How Waterproof Coated Fabric Is Made

Waterproof fabrics are essential components of raincoats and tents alike, but how exactly do they keep us dry? The secret lies in a special coating that repels water away from its surface - but what process goes into producing this fabric? In this article, we'll look at this coating process, along with what makes fabrics like nylon or polyester waterproof.

Water-resistant fabrics are made of tightly packed yarns with few pores for moisture absorption. Some can even feature Durable Water Repellent (DWR) treatments which keep liquid from seeping into their core, instead beading up on its surface.

Woven fabrics can be waterproofed by applying a polymer that forms a barrier between fibers and liquid, such as vinyl, polyvinyl chloride, silicone elastomer, or fluoropolymers. This chemical may be added during production or applied as an afterthought during finished products such as jackets and tents using spray-on methods; such a coating can be applied to both natural and synthetic fabrics.

As well as polymer coatings, many fabrics receive treatment that alters their surface fibers to make them hydrophobic, known as durable water repellent (DWR) treatments. These can be applied to both woven and non-woven fabrics; DWR treatments prolong waterproof properties over untreated fabrics.

Fabric designers have placed great effort and focus into developing water-resistant and breathable outdoor fabric for activities such as hiking, camping, skiing and other athletic pursuits. Unfortunately, as fabrics become more water-resistant through tight weaves or coatings that provide more water resistance, their breathability may decrease; dense weaves or waterproof coatings create a plastic layer that prevents moisture vapor from escaping, leading to dampness or hypothermia in extreme cases. In response to this challenge, designers have developed technologies that both increase water resistance while simultaneously increasing breathability;

Although advances have been made in waterproof fabrics, much work remains to develop safer and more effective water-repellent materials. Traditional waterproof materials often leave behind toxic chemicals that are detrimental to both human health and the environment. Studies have revealed that these toxins persist in ecosystems while also building up in our bodies over time. Researchers from MIT have developed an innovative new technique for adding water-repellency to fabrics, which is both safe and more effective than existing methods. Their nanoscale technique works similarly to sandblasting but at much lower temperatures; additionally, it spreads its nanoscale coating more evenly across the fabric so there are no hotspots where waterproofing may break down or wear off prematurely.