Wool Meets Plasma Science

Post date: Feb 04, 2010 6:50:11 PM

It amazes me that while I find the felting phenomenon magical, many consider it an annoyance. In their minds, the use of wool often means (gasp) hand washing or shrinking sweaters. In an effort to combat the flooding of the market with synthetics, the wool industry has been promoting felting, and it is now a growing craft.

You may have also noticed there are now “washable wools” on the market. The SmartWool brand is an example and is widely sold around the United States. They offer apparel made of 100% wool, totally soft and itch free. So how do most companies produce a felt free product made of 100% wool? Here is where wool meets science …. Woololgy.

Wool is able to be felted because the small scales on the fibers become completely entwined and are then unable to be separated. However, if the scales are damaged on the microscale, the wool becomes "felt proof." In general, the removal of the scales is done by either surface modification through physical/chemical methods or by coating a polymer over the scales. These methods are expensive and complicated to apply. In addition there are environmental issues of disposing of the aqueous solutions used; they often contain chlorine and or sulphur.

Recently, my husband stumbled across a paper published in a technical journal. The authors investigated the effects of treating wool with a low temperature plasma (LTP) in order to damage the scales on the cortex of the wool, making it felt proof. As a former heat transfer engineer and a wool lover who happens to be married to a plasma engineer, I found this article very interesting. Why would something so “dry” be interesting, you ask?

A low temperature plasma is much more environmentally responsible than a chemical dip because the gases used are often inert (i.e. Oxygen, Nitrogen, Hydrogen). This keeps pollution to a minimum and is far cheaper for industry to use. How does the low temperature plasma work? I KNEW you would be curious ….. Contact me via email at mhfiber@gmail.com and I’ll fill you in.