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Increased use of woven and nonwoven textiles, as well as growing awareness of microbes and their associated healthcare concerns, has been driving demand for antimicrobial use in textile applications. The inclusion of antimicrobials has especially been emphasized in performance and medical textiles where biological burdens are heavy, adding layers of protection and freshness to everything from scrubs and surgical masks to bedding, sheets, and curtains. Antimicrobials are also widely used for odor control and to effectively combat the stains and smells that microbe colonies produce.
While antimicrobial usage in textiles is not a new development, shifting market conditions and price pressures are now changing paradigms around how antimicrobial materials are chosen and integrated into textiles—and are requiring research and development focused on finding alternative chemistries to meet the changing needs of the market, as a result.
How antimicrobials are chosen
The choice of an ideal antimicrobial product for a given application depends on the spectrum of efficacy desired against various microbes, finer details of the environment that the product will encounter, chemistry of the textile material and the regulatory landscape.
Manufacturing processes. The manufacture of textiles from synthetic, fiber-forming materials such as polyester and nylon is a complicated, multi-step process. The first step in this series of processes is the manufacture of synthetic fibers by a melt extrusion process wherein the fiber-forming polymer is extruded through a spinneret, followed by texturing and weaving. Antimicrobial properties can be integrated into textiles either during fiber spinning or they can be applied topically further downstream in production, after a textile has already been produced.
Incorporation of antimicrobials at the fiber-forming stage through the use of a masterbatch offers durability of antimicrobial performance, since the antimicrobial additive becomes an integral part of the fiber. On the contrary, antimicrobial properties using topical treatments, while lower in cost, are not permanent and degrade over time. As a result, adding antimicrobials during yarn manufacturing is widely regarded as preferable from a performance standpoint. As such, there is often a cost/performance tradeoff to pursuing post-production antimicrobial agent application.
Material choice. Silver has long been regarded as the most effective chemistry for combatting bacterial growth. In recent years, however, the cost of silver has increased dramatically, pushing cost-conscious textile manufacturers to seek alternatives. Organic chemistries, on the other hand, exhibit limited thermal stability and are not effective for incorporating into textile fibers during the spinning process.
A shifting marketplace
As costs for antimicrobial additives have risen in recent years, some textiles manufacturers have turned to the use of topical antimicrobials, despite their more limited performance characteristics. Meanwhile, producers at every stage of the manufacturing process continue to feel pressure to keep antimicrobial additives affordable in the face of volatile raw material costs.
Demand for antimicrobial textiles remains high, especially in the face of trends such as the battle against healthcare-associated infections (HAI) that afflict an estimated 1.7 million people and are associated with 99,000 deaths per year in American hospitals alone, according to the U.S. Center for Disease Control (CDC).
That said, even in the face of such biological challenges, there is intense pressure on healthcare providers to reduce costs. Disposable garments and masks tend to still have antimicrobials spun into textile fibers, as they also tend to be made with lower-priced materials in general, but materials, such as pillow covers and other more frequently reused products, are being treated with topical solutions that do not provide the same level of performance that silver or related chemistries might.
How the industry is adapting
Clearly, the need for antimicrobial-treated textiles is strong, but many of the antimicrobial solutions the industry has relied upon to date are either not meeting the performance needs or not meeting the cost needs of manufacturers currently. As a result, industry research and development scientists are approaching the market challenges from multiple angles:
- There is an effort to find more sustainable solutions from an environmental perspective that are also cost-effective. This is something that would benefit the marketplace, but can also take significant time to research and develop, so it is safe to expect that developments on this front could take some time to manifest.
- Americhem is working to bring new antimicrobial offerings to the market for melt-spun fibers. Americhem’s nShield™ family of products offers custom solutions based on silver and other inorganic, as well as organic, additives. As the company experiments with new chemistries, it’s also focused on ensuring that the solutions developed have high efficiency and excellent processability, and meet the regulatory requirements in various parts of the world.
Unless some of the inherent performance longevity and sustainability concerns around topical antimicrobial applications can be addressed, melt-spun, fiber-fused antimicrobials will continue to be the best option for textile producers moving forward. In the coming years, the industry can expect to see more solutions enter the market that deliver the lasting performance that comes from integration of mineral-based antimicrobial agents in the fiber production phase, while addressing the cost concerns of the marketplace through innovative chemistries.
It is useful to remember that every application is unique, and it is worth consulting fiber manufacturers to find out what options make the most sense for one’s product design to create the level of efficacy desired at a price point that makes sense. Once a path is determined, work with experienced material scientists to find ideal use rates and processes that provide the best value for your situation.
Vaman Kulkarni, Ph.D., is Americhem’s global business development director. He has expertise in synthetic fibers, additives, international and new business development.
“Preventing Healthcare-Associated Infections.” U.S. Center for Disease Control. https://www.cdc.gov/washington/~cdcatWork/pdf/infections.pdf