Start with good performance. Carpet performance can be the result of:
Good performance begins with clear specifications which meet the needs of the functions to be performed and is completed with a maintenance plan to be put into effect immediately upon installation. The omission of any of these four items can seriously affect the perceived or actual performance of the carpet. Satisfactory performance of any carpet selected depends on the specification of proper construction, color and carpet fiber content. Maintenance will have a greater effect on the appearance of the carpet than any other single factor.
Making an informed floor covering choice for commercial facilities, schools, and offices can be a difficult task. Budget concerns such as maintenance costs must be considered in addition to facility needs and the needs of the occupants.
One of the first decisions which should be made is the type of carpet fiber system preferred. All fiber systems have specific advantages. The two primary fiber systems used in commercial applications are olefin (polypropylene) and nylon.
Olefin has become one of the fastest growing fiber systems used in the manufacture of carpet. Olefin is one of the most inexpensive fiber systems available because of the capability that carpet producers have in extruding their own yarn. One of the limitations of olefin is the restrictive number of color choices. Limitations in color are a result of the dye method that must be used.
Most yarn systems such as nylon, polyester, wool, or cotton are dyed using a topical treatment of liquid dyes. These yarn systems contain tiny holes (dye sites) which allow the dyes to penetrate the yarn. Dye can be applied in a dye bath (beck) or sprayed-on topically. Olefin does not contain dye sites which allow dye to penetrate the fiber. Olefin is dyed using a solution-dye method. Solution dyeing occurs when the yarn is transformed from polymer chips to fiber. Polymer chips are added to a chamber and heated. Color chips are added during the heating process.
At the bottom of the chamber is a device called a spinneret which contains hundreds of tiny holes. As the solution melts and pours through these holes filaments of fiber are formed. It may take 1500 or more of these filaments to make up one-plyed yarn. As the color chips and polymer chips melt, the yarn is dyed through and through with color. Olefin's limitations in dyeing capabilities also can be considered an advantage.
Most carpet stains occur due to penetration of the dye sites. Olefin does not contain dye sites, making it almost impossible to stain. Another advantage of solution dyeing is the ability to withstand bleaches and oxidizing agents. Since the color is throughout the yarn, fading and bleaching cannot occur. Nylon can also be dyed using the solution-dye method but most nylon is dyed using the less expensive topical or beck dyeing method.
Nylon has been the fiber of choice for many years. Approximately 80% of the carpet manufactured in the United States is produced using nylon. It has very good resiliency, offers excellent color choices, and recent innovations in stain technology have improved nylons' ability to withstand stains. Solution-dyed nylon is even more stain resistant due to the dye method.
The construction of a prospective style of carpet has a major impact on the life expectancy and performance a carpet will provide. Carpet density is the major factor of construction that should be considered. Density is a combination of several factors. Gauge rate is the distance between tufts (loops) or needles in the widthwise direction.
# of needles per:
|Gauge||per Inch||# across 12 ft width|
Stitch rate is the distance between tufts (loops) or the number of times the needle bar strikes in the lengthwise direction. Various styles may be measured differently. Stitches per inch is the most common unit of measurement but stitches per 6 inches may be found frequently.
Pile height is the length of the tuft (loop) from the base of the tuft (primary backing) to the tip of the tuft. Pile height is normally measured as a fraction of an inch or as a decimal equivalent.
3/16" = .188
1/4" = .250
5/16" = .313
3/8" = .375
Twist level has recently been identified as a major performance factor in many commercial cut-pile and residential cut-pile constructions. Twist level is measured in twists per inch. A close look at the tufts on a cut-pile product will reveal two bundles of yarn that have been plyed (twisted) together and heatset to "lock-in" the twist. Generally speaking, the more twists per inch, the better the performance.
Density can be defined as the amount of face yarn per unit area. There are several methods used for determining density. The primary method uses a simple empirical formula to quantify density.
Average Pile Density = 36 X Pile Yarn Weight / Pile Height (or pile thickness) in inches
Variations may occur due to differing methods of quantifying pile height. There are essentially 3 methods for determining pile height. Each method will deliver differing results.
In the first instance (pile height), a small ruler is inserted down to the backing to read the overall height of the tuft. This is not a precise method due to variations in results by various technicians. There may also be variations due to measurement timing (preshearing or post shearing).
The second method for determining pile height (pile thickness) is a much more precise method due to consistency of results. This is a much more complex method but it is the preferred method for determining pile height. This method involves the use of a compressometer, which measures thickness of materials under a slight load, between a platen and a circular foot. In using this method, the total thickness of the pile and backing material are quantified. The pile is then sheared and the backing thickness is calculated. These values are deducted and pile thickness is determined.
The third method, (tuft height) is also a laboratory technique which is reproducible. Ten tufts are sliced from the primary backing and inserted into a metal block. These "V" shaped tufts are then covered with a clear plate and measured using a precision scale. Problems can develop when product specifications are written using varying methods. A 30%-40% variance is possible on similarly manufactured goods when less precise methods are used.
Problems can develop when product specifications are written using varying methods. A 30%-40% variance is possible on similarly manufactured goods when less precise methods are used.
Few people realize the importance that carpet color selection has on carpet performance. Most people believe color should be selected based on aesthetic needs rather performance requirements. Carpet color can significantly reduce the cost of maintenance by reducing the appearance of soiling. Very light tones and very dark tones tend to reveal more soiling while middle-tones, multi-tones, patterned, tweed, and heathered tones can hide the effects of soiling. The geographic soil conditions should also be considered when carpet color is selected.
Traffic conditions may play a very large role in color selection. Carpet has the ability to trap tracked-in soils and restrict them to entryways. This can enable a specifier to alter carpet color with soil type and traffic load at each entryway.
Proper installation can directly affect carpet performance and increase the life expectancy of carpet. A large number of carpet installations are replaced due to installation failure rather than carpet failure. In many of these instances carpet replacement could have been prevented if proper installation guidelines had been followed. These guidelines are listed in Publication CRI-104 for commercial installations and CRI 105 for residential applications. A copy of these guidelines should be obtained and reviewed prior to carpet installation. They can be obtained through The Carpet and Rug Institute (706)-278-0232.
Prior to installation several points should be reviewed with the flooring contractor or architect/specifier.
About the Author
Michael Hilton was the original creator of Carpet Buyers Handbook. Having owned and operated a carpet wholesale company, Hilton has a vast knowledge about all-things carpet related as well as other types of flooring.