Chemical Effects of Laundry Additives on Surface Resistivity of E-textiles

Abstract

Wearables are electronic devices worn on the body, either as an accessory or integrated into clothing (ASTM Committee D13, 2020). Wearables have conductivity capabilities, advanced circuitry, and data communication functions. Growing since the 1970's, the wearable technology market is now a $32.63 billion industry, evolving to move data collection, analysis, and communication from smart devices directly to the body via sensors and electronic textiles (or etextiles). Products made with fully integrated, wearable technology are referred to as 'smart clothing' or 'smart garments.' Due to their intimate contact with the human body, wearables become soiled and must be cleaned. One of the most significant challenges of smart garments is performance reliability post-laundering (Balsamo et al., 2017;Jansen, 2019;Rotzler, 2020). To achieve their full potential, wearable e-textiles (smart garments) must overcome these challenges to become everyday wear (Begovic Johnson, 2020). An e-textile is "a fiber, yarn, fabric or end product comprising elements that result in an electrical or electronic circuit, with or without processing capability, or the components thereof" (ASTM Committee D13, 2020). Like traditional wearables, e-textiles send data to secondary devices where the user can evaluate the information. Most e-textile products are still in the research and development stage (Gonçalves et al., 2018), falling short in either functional performance, ease of use, production capability, price point, comfort, and/or maintenance, which includes washability (European Commission, 2016). Body soils may negatively impact smart garment functionality and also need to be removed for hygienic reasons. Thus, future wearables must be washable on-demand (European Commission, 2016). Current care instructions for etextiles are limiting in terms of wash conditions. E-textile specification sheets may note that washing of any type (wet or dry) will eventually degrade metallic coatings and thus reduce functionality. When e-textiles are fully integrated into smart clothing, these laundry practices are inadequate for hygienic cleaning, inconsistent with behaviors of apparel consumers (Shin, 2000), and incompatible with garment longevity. Quantifying the impact of machine laundering conditions, specifically the impact of detergents or other additives, is crucial to establishing effective and realistic methods for repeatable care of smart clothing. In this study, the influence of detergents and laundry additives on e-textile surface resistivity is researched. The purpose of this study is to add to the body of knowledge pertaining to e-textiles and wash conditions which may contribute to the development of appropriate smart garment care labels, thus, assisting in the preservation of product functionality. Seven e-textiles (see Table 1) were tested for a change in surface resistivity post-laundering. The detergents and other laundry additives were selected to represent a range of commonly used formulations and chemical laundering conditions. These in...