What is Carbon Fiber?
Carbon fibers are made from precursors such as polyacrylonitrile (PAN) and rayon. The precursor fibers are chemically treated, heated and stretched, then carbonized, to create high-strength fibers. These fibers, or filaments, are then bundled together in tows which are identified by the number of carbon filaments they contain.
Common tow ratings are 3k, 6k, 12k and 15k. The “k” refers to a thousand, so a 3k tow is made of 3,000 carbon filaments. A standard 3k tow is typically .125” wide, so that is a lot of fiber packed into a small space. A 6k tow has 6,000 carbon filaments, a 12k has 12,000 filaments, and so on. This large number of high-strength fibers bundled together is what makes carbon fiber such a strong material.
Carbon fiber typically comes in the form of a woven fabric, which makes it easier to work with and can give additional structural strength depending on the application. Because of this there are many different weaves used for carbon fiber fabric. The most common are Plain, Twill and Harness Satin, and we will go into more detail for each.