Merino wool is a fine, natural fiber harvested from Merino sheep, prized for its softness and performance qualities. Lanolin, also known as wool grease, is a natural wax secreted by the sheep’s sebaceous glands. Understanding the relationship between these two substances requires examining lanolin’s biological function and the industrial processing of the wool.
The Origin and Purpose of Lanolin
Lanolin is a waxy secretion produced by the sebaceous glands of sheep. Chemically classified as a wax, its natural function is to coat the wool fibers and the sheep’s skin, creating a protective barrier. This coating helps the fleece shed water, protecting the animal from extreme weather and environmental elements. Raw, shorn wool, prior to any processing, can contain a significant amount of lanolin, sometimes accounting for up to 10–25% of the fleece’s weight.
How Raw Wool is Processed to Remove Lanolin
The Scouring Process
The process of turning raw, greasy fleece into usable textile fiber involves an industrial cleaning method known as scouring. Scouring is the first major mechanical step after shearing, designed to remove lanolin, dirt, and other contaminants, which can account for 35% to 40% of the fleece weight. The process involves continuously transporting the wool through wash bowls containing warm water, detergent, and sometimes an alkali. These agents emulsify the lanolin, separating the waxy substance from the wool fibers.
Residual Lanolin
This step removes the bulk of the lanolin, which is often collected and refined for use in cosmetics and pharmaceuticals. While scouring is highly effective, trace residual amounts of lanolin often remain chemically bound or physically trapped within the fiber structure. In most commercially processed merino wool fabrics, residual lanolin levels are typically less than 1% by weight.
The Characteristics of Finished Merino Fiber
Finished merino fiber is known for its exceptional characteristics. Merino wool is defined by its fineness, with fibers generally measuring less than 22 microns in diameter, making them significantly finer than traditional wool. This low micron count provides softness and flexibility, allowing the fiber to bend away from the skin without causing the prickle or itch sensation associated with coarser wools.
The extremely low concentration of residual lanolin is generally not a concern for individuals with sensitivities or allergies. The remaining lanolin is often altered or tightly bound, minimizing the potential for an adverse reaction in the finished garment. Merino fiber is also valued for its performance properties, such as its ability to regulate temperature and manage moisture. The fiber can absorb a significant amount of moisture vapor, helping to keep the wearer dry and comfortable.