Wool has been used for weaving for thousands of years. Its a quite remarkable material. Nature has made a fiber that performs much better than any man made fiber in most situations. In fact, There are only a few things that a Polypropylene does better than wool. Polypropylene or just “Poly” as it will be here is almost totally waterproof. This means that it is almost stain proof. The color component is added to the molten plastic before fiber extrusion so the color is not removable even with oxidizers like bleach. When it comes to spills, Poly is bomb proof. This is a good choice for people with pets or young kids. Poly is a good choice for any area that food and drinks will be consumed in. Poly rugs have evolved from scratchy rough rugs to rugs with all the soft feel you would expect from silk. Technology has allowed combinations of thin and extra thin fibers in a single yarn to give a sifter feel but still have the strength and stain protection of the poly material. New machines can weave these poly rugs very fast and with more parameter variations possible to allow many different designs. In addition to paying less for a Poly rug than a wool one, you can expect a Poly rug to be cheaper to have professionally cleaned and also more effectively spot cleaned at home with a bottle of neutral spot cleaner like Carpet rescue available at carpetanswer.com. Although Poly rugs are all around less expensive than wool, they are not cheap rugs. They have their place, and are a good match for active households.
Wool fibers have a unique shape that can only be seen with a microscope. The hollow twisted tube structures within the wool fiber are amazing temperature insulators. Wool rugs are great at insulating a cold tile floor so walking bare foot is comfortable. Some rugs from Tibet and Nepal are woven thick and coarse to give amazing insulation from a floor that could be below freezing temperature.
Wool rugs have shown us over long periods of time that they hold up better to foot traffic than any other fiber. Its not so much the structure of an individual wool fiber that resists abrasion, its that when put together side by side with lots of other wool fibers in a pile carpet, the fibers act together and absorb foot traffic and particle abrasion very well. The denser the pile yarns are squeezed inside the perimeter of a rug, the better the rug will resist foot traffic wear. When the fibers are packed tight(plush), all foot contact it hitting the fiber on the top tips instead of the long side. This makes the lifespan many times longer when the pile is dense. A rug with a dense pile will cost more due to more material costs. This extra cost is well spent money by a consumer. A 20% increase in price can result in double the lifespan.
Wool has an amazing ability to resist breakdown from oxidizing air and atmospheric conditions along with an ability to resist mold and decay. Wool has a sulfur component that is responsible for the wet wool smell that some people say reminds them of a wet dog. This sulfer keeps the wools natural pH way below what we call neutral(7). This helps protect it in many ways, one of which is helping the fiber resist oxidizing damage from the elements. Wool is very cleanable. It does not wear down the rug to have it professionally washed. A major and perhaps the most important part of a quality rug washing procedure should be removing dry soil from the core and pile of the rug. This dry soil which is made up partially of sand, is responsible for the wearing of the pile of any rug. It acts as sandpaper under a walking shoe sole. Because wool is an opaque fiber, it hides the appearance of dirt longer than a shiny fiber like Poly. A poly rug will look much dirtier sooner than a wool rug. The wool fiber is already sort of dull in appearance so when the sand in a rug starts to wear down the rug, It still looks like it always has but just more worn. When a Poly rug gets worn from foot traffic, it is sanding down a once shiny poly fiber to now be dull. The result overall looks like a dirty traffic lane but in reality the dirt is only one part of the problem. After the dirt is removed by washing, there is still a dirty looking path across the rug. This is where the fibers are all dull and are simply not reflecting as much light as the adjacent non-sanded down fibers. A Poly rug with a very densely packed pile can minimize this dulling effect but a wool rug will always look better in every stage of its life than a poly rug. Wool has been used for a long time and will continue to be the best fiber on the planet. It is renewable, it supports local farmers in the rug weaving communities, it is dye-able with non toxic dyes, biodegradable, and is an all-around great fiber.