Carbon fiber (also known as carbon fibre) is one of the strongest and most lightweight materials available on the market today. Five times stronger than steel and one-third its weight, carbon fiber composites are often used in aerospace, aviation, robotics, racing, and a wide variety of industrial applications.
Carbon fiber starts as very, very thin strands of fiber that are finer than human hair. These strands are twisted together like yarn (called a tow) and woven into carbon fiber fabric which typically comes in 3k, 6k, and 12k weights. A 3k fabric has 3,000 strands of carbon in each tow while a heavier weight 6k fabric has 6,000 strands per tow.
The fabric comes in a variety of weaves that have different strength properties. The most common are plain weave, harness satin weave, twill weave, and unidirectional.
Weave is critical for two reasons: appearance and functionality. Each weave looks very different and sometimes people prefer the look of a certain weave for a specific application. Weave also impacts product strength.
A unidirectional weave creates a sheet that’s very strong in the direction of the fibers, but weak in the opposite direction. Plain and twill weaves, on the other hand, have more uniform strength since they’re strongest at the points where the fibers cross in either direction.
To make a sheet (also known as a composite), carbon fiber fabric is saturated or infused with epoxy resins and heated at high temperatures. Shaped pieces are made by layering several pieces of fabric over a mold, saturating them with resin, and heating it until the resin has infused through all layers.
Carbon fiber composites stand out from the crowd for several reasons. Here are a few: