Coated or Sized Fabric

Coated fibers are tightly woven or knit-based fabric that is coated on one or both sides with a synthetic or natural elastomer. The selection of fiber and fabric for coating depends on the application. Coating is used to enhance the strength, abrasion resistance, stiffness, thermal stability, water repellency and air permeability of the fabric. This technique is often seen in applications such as in life rafts and diving suits. Woven, knit, tufted, and non-woven fabrics are used in coating. There are many materials that can be used for the coating and there are several options available for applying the coating.

Sized fibers have been treated to reduce the hairiness around the fiber. It is part of a slashing process and reduces the hairiness that would interfere with the weaving process. This protects the yarn from yarn-to-yarn and yarn-to-loom abrasion as well as increasing the strength of the yarn so it can make it through the loom without breaking. If the process is done incorrectly, the long hair fibers around the yarn will be glued to the adjacent yarns and the strands will be damaged when they put through the loom. Proper sizing requires the size film, which can be a variety of polymers, to coat the yarn surface without excessive penetration into the body of the yarn bundle.