Far-infrared polyethylene terephthalate (FPET) fibers have been commonly used in clothing in order to attain heat retention, and the combination of three-dimensional crimped hollow polyethylene terephthalate (TPET) fibers makes the clothing to be fluffy and air permeable, and thereby improves the wearing comfort. This study aims to make thermally insulating nonwoven composites by using recycled far infrared fibers. The composites are used to cover the heat transfer lines and prevent the heat emissivity. A specified amount of low-melting-point polyethylene terephthalate (LPET) fibers and FPET and TPET fibers at different ratios are blended, followed by being needle punched at 100-300 needles/min, and then hot pressed at 120 degrees C, in order to form thirty nonwoven composite types. These nonwoven composites are measured for their porosity, thickness, and air permeability, and are tested for thermal insulation and temperature-rise slope under a constant ambient temperature.
