Carbon fibre car parts are made through a detailed and precise process that involves several steps, including the creation of carbon fibre fabric, layering, molding, curing, and finishing. Here is a step-by-step overview of the process:
1. Creation of Carbon Fibre Fabric:
- Carbon fibres are produced from a precursor material, typically polyacrylonitrile (PAN) or pitch.
- The precursor is stretched and oxidized to align the molecular structure.
- It is then carbonized in high-temperature furnaces (up to 3,000°C) in an inert atmosphere to remove non-carbon elements, leaving behind a fiber composed almost entirely of carbon atoms.
- The resulting fibers are bundled into tows, which are then woven into fabrics or used directly in composite manufacturing.
2. Preparation of the Mold:
- A mold is designed and created based on the shape of the car part. This mold can be made from various materials, such as aluminum or fiberglass.
- The mold surface is treated with a release agent to prevent the carbon fiber part from sticking to it.
3. Lay-Up:
- Layers of carbon fiber fabric are cut to shape and laid into the mold. This can be done manually (hand lay-up) or by automated machinery.
- The fibers are arranged in specific orientations to achieve the desired strength and stiffness characteristics.
4. Resin Impregnation:
- The carbon fiber layers are impregnated with a resin, typically an epoxy, to bind the fibers together.
- This can be done in several ways, including wet lay-up (manually applying resin), resin transfer molding (RTM), or prepreg lay-up (using pre-impregnated carbon fiber sheets).
5. Vacuum Bagging and Curing:
- The lay-up is covered with a vacuum bag, and a vacuum is applied to remove air bubbles and ensure proper resin distribution.
- The assembly is then placed in an autoclave (a high-pressure oven) or an oven for curing. This involves heating the part to a specified temperature to harden the resin.
- In the autoclave, high pressure is also applied to consolidate the layers and eliminate any voids.
6. Demolding:
- Once the curing process is complete, the part is allowed to cool and then removed from the mold.
7. Trimming and Finishing:
- The cured carbon fiber part is trimmed to the final dimensions using precision cutting tools.
- Any necessary holes or fittings are machined.
- The part may be sanded and polished for a smooth finish, and protective coatings or paint may be applied.
8. Quality Inspection:
- The final part undergoes rigorous inspection to ensure it meets the required specifications and quality standards.
- This may include visual inspections, dimensional checks, and non-destructive testing methods like ultrasound or X-ray.
This process allows for the creation of lightweight, high-strength components that are highly valued in the automotive industry for their performance benefits, particularly in high-performance and racing applications.
Hopefully this provides a little insight into the work that goes intot creating your carbon fibre parts.