Mid-infrared emissivity of nylon, cotton, acrylic, and polyester fabrics as a function of moisture content

Abstract

The effectiveness of material to emit energy as thermal radiation is important in determining the apparent temperature in infrared thermographic measurements. For this reason, a number of measurements of the thermal emissivity in the mid-infrared thermographic (8–12 µm) region have been reported for fabrics. However, many fabrics adsorb moisture from the air, and condensed water has a relatively high thermal emissivity. In this manuscript, we report measurements of adsorption isotherms and mid-infrared thermal emissivity for nylon, cotton, polyester, and acrylic as a function of their moisture content in weight percent at temperatures just above ambient. We find that the order of water mass percentage gain for the fabrics in high humidity conditions are polyester < acrylic < nylon < cotton. The thermal emissivity is ∼0.88 independent of moisture content for the fabrics polyester, cotton, and nylon, while acrylic shows a pronounced increase in thermal emissivity as moisture content increases, ranging from ɛ ∼ 0.81 at low humidity conditions to ɛ ∼ 0.88 under high humidity conditions. In this work, emissivity measurements are made by imaging through a novel infrared window made from household cling wrap and interpreted with equations that are independent of window transmittance and sample temperature.

Multifunctional cotton fabrics with novel antibacterial coatings based on chitosan nanocapsules and polyacrylate

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Influence and stabilization of environmental conditions on teraohmmeter measurements of textile materials

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Super-Hydrophobicity of Polyester Fabrics Driven by Functional Sustainable Fluorine-Free Silane-Based Coatings

“…Moisture content has a crucial role in both cost and quality in a wide range of products, coatings and finishings. Compared to other synthetic fibers, polyester has a greater ability to avoid moisture absorption; this is one of the reasons why some types of polyester often tend to dry quickly [59,60]. Despite that, the presence of moisture also affects polyester fabrics, leading to harmful breakdown processes because the macromolecular chains hydrolyze, significantly reducing their molecular weight and material integrity [61,62].…”