关键词: 单向导湿, 双面针织物, 热湿舒适, 超细纤维涤纶, 灰色关联度分析

Abstract:

Objective At present, light exercise is important for people's health. However, the conventional cooling and heating system has consumed significant amounts of energy to ensure optimal human body temperature during the light exercise. Sweat evaporation is an effective method for heat dissipation to maintain human thermal balance. The conventional textiles such as cotton fabric inevitably retain excessive sweat at the interface due to the intrinsic hydrophilicity, leading to wet and cool feeling. Therefore, fabrics with moisture and heat management capability is expected to transport liquid directionally, maintaining the skin dryness and finally achieving energy conservation and wearing comfort.

Method When a density difference exists on both sides of a single fabric, additional pressure difference will be generated to make water transfer spontaneously, according to the principle of differential capillary effect. Based on this principle, two polyester yarns (55.5 dtex(24 f) and 93.3 dtex(384 f)) were selected. Four concave-convex lattice fabrics were created with variations in structure, number, and distribution of connecting points, denoted as process A, B, C and D. In process A and B, the 55.5 dtex(24 f) polyester yarn was replaced by the 33.3 dtex(12 f) polyester yarn at the connecting coil to form obvious mesh, named as A2 and B4, respectively. In order to explore the influence of different coil structures on the moisture and heat management performance of fabric, 6 different fabrics A1, A2, B3, B4, C5 and D6 with the capability of moisture and heat management were prepared.

Results Fabrics in process A are configured with looping connecting coil and single tuck connecting coil, while process B incorporates three types of connecting coils: looping, single tuck, and double tuck coils. In contrast, process C only utilizes single tuck as the connecting coil, and process D incorporates looping connecting coil. Following the addition of 33.3 dtex(12 f) polyester yarn, fabrics A2 and B4 exhibited a noticeable mesh formation compared to A1 and B3. In order to assess the performance of the fabrics, various tests were conducted, including evaluation of moisture permeability, moisture management, droplet spreading, evaporation rate, and insulation rate. Analysis of the moisture permeability data revealed that fabric A1 outperformed the others. The presence of tuck connecting coils in processes B and C, spanning multiple horizontal rows, led to moisture condensation on the yarn/fiber and subsequent decrease in moisture permeability. Notably, the air permeability was primarily influenced by the fabric structure, with the introduction of 33.3 dtex(12 f) polyester yarn enhancing air permeability due to the formation of mesh. The weight of the fabrics demonstrated a positive correlation with unidirectional moisture transport capability. Thicker fabric D6 facilitated moisture transport, while the liquid easily penetrated soft fabrics. Fabric C5, featuring single tuck connection coil, displayed good unidirectional moisture transport and a large area change of droplet spreading due to the formation of transport channels. The relationship between evaporation and thermal insulation indicated a negative correlation, as faster liquid evaporation led to increased heat dissipation and decreased thermal insulation rate. The fabrics with a high proportion of microfibers, exhibited slow evaporation due to water absorption. Additionally, the mesh structure, provided improved evaporation efficiency. Overall, the connecting coils and fabric structure coordinately influenced the performance of fabric. As demonstrated by the correlation degree rankings, the comprehensive evaluation of the designed fabrics through grey relational analysis revealed that the tuck connection points in the process structure significantly influenced the fabric's heat and humidity management capabilities.

Conclusion Overall, the experiments show that the inner side of garment woven with 55.5 dtex(24 f) polyester yarn and the outer side knitted with 93.3 dtex(384 f) microfiber polyester achieved excellent unidirectional water transfer ab ability. It has been identified that the materials and structure jointly affected the comprehensive performance. The involvement of hydrophilic microfibre was found to reduce the moisture permeability and water evaporation rate. The connection coil of tuck was beneficial to unidirectional moisture transport but adverse to permeability. To the contrary, the structure of mesh was conducive to air permeability but poor in unidirectional water transport capability. In the final comprehensive evaluation, it demonstrated that single performance can not determine the overall moisture and heat management ability of the fabrics. The six fabrics used in this research are easy to produce without physical and chemical modification, which provides theoretical and experimental basis for the development of light sportswear fabrics with good moisture and heat management ability, environmental protection and durability.

Key words: one-way water transport, double jersey, thermal and moisture comfort, polyester microfiber, grey relational analysis