Materials Science: Interesting Facts About Carpet Materials

Although polyester also occurs naturally, the term generally refers to the large family of synthetic polymers that are used in many fields today. The properties of polyester can be varied depending on the type of monomers used. Polyester is extremely popular in the production of upholstery fabrics and carpets, in part because it offers many design options. An overview of the advantages:

• Polyester fibers are durable, sturdy, and lightfast
• They are highly elastic and retain their shape well. Polyester fibers are stain-resistant, quick-drying, and easy to care for.
• Polyester provides thermal insulation
• Generally resistant to moth damage
• Also suitable for heavy-duty use, such as in children's rooms or hallways
• Can also be used in the bathroom
• Shag and short-pile carpets are available

Polypropylene is one of the lightest commercially available fibers. It was developed in Germany in the mid-1950s. In the textile industry, the combed yarn Polycolon is primarily used for the production of home textiles, sportswear, and carpets, among other things. An overview of the material’s properties:

• Extremely Lightweight Fiber
• High surface tension, which allows the liquid to be transported particularly quickly
• Extremely durable, abrasion-resistant, and sturdy
• High impact sound and thermal insulation
• A particularly versatile fiber that is suitable for a wide range of design applications, including high-pile and low-pile carpets

Carpets made of polypropylene fibers are durable all-around options that can be used anywhere in the house, even in the kitchen, bathroom, or hallway.

Thanks to its soft sheen, viscose is often used as an affordable substitute for silk. Viscose is a natural synthetic fiber. This contradiction becomes clear when you take a closer look at how it’s made. Cellulose fibers, which are derived from various types of wood as well as from banana and bamboo fibers, serve only as the basis for viscose. Through the addition of chemicals, the cellulose is transformed into a viscous mass that is spun into fibers using a wet process. Viscose has properties similar to cotton but can be processed even more finely. As a result, viscose rugs are usually more densely woven and feel softer and more velvety. An overview of the material’s properties:

• Appearance: Silky sheen, unique color effect
• High absorbency, similar to cotton
• A renewable, affordable raw material
• Also suitable for people with pet dander allergies

Please note: Viscose is not quite as durable as silk. It is less elastic and less effective at regulating body temperature than, for example, virgin wool.

Modal is a modern, high-quality carpet fiber also known as “premium viscose.” Modal is derived from the plant fibers of beech wood, is biodegradable, and is considered an innovative synthetic fiber of natural origin. To produce modal, the wood is debarked, split into chips, and the fibers are extracted from the cellulose through a mechanical spinning process. Modal carpets are sturdy, durable, and breathable. They have a distinctive look, are very soft, and lend rooms a pleasant, cozy atmosphere. Modal retains its shape, is durable, and is heat-resistant. Modal is also machine-washable and absorbs moisture better than other materials. These are just a few reasons why modal carpets are something truly special.

A

Abrasch

In Arabic, “abrash” means “shade” and refers to a variation in shade within a single color, such as in solid-color rugs. Rugs that display abrash are always hand-knotted. The varying shades indicate the use of wool from different dye lots. Abrash should by no means be considered a defect.

Age Classification of Carpets

With carpets, the designation indicates how old a particular piece is. Customs regulations stipulate that carpets over 100 years old are classified as antiques. Carpets over 30 years old are called “old carpets.” If a carpet is between 10 and 15 years old, it is classified as “demi-old.” Carpets younger than 10 years are considered new carpets.

B

Beni Ourain

Pronounced “Beniquarein”—this term refers to woven or knotted rugs made by Berber women from the northern Atlas Mountains. Only undyed sheep’s wool is used. The rugs have fringes on only one side.

Berber rug

Traditional Berber rugs usually come from Morocco. These rugs are always hand-knotted, with the warp and weft made of cotton, while the pile is knotted from 100 percent virgin wool. Various knotting techniques are used, with a choice of two, four, or six threads. Berber rugs are usually very thick, with a pile height ranging from 14 to 30 mm. Once the rug is finished, post-processing such as stretching or shearing is necessary.

Bleaching

Bleaching refers to the process of lightening the color of the carpet and removing stains from the carpet material.

Bridge

A "Brücke" is a particularly small rug (usually measuring 70 x 140 cm)

Border

A border is also called a trim and refers to the decorative edge of a rug.

Bouclé

Bouclé refers to a type of fabric with a coarse surface texture. It is made partly or entirely from hair yarn and fancy yarn, often incorporating knots, nubs, and loops that remain visible.

C

Chenille Pile

Carpets with a chenille pile are especially plush. Chenille carpets are usually machine-made.

D

Djufti Knot

The Dujfti knot involves a particularly economical use of common knot types. Instead of tying two knots, the weaver ties only one knot in the direction of the weft. This is a simple and ancient weaving technique designed to save material and, above all, labor. However, the Dujfti-woven pile is noticeably thinner due to its reduced density.

Do-rudjeh

"Do-rudjeh" refers to very rare, special Oriental carpets that have a pile on both sides.

Dorri

Dorri, also known as Dhurrie or Durrie. This is an Indian cotton rug produced throughout India. They are very popular because they are durable, affordable, and colorful.

E

real carpet

All handmade rugs are considered genuine rugs. It doesn't matter whether they are knotted or woven. Their origin is also irrelevant.

true colors

"True colors" refer to the use of yarn that has been dyed using the correct technical process and is colorfast.

Eulanize

Eulanization refers to a protective treatment against moths that involves the use of an insecticide.

Entry

"Threading" refers to the process of threading the needle.

F

Fiber Blend

A fiber blend refers to a mixture of different types of fibers that have been used.

Flax

When used, flax fiber imparts a uniquely subtle sheen. Flax fiber is smooth, tear-resistant, and extremely elastic. Flax is strong and, unlike cotton, does not need to be re-stiffened. The fiber is lint-free and resistant to dirt and bacteria; it is also antistatic and stain-resistant. Furthermore, flax fiber absorbs up to 35% of the ambient humidity and quickly releases this moisture back into the air. As a result, flax has a slightly cooling effect.

Flor

Pile refers to the raised fibers on the surface of a carpet. A distinction is made between velour, loop pile, twisted pile, cut pile, corduroy, weft velvet, and velvet.

Turf density

The term "pile density" refers to the weight of the pile yarn used per unit volume of the carpet. The closer the fibers are to one another, the denser the carpet surface is and the more durable the carpet is.

Pile weight

Pile weight refers to the total weight of the carpet's surface.

Pile height

Pile height refers to the length of the fibers, measured from the tip of the fiber to the carpet's backing.

twisted staple fiber

Twisted pile fibers consist of two or more yarns twisted together.

Subject

In weaving or knotting techniques, the term "shuttle" refers to the space between the front and back warp threads. The weft thread is inserted into this space.

Color fastness

Colorfastness refers to the resistance of colors to all environmental factors and thus indicates the use of high-quality dyed yarns.

Flat-woven fabric

Oriental rugs without a pile are referred to as flat-woven rugs.

Flokati

Flokati rugs are particularly plush rugs with a high pile and originated in Greece.

Fringes

Fringes are the loose warp threads at the crosswise ends of a rug.

Filler shot

"Filling closure" refers to an additional weft thread that is woven in to give the hand-knotted rug elasticity.

Lint

Lint refers to the excess fibers in a pure-wool carpet. A new carpet contains more lint than an old one because it hasn't been vacuumed as often yet.

G

Gabbeh

Hand-knotted Persian wool rugs featuring simple geometric diamond and animal patterns are also produced today in India and Pakistan.

Yarn Production

The raw material for all fabrics, whether pile or non-pile, is yarn. To produce yarn, the fibers of the raw material are aligned parallel to one another. This process is called carding. The individual fibers are then twisted together; this is called spinning. Several twisted yarns are combined to form a twisted yarn. There are both hand-spun and machine-spun yarns.

pile carpet

A layered carpet is characterized by the fact that two warp threads of the base fabric stand almost vertically one above the other. On the back of the carpet, only one of the two legs of each knot is visible as the knot loop; the other is hidden beneath it.

woven

In woven carpets, the pile is woven into the integrated backing.

Shine Wash

"Full wash" refers to a finishing process using sodium hypochlorite that imparts a special sheen.

Gallery Rug

Gallery rugs are long, narrow rugs designed for hallways and corridors. The length of a gallery rug is at least three times its width. Lengths range from approximately 2.5 meters to 20 meters, and widths range from 0.5 to 1.5 meters.

H

Hand-tufted rug

Tufting is not only done commercially using machines (such as those used for carpeting), but also by hand. Using a tufting gun, the pile yarn is inserted from the back of a backing fabric made of 100% cotton in such a way that any desired texture, cut pile, or loop pile can be created on the front side of the fabric. Any desired size and shape can be tufted, and the material, shape, color, texture, and design can all be customized. Hand-tufted carpets are manufactured in Germany, Central Europe, India, China, Thailand, Singapore, and Hong Kong. After the pile yarns are tufted, they are coated with a latex compound on the back of the carpet, thereby anchoring them in place. The carpets are then dried in the sun or in drying rooms. Next, the carpet is fitted with a cotton backing, the edges are bound, the pile is sheared smooth, and the pattern is highlighted by a relief cut. These steps are performed entirely by hand. The material and the weight of wool used per square meter are the main factors determining differences in quality and price.

Hemp

Hemp is a genus of plants in the Cannabaceae family and is used, among other things, as a fiber crop. Hemp fibers are particularly long, tear-resistant, and durable, and their structure is similar to that of cotton fibers.

horizontal loom

A loom is referred to as a "horizontal loom" when, as is the case with nomads, it lies flat on the ground.

J

Jute

Jute is a bast fiber derived from the stems of Corchorus plants. These annual, herbaceous plants can grow up to 4 meters tall and are native to East Asia. Jute is used to make natural-fiber rugs.

K

Cashmere wool

Cashmere wool is a particularly fine-fibered wool from the Himalayas, similar to angora wool. It is obtained by combing the undercoat of the cashmere goat and is very valuable, though it is not durable enough for carpet production.

Kelim

A kilim is a handwoven Oriental rug without a pile. It is also known as a flat-woven rug and looks the same on both the front and the back.

warp threads

Warp threads are the threads that are stretched lengthwise on a loom in a weaving mill. In the finished fabric, they run parallel to the selvedge.

Tying

To create the fabric, a base structure of warp threads is required (see Weaving), to which the weft yarn—made of silk or wool—is knotted by hand, row by row. The higher the knot count (at least 1 million per square meter), the higher the price.

synthetic fiber

Synthetic fibers are defined as all types of fibers that do not come from plants or animals and are produced through chemical processes. These include, among others, the cotton-like cellulose fiber viscose, which is very soft, lustrous, and takes dye exceptionally well, but does not tolerate moisture very well. So-called synthetic fibers include polyester, polyacrylic, and polypropylene. They are very sturdy, durable, and resistant to moths and light.

L

runner

"Runners" are long, narrow rugs that are ideal for hallways.

Chandelier

In other words, luster refers to the sheen of a carpet's pile.

M

Mercerizing

Mercerization refers to a special process in which cotton is treated in a bath of strong, cold caustic soda solution to give it a silky sheen.

Pattern Repeat

A pattern repeat refers to a continuous, uniform sequence of patterns on a rug.

Machine-woven carpet

Machine-woven carpets are produced by feeding yarn from thousands of spools into a large mechanical loom, which weaves the carpet according to a specific pattern in a short amount of time. During the manufacturing process itself, different patterns and sizes can be produced simultaneously. The number of colors that can be used is limited; typically, 8 to 10 colors can be combined.

Dimensions

The length of a rug is measured without the fringes. For some rugs, the length may also vary depending on whether the rug has shrunk slightly during cleaning or if there were other irregularities during production. For nomadic rugs, the width may also differ from the actual measurement.

N

New Zealand wool

New Zealand wool bearing the “Wools of New Zealand” seal of quality is exceptionally high-quality, pure new wool. New wool is elastic, naturally stain-resistant, does not build up static electricity, provides excellent warmth, and is ideal for any room.

O

Oriental rug

Oriental rugs are defined as all rugs that are handmade and originate from the countries of the Orient.

P

Plant-based fibers

Plant-based fibers include banana silk, cotton, jute, hemp, and flax.

Palace carpet

"Palace carpet" is the trade name for large-format, high-quality Oriental carpets.

Portrait Carpets

Portrait rugs are Oriental rugs featuring portraits of famous people.

R

Blank

A "blank" refers to a fully woven rug that has not undergone any post-processing.

Pure New Wool

"Pure new wool" is a protected term worldwide. It may only be used to describe new wool sheared from live sheep.

Relief Shearing 

The term "relief shearing" refers to the process of shearing out the contours to emphasize the boundaries of the pattern.

Rips

Rib refers to a special weaving technique that creates the appearance of a ribbed pattern in the fabric. Rib is woven using two types of weft threads—one coarse and one very thin—which create the ribbed pattern. Rib carpets are woven with a cotton warp; changing the color of the warp creates a checkered pattern.

S

Silk

Silk is a fine and precious natural fiber obtained from the silkworm cocoon.

Sumac

A sumak is a non-pile woven rug. It differs visually from a kilim in its shaggy threads—which are about 10 cm long and hang down from the back of the rug—and its herringbone-like pattern on the surface.

Loop Pile

In loop-pile carpeting, the yarn is pulled through the carpet backing in a loop-like pattern.

Warp threads

In the manufacture of a fabric, the weft threads are those parallel threads of a textile fabric that run perpendicular to the warp threads stretched on the loom.

Sheep's wool

Sheep's wool, which consists of a protein compound (keratin), is by far the most common and most important yarn material used in the production of woven and knotted carpets. It is used for the pile as well as, in some cases, for the warp and weft of the base fabric.

Scissors

"Shearing" refers to the process of trimming the pile during and after the carpet is completed.

Clamping

The term "stretching" refers to the process of smoothing out wavy carpets.

Stroke Direction

The direction in which the pile points is called the style

Shaggy Rug

A shaggy rug is a high-pile rug that is characterized by its shaggy and scruffy appearance. It is particularly soft.

Sisal Rugs

Sisal rugs are undyed, simply woven rugs made from fibers extracted from the leaves of the sisal agave.

Soumak Technique

A technique in which the yarn is passed over four warp threads and back under two warp threads.

T

The History of Carpets

There is little disagreement regarding the origins of hand-knotted carpets. The general consensus is that the first carpets were made by nomads to protect themselves from the cold. These were flat-woven carpets. Carpet-making is a very ancient craft. During archaeological excavations in 1949, a carpet dating back to 500 B.C. and exhibiting high artistic and technical quality was discovered in southern Siberia. In antiquity and the early Middle Ages, carpets were used as gifts for guests. With the emergence of Islam in 662 A.D., carpets began to spread more widely. According to the Quran, every believer should use a clean surface for prayer. The simplest solution was to use a carpet. Mosques were also decorated with carpets. Through trade, carpets found their way to Europe during the Middle Ages and the Renaissance. At that time, collecting carpets was an expensive hobby for wealthy Europeans and, later, Americans. The first import companies established themselves in the countries of origin around 1880 to organize transportation and production. Beginning in 1990, the second wave of carpet popularity took place in the West. Carpets became affordable and met Western standards.

Animal Fibers

Animal fibers include sheep's wool, cashmere, goat hair, and silk.

Turkish Knot

The Turkish knot is tied symmetrically over a pair of adjacent warp threads; both threads are completely enclosed by the weft yarn.

Tibetan Knot

The Tibetan knot resembles the Persian knot, but is looped around a rod. When a row of knotted loops is placed in the direction of the weft, the upper loops are cut open, causing the pile to fan out. This results in a “striped” knotted pattern typical of Nepal, which clearly reveals the individual rows of knots in the pile.

Carpet Size Designations in Germany

In Germany, traditional size designations based on so-called “quarters” are still in use. They are based on the old Prussian ell. The first number indicates the width in quarters of an ell: Carpet size specifications: 4/4 is approx. 70 x 140 cm, 6/4 is approx. 90 x 160 cm, 8/4 is approx. 120 x 80 cm, 9/4 is 140 x 200 cm, 10/4 is approx. 170 x 240 cm, 11/4 is approximately 200 x 250 cm, 12/4 is approximately 200 x 300 cm, 15/4 is approximately 250 x 300 cm, 16/4 is approximately 250 x 350 cm, and 18/4 is approximately 300 x 400 cm.

Carpet underlay

The carpet pad is placed under the carpet to protect it from wear and prevent it from slipping on smooth floors.

Tufting

Tufting refers to a technical process for embedding pile yarns into a base fabric.

Talim

The term for a design template for a hand-knotted rug. Usually a pattern drawn on graph paper.

U

Re-stringing

In the edging process, the carpet or runner is edged with color-coordinated ball yarn or wool using a chain stitch. This creates professional, clean edges and prevents the cut edges from fraying.

uncoated carpet

In an unpile carpet, all warp threads lie side by side on the same plane. Since each knot consists of two legs, two adjacent loops are visible on the back of the carpet for each knot; these must be counted together as a single knot.

University Rugs

Solid-color rugs are called "uni."

V

vertical loom

Among sedentary weavers and in weaving mills, the looms are usually upright—these are known as vertical looms.

Finished Linen

A cleaning treatment to change the carpet's colors and overall appearance.

Viscose Process

Industrial process for the production of rayon from cellulose.

Nonwoven fabric

"Fleece" refers to sheared sheepskin that is still in one piece.

W

Weaving

In weaving, one of the oldest crafts, two sets of threads are interlaced at right angles, either by machine or by hand: the vertical, pre-tensioned threads are called the warp, and the threads inserted across them are called the weft. Woven rugs generally have no pile.

Tapestry Carpets

A term used to describe Oriental rugs without a weft or pile.

Y

Yak hair

The yak is a species of cattle native to Central Asia. The hair of this species is quite stiff and is found exclusively in old and antique carpets from the Tibetan region.

Z

A Z-twist refers to the direction of yarn twisting, which is counterclockwise.

Cellulose

Cellulose is a product derived from pulp that is used to manufacture “artificial silk.”