Columbia Sportswear's Omni-Wick™ EVAP technology features hydrophobic microparticles that enable accelerated wicking and evaporation of perspiration.
Janet Bealer Rodie, Managing Editor
Columbia Sportswear is offering its Omni-Wick™ EVAP technology in its Spring 2012 collection of outerwear including waterproof breathable shells.
Columbia points out that traditional wicking technologies, which feature hydrophilic fibers to attract moisture, draw moisture away from the skin, but the moisture is held in the fibers and doesn't always evaporate very well. The Omni-Wick Evap technology involves bonding of hydrophobic microparticles to a very lightweight, ultra-high-molecular-weight polyethylene membrane such as Columbia's Omni-Dry® ultrabreathable waterproof membrane, according to Woody Blackford, Columbia's vice president of innovation. "These microparticles don't absorb moisture, but they do break the moisture apart and put it into the right cluster size to evaporate quickly through the waterproof membrane," he said, comparing the microparticles to grains of sand — which also do not absorb water but allow it to run through the mass of sand and dissipate quickly — as opposed to a patio stone — on which, as on the classic waterproof membrane, the water will pool and evaporate more slowly. Further, he noted, the surface area of the microparticles in one jacket equals the surface area of a football field, which allows a lot of surface from which the water can evaporate.
Making the technology visible to the consumer, Columbia bonds the microparticles onto the membrane in a geometric pattern in what Blackford described as a "dual density" application that creates a capillary effect in the higher-density areas to draw the moisture into the fabric. The darker black lines in the pattern have close to 100-percent particle density, while the lighter gray areas within the lines have more like 30-percent density and also allow the fabric to breathe. The moisture moves from the "capillaries" into the membrane, where it spreads and evaporates, as described above.
Creating a capillary effect, lines of highly dense hydrophobic microparticles draw moisture from the skin and spread it into the ultrabreathable, waterproof membrane to evaporate quickly, while the lighter areas between the lines have a lower density of particles, allowing the membrane to retain its breathability.
"If the density were all 100-percent, the membrane would be fantastic at spreading moisture, but that would affect other qualities, such as air permeability," Blackford said. "The patent-pending capillary pattern of high density draws moisture along that pattern. The light gray surface does not resist moisture spread, but it's not really a spreader to the same degree. This creates a visual pattern that can be identified with moisture processing," he added.
There is no inner liner in the jacket, so the printed pattern interacts directly with the skin and any perspiration. "As the moisture spreads into the first layer of particles and moves into the membrane to evaporate, you're left with a fairly dry feeling against the skin," Blackford explained. "You're in contact with dry particles, and even though moisture in the garment is being processed, the garment dries completely much faster than it would without that finish."
Fabric materials used in the first jackets in the collection depend on end-use. A mix comprising a soft, lightweight polyester mesh and abrasion-resistant woven polyester is used in a very lightweight jacket targeted for cycling, running and similar activities. A heavier-duty backpacking jacket is made with a nylon fabric.
For more information about Columbia Sportswear's Omni-Wick™ EVAP, contact Andy Nordhoff +503-985-1739; email@example.com.
October 18, 2011