Asymmetric thermal and water vapor transport of polyester spacer and cotton nonwoven fabric assembly

Abstract

Spacer fabric is often used in cushions, footwear, filter material, and other products because of its high air permeability and three-dimensional (3D) structure. However, for practical applications, it is typically combined with other materials. We investigated the thermal properties and water vapor permeability of assembly-combined thicker spacer (16 mm) and various cotton nonwoven fabrics. The assembly-combined lightest nonwoven (30 g/m2) and spacer fabric exhibited the highest thermal resistance, increasing by 66.62% compared with the bare spacer fabric; however, no significant difference was observed when combined with the heaviest woven fabric (60 g/m2). Furthermore, the fabric arrangement during assembly could affect the heat and moisture-transfer efficiencies. The assembly-combined lightest nonwoven (30 g/m2) and spacer fabric under the upward test condition exhibited the highest thermal resistance, highest Clo, lowest heat transfer coefficient, highest insulation ratio, and lowest evaporation resistance among all assemblies. Higher thermal resistance and lower evaporative resistance could benefit physiological comfort. However, the assembly-combined heaviest nonwoven and spacer fabric under the downward test condition exhibited similar thermal resistance to the spacer fabric and the highest evaporation resistance. The asymmetric heat- and moisture-transfer properties of a porous assembly can contribute toward developing new materials for applications in other engineering fields. 间隔织物由于其高透气性和三维（3D）结构，经常用于垫子、鞋类、过滤材料和其他产品. 然而，对于实际应用，它通常与其他材料结合. 我们研究了组合较厚垫片（16 mm）和各种棉质非织造织物的热性能和水蒸气渗透性. 组合最轻的非织造布（30 g/m2）和间隔织物的组件表现出最高的热阻，与裸间隔织物相比增加了66.62%; 然而，当与最重的机织物（60 g/m2）组合时，没有观察到显著差异. 此外，组装过程中的织物布置可能会影响热传递和水分传递效率. 在向上测试条件下，组合最轻的非织造布（30 g/m2）和间隔织物的组件在所有组件中表现出最高的热阻、最高的Clo、最低的传热系数、最高的绝缘比和最低的蒸发阻力. 较高的热阻和较低的蒸发阻力有利于生理舒适. 然而，在向下测试条件下，组合最重的非织造布和间隔织物的组件表现出与间隔织物相似的热阻和最高的蒸发阻力. 多孔组件的非对称传热和水分传递特性有助于开发其他工程领域应用的新材料.