Why do polyester fibers attach so well to wool?

Here at Spicer Art Conservation, LLC, we are finishing the treatment of several wool uniforms from several military conflicts. The uniforms were stabilized, then mannequins were custom made for all of them. As all conservators do, we keep our work space clean and tidy, vacuuming on a regular basis. However, no matter what we do, those pesky polyester fibers find themselves on the surface of the wool uniforms. And to make matters worse, they are not easy to remove. Why is this?

White polyester fibers on black wool. Why do they attach so well!?

Well, with my research on magnetic systems, I have been investigating various issues regarding the materials that are frequently placed and used within the magnetic system, other wise known as the "gap". How these materials behave is related to many things, the topography, friction, cohesion, and static charge of the materials. All have an additional influence on how the magnetic system functions. In the mentioned scenario, several of these things have a role.

Where I am going with this, is that when materials are in contact with one another, they share electrons, which assists with the cohesion of materials to one another. The amount of sharing from one material to the other is related to their placement on the Triboelectric series.

The Triboelectric series? What is that?

Well, it is a ranking of materials in the order of their propensity to gain or lose electrons. It is based on the conductivity of the individual materials as seen in the table below. How it works is if two materials in contact are neighbors on the scale, there is less exchange. But if they are far apart, no matter where they lie on the scale, exchange occurs.

Schematic of electron exchange when two different materials are in
contact and then separated. The extent of this exchange is based
on the materials placement on the Triboelectric series.

To go back to the wool uniform and polyester fibers: referencing the chart below, notice how wool is neutral, close to cotton? It is not too often that I find myself trying to remove cotton fibers from wool. But, polyester is far away from neutral on the scale!

So the next time you find yourself complaining about the challenges of polyester fiber removal, do not blame the wool, blame those electrons!

Table: Material order of the Triboelectric series.

Charge	Material	Notes
+++	Air
	Polyurethane foam
	Hair
	Nylon, Dry skin	Dry skin has the greatest tendency to give up electrons and becoming highly positive in charge.
	Glass
	Acrylic, Lucite
+	Leather
	Rabbit's fur	Fur is often used to create static electricity.
	Quartz
	Mica
	Lead	Surprisingly close to cat fur.
	Cat's fur
	Silk
	Aluminum
	Paper
	Cotton	Best for non-static clothes
	Wool
NEUTRAL
	Steel	Not useful for static electricity
	Wood	Attracts some electrons, but is almost neutral
	Amber
	Sealing wax
	Polystyrene
	Rubber balloon
	Resins
	Hard rubber
	Nickel, Copper
	Sulfur
	Brass, Silver
	Gold, Platinum
	Acetate, Rayon
	Synthetic rubber
	Polyester
	Styrene & Polystyrene	Why packing peanuts seems to stick to everything.
-	Plastic wrap
	Polyethylene
	Polypropylene
	Vinyl, PVC
	Silicon
	Teflon	Teflon has the greatest tendency of gathering electrons on its surface and becoming highly negative in charge.
	Silicone rubber
- - -	Ebonite

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Gwen Spicer is a textile conservator in private practice.  Spicer Art Conservation specializes in textile conservation, object conservation, and the conservation of works on paper.  Gwen's innovative treatment and mounting of flags and textiles is unrivaled.   To contact her, please visit her website.

Learn more about magnets and their many uses in the new publications Magnetic Mounting Systems for Museums and Cultural Institutions. Available for purchase at www.spicerart.com/magnetbook.