Fiber: The Final Frontier

Today we continue our talk about the different varieties. And of course; the natural floor.

Natural fibers made from organic sources that have not been chemically altered include wool, cotton, silk, sea grass, jute, and hemp. Natural fibers require more drying time because they are very absorbent, are more easily damaged by chemicals, shrink, stain easily, water spot, fade, and are readily attacked by mold and insects.

Silk is the only natural filament fiber. The fibers usually are about 1000 feet long. It is a protein fiber obtained by unreeling the cocoons of various silkworms. Characterized by a very high sheen, silk is very sensitive to alkali, sunlight, etc., and tends to yellow when exposed to alkaline detergents. Dye loss, yellowing, and ringing are common problems when cleaning silk. Silk is normally dry-cleaned. Wet cleaning is very risky because of the possibility of water spotting and watermarks. If silk is wet cleaned, only use a neutral detergent. The absorption of water breaks the bonds in the silk fiber and causes silk to lose approximately 20% of its strength. “Washable silk” results from a modification in the dye or a resin treatment to prevent fiber degradation. See the glossary for more detailed information.

Wool is normally from fleece (sheep hair), but in antique rugs the wool can also come from other animals like goat hair, etc. At one time, wool was the primary fiber in carpet, but its cost resulted in steadily decreasing market share. Wool has several excellent qualities. It hides soil much better than synthetic fibers because it is not clear and, therefore, soil cannot be seen through it, plus it has scale edges to further hide microscopic particles of soil. It is also the preferred fiber where cigarette burns are a problem, because it does not melt. Wool’s high moisture content and protein constituents provide natural flame resistance. Wool also “feels” softer to the touch. Wool carpets wear well and age beautifully and have a look and feel that is unmistakably their own. However, nylon and olefin carpets will last longer in high traffic areas.

Wool cells come in two different types: the paracortex and the orthcortex, which lie on opposite sides of the fiber and grow at slightly different rates. This causes a three-dimensional corkscrew pattern of coiled springs much like shock absorbers, giving wool high elasticity and a “memory” that allows the fibers to recover and resume normal dimensions. Wool fibers can be stretched up to 30 percent without rupturing and still bounce back.

However, wool is expensive, is easily stained by nearly everything, has very poor chemical resistance making spotting and stain removal much more difficult, mildews, is attacked by carpet beetles and moths, fades easily in direct sunlight, and attracts and stubbornly holds on to protein soils such as urine, blood, and meat juices. On the plus side; static electric shocks!

Here’s a chart explaining some of the discussed material’s properties.

The newer generation polyesters (P.E.T. or recycled bottles) are now rated higher due to improvements in manufacturing. They are RNB Floorings first choice for residential carpet.