Certain issues need to be addressed in order to specify carpet, regardless of the type of installation site. The specifier needs to determine the expectation for the carpet and which of the selection criteria are most important. The following basic issues should be considered to determine carpet specification:
-Aesthetics: color, texture, design/pattern, luster and appearance.
-Appearance: durability, wearability, cleanability, installability, color retention and fastness, texture retention, appearance retention, etc.
-Functionality: flammability, static propensity, indoor air quality, acoustical value, insulation, value, etc.
-Cost: initial product cost, installation, maintenance, disposal, life cycle.
-Government or building code requirements.
There are two types of carpet specifications: construction and performance. Construction specifications tell the manufacturer in very precise terms how the carpet is to be made (look, size, weight and manufacturing of raw materials and processes) without directly stipulating performance needs or end-use requirements. A construction specification would include the following:
-Construction type: tufted, woven, knitted, needlepunched, etc.
-Construction materials: fiber (fiber type, size), backing (type, weight) and adhesives.
-Construction methods: yarn manufacturing (yarn size and ply), fabric formation (gauge, pile height and texture, density, total weight), coloration techniques (dyeing methods), finishing and treatments.
-Product characteristics: texture, color/design, size/type and functional enhancements.
Common errors in construction specifications are either to under- or over-specify. When too many minor details are included, there is a tendency to specify beyond the possibilities of the manufacturer or to limit the flexibility of new technology. The specification for yarn size might be too large for a particular gauge, or the yarn size, gauge, stitch, pile height and weight might be impossible to create in the specified combination. There also is a tendency to perceive that more is better-more pile weight, more plies, more rows, etc., mean better durability. Each of these does play a role, but the "more" perception may not relate to better performance or product.
Another consideration is that with current manufacturing technology and anticipated technological developments, many of the standard terms may not apply today. For instance, air-entangled yarns are really not plied; therefore, twist per inch does not have the same meaning as for twisted yarn. Scrolling, shifting, eccentric or pattern tufting machines provide mixed gauges and stitches and, with overtufting, even changing gauges.
Construction specifications should be used to describe the overall look of a product and not be so detailed as to limit the manufacturer from making a quality product.