Milkweed Fibre
category
Milkweed (Asclepias syriaca) seed floss is a hollow cellulosic fibre (lumen/total diameter ratio 80–86%, fibre diameter 18–35 µm, length 20–35 mm) harvested from the follicle pods of the milkweed plant at 200–400 kg/ha in North American wild-collection and cultivated systems. Cellulose content 53–58%, hemicellulose 11–15%, lignin 7–10%, and wax 4–6%. Fibre hollow ratio (86%) exceeds kapok (80%) and down (50%), providing thermal conductivity of 0.032–0.034 W/m·K and bulk density of 8–12 kg/m³ — the lowest of any commercially processed natural fibre. Milkweed-polyester blends (25–30% milkweed) in outerwear insulation achieve 1.0–2.0 CLO equivalent to 100% down fill power 550–650 at 25–35% weight reduction. Patagonia has commercially incorporated milkweed in Yulex and Macro Puff product lines since 2019. Global commercial production is nascent at 500–1,000 tonnes/year.
Role
Emerging renewable, cruelty-free, and wildlife-supporting insulation fibre for sustainable outdoor apparel, providing down-comparable thermal performance from a North American wild-harvested crop that simultaneously supports monarch butterfly habitat restoration.