Tiny Beads for Always-Fresh Clothes

March 11, 2003 -- Fit, comfort, color, design, and style all play important roles in how most people choose their clothes. But how about picking garments based on the way they smell?

For the past few years, some clothing and textile makers have been experimenting with embedding fabrics with unique fragrances and scents.

However, the issue with most early attempts is durability. Not many cologne-containing cloths could stand up to repeated washings and quickly wear out.

Quest International, the Netherlands-based chemical research unit of the ICI Group in London, and the Woolmark Company, a global wool textile organization, thinks they have developed a unique solution.

Called Sensory Perception Technology (SPT), the basic approach is similar to previous attempts made by other companies. It uses so-called micro-encapsulation: microscopic balls designed to hold the designed chemicals and "bond" them within the fibers of fabrics.

Made Mighty by Melanin

But what's different about SPT is that its micro-balls are made of a chemical that is similar to melanin, the compound that gives human skin its color and some of its protective properties.

Since melanin is naturally water- and heat-resistant, it makes an ideal choice for holding the fragrances and other chemicals, says David Hellens, marketing director for Woolmark.

"[The capsules] are waterproof and can stand temperatures of up to 150 degrees Celsius," says Hellens. "That keeps the 'ingredients' fresh in water and hot environments."

And, "What's really smart about this technology, wrapped around the microspheres are certain binders which create a cationic bond — a chemical weld — with the fibers," says Hellens. "The only way they release [their chemicals] is if they're broken during movement."

What's more, adding SPT to almost any fabric isn't all that hard or expensive to do, say Quest and Woolmark.

Once a fabric-maker decides what fragrances or chemical properties it wants the cloth to have, the liquid SPT solution can be added into the final textile production process — just like washing in a fabric's dye.

To Smell or Not to Smell

Shibani Mohindra, new business development director for Quest, says the joint SPT development project has been under way for more than three years. But in the last 18 months, the companies have been looking for new applications for the now-ready technology.

For example, imagine clothes that could actually repel or negate odors.

Mohindra says Quest has developed a unique set of ingredients that is the equivalent of "white noise" to tobacco smoke which can be added to clothes via SPT.

"If you go into a smoky restaurant, at the end of the night, you can just go home, give your jacket a shake, and it's refreshed and ready for wear the next day," says Mohindra.

Woolmark's Hellens says they are also looking at non-clothing applications too. For example, the SPT process can be used on fabrics and fibers used for seats or even carpeting. That, he says, could lead to "smart environments" which always smell fresh just by normal, everyday human interaction.

"Imagine this being used in heavy traffic areas — say, London's Underground [trains], or at airport terminals," says Hellens. "Wouldn't it be wonderful to always have a fresh-smelling train or area despite the busyness?"

Sweet Smell of Success?

Such applications of SPT might be far off, but not entirely far fetched since microencapsulation technologies have been studied and in use of years.

The military, for example, has been looking at microencapsulating technology for use in the battlefield. The technology could be used to deliver drugs and food to soldiers through use of "skin patches." And embedded in clothing, it could lead to uniforms that could detect — and possibly protect — chemical hazards.

And some microencapsulated clothes are available to consumers right now.

Sara Lee Hosiery, for example, makes ladies' pantyhose and undergarments that use the technology to deliver moisturizers and "anti-aging" chemicals to the wearer. But since the garments — marketed under the L'Eggs and Hanes brand names — don't use SPT, a spokeswoman says the garments' chemical benefits are exhausted after five washings.

Quest's Mohindra says SPT-treated garments don't require any special care and are designed to last up to 30 washings. Still, she admits: "To be honest, you are going to lose [microcapsules] through agitation [in the washing process]."

Still, she says that the SPT process is still promising enough that it's undergoing several trials with "a number of textile houses."

Both Quest and Woolmark expect the first products to use the SPT microcapsules — most likely lingerie and sports garments — should be available by the end of the year.