Why Choose Wool for Diaper Covers?
Wool keeps sheep dry.
Why? Wool's structure produces an elegant combination of water repellence, breathability and moisture absorbency.
Repellance. At a microscopic level wool consists of a series of overlapping scales (called cuticles) which have a tendency to repel water droplets. This structure, in combination with a thin coating of lanolin (an oil secreted from the sheep's skin) causes water to run off the fibers. (The duck's back effect is also a sheep's back effect.) Natural water repulsion makes wool a good candidate for a diaper cover.
Breathability. Many artificial fibers also repel water, but that alone does not make them a good choice for a diaper cover--a plastic bag would fill this condition. It is important that the fabric also be able to breathe, or the temperature next to baby's skin will rise. Breathability (and hence reduced skin temperature) is an important factor in preventing diaper rash. When a woven wool fabric is boiled, the fibers become entangled and they form a lofty mesh with many tiny air pockets. This process is called fulling. Fulled wool is a highly water-resistant, breathable fabric.
Absorbency. There are artificial fibers that both repel water and breathe--Goretex is one such fabric. The third important property of wool is that it also has the ability to absorb moisture at a microscopic level. Beneath the water-repellant outer cuticle of the wool fiber is a highly porous core. The voids in this core can store minuscule water droplets--up to 30% by weight of the fiber itself--so that wool is able to both absorb and transmit moisture simultaneously. This is a very elegant, balanced mechanism, and there is no artificial fiber that can do this.
Sustainability. It is also worth noting that even if an artificial fiber could be manufactured that exactly duplicated the properties of wool, it would still be a less desirable choice. Without exception, attempts to mimic nature are highly energy and resource-intensive, even if they achieve their goal.
The sheep keep growing the wool. Wool can be grown and processed organically. That is not to say that all sheep are grown sustainably or that all wool is processed sustainably. On the contrary, it is difficult to find wool that is BOTH grown and processed organically. Notice when you buy organic wool, if the label is very specific: "Organically grown," this may mean the wool is not organically processed. And despite all good intentions, sheep in certain areas would die without certain treatments for parasites (in some places they are inside, in some places they are outside). Such treatment disqualifies wool from most organic certification. Despite the difficulty in finding well-treated wool, wool remains the best choice for diaper covers because of its performance.
The functional combination of water-repellence, breathability and moisture absorbency make wool a good choice. When you consider sustainability as well, wool is unparalleled as a choice for diaper covers.
Simple wool keeps sheep dry. It will keep your baby dry, too.
For articles and links on wool, see our wool resource page.
by Marc Pehkonen
copyright © 2000 - 2011 Marc Pehkonen. Used by permission.