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Carpet Backing and Coating
Which way does the fuzzy side go?
Most everyone in the carpet business is familiar with the saying “fuzzy side up.” That fuzzy side is the “face” of the carpet. The “back” is that other side, and it can be made from a variety of fabrics, yarn, natural or synthetic materials. A carpet may have only a primary back, which is the fabric that the fuzzy material is tufted, woven or bonded into. A tufted carpet with a single back is referred to as a “single” or “unitary” back carpet. A “conventional tufted carpet” is one with both a primary and secondary back with some type of scrim or attached cushion that is laminated to it.
Back, Woven & Knitted Carpet:
The most common backing materials are jute, kraftcord, linen, polyester, olefin (polypropylene), rayon, cotton and combinations of these materials. These materials are the “construction yarns” comprising chain warp, stuffer warp, and shot or fill which are interwoven with the face yarn during the manufacturing of the carpet.
Primary Back Tufted Carpet
Primary backing materials are manufactured as both woven and non-woven fabrics in which the pile yarn is inserted by tufting, needle punching, stitching, embedding or bonding. Primary back is the carrier fabric for the pile yarn and should not be confused with secondary backing which is a reinforcing fabric laminated to the back of tufted carpet subsequent to the tufting process. Some synthetic primary backings have nylon fiber attached to their upper surfaces to make them union dyeable with nylon pile yarns.
Secondary Back “Fabric” Tufted Carpet
Usually woven jute, or woven or non-woven olefin (polypropylene). The fabric is laminated to the back of carpet (usually with latex adhesive) to reinforce and increase dimensional stability, strength, stretch resistance, stiffness, and hand. Because secondary backing is visible, whereas primary backing is concealed under the pile yarn in finished carpet, dealers and installers often refer to secondary backing simply as “backing.”
Backing Fabrics
Both woven and non-woven primary and secondary backing is made for tufted carpet. It is primarily polypropylene, but some jute and other materials are used. It is important to remember that woven backing is not the same as woven carpet.
Woven polypropylene backing presently accounts for 95% of the secondary market and 90% of the primary market. As of 1996 the secondary market was shared by Amoco and Synthetic Industries with additional companies sharing part of the primary production. Amoco is the world’s largest backing supplier with their woven polypropylene primary backing representing more than 50% of the North American primary backing and their ActionBac representing more than 50% of the secondary backing market. Polypropylene backing can now be made from recycled polypropylene and these are expected to be a player in the near future.
Spunbonded backings are made in both polyester and polypropylene. They are primarily used in the automotive industry as moldability and dimensional stability are very important. They also represent about 80% of the carpet tile and six-foot roll market. Some spunbonded is used for lower price printed loops as they create less needle deflection than woven backing.
Secondary Back Attached Cushion
This cushion is laminated to the primary back. The most common cushions are polyurethane foam, high-density foam, sponge rubber, woven fiber, latex with an embossed pattern, solid vinyl and foam-type vinyl.
Unitary Backing
A single fabric backing with high rubber content latex or hot-melt resin compound laminated to the bottom side. A unitary backing system is used to increase dimensional stability, tuft bind of the individual fibers, minimize edge ravel at seams and snagging of rows on looped pile construction.
Article from Carpet Inspectors Handbood
by Terry Weinheimer and Kevin Weinheimer
FloorCentral.com
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April 23rd, 2008 at 4:40 pm
[...] Kristen Seymour wrote an interesting post today onHere’s a quick excerptThe backing of a carpet can often be overlooked and yet it is one of the most important factors of the carpet’s construction. A carpet’s primary backing is the depository of the face yarn. Both the primary and secondary back provide … [...]