What is Wool?
Wool is an intricate natural fibre procured from the fleece of sheep. Wool sheep are classified as Ovis aries aries. Merino, Rambouillet, Blue Faced Leicester, and Corriedale breeds are among the best-known wool sheep.
Worldwide, there are estimated to be more than 1,000 different breeds of sheep. Sheep grow wool in a range of colours, textures and lengths. Wool can therefore vary considerably, depending on the breed of sheep, country of origin, and even the weather can play a role.
Wool composition: protein at its core
At the heart of wool’s composition is a protein called keratin. Keratin is a fibrous and flexible protein that forms the basis of not only wool but also human hair, nails, and other animal fibres. This protein provides wool with its remarkable attributes such as elasticity, strength, and the ability to withstand repeated bending and stretching.
Complex structure: from macro to micro
Wool’s structure is a captivating interplay of various levels, each contributing to its unique properties.
At the macro level, wool fibres consist of cuticle scales that resemble shingles on a roof. These scales are arranged in an overlapping pattern, offering protection to the inner layers of the fibre.
Zooming in, the middle layer, known as the cortex, constitutes the bulk of the wool fibre. It is here that the keratin fibres are tightly bundled, forming a helical arrangement. This helix provides wool with its inherent elasticity, allowing it to return to its original shape even after being stretched.
Beyond the cortex lies the medulla, a central channel found in some wool fibers. This layer is responsible for the crimp characteristic seen in wool. Crimp refers to the natural waviness or curliness of wool fibers, contributing to the fiber’s insulating properties by trapping air and enhancing warmth.
How wool is measured: micron