Types of Fiber
The three commonly used fibers in a woven fabric are Fiberglass, Carbon, and Aramid(Kevlar). Fiberglass fibers are available as E-Glass or S-Glass, with E-Glass being the most commonly used all-purpose fiberglass while S-Glass is a high strength Fiberglass. Carbon fibers (Graphite) are one of the strongest and stiffest fiber types available. Carbon fibers are offered with low, Intermediate and High Strength properties. Kevlar(Aramid) fibers provide a combination of high strength, high stiffness and flexibility.
Carbon Fiber Strand Cross Section
This is a magnified view of a single strand of Carbon Fiber.
Hybrid woven fabrics are also available which contain different fiber types such as Carbon Fiber and Kevlar or Carbon Fiber and Fiberglass. Hybrid fabrics provide combined properties of each component.
Yarn Weight and Thread Count
Fabric thickness and weight are determined by the size of yarn and thread count of each woven fabric. Yarn (tow) is what is used to weave fabrics and is available in many sizes. The size is controlled by the number of filaments per strand. Common sizes of Carbon Fiber are 1K, 3K, 6K, 12K, and 50K. The K refers to thousands, for example a 3K yarn would have 3,000 filaments per strand and a 6K would have 6.000 filaments per strand. Fiberglass and Kevlar fibers are measured in Denier. The thread count of a woven fabric controls how tight the weave is; the more warp and fill yarns per inch results in a tighter woven fabric. Tighter weave fabrics would most likely be used for flatter applications as the tighter weave allows for a stiffer fabric. Loose woven fabrics offer more flexibility and are likely to be used as a finishing fabric or in an application with curved features.