Fleece is an animal fiber typical of certain goats (such as sheep) and camelids (such as llama and alpaca). Fleece originates from the skin of living animals, which produce it to keep warm and preserve body heat.
It occurs in the follicles, internal structures of the animal's skin that penetrate deep into its dermis, linked to the sebaceous and sweat glands.
Origin of fleece
Fleece originates, as we said before, from the skin of live animals, who produce it to keep warm and preserve body heat.
It is produced in the follicles which are internal structures of the animal's skin that penetrate deeply into its dermis, linked to the sebaceous and sweat glands.
Depending on the life cycle of the animal, fleece is generated from certain stages, and may even vary in properties (and therefore, in quality). For example, the most valuable fleece of the sheep is produced between its 3 and 6 years of age.
Composition of fleece
Fleece can vary slightly depending on the animal species, but in general, this is mainly composed of proteins called keratins. These proteins are the same ones found in human hair and nails.
Fleece can be classified according to the animal that produces it such as: llama, alpaca, sheep, etc. However, the most used is sheep's fleece, which is usually classified into:
Merino. Produced by the sheep of the same name, it has short, very fine fibers, and wrinkles. It is used in the manufacture of fine garments, so it is much more valuable.
Woven. Of medium length and less fine than the previous one. It is used in the manufacture of fabrics, upholstery, carpets, and blankets, or often in mixtures with Merino fleece or for carded fabrics.
Ordinary. It is a type of fleece long, soft, and with great thickness. It is often used to make pillows, mattress fillers, and other similar products.
In its different versions, fleece is a thick and elastic fiber, which retains heat very well since it is an exceptional thermal insulator.
Physical properties of fleece
It is an extensible fabric, capable of stretching without breaking since its fibers are usually folded together. But it is also elastic, so it tends to preserve its shape, and is extremely flexible.
Perhaps the most interesting property is its enormous thermal insulation capacity, since its fibers, not being compacted, maintain an air space that works as an insulator.
Chemical properties of fleece
Fleece is fireproof, doesn’t produce flames and to burn requires high temperatures. Likewise, it is resistant to organic solvents and mild acids, but not to alkalis, which are capable of denaturing keratin and breaking the macromolecule.
Its chemical constitution also gives it a margin of resistance to the proliferation of fungi and bacteria, but at the same time makes it vulnerable to insects, which can feed on it.
Fleece production process
Obtaining fleece goes through different processes, which are:
Shearing. Once a year the animals are gathered and pruned, without harm, gathering raw fleece.
Washing. Raw fleece is usually dirty and must be washed industrially, removing dust, sand, and other impurities (plant debris, insects, etc.).
Spinning. Using industrial or traditional methods, fleece fibers are twisted to form a thick yarn. With this, the pieces of clothing or whatever you want are manufactured.
Tinted. Natural or artificial tints are used to give the fleece its desired colors.