Melt-spun HDPE/PLA core–shell fibres: a sacrificial-shell route to capillary moisture transport in polyethylene textiles

High-performance textiles demand fibre architectures that combine mechanical integrity, efficient moisture transport for wearer comfort, and scalable processing, all while meeting stringent sustainability expectations in one of the world’s most environmentally burdensome industries. Here we present a proof of concept for engineering capillary moisture transport into polyethylene by melt-spinning bicomponent fibres with a high-density polyethylene (HDPE) core and polylactic acid (PLA) shell that was selectively dissolved after weaving. Fibres collected at winding speeds of 1000 and 2000 metres per minute (mpm) exhibited mean diameters of 11.96 ± 0.85 μm and 9.63 ± 0.94 μm, respectively, and HDPE crystallinities of 65.6% and 68.7% by DSC. TGA showed that PLA degraded first, with an onset at 293 °C, compared with 395 °C for the fibres recovered after dissolution (HDPEAD). After selective PLA removal, SEM revealed aligned inter-fibre channels and longitudinal surface ridges consistent with along-the-fibre water transport, and infra-red thermography showed that the resulting woven HDPEAD fabrics wick water, reaching saturation in 7-8 min (n = 3), compared with 4 min for cotton and 2 min for polyester, whereas TyvekTM (a commercial nonwoven of flash-spun HDPE) showed no uptake under the same conditions.