Orifice-Free Melt Blowing of Highly Curved Polypropylene Nanofibers for Superior Warmth Retention

Maintaining body heat is crucial for comfort and survival, driving the demand for advanced thermal insulation materials. Conventional textiles often require added bulk to achieve adequate insulation, limiting their use in lightweight applications. Herein, we present a novel turbulence-driven orifice-free melt-blowing method using a tailor-made mesh configuration to fabricate highly curved polypropylene (PP) nanofibers on a large scale. These materials offer superior warmth retention performance, surpassing even high-quality goose down alternatives. By precisely regulating the jet-gas interaction, significant fiber refinement and high curliness are achieved simultaneously, yielding fluffy nanofiber networks. The resulting PP garment demonstrates an outstanding thermal insulation value of 0.53 clo mm^-1, exceeding that of goose down. Additionally, the synergy of high porosity and tailored wettability ensures excellent breathability and effective moisture management, enhancing the overall thermal comfort. This work highlights the potential of turbulence-assisted fiber engineering in developing ultrafine materials that outperform natural down in thermal comfort.