The rise of fast fashion in modern society has been heavily dependent on synthetic textiles, the most common of which is polyester, a plastic produced from crude oil. Hydrophobic polyester fibers give apparel quick-drying properties, however, they also naturally attract oils from our skin that can serve as a food source for bacteria, creating a challenge for clothing manufacturers to find ways to keep garments fresh for longer.
This article discusses the microbial phenomenon of odor build-up in polyester and polyester-rich blends, and how recent metal-free, sustainable innovations in odor control can be incorporated into fabrics to overcome this pertinent issue.
A synthetic stumbling block
Polyester is a synthetic textile, usually derived from petroleum, that is used in thousands of different consumer and industrial applications, from hospitality and home furnishings to upholstery and apparel. The consumer stance on polyester has changed dramatically over the years; it was originally marketed as a low maintenance, standalone ‘miracle fabric’ but, today, it is more often included in products alongside higher quality natural fibers like wool and cotton.
Nonetheless, polyester retains a key role in the fashion industry, making up more than half of all retail clothes produced globally.1 Unlike natural fibers, polyester is formulated in a laboratory to improve the durability, affordability, shrinkage, and wrinkling profile of fabrics, as well as their resistance to heat, wind, and rain. These attributes are widely sought after, but synthetic garments also have their drawbacks—including a lack of breathability and a tendency to hold onto grease and oils—making them susceptible to odor retention, staining, and fabric degradation.
Wear and tear, discoloration, and malodor are all inevitable occurrences in the life cycle of synthetic fabrics subject to a typical pattern of wear, wash and dry.2 Textiles in close contact with human skin from day to day are exposed to sweat and sebum, as well as materials transferred from the environment, creating a humid, lipid-rich habitat for microbial propagation. Following this, the collection and storage of dirty laundry before washing creates ideal conditions for microbes to spread. The microorganisms that accumulate on polyester metabolize sweat and generate acidic odorants responsible for body odors, including both isovaleric and acetic acid, the compounds responsible for smelly feet and vinegar aromas, respectively.
Although the issue of long-term malodor—known as ‘permastink’—is very common, it can quickly make clothes unpleasant to wear, causing social stigma and embarrassment, and significantly decreasing consumer satisfaction. This, in turn, can render synthetic apparel unfit for use, and lead to the premature disposal of garments to landfills.
The goal of laundering is to remove visible dust, dirt, and stains from textiles while eliminating less visible bacteria and metabolites.2 Unfortunately, the antimicrobial action of laundering has been impaired by decreases in washing temperatures in recent years as part of attempts to improve energy efficiency. Washing alone therefore does little to remove unpleasant aromas in the long term.
Fortunately, there are actions that can be taken to prevent temporary odors from evolving into irreversible ‘permastink’, and fabric manufacturers are now looking for ways to impart built-in scent control to textiles during the production process, helping to keep fabrics fresher for longer.
The search for effective odor absorbents
Integrated odor control solutions for fabrics typically take one of two approaches: tackling malodor production at the source by applying treatments to help fight bacteria, or incorporating odor neutralizing technologies that counteract odorous bacterial metabolites. While approaches that inhibit bacterial growth can be effective, odor capture technologies—which rely on the physical or chemical absorption of odorous substances to reduce their volatility—are becoming increasingly popular.
However, traditional odor neutralizing technologies pose several issues: they are not always suitable for incorporation into textiles, they often leach out of fabrics during repeated washing, and they frequently contain heavy metals that give rise to environmental concerns. These issues have opened a gap in the textile market for efficient, fiber-compatible, and sustainable odor management solutions for fabrics.
A fresh approach
In response to consumer demands for products with effective odor management, advances in odor control have led to the production of modern, innovative, and heavy metal-free odor capture technologies that can integrate into man-made textiles without influencing existing fabric properties. These pioneering odor capture solutions can retain their ability to neutralize carboxylic acids even after repeated laundering, lending permanent odor reducing effects to garments and prolonging their useful lifespan.
The world of fashion is moving away from a single-use, throwaway culture to focus on longevity and sustainability, and groundbreaking odor capture technologies can keep synthetic fabrics odor-free for longer, resisting malodor and making ‘permastink’ a thing of the past.
Ryan Scott is senior formulations engineer at Microban International, Ltd. He graduated with degrees in chemistry and business administration from the University of Akron. He has 10 years of expertise in the research and development of liquid formulations for a variety of applications, supporting the apparel, architectural, industrial, aerospace and marine industries.
- Analysis of the polyester clothing value chain to identify key intervention points for sustainability. Environmental Sciences Europe, 33(1). doi: 10.1186/s12302-020-00447-x.
- Biological and chemical processes that lead to textile malodour development. Microorganisms, 8(11), 1709. doi: 10.3390/microorganisms8111709.