Development of Infrared Transmission Flame-Retardant Polyethylene Melt Blends and Melt-Blown Nonwovens

Polyethylene (PE) melt-blown nonwoven materials exhibit excellent infrared transmission properties, making them well-suited for applications in infrared physiotherapy and smart building technologies. However, their high flammability and tendency to generate melting droplets and smoke seriously limit their applications. Herein, phosphorus-silicon flame-retardant PE melt-blown blends were prepared by the melt blending of ammonium polyphosphate (APP) and nano-silica (SiO₂). Next, the thermal, rheological, and crystallization properties of the blends were investigated. Subsequently, flame-retardant PE melt-blown nonwoven materials were prepared and tested. It was found that APP and SiO₂ decreased the melt flowability of the material, while slightly decreasing the melting point, increasing crystallinity and enhancing the thermal stability by shifting the decomposition temperature by 51 °C. Moreover, the presence of flame retardants increased the roughness and diameter of fibers. The limiting oxygen index (LOI) of the PE melt-blown materials with 10% APP and 1% SiO₂ reached 28.6%, reaching the flame-retardant level without dripping during combustion. This highlights important guidelines for developing infrared-transmitting, flame-retardant PE nonwovens for safe and sustainable applications.