The Mechanism of Moisture-wicking And Quick-drying Fabrics

The research and development of moisture-wicking and quick-drying fibers are primarily achieved through two approaches: physical modification and chemical modification. Physical modification involves altering the shape of spinneret holes to produce profiled fibers with surface grooves. Leveraging capillary action, these fibers facilitate rapid water transport, diffusion, and evaporation, efficiently removing moisture and sweat from the skin surface and discharging it to the outer layer for evaporation. Alternatively, blending or composite spinning methods can be employed using polymers containing hydrophilic groups (such as hydroxyl, amide, carboxyl, or amino groups) to create fibers with moisture-wicking properties. Chemical modification, on the other hand, introduces hydrophilic groups into the macromolecular structure through graft copolymerization, thereby enhancing the fiber's moisture absorption and quick-drying capabilities

Moisture-Wicking Fabrics

Moisture-wicking fabrics alter a material’s ability to absorb, transport, and release moisture through structural design or fiber modification, enabling both water absorbency and rapid drying. Current functional fabrics include knitted and woven structures, categorized by layer count: single-layer, double-layer, or multi-layer configurations.

With the rapid advancement of post-finishing technologies, various functional textiles have emerged. Moisture-wicking and quick-drying finishes address thermal-humid comfort by enhancing sweat transport, resolving issues like 闷热 (mugginess) and discomfort during perspiration.

1. Single-Layer Unidirectional Moisture-Conducting Fabrics

Early developments focused on single-layer structures, typically woven from pure or blended yarns of moisture-wicking fibers. Recent technological advancements have introduced unidirectional moisture-conducting fabrics, where the fabric’s inner and outer surfaces exhibit distinct moisture absorption/desorption properties. These fabrics spontaneously transport sweat from the skin-contacting inner layer to the outer layer for evaporation, maintaining dryness and significantly improving thermal-humid comfort. Theoretically, their moisture management performance surpasses that of bilaterally isotropic fabrics.

• Case Studies:

• Wang Nanfang et al. applied paste dot printing to hydrophobize cotton knits, achieving excellent wash resistance. Compared to untreated fabrics, air permeability decreased by ~10%, and capillary rise (wicking height) dropped by 5–7%.

• Wu Jihong et al. developed moisture-conducting knits by first water-repellent treating yarns, then weaving and dyeing. However, this process faced challenges like complex weaving, uneven dyeing, and high costs.

• Wu Yefang et al. achieved moisture-wicking through single-side coating of cotton fabrics, but coating reduced air permeability, compromising wearability.

• He Tianhong et al. developed double-sided moisture-wicking cotton knits via single-side finishing.

2. Double-Layer or Multi-Layer Unidirectional Moisture-Conducting Fabrics

Driven by consumer preference for natural fibers, cotton usage has increased. However, cotton’s wet swelling clogs fabric pores, hindering heat-moisture exchange, while its exothermic moisture absorption followed by endothermic evaporation causes discomfort (first muggy, then cold). Double/multi-layer structures address this by using hydrophobic synthetic fibers as the inner layer, with four main types:

① Hydrophobic Inner Layer + Hydrophilic Outer Layer

• Structure: Synthetic fibers (inner) + natural fibers (outer), with point-contact between inner layer and skin.

• Mechanism: Gaseous sweat is absorbed by the hydrophilic outer layer, while liquid sweat is transported via capillary action through the hydrophobic inner layer to the outer layer for evaporation. The air layer between skin and fabric provides thermal insulation, preventing stickiness and chill.

• Example: Cotton-covered polyester knits are typical. The inner polyester (hydrophobic) and outer cotton (hydrophilic) create rapid moisture diffusion. Wang Xiao et al. found that hollow polyester inner + cotton outer fabrics exhibited better warmth and inner-layer dryness than all-cotton fabrics, with optimal performance at 30% hydrophobic fiber content.

② Different Synthetic Fiber Specifications in Layers

• Mechanism: Uses hydrophobic synthetic fibers in both layers but with different specifications (e.g., fiber fineness), creating a "cedar tree effect" via capillary pressure differences. Fine outer fibers (higher capillary pressure) draw sweat from coarse inner fibers to the surface for evaporation.

• Example: Toray’s Airfine Field Sensor multi-layer knits feature this structure, with moisture-wicking capacity twice that of their Field Sensor line, used in sportswear and workwear.

③ Composite Structure with Wick-like Absorption Points

• Structure: Two-layer knits with a hydrophobic exudation layer (inner) and absorbent layer (outer), connected by wick-like yarn junctions (e.g., cotton) distributed in a predefined pattern.

• Case Studies:

• The Czech Bnro Knitting Institute developed color cotton wick-point layered fabrics using Fukuhara V-LEC4BS computer jacquard weft knitting.

• Hou Qiuping et al. designed double-layer fabrics with inner polyester/cotton blend and outer brown color cotton, testing wick-point densities (50%, 25%, 12.5%). Results showed lower density improved moisture conductivity when inner/outer materials were identical.

• Gu Zhaowen et al. developed high-performance wick-point knits using H-shaped moisture-wicking PET and color cotton. Hydrophilic finishing reduced permeability and drying speed, indicating such fabrics are unsuitable for hydrophilic treatments.

Summary：

The thermo-humid transfer performance of clothing is a critical factor in maintaining human thermo-humid balance and determining comfort. When sweat cannot pass through fabric smoothly, the humidity and temperature within the microclimate zone between the skin and clothing increase, enveloping the skin in heat and moisture, which causes a 闷热感 (muggy discomfort). Therefore, moisture-wicking and dry-touch finishing of fabrics has become essential.

While natural fibers are favored by consumers and dominate apparel markets, they have inherent limitations. For example:

• Cotton fabrics exhibit slow moisture dissipation. As water displaces air within the fabric, its thermal insulation decreases, creating a 阴冷感 (chilly sensation). Thus, pure cotton often performs poorly in thermo-humid comfort.

• Silk fabrics are soft and have high skin contact area, instantly absorbing significant heat for an initial cool feeling. However, their thin structure causes sweat-soaked fabric to cling to the body, feeling clammy. Without special treatment, silk garments remain problematic for summer wear.

Given the wide applicability of cotton textiles, moisture-wicking and quick-drying finishes for cotton products are particularly critical. These treatments address the inherent shortcomings of natural fibers, enhancing both comfort and functionality in apparel.