Terminology

• Gossypium hirsutum: upland cotton, about 90 percent of world production
• Gossypium barbadense: long-staple cotton (Pima, Egyptian), over 5 percent
• Ginning: separating fiber from seed
• Denim insulation: batts made from recycled cotton and denim

History and demand

Sourcing

• 2024/25 (USDA, March 2025): world production about 121.0 million bales; China about 31.75 million bales, India about 25.0 million, United States about 14.4 million

Demand trend

• World production about 25 million tonnes (110 million bales) a year on 2.5 percent of arable land

Composition and production

Raw materials

• Cellulose, predominantly alpha-cellulose, with traces of waxes, pectins, and minerals

Product forms

• Yarn and woven fabric; recycled-denim insulation batts

Properties

Physical

• Density: 1.54 to 1.56 g/cm³ (about 96 to 97 lb/ft³) for bleached cotton

Thermal and moisture

• Moisture regain: about 8.5 percent at standard atmosphere
• Insulation batts: R-3.5 to R-4 per inch (denim batts)

Fire behavior

• Limiting oxygen index: 18 percent; ignites at a lower temperature than wool

Uses in buildings

Building elements

• Wall and Roof Insulation: recycled cotton and denim batts, about 80 percent recycled fiber (UltraTouch)

Pros and cons

Pros

• Renewable, plant-based fiber
• Recycled content in insulation batts

Cons

• Burns more readily than wool
• Absorbs moisture (regain about 8.5 percent)
• Heavy water use in cultivation

Sustainability

Water use

• Cultivation averages 8,000 to 10,000 L/kg of fiber, up to 22,500 L/kg in some dry areas of India

Recycled content and end of life

• Insulation batts use post-consumer recycled denim and cotton

Manufacturing and cost

Main manufacturers and suppliers

• Bonded Logic

Trade association: National Cotton Council.

Sources

• Wikipedia: Cotton, https://en.wikipedia.org/wiki/Cotton
• Online Clothing Study: Properties of cotton fibre, https://www.onlineclothingstudy.com/2021/11/properties-of-cotton-fibre-physical.html
• Architect Magazine: Insulation product review, https://www.architectmagazine.com/technology/products/product-category-review-insulation_o
• Bonded Logic: UltraTouch denim insulation, https://bondedlogic.com/?p=1398
• Wikimedia Commons: Cotton boll nearly ready for harvest.jpg, photo by Michael Bass-Deschenes (CC BY 2.0), https://commons.wikimedia.org/wiki/File:Cotton_boll_nearly_ready_for_harvest.jpg
• USDA Economic Research Service: cotton and wool outlook, March 2025, https://ers.usda.gov/sites/default/files/_laserfiche/outlooks/111125/CWS-25c.pdf