Carpets and Rugs can be made from many singular or blended natural and synthetic fibres. Fibres are chosen for durability, appearance, ease of manufacture, and cost. In terms of scale of production, the dominant yarn constructions are polyamides (nylons) and polypropylene with an estimated 90% of the commercial market.
Nylon is the most common material for construction of carpets. Both nylon 6 and nylon 66 are used. 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 fibre. 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.
Polypropylene is used to produce carpet yarns because it is inexpensive. It is difficult to dye and does not wear as well as wool or nylon. Large looped Berber carpets made from this fibre 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.
Wool and Wool-blends
Wool has excellent durability, can be dyed easily and is fairly abundant. When blended with synthetic fibres such as nylon the durability of wool is increased. Blended wool yarns are extensively used in production of modern carpets, with the most common blend being 80% wool to 20% synthetic fibre, giving rise to the term "80/20". Wool is relatively expensive and consequently a small portion of the carpet market and a large percentage of the rug market.
The polyester known as "PET" (polyethylene terephthalate) 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.
Another polyester, "PTT" (Polytrimethylene terephthalate) , also called Sorona or 3GT (Dupont)or Corterra (Shell), is a variant of PET. 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 fibre 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.
The binding in woven carpets and rugs is usually cotton and the weft is jute or hessian .