Fleece: From Toilet Seats to Everest – History, Production, Properties, and Environmental Impact

The Invention and Evolution of Fleece

• 💡 Fleece is a synthetic knitted material, invented 46 years ago by Malden Mills as a lightweight, breathable, and moisture-wicking substitute for wool.
• 🔑 In 1979, Malden Mills developed "polar fleece," and its CEO, Aaron Feuerstein, notably refused to patent it, contributing to its rapid global spread.
• 📌 Patagonia collaborated with Malden Mills to create Synchilla, a new type of fleece inspired by fuzzy polyester fabric used for toilet seat covers, aiming for warm, lightweight jackets.
• 🚀 Malden Mills later rebranded as Polartec in 2007, a name that became synonymous with high-quality fleece products.

Fleece Production Technology

• 🔬 Fleece production begins with polyester yarns knitted into a jersey fabric on circular knitting machines, often using a plush or terry weave.
• 🛠️ The knitted fabric undergoes napping, where needles break elementary fibers to create a soft, fluffy pile, followed by shearing to even out the pile length.
• ✅ The final step is heat-setting, which stabilizes the fabric's dimensions, reduces shrinkage, and fixes the pile position, preparing it for garment manufacturing.

Key Properties and Disadvantages

• ✨ Fleece offers excellent thermal insulation by trapping air within its millions of fibers, making it warm, lightweight, and soft to the touch.
• 💧 It has low hygroscopicity, meaning it wicks moisture away from the body and dries approximately ten times faster than wool.
• ⚠️ Disadvantages include being 100% synthetic (can cause static, melts rather than burns), offering poor wind protection without special membranes, and potential pilling in lower-quality versions.

Modern Fleece Varieties and Applications

• 📊 Fleece density ranges from 100 to 600 g/m², with lighter microfleece for thermal underwear and denser versions for extreme cold or outerwear.
• 🚀 Modern fleece products often incorporate recycled plastic and can feature water- and windproof membranes like Softshell or Windbloc for enhanced performance.
• 🎯 Polartec offers diverse lines such as Classic, Thermal Pro, High Loft, Alpha, and Wind Pro, each designed with specific properties for various outdoor activities and conditions.

Environmental Considerations

• ♻️ Leading fleece manufacturers are actively working to address environmental concerns, particularly the release of microplastics into wastewater during washing.
• 🌱 Efforts include developing special filters for washing machines to mitigate the environmental impact of fleece production and use.