Woollen socks have good moisture-wicking properties

The unique physical structure of wool fibers is the core of woollen socks' moisture-wicking properties. Wool fibers are composed of three layers: the outer scale layer, the middle cortex layer, and the innermost medulla layer.
Scale layer: natural barrier and moisture diffusion path
The surface of wool fibers is arranged by overlapping tiny scales, which can prevent external liquid moisture from directly entering the fiber, playing a preliminary barrier role. However, these scales are not completely closed, and there are tiny gaps between them to allow air circulation. While air circulation, it also allows sweat or moisture to gradually diffuse, and excess moisture is taken away through the evaporation process. This layer of scale structure can not only remove moisture from the outside, but also transport internal moisture to the fiber surface through "capillary action", promote evaporation, and keep the fiber dry.
Cortex layer: dual role of moisture absorption and moisture removal
The core of wool fiber is the cortex layer, which is composed of two types of cells: positive cortex cells and paracortex cells. The different structures and chemical properties of these two cells cause wool fibers to have natural curling. The curled fiber structure can form tiny air spaces between the fibers, which can store air and improve thermal insulation, while also promoting moisture evaporation and air circulation.
The hydrophilicity of the cortex determines the moisture absorption capacity of wool. Wool fibers can absorb up to 30%-35% of their own weight in water and lock the moisture in the amino acid groups inside the fiber. However, wool does not feel wet while absorbing moisture because the moisture is effectively locked deep in the fiber, while the surface of the fiber remains dry. This moisture absorption ability allows woolen socks to cope with heavy sweating without causing discomfort to the wearer.
Medulla: Promotes air circulation
The medulla layer of wool fibers is hollow in some types of wool fibers. This hollow structure provides wool with excellent thermal insulation properties and also improves the breathability of the fiber. During the air circulation process, the medulla layer can promote the evaporation and dissipation of moisture. This air circulation mechanism is the key to the moisture wicking performance of woolen socks, allowing moisture to be quickly transferred to the outside of the fiber and evaporated in the air, keeping the feet dry.