides the basis for the formation of tightly bonded carbon crystals after carbonization. Before charring the fibers, they must be chemically altered to change their linear atomic bonding to more stable ladder bonds. To do this, the fibers must be heated in air to about 380-600 F for an hour or so. This causes the fibers to pick up oxygen molecules and rearrange the structure of the atomic bond. Once this process is complete, the fibers will settle.
Once the fibers have settled, the carbonation process begins. The fibers are heated to 1800F to 5300F for a few minutes in a furnace filled with a mixture of gas and no oxygen. The lack of oxygen prevents the fibers from igniting at the high temperatures required for this step. Oxygen is kept out by means of an air seal as the fibers enter and exit the furnace and keep the gas pressure inside the furnace higher than that of the outside air. As the fibers heat up, they begin to lose their non-carbon atoms in the forms of gases such as water vapor, ammonia, hydrogen, carbon dioxide, nitrogen, and carbon monoxide.
When the non-carbon atoms are removed, the remaining carbon atoms begin to form tightly bound carbon crystals aligned with the long side of the fiber. After this carbonization process is completed, the fibers will have a well-formed non-cohesive surface. In order to give the fibers better bonding properties, their surface must be oxidized, giving the fibers a rough texture and increasing their mechanical bonding ability.
Next is the sizing process. For this, the fibers are coated with a substance such as epoxy or urethane. This protects the fibers from damage in the winding and weaving phase. Once covered, the fibers are spun into cylinders called bobbins. The spools are then put into a machine that converts the fibers into filaments. These filaments can then be used to weave a carbon fiber filament fabric 1mm carbon fiber sheet.
In the next step, a durable, lightweight cuticle is created using a process called overlay. In this process, carbon fiber fabric is placed over a mold and combined with resin to create its final shape. There are two methods that can be used for the overlay process. The first is called “wet wet carbon fiber”. In this process, a dry carbon fiber sheet is placed over the mold and wet resin is applied to it. The carbon fiber resin gives rigidity and acts as a bonding agent. The second process is called “prefabricated carbon fiber laying”.