How Low-Friction Coatings Affect Microplastic Fiber Release When Laundering Coated and Uncoated Textiles Together

Laundering synthetic textiles releases a significant amount of microplastic fibers (MPFs), a major contributor to plastic pollution and one that poses numerous health hazards. When fabrics come into contact during laundering, frictional abrasion eventually causes MPFs to break off and release into the environment when the wash water is discharged. Certain polydimethylsiloxane (PDMS)-treated textiles have been shown to significantly reduce MPF release via a reduction in surface friction. However, the extent of MPF release when PDMS-coated textiles are washed with uncoated ones, the most likely real-world scenario, has yet to be investigated. In this work, a PDMS-based coating was used as a finish for polyester fabrics that were laundered with the same unfinished polyester fabric but dyed a different color such that MPF origin could be identified. To ensure the fabrics were in contact during the simulated laundering process, one piece of fabric was adhered to the bottom of a crystallization dish, while the other was sewn around a magnetic stir bar. After laboratory simulated washing, the amount of MPFs released from the different colored fabrics was counted. Both the fabric finish and the orientation were found to affect MPF release. When the bottom fabric was finished and laundered with the uncoated fabric surrounding the stir bar, MPF release was reduced by 42% for the bottom fabric, 28% for the stir bar fabric, and 37% overall. When the orientation was reversed, MPF release was reduced by 33% from the unfinished bottom fabric, 20% from the finished stir bar fabric, and 27% overall. These findings suggest that MPF release can be reduced during laundering even when some of the textiles are unfinished and that these types of finishes can reduce MPF release from unfinished fabrics.