Understanding Carpet Fiber and Pile Cuts

Nylon

Nylon is very soft, durable, and resistant to stains and abrasion. It is the most popular of carpet fibers by a large measure—by some estimates, about two-thirds of all synthetic carpets are made of nylon. It has good resistance to wear, mold, mildew, and rot, and it is easy to dye and holds its color well. It is usually affordably priced—less expensive than wool but more expensive than other synthetics. These carpets, if cared for well, can last 12 to 15 years, making it the most durable of the synthetic fibers.

Polypropylene (Olefin)

Polypropylene is another popular carpet fiber, used in commercial applications and in growing numbers of residential settings, and is almost as soft as nylon. Also known as olefin, polypropylene fibers are similar to natural wool and are often used as a synthetic wool substitute. This fiber is highly stain-resistant but is prone to soiling and holding onto oils which in turn, collect dirt. It is, however, relatively easy to clean—bleach can even be used in some cases. Polypropylene is not as resilient as nylon, so is therefore commonly used for loop-style carpets, such as berbers. The cost of polypropylene is slightly less than most nylon carpets, but more than polyester and acrylic.

Polyester

Polyester is prized for its ability to hold vibrant, fade-resistant colors. Because it is man-made, the fiber is also more hypoallergenic than some others. One type of polyester carpet, known as polyester/PET, is made from recycled plastic bottles, making it eco-friendly. Its main drawback is that polyester is prone to flattening under weight, making it a bad choice for high-traffic areas. It can also be prone to oil stains, which are very hard to remove from polyester fiber.

Acrylic

Sometimes marketed as "synthetic wool" because it offers the feel and appearance of wool at a fraction of the price, acrylic has good resistance to static electricity, moisture, mildew, fading, and staining. But it is not a very durable material, and it doesn't hold up well in high-traffic areas. It is sometimes blended with wool. Acrylics can sometimes turn brown if stained with certain alkaline chemicals, such as those found in cleaning products.

Wool

Wool, a natural, luxurious, long-lasting material, is the softest carpet fiber you can find. Unfortunately, low-grade wool is more susceptible to staining, while high-grade wool is extremely expensive. Some manufacturers combine wool with synthetic fibers to create a carpet with the benefits of both. Wool/acrylic blends are especially common.

Pure wool carpet is made with no chemicals or additives, which makes it an excellent choice for those with allergies or sensitivities to chemicals. But as a natural material, wool can be prone to damage from mold and mildew, which feed on organic substances. Wool is therefore not a good choice for areas where high humidity and moisture are an issue.

Loop Pile

Also known as "uncut pile" or "Berber pile" (named for a particular type of knotted pile used in North Africa), loop pile leaves the entire yarn loop intact on the surface of the piece. These carpets tend to be highly durable, easy to clean, and resistant to stains, making them perfect for high-traffic commercial applications or high-traffic family areas, such as recreation rooms. Loop pile carpets also don't show indentations caused by footprints and vacuum marks.

Loop pile carpet comes in variations, such as level loop, where the fiber loops are all the same length, and patterned loops, where the loops are different heights. It is also possible for a carpet to have cut-and-loop construction, where some fibers are cut and others are looped.

A particular type of loop-pile carpeting is the sisal carpet, in which loops of different colors, and sometimes different heights, are arranged in rows, to produce a textured, patterned surface.

• Caution: The loops of uncut pile are not only less soft and padded than cut-pile fibers, but experts warn how they can also be a snagging hazard, particularly for pets or small children.

Cut Pile

Cut pile is a style of carpet where the exposed fibers are sheared off. This typically produces soft, inviting, easy-to-clean carpets. Different styles can be created by changing the angle of the shearing that slices the loop, or by using different treatments on the thread before and after it is inserted into the backing. Cut pile comes in different lengths and thicknesses, and these carpets work well when an entire house is carpeted, as it blends well from room to room.

On the downside, cut pile makes it easier to see footmarks and vacuum trails. This tendency can be reduced by the twist of the fibers. The individual fibers contain a twist that helps the carpet stand up against matting and crushing. The heavier the twist, the more resistant the carpet will be to matting. Heavy twist also helps create texture that hides wear and dirt.

Although much more popular than loop-pile carpet, cut-pile carpets are not as durable and will need to be replaced more often. They come in several variations, including shag carpet, a term which refers to a deep pile carpet featuring long-haired fibers that are soft to touch. Shag carpet is now relatively rare, but other specialty cut-pile forms (described below) are quite popular and used for particular effects.

Saxony Cut

The term Saxony pile refers to a particular type of cut-pile carpet with fibers that are very soft and dense. The relatively short fibers stand straight up and down to create a lush, fuzzy surface. The drawback to this style is that those strands are easily crushed down by feet and vacuum cleaners, leaving impressions on its surface. It is also susceptible to wear-and-tear, as well as staining, making Saxony carpets a floor treatment best suited for use in low-traffic areas, such as formal living rooms or dens. They are also somewhat more expensive than traditional cut-pile carpets.

Plush Pile

Sometimes called velvet-cut pile, this style is a variation of cut pile in which the fibers are even shorter than with a Saxony cut and very densely packed, which creates a rich and luxurious carpet surface. Unfortunately, this carpet style is fairly temperamental. Prone to wearing down, scuffing, and showing footprints, velvet carpet pile should only be used in luxurious, low-traffic settings.

Textured Cut

The term textured-cut pile refers to a form of cut-pile carpet in which the fibers are of uneven lengths. They are also twisted into spiral strands using a special steam treatment that curls the individual strands so that they remain kinked. This style is also called "trackless" because it doesn't show footprints and other marks on its surface as do other cut piles, such as Saxony. The spiral strands do not reflect light as much as straight strands, so it's not as noticeable when spirals are crushed down. This pile is suitable for mid- to high-level traffic areas.

Frieze-Cut Pile

The term frieze-cut pile refers to a carpet in which relatively long cut fibers are twisted together and kinked, causing them to curl erratically across the surface of the carpet. (This style is sometimes known as California shag.) This highly durable style tends to hide dirt and wear and is suitable for high-traffic and commercial settings.

Sculpted Pile

A sculptured carpet has both looped and cut-pile fibers, which creates height and texture variations in the surface of the carpet. These carpets are sometimes known as cut-and-loop or patterned carpets. The different fiber cuts are sometimes arranged in geometric patterns, giving the carpet a three-dimensional texture. The different fiber cuts can all be the same length (level cut-and-loop), or they can be at different heights (textured cut-and-loop).