A Look Inside the Carbon Fiber Fabrication Process

Carbon fiber is a material that is used in many different industries. It has been around for decades, but it continues to be popular today because of its versatility and durability.

The carbon fiber design process is unique depending on what the carbon fiber will be used for. While some processes are more difficult than others, each one takes time and patience to complete correctly. Keep reading to learn how carbon fiber is designed.

How Carbon Fiber is Made

Step 1: Precursor

To produce carbon fiber, an organic polymer precursor is required. The raw material is processed with heat and chemical agents to form carbon fiber.

The most common high-performance carbon fiber is currently made from polyacrylonitrile (approx 90%) and petroleum pitch or rayon (10%).

Step 2: Manufacturing

Carbonization is the first step in creating high-quality carbon fiber. Typically, a precursor polymer contains a high percentage of carbon atoms; therefore this step eliminates most non-carbon elements.

Before the material can be made, it must first be pulled into long fibers. These fibers are heated to very high temperatures in an anaerobic gas mixture (without the presence of oxygen) to ensure the materials don’t burn. This process energizes the atomic structure and drives off most non-carbon atoms.

Step 3: Treatment

After the carbonization is done, minor surface treatment is needed to improve chemical and mechanical bonding properties. Oxygen helps oxidize the fibers which improves adhesive strength while roughening up the surface of the fiber enhances mechanical adhesion.

There are several ways to oxidize carbon fiber, which include exposing it to certain gases such as carbon dioxide or ozone, liquids such as nitric acid, and processed electrolytically.

Step 4: Sizing

Prior to weaving, the carbon fibers are sized by coating them with a polymer. They are then wound onto bobbins, spun, and processed into various weaves and formats depending on their use.