Fibers and yarns used in carpet
Carpet can be made from many single or blended natural and synthetic fibers. Fibers are chosen for durability, appearance, ease of manufacture, and cost. The most important yarn constructions are:
Wool and wool blended with synthetic fibers: Wool has excellent durability, can be dyed easily and is fairly abundant. When blended with synthetic fibers such as nylon the durability of wool is increased. Blended wool yarns are extensively used in production of modern carpet. Wool is relatively expensive.[5]
Nylon: This is the most popular synthetic fiber used in carpet production. Nylon can be dyed topically or dyed in a molten state (solution dying). Nylon can be printed easily and has excellent wear characteristics. In carpets Nylon tends to stain easily because it possesses dye sites on the fiber. These dye sites need to be filled in order to give Nylon any type of stain resistance. As nylon is petroleum-based it varies in price with the price of oil.[6]
Polypropylene: This polymer is used to produce carpet yarns because it is cheap, although it is difficult to dye and does not wear as well as wool or nylon. Large looped Berber carpets made from this fiber are usually only suited for light domestic use and tend to mat down quickly. Berber carpets with smaller loops tend to be more resilient and retain their new appearance longer than large looped Berber styles. Commercial grade level-loop carpets have very small loops, and commercial grade cut-pile styles are well constructed. When made with polypropylene (also called Olefin) these styles wear very well, clean easily and are suitable for areas with heavy foot traffic such as offices. Commercial grade carpets can be glued directly to the floor or installed over a 1/4" thick, 8-pound density padding. Outdoor grass carpets are usually made from polypropylene.[7]
Polyester: Polyester Also known as "PET" is used in carpet manufacturing in both spun and filament constructions. After the price of raw materials for many types of carpet rose in the early 2000s, polyester became more competitive. Polyester has good physical properties and is inherently stain-resistant because it is hydrophobic, and, unlike nylon, does not have dye sites. Color is infused in a molten state (solution dyeing). Polyester has the disadvantage that it tends to crush or mat down easily. It is typically used in mid- to low-priced carpeting.[8]
PTT: PTT polymer, also called Sorona or 3GT (Dupont)or Corterra (Shell), is a variant of Polyester. Lurgi Zimmer PTT was first patented in 1941, but it was not produced until the 1990s, when Shell Chemicals developed the low-cost method of producing high-quality 1,3 propanediol (PDO), the starting raw material for PTT Corterra Polymers. PTT is similar to Polyester, but its molecules have a "kink", similar to a spring, that makes the fiber more crush resistant, resilient, and easy to clean. PTT also does not have dye sites, and is inherently stain resistant because color is infused in a molten state. Carpets made with PTT dry quickly and are resistant to mold.[9]
The binding in woven carpet is usually cotton. and the weft is jute.[10]
http://en.wikipedia.org/wiki/Carpet