Cross-shaped Cool Sensation Fiber

1. Profiled spinneret – the cruciform cross-section is formed by a dedicated profiled spinneret; the holes are arranged in a plus shape, and hole geometry plus length-to-width ratio determine groove width and depth, which tune cool-touch intensity and hand feel.2. Cool-powder compounding – surface-treated cool-conducting mineral powder is compounded with PET chips in a twin-screw extruder before spinning (typical loading 2%– 8% by weight, per formulation); the powder disperses uniformly in the PET matrix with no adverse effect on spinnability.3. Heat conduction – the thermal conductivity of the mineral filler is higher than that of the PET matrix (PET ≈ 0.2–0.3 W/(m·K)). On skin contact, heat flows quickly along the filler–matrix interface into the fiber and dissipates into the surrounding air, producing the instant cool sensation characteristic of Cool Touch Fibers.4. Moisture transport – the four longitudinal grooves act as capillary channels; sweat is wicked along the grooves from the skin side to the outer surface and evaporates, keeping the skin side dry.5. Q-max test – Fabrics made from this ice fiber reach Q-max ≥ 0.30 W/cm², meeting the cool-feel criterion of GB/T 35263-2017 (≥0.15).