Science / Medicine : Researchers Think Small to Create Fluff

A synthetic insulating material that is virtually identical to goose down in its insulating properties has been developed for the Department of Defense, according to chemist James G. Donovan of Albany International Research Co. of Mansfield, Mass. The key to the new material, he said, is not the composition of the synthetic fibers that constitute it but their size.

The Albany team examined goose down and found that the key characteristic was the extremely small size of fibers on the quills. The large number of small fibers trap large quantities of air, providing high insulation, while the thicker quills provide resiliency.

By producing polyester fibers with a diameter of 7 microns--about one-quarter the size of a human hair and less than half the size of the smallest commercial polyester fibers--Donovan and his colleagues were able to reproduce the insulating power of down. Combining these with 20-micron fibers provided resiliency. The material costs only “a few dollars per pound,” he said, compared to $28 to $32 per pound for goose down.