Nylon
Summary
Nylon is a family of polyamides, chiefly nylon 6 and nylon 6,6, with a density near 1.15 g/cm³ that melts rather than burns. It reaches buildings as carpet fiber and molded electrical parts, where moisture absorption and end-of-life recycling are the practical issues.
Cols
Terminology
- Nylon 6: from caprolactam by ring-opening polymerization; melts at about 220°C
- Nylon 6,6: from hexamethylenediamine and adipic acid; melts at about 265°C
- Polyamide: polymer with amide links
- Hygroscopic: absorbs moisture from the air
History and demand
Invention
- February 28, 1935: Wallace Carothers at DuPont first synthesized nylon 66; announced October 27, 1938
- First commercial use: a bristled toothbrush in 1938; stockings shown at the 1939 New York World's Fair and sold in 1940
Sourcing
- China held over half of the 11.6 million tons a year of global polyamide capacity in 2023 (ResourceWise)
- Asia-Pacific holds about 52 percent of nylon 6 capacity in 2025, with China above 3.4 million tons a year; Invista is cited as the leading PA66 producer at 23 percent (market research)
Demand trend
- Worldwide nylon production estimated at 8.9 million tons in 2020
Composition and production
Product forms
- Textile and carpet fiber, molded automotive and electrical parts, and packaging film
Grades and types
- Nylon 6: melts at about 220°C (428°F)
- Nylon 6,6: melts at about 265°C (509°F)
Properties
Physical
- Density: about 1.15 g/cm³ (about 72 lb/ft³)
Thermal and moisture
- Melting range: roughly 190 to 351°C (374 to 664°F) by type
- Moisture: hygroscopic, though it absorbs less than wool or cotton; absorption changes electrical resistance and lowers glass transition temperature
Fire behavior
- Less flammable than cotton and rayon; melts rather than burning, and molten fiber can stick to skin
Durability
- Hydrolyzes slowly at room temperature and neutral pH, faster in strong acids
Uses in buildings
Building elements
- Carpet Tile: carpet face fiber, including solution-dyed nylon
- Wiring Devices: wall plates
Pros and cons
Pros
- Durable fiber
- Lower flammability than cotton and rayon
- Higher-melting 6,6 grade at 265°C
Cons
- Hygroscopic
- Melts when heated
- Rarely recycled
Sustainability
Recycled content and end of life
- United States 2018 (EPA): 9.2 percent of carpet fiber, backing, and padding recycled, 17.8 percent incinerated, 73 percent landfilled
- Discarded nylon fishing nets contribute to ocean debris
Manufacturing and cost
Main manufacturers and suppliers
Trade association: American Chemistry Council.
Sources
- Wikipedia: Nylon, https://en.wikipedia.org/wiki/Nylon
- Wikimedia Commons: Carvico-Matte-Nylon-Lycra-Fabric-Coccinella-Red-Italian-Stretch-Fabric-For-Swimwear-Solid-Stone-Fabrics-Inc..jpg, photo by Svillarreal18 (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:Carvico-Matte-Nylon-Lycra-Fabric-Coccinella-Red-Italian-Stretch-Fabric-For-Swimwear-Solid-Stone-Fabrics-Inc..jpg
- ResourceWise: polyamide plastics, opportunity and trade options in 2024, https://www.resourcewise.com/blog/chemicals-blog/polyamide-plastics-opportunity-and-trade-options-in-2024
- Staticker: nylon 6 market, https://staticker.com/?p=4077