New compound gets water out of clothes
Researchers discover a way to help fabrics in the spin cycle shed water, which could lead to savings in energy.
The results of the research, sponsored by Procter & Gamble, could find its way into products in five years or so, said Daniel Carter, a doctoral candidate in chemical engineering and one of the inventors.
"The chemicals that we use are the same things found in fabric softeners and detergents," he said. "It is the way that we apply it that is different."
Shedding water during the spin cycle means less time in the dryer, which in turn translates to lower energy bills. A 10 percent reduction in drying time could save consumers $266 million annually nationwide, estimated Carter and professor and co-inventor Dinesh Shah.
More than 56 percent of Americans own electric dryers, with a typical dryer handling 300 loads per year. With the average load requiring from 2.7 to 3 kilowatt hours of electricity, drying clothes equates to 5 percent of total residential electricity consumption.
The discovery is part chemical engineering and part unconventional thinking. Carter and Shah went on the assumption that the spaces between fibers in a fabric form an independent capillary, or tube. Capillaries retain water due to surface tension. The principles of surface tension can be seen in how a drop of water can remain quite large until disturbed by a slight touch of a finger.
The primary difference is that the space between fibers is not physically circumscribed the same way a straw or any other standard capillary is. Nonetheless, the space between the fibers is contained enough to allow for capillary behavior, the two scientists reasoned. Researchers in the 1950s found that the spaces between fibers in a bundle could create capillary action.
"We just applied this to woven fabrics," Carter said. Still, "we had our skeptics."
The quest then became to find the right mix of chemicals to break the surface tension. Carter and Shah found that a 5-to-1 mixture of a particular detergent to softener broke the tension. The two, however, have not revealed the exact process. The university is applying for a patent, which it will license to Procter & Gamble.