Cleaning Wool Carpet

Simply stated, Wool is a great fiber! It is the fiber system that all other fiber systems try to emulate and while wool is among the closest fibers to perfection that we will ever know, it is not without its disadvantages.

Wool is a natural protein fiber obtained from sheep. Wool is the fiber to which all other fibers are compared. I have often heard carpet retailers describing the coloration of some carpet style by saying it looks like wool. While wool is not a perfect fiber, it is durable, flexible offer good bulk, and is highly resilient. It is sensitive to color change, yellowing, and degradation when exposed to direct sunlight and it has a narrow pH range for cleaning. Wool cleans best between a pH of 5 and 8 and the cleaning chemistry must not contain bleaching agents or optical brighteners. Wools of New New Zealand publishes a listing of acceptable cleaning chemicals approved for wool pile fibers. Temperature in cleaning wool should never exceed 150 degrees and excessive agitation when used with high temperatures should be avoided.

If you were to examine a wool fiber under a microscope, it would appear almost like fish scales. The outer skeleton of wool is made up of overlapping, interconnected "scales" which prevent soil from penetrating deeply into the pile or fiber itself. This "armadillo-like" armor can be stretched up to 30% without breaking and can absorb up to 33% of its weight in moisture.

This moisture absorption can be viewed as a positive benefit and a negative benefit. In terms of drying time. This is a negative. Its ability to hold water may prolong drying time and Wools has the tendency to shrink during the drying process. In wall-to-wall installations, it may pull away from the walls as a result of shrinking. much of the shrinking in wool products may attributed to jute or cotton back material, but over wetting should be avoided at all costs.

In terms of dry soil removal, wool releases dry soil more readily than synthetic carpet fibers. Wool offers excellent dry particle release properties, which makes it an ideal fiber for do-it-yourself dry compound cleaning. These dry compounds, like Host, can be sprinkled onto the carpet surface, agitated, and then vacuumed to remove compound and attached soil. Use caution with overly aggressive agitation. Damage to wool carpet is generally attributed to over-wetting, too much agitation and improper chemical selection.

Wool fibers should be cleaned with solutions on the neutral or acid side of the pH scale. Alkaline cleaning solutions (pH of above 7) may contribute to browning of fibers. There are 4 basic recommendations Made by the Wools of New Zealand for chemistry selection:

1. low alkalinity (pH of 7 or less)
2. Select a solution that leaves no sticky residue following drying
3. Select a product with good cleaning efficacy
4. Do not use cleaning products with added bleaches or dyes

Some cleaning chemistry is not appropriate for wool fibers. To be certain that the solution is appropriate for wool fibers look for one of the wool logos to the right.

About the Author
Michael Hilton was the original creator of Carpet Buyers Handbook. Having owned and operated a carpet wholesale company, Hilton has a vast knowledge about all-things carpet related as well as other types of flooring.