Carpet Types, Properties, Manufacturing, Uses and Maintenance

Saiful Sabuz
Department of Textile Engineering
Ahsanullah University of Science & Technology (AUST)
Email: saifulsabuz.tex23@gmail.com

Carpet:
Carpet is a rich floor covering which is basically a textile product consist of two layers, upper layer call “pile” attached with pre woven lower layer. Carpet is generally made from wool, jute fiber or manmade synthetic fibers. There is a difference between carpet and Rug. Carpet is basically use wall to wall when rug is smaller in size and can be used here and there in the room. Carpets have a minimum weight of 200 g/m². Generally, the surfaces and the backs of carpets are made of different materials.

Different Types of Carpet:
An overview of the various types of carpet are given in below figure.

Plain carpets:
Plain carpets are composed of warp and weft threads without a thread system that would constitute the pile. Plain types of carpet are usually manufactured by hand in plain weave.

Pile carpets:
Besides the basic weave, pile carpets have an additional thread system that makes up the upper side of the carpet. With loop-pile carpets, the pile threads appear in loops on the carpet surface. With cut-pile carpets, the pile threads appear sheared on the surface of the carpet.

Wire carpets:
These carpets have a layer of wire plush piles.

Axminster carpets:
These are woven cut-pile carpets, where several warp pile threads in one longitudinal nep row are pulled out or lifted to form the pile.

Rapier-Axminster carpets:
The pile threads are inserted by a rapier, while the choice of the colored pile threads is controlled by a Jacquard system. Each pile nep corresponds to one rapier.

Chenille carpets:
Premade chenille ribbons are used as weft pile yarn.

Double carpets:
These carpets are manufactured as upper and lower sides by cutting open a double fabric produced in one processing step.

Knotted pile carpets:
Short pieces of pile thread are knotted around two or more warp threads between the weft threads.

Tufted floor coverings:
Pile threads are inserted with needles or sewn into a textile fabric. For the carpet backing, the woven fabric needs to have good tenacity, uniformity, and shape stability.

The density of the backing fabric has to be such that the sewn, loose pile neps are stable during finishing, as they are inserted without loop formation. Suitable materials for this are jute as well as many other natural and synthetic materials such as polypropylene (PP) bands or spun bonds.

Knitted Carpet:
Similar to woven carpets, knitted carpet can also be distinguished as either flat or pile types. Flat carpets are produced on knitting machines and have no pile-producing thread system. However, pile carpets consist of a ground knit fabric and a pile — both produced simultaneously. Piles are one or more thread systems or fiber bands on top of the carpet. They are bound to the ground layer. Either the pile thread is bound in the ground or it is formed to a stitch in the ground.

Knitted carpets can also be distinguished in cut-and-loop pile carpets. The layer between the pile layer and the back side of the carpet is defined as the ground layer. Furthermore, warp-knitted carpets belong to the group of carpets produced according to the principle of knitwear production. They are so-called warp-knitted fabrics in which the pile threads are bound in a ground material as pile thread end or a pile loop.

Properties of Carpet:

Aesthetics:
Carpets are available in a wide variety of styles, textures, designs and colors which the skilled interior designer can use to create a stylish interior suited to the activity conducted in the carpeted area. In the home, carpet helps to provide a warm and comfortable environment away from the harsh realities of the everyday world. In commercial buildings carpet helps to make a statement about the enterprise and creates an environment conducive to efficiency.

Thermal insulation:
Carpets are excellent thermal insulators, a property that is enhanced further by a good underlay. With conventional heating systems the insulation properties of carpet and underlay can significantly reduce heat loss through the floor. In the case of under-floor heating, however, the apparently excellent thermal insulation properties of the carpet do not excessively impair the efficiency of the heating system.

Acoustic insulation:
Changes in lifestyle in recent years, in which smooth floors, particularly tiles, wood and laminate floor coverings, have gained in popularity, have demonstrated to the public just how noisy an uncarpeted room can be. Carpeting is one of the most effective ways of reducing noise and the best carpets can provide acoustic insulation to the same level as dedicated acoustic insulation materials. There are three ways in which carpet can provide acoustic insulation. Possibly the most important of these is impact sound absorption.

Safety:
The textile surface of a carpet and its three-dimensional structure make carpet a particularly safe surface on which to walk. The carpet surface will have excellent slip resistance and will offer a soft, forgiving surface should falls occur.

Impact upon human health:
A misperception is that people with asthma and allergies should avoid carpet in the home. Actually, the opposite is true. Studies have shown that properly cleaned carpet helps reduce symptoms and is the best flooring choice for those dealing with asthma and allergies. A carpet has an important role to play in significantly reducing the allergen content of indoor air. Wool, in particular, is known to absorb gaseous toxic pollutants from the atmosphere such as formaldehyde, sulphur dioxide and oxides of nitrogen. The large fiber surface presented by the pile of a carpet allows significant amounts of such pollutants to be absorbed, thereby contributing to improved indoor air quality.

Carpet Manufacturing and Construction:
Carpets do have three types of construction.

Woven: Woven carpet is longer wearing and more stable than tufted carpet, but it is lower and more expensive to produce. The traditional method of carpet making is to interweave the fibers with the backing. There are three basic weaving techniques. Velvet, Wilton and Axminister. Axminister and Wilton carpets can contain many colors, but Wilton construction of interwoven pile and backing allows for a maximum of five colors to be used. While a color doesn’t appear in the pile it is woven into the backing producing an extra-thick strong carpet.

Tufted: The majority of carpet produced today is tufted. Tufting involves stitching face yearns into a backing material with multi needed machines. The fibers are secured to the pre-woven backing with a heavy latex coating. A secondary backing may be added for greater dimensional stability.

Bonded: Bonded carpets have pile that is bonded, often heat-fused on to pre-made backing, as a result they are relatively inexpensive.

Two individual woven fabrics are connected by pile threads during carpet manufacturing.

Fig: Traverse section through double woven fabric

In carpet manufacturing, the pile threads are cut between the two basis fabrics. The distance between the two basis wovens corresponds to twice the pile height of the two carpets. In technical applications, double wovens with uncut piles are used more and more often.

For carpet design the following parameters are significant:

Pile height: height of the pile above the backing (mm)
Number of punches: number of stitches per 10 cm
Yarn mass,
Weight: total weight minus weight of backing
Beats/m²: number of tufts/m × tufted rows/m
Surface pile density: weight of wear layer: pile thickness, 1000 g/m³

During carpet production, the following parameters are important:

Spacing: distance of two pinpoints in inches, for example, 5/64 in. = 1.98 mm
Width: working width = fabric width without support edges
Needle shift
Pattern possibilities
All velour fabrics have to be sheared; loop-pile fabric skips this processing step

Different Types of Carpet Textures:

Velvet: (also known as plush, frieze and splash)

Has an even, generally dense pile.
Tends to show foot prints, which is desirable for shadowing
(Takes away from the ‘flat look’)
Resists crushing and bending
Tends to show soil more than others, not the
Best for stair covering.

Shag:

Comes in varying yarn lengths (up to two inches)
Gives grass like appearance
Used for both formal and informal setting
Does not wear well on stairs
Look for dyed back, which camouflages wear.

There are two characteristics that make shag carpet stand out from other types of carpet and rug designs. The first is the length and configuration of the individual carpet yarns that are used in the design. Along with being longer sections of yarn, the fiber is also twisted in a loose design, rather than the tight design that is used with short loop carpeting techniques. The relaxed twist is combined with a pattern that space the individual yard strands further apart than in a conventional weave. As a result, the look of a shag carpet is somewhat like that of a section of grass that allows the blades or strands to lay in a variety of different directions.

Velvet Shag:

A high, soft pile that easily shows indentation Form traffic.
Tends to mat in high traffic areas.

One-level looped:

Tightly woven looped carpet
Very strong, withstands water and stains
Wears well on stairs

Level loop pile is made by weaving even loops of yarn into carpet backing at both ends. Higher loops create a more luxurious appearance, yet offer durability and track resistance because of its strong loops. Level loop piles with short and densely packed loops prevent dirt from filtering into carpet and are easy to clean, making it ideal for high traffic areas.

Two-level looped:

Or sculptured
Has sculptured effect, very durable
Wears on stairs

Carpet Durability:
The main factors that affect the durability of a carpet are:

Fiber weight – The heavier the fiber weight, the harder wearing the carpet will be.
Pile density – The higher the density, which depends on the tightness of the yarn twist, the better.
Yarn stitches per inch – The more the better, improving the crush resistance of the carpet.

Benefits of Carpet:

Carpet provides thermal resistance, it retains warm air longer and make place comfortable to sit.
Carpet can add beauty and style to the room.
Carpet softens slips and falls.
Carpet insulates floors as it provides a psychological feeling of warmth.
Carpets are easier to maintain and clean.
It can reduce noise by absorbing noise.
There are hundreds of patterns, cuts, and colors.
Carpet traps allergens, dust, and other contaminants, holding them until they can be properly removed.
The carpet industry is minimizing carpet’s impact on the environment through the “3 Rs” – Reduce, Reuse, Recycle.

Uses of Carpets:
Carpet is a common household item that may be used in a variety of ways. Carpet improves the indoor climate as it retains airborne dust particles. Carpets are used for a variety of purposes, including insulating a person’s feet from a cold tile or concrete floor, making a room more comfortable as a place to sit on the floor. Carpets are used in two sectors; residential use and commercial use.

Residential use:
Carpets for residential use are made throughout the world with particularly important centres in the USA and Western Europe. Carpet is a popular feature in home decorating, and it is often incorporated into a home’s interior design.

Commercial use:
Carpets intended for commercial use are often subjected to greater concentrations of traffic and need to withstand this. Commercial use is varied and can include offices, retail premises, hotels and leisure centres, casinos, theatres and airports. Carpets for offices, particularly modern open-plan offices and for some larger retail premises, feature hard-wearing dense low loop-pile constructions usually with polyamide pile. The carpet tile has found particular favor for this end-use.

Care and Maintenance of Carpet:
Everybody wants their carpet to stay looking good over time. Professional carpet care and cleaning is required to maintain the carpets rather than regular vacuuming. However, frequent vacuuming can help to keep grit from becoming embedded into the carpet. Most carpets need hot-water extraction, either in isolation or in combination with cleaning, for their maintenance. Some carpet designs may need special means to be cleaned. The carpets should be cleaned by carpet care professionals at least every 18–24 months to refresh the texture and rejuvenate the fibers in the carpet.

Fiber content is the most important parameter in selecting a care process for carpets. Most recent carpets are fabricated from synthetic fibers such as nylon, polyester or polyolefin, which may be cleaned with most cleaning methods. The carpets manufactured from natural fibers such as wool, cotton, silk and sisal require specialized care.

Any attempt to remove the stain by rubbing can lead the spill of the stain into the pile and damage the fibers of the carpet. The stains should be covered by a towel for blotting them. This is repeated using dry towels until all the liquid has been absorbed. In the case of large spills, a wet-dry vacuum can be used to remove most of the spills before blotting.

Here are the European Flooring tips for maintaining your carpet:

Use a doormat or off cut from the carpet to help reduce the how much it will soil. Vacuum regularly to prevent dirt matting the carpet fibers. Note that a vacuum fitted with brushes or beater bar should be used on cut pile carpets while a vacuum only should be used on loop pile carpets. Also note that newly laid carpets often shed loose fibers, which is fine.
One can save wear and tear on carpet by asking everyone to take off his or her shoes before entering home.
When cleaning your carpet, detergents such as washing up liquid and soap should not be used. Instead, reputable carpet care treatments should be used.
When dealing with spillages, act swiftly as this will improve the chance of avoiding stains. Liquids should be blotted (not rubbed) using clean white absorbent cloth or kitchen roll, and you should start from the outside of the stain and work inwards. Apply your cleaning agent to the cloth and not the carpet directly, and rinse with water afterwards. Use a hair dryer to dry the area and finish by brushing up the carpet pile.
Change air filters in heating and air-conditioning systems as recommended by the manufacture’s directions. The more dust and particles remove by the filter, the less that fall on the carpet.

Conclusion:
Carpet flooring provides unequalled warmth and comfort, and is more economical than many other floor types with the product and installation being cheaper. However it can require a greater level of maintenance, especially in rooms with lots of traffic.

References:

Advances in Carpet Manufacture, 2nd Edition Edited by K. K. Goswami
Textile Technology-An Introduction, 2nd Edition by Thomas Gries, Dieter Veit and Burkhard Wulfhorst
Care and Maintenance of Textile Products Including Apparel and Protective Clothing By Rajkishore Nayak and Saminathan_Ratnapandian
The Substrates — Fibres, Yarn and Fabrics By Mathews Kolanjikombil
https://en.wikipedia.org/wiki/Carpet
http://www.madehow.com/Volume-2/Carpet.html
http://www.carpetandrugpedia.com/Carpet_Manufacturing_Process.htm
http://tlc.howstuffworks.com/home/how-is-carpet-made1.htm
http://carpetinfo.co.uk/all_about_carpet/carpet_fibres.htm
http://voices.yahoo.com/carpet-yarn-count-most-important-factor-choosing-1047463.html
http://www.interiordezine.com/finishes/natural-carpet-fibers/
http://www.bwmpl.com/carpet_yarn/woollen_yarn/carpet-yarn-making
http://www.ehow.com/list_7606204_uses-carpets.html
http://www.wisegeek.com/what-are-the-different-types-of-carpet.htm

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Mazharul Islam Kiron

Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.