Cotton Fabrics Damaged By High Dryer Temperatures

NEW ORLEANS, La., Aug. 25 -- Using high temperature settings on clothes dryers can damage cotton fabrics, according to a study presented here today at the national meeting of the American Chemical Society, the world's largest scientific society. When repeatedly machine dried at high temperatures, cotton fabrics eventually tear more easily than those tumble-dried at room temperature, drip-dried indoors or dried outdoors by sunlight, the study concludes.

"While cotton can be dried at the relatively high temperatures in clothes dryers without immediate catastrophic damage, serious abrasions and cracking damage occur with repeated dryings," says the study's lead author, Young-Sook Lee Buisson, Ph.D., of the U.S. Department of Agriculture's Southern Regional Research Center in New Orleans.

The cracks that appear in cotton fibers after high-temperature drying can reduce fabric strength by 25 percent or more, claims Buisson. Not only does hot drying cause your clothes to wear out faster, it produces more lint, she notes.

In many cases, drying time could be reduced by 10 to 20 percent, thus avoiding much of the damage, according to Buisson's study. People would have to take the clothes out before the end of the machine's drying cycle, however, since "current moisture sensors are not sensitive enough to stop the drying that soon," she adds.

Abrasion from the tumbling action of dryers also contributes to fabric damage. Tumbling of cotton fabrics when they are wet causes more damage than tumbling them partially dry, the study finds. Most dryers use a warm-up phase that heats and tumbles clothes while they are still wet. If clothes were tumbled only after they had partially dried, damage would be minimized, says Buisson.

Although the 18-month study focused specifically on 100 percent cotton fabrics, Buisson hypothesizes that blended cotton fabrics, such as those containing polyester, would suffer less dryer damage. She hopes to test that in a future study, as well as evaluate the effects of laundry softener additives on fabrics.