Carpet Construction and Identification
Carpet construction and identification tests whether you can look at a carpet, read its specifications, and predict performance. Exam questions cover fiber families, yarn types, pile terminology, backing systems, and the density math that separates a durable carpet from a plush-looking one.
Fiber and yarn
- Nylon 6 and nylon 6,6: strong abrasion resistance; nylon 6,6 generally has a higher melt point and better resilience, while nylon 6 dyes more readily.
- Polyester (PET): stain resistance and color clarity; less resilient and has an affinity for oily soil.
- Olefin (polypropylene): moisture and chemical resistance; low melt point; oil-loving, so oily soil can be hard to remove.
- Wool: good resilience and soil hiding, but sensitive to high pH and bleach.
- BCF yarn is continuous filament and low-shedding; staple yarn is spun from short fibers and may fuzz or shed initially.
Construction and backing
Common constructions are tufted, woven, needlebond, and flocked; tufted dominates commercial work. The primary backing holds tufts; the secondary backing adds stability. Action back, unitary, foam, and cushion backings change installation and moisture sensitivity. Gauge is stitches per inch, so 1/10 gauge means 10 stitches per inch. Stitch rate and pile height together determine density.
Worked example
A sample reads 28 oz/yd² face weight and 1/4 in pile height. Density = face weight × 36 ÷ pile height = 28 × 36 ÷ 0.25 = 4,032 oz/yd³. A second sample is 40 oz/yd² at 1/2 in: 40 × 36 ÷ 0.5 = 2,880 oz/yd³. The lighter sample is denser and likely more durable in a traffic lane, showing why face weight alone misleads.
Traps
Confusing face weight with total weight; assuming a heavier carpet is denser; treating gauge as pile height; ignoring backing type when choosing a cleaning method; and identifying fiber from feel alone rather than from specifications and a burn or float test where appropriate.