For years, athletes, both professional and amateur, have used garments made of fabrics designed to wick moisture away from the body to increase their comfort and improve their sports performance. Often referred to as "moisture-wicking," t-shirts, pants, and other clothing items made with these fabrics are often worn alone during sports occasions to keep wearers drier and more comfortable than they would be otherwise. Recently, however, garments boasting moisture wicking and "performance" qualities have entered a range of additional markets, including sleepwear marketed to women undergoing menopause, as well as people who choose to layer these garments under their regular clothing to stay cooler throughout the day. So here's the big question: how does this stuff really work?
The Technology of Moisture Wicking Clothing:
Most garments marketed as "moisture wicking" use this terminology to refer to two different mechanisms: the clothing's ability to absorb, or wick, moisture from the wearer's skin, and its ability to then dry quickly in order to keep the wearer more comfortable by avoiding the chills once they have completed their activity. A shirt's ability to wick is determined mainly by the type of fiber used to make the fabric. Natural fibers, such as cotton, have excellent moisture absorption and retention properties. They are considered hydrophilic, or water-loving. The problem with hydrophilic fibers is that they tend to dry slowly.
Ever heard the saying "cotton kills" among hikers and other outdoor enthusiasts? This popular saying refers to the fact that a cotton base layer will often be great at absorbing your sweat, but will then make you extremely cold when you stop moving and are left wearing a soaking wet garment. In contrast to 100 percent hydrophilic garments, you can find a range of offerings that are made with 100 percent hydrophobic, or water-hating, fibers. These fibers, which include polyester, are great at shedding moisture and drying quickly, but not at absorbing it. This means that sweat simply becomes trapped between your skin and your garment, still making you uncomfortable.
So how do manufacturers resolve this tension between hydrophilic and hydrophobic fibers to provide garments that can absorb sweat AND dry fast? There are a couple of answers to this question.
Finding the Comfort Sweet Spot:
Pick up your latest workout shirt, shorts, or pants and check out the label. Chances are that if you're wearing some of the most popular brands today, the label will say 100 percent polyester. Now how can these brands claim they're moisture wicking when they are using a completely water-hating fiber? The answer lies in what happens to the fabric during the finishing process. Once fabric has been knitted or woven, dyed, and gone through any other processes, final steps can be taken to apply topical solutions that will impart absorption properties onto fabrics that would not otherwise have them. These topical treatments can help a polyester garment obtain some of the absorption properties found in clothing made from natural fibers.
Another option to achieve this same result is to take fibers that are hydrophilic and fabrics that are hydrophobic and create what is called an intimate blend that results in a yarn that contains both types of fibers in a specific, optimal blend of hydrophilic to hydrophobic fibers. This yarn can then be used to make fabric and clothing that brings users the best of both worlds without requiring the use of topical finishes or treatments. The key behind unlocking the benefits of moisture wicking and fast drying is to use the optimal blend of hydrophilic to hydrophobic fibers. For example, a 50/50 poly/cotton shirt will not perform as well as an 85/15 poly/cotton blend.
While many brands still rely on topical finishes due to lower complexity of those processes, some leading edge garment manufacturers do produce garments made with the optimal, intimate fiber blend.
Expanding Applications for Moisture Wicking Apparel:
While moisture wicking apparel has historically been most relevant to athletes and weekend warriors, more and more people are finding this technology relevant in their own workplaces. Most notably, professions where employees have physically demanding jobs or are exposed to environments where they are likely to sweat are starting to see benefits in choosing moisture wicking apparel for work tasks. Moisture wicking options are even finding their place in markets where garment options were previously quite limited, such as flame-resistant apparel.
Workers required to wear flame resistant apparel are often engaged in physically demanding situations, such as climbing poles to fix electrical lines, patrolling neighborhoods in our country or overseas during military deployment, or fighting fires, to name a few. For these workers, safety is paramount and lack of comfort can be a deadly distraction. Thankfully, moisture-wicking options exist that allow these workers to avoid the trade-off between comfort and compliance, ensuring that they can focus on the task at hand rather than what they're wearing. Needless to say, the wicking t-shirt has come a long way!