Clothes Made to Smell (in a Good Way)

Feb. 2, 2007 — Vanilla candles, carpet fresheners, air mist sprays and other home fragrance products accounted for $3.4 billion in sales last year. Now researchers are looking at ways to permanently infuse scents into textiles.

The scent-infused fabrics could lead to pleasant-smelling blankets and sheets, give holiday linens a festive fragrance and make gym clothes less odoriferous.

"Some of the strongest ideas we have are in athletic clothing…but we're going to see success in apparel and home textiles, such as towels, too," said John Pierce, associate professor of psychology at Philadelphia University.

Pierce and associate professor of engineering Fernando Tovia, and assistant professor Natalie Weathers are in the second year of a three-year project to assess the fabrics.

The team is pursuing a new method for imbedding the scent directly into the fibers. Conventional methods rely on tiny scent-filled capsules that are added on top of the yarn after it has been woven into a fabric. The capsules release their fragrance when they crack open during normal wear and use.

The problem, said Pierce, is that the capsules frequently break before the garments are on the shelves, and then break some more before the customer can get the product home.

Pierce and his team have developed an alternative method that infuses the scent and the color into the yarn at the time it is made. Their yarn is essentially a core containing strands of scent and color sheathed in an outer layer — all produced in one step.

The researchers think that their fabrics should retain the fragrance for 10 to 15 washes — about the same as those with microcapsules, but should be cheaper to manufacture (no microcapsules to purchase, nor microcapsule-applying machinery).

But for the fragrance to survive washings, it has to withstand the manufacturing process.

"Some of the challenges of the project would be for the fragrance to survive the melt processing temperatures of the fiber," said Cheryl Gomes, senior engineer in the composites and advanced textiles materials technology group at Foster-Miller, in Waltham, Mass.

And there is also the psychological issue, she added. "Some people might not like the scent of lemon on a shirt while others do. I actually have two shirts that have a coconut scent, which is great in the summer because everyone thinks of sun tan lotion, and it's fun to wear something that has a cool scent. But then others might not like the scent."

Recently the researchers had the fibers woven into about 100 scarves in purple, white and orange that smell of lavender and citrus. Volunteers will wear the scarves to assess the performance, and whether the scents make life a little more pleasant.