What is wool?
Wool is a protein fiber derived from the fleece of sheep and other animals and it is also the fabric made from the wool fibers.
There are about 100 or more species of sheep that gives fleece that gets to be wool with varying degrees of perfection in length, fineness and colour. But it is not sheep alone that gives wool. Coats of goats and rabbits are also called wool; Cashmere or Mohair from different types of goats, Qiviut from the undercoat of musk oxen, and Angora wool from rabbits- all are wool. (Checkout this post on animal fibers/fabrics for more details)
The manufacturing process of wool is costly and makes wool expensive when compared to other fabrics. Australia, Newzealand, and China produce most of the wool in the world with Australia leading the production.
How is wool fabric made from wool fibers – production & processing
The wool is sheared or clipped from the animals during springtime (Once a year). Wool, as it is shorn from the sheep, is called grease wool. It may be stiff and sticky due to lanolin/wool grease at this point.
Sheep can be categorized according to the kind of fleece they give. Fine wool sheep gives the finest of wool. The carpet wool sheep gives a coarse fur, the kind that is used in making carpets. The wool obtained at the first shearing after 6 months is called Lambswool. Wool obtained in the first or second shearing after 10 to 12 months is called yearling wool.When wool is taken from a healthy living sheep it is called virgin wool but when it is taken from a sheep that have died from natural cause it is called fallen wool. Wool from slaughtered sheep is called skin wool.
The fleece thus obtained is then sorted according to their length, colour and fineness (quality). Separating fleeces into groups according to fineness and length is called grading of wool. Fine, Medium, Crossbred, Long, and Coarse are the basic types of categorization. At this point, the wool is called Raw wool. Fleeces or parts of fleeces may be rejected at this point because of being badly stained, undesirable in color, or carrying unwanted vegetable matter
The wool fibers are then washed in a soapy mildly alkaline and warm cleansing solution. This will remove all impurities like oil, perspiration, dirt, grease, and vegetable matter etc from them. Carbonizing is the process of removal of burrs from wool by immersion in sulfuric acid.
The fibers may be dyed at this point, but they can also be dyed after spinning or weaving.
The fibers are then processed in a carding machine, which pulls it straight. Here the fibers are separated into long and short fibers. The manufacturing process in which the short fibers (noils) are separated from the longer fibers which are combed into a continuous strand of parallel fibers called top is called combing. The short wool fibers removed in the combing process are called Noils.
Yarn is then woven/knitted into wool fabric. The short yarns are spun into woolen yarns and the long yarns make worsted yarns . Textured wool is woven in a combination of two or more colours or two or more shades of the same colour
You can read more about the process of converting fleece to wool fabric here.
Categories of wool
2 main categories of wool fabric according to the length and quality of its yarn are Woolen fabric & Worsted Fabric
Woolen fabric is a soft fabric with a fuzzy texture. It is bulky, heavy and very warm and quite inexpensive compared to worsted fabrics. It is made from woolen yarns made from short woolen fibers, which are loosely spun with a low or medium twist. Large amounts of shorter wools, such as noils, wool wastes, and reworked wools are also used in addition to virgin wool. As the woolen yarn is not combed, the fibers lie in an uneven fashion. This is the reason for the fuzzy texture of the woolen fabric
Woolen fabrics are generally weaker than worsted fabrics. They are also quite easy to sew. One disadvantage of woolen fabric is that it has slubs and low twist so that the fabric tends to pill very easily. Another is that it stains/soils easily.
Examples of woolen fabrics are Coating woolen fabric, flannel, tweed. You can make garments like Jackets, coats, skirts, and blankets with the woolen fabric. It is the preferred fabric for felting
Worsted fabric is a smooth, strong, textured, lightweight and lustrous fabric. They are longer lasting with less wear and tear and stronger because of their strong tight weave. The worsted fabrics are faster drying than woolen fabrics. When you press worsted fabric it holds that way for some time. It is made from worsted yarns made from long woolen fibers, which are tightly spun with a medium to high twist. So no fear of sagging of fabric at all. examples of worsted fabrics are Gabardine, serge, wool poplin, tropical worsteds, worsted flannel, Twill Suiting fabric, and crepe.
Properties of wool
Wool is not like hair or fur. What distinguishes it from hair or fur are the crimpness, flexibility.
There are so many reasons for the endurance of this popularity of wool – after all the technological advances, man has still not been able to develop a better fabric than wool for a lot of its uses.
Wool is made up of keratin. The outer layer of the cuticle of each wool fiber is a protective layer made of scales pointing towards the tip. These surface scales give wool its unique felting and shrinking qualities. The scales tend to cling together when two fibers come in contact. This particular quality helps in spinning the wool. These scales also cause water to roll off helping wool to repel moderate spills. At the same time, wool is hydrophilic and shrinks when absorbed with water. But this hydrophilic quality makes wool easy to dye into any color
Here is a list of its main properties and the different types of wool fabrics that are used for sewing
Properties of Wool
- Great absorbancy
It has a special hydrophilic ability to wick away excess moisture. It wicks moisture away from the body and evaporates it into the air. This property is a major advantage in favour of wool when compared to other textiles. This can keep a person warm when wearing wool because wool removes moisture from the skin
- Insulating capacity and Climate control
I am quite surprised to learn that wool does not just keep you warm, it can also keep you cool in summer. This is because of its insulating property which keeps your body in optimal temperature. It can keep you in comfort whatever is the temperature outside. When it is cold outside it can trap dry air and warmth near the skin. When it is warm outside wool pulls excess heat and moisture from your skin helping your body stay cooler
- Built-in U V Protection
As a tightly woven fabric it protects your skin from UV radiation to a degree. You can read more about this property here.
- Water repellent
Wool has scales in its fibers and they repel water droplets. This is more so because of lanolin inherent in wool. It is water-resistant and repels light rain or snow.
- Natural wrinkle resistance and recovery
When wool fibers are stretched they will bounce back to their original shape. This recovery property helps in fighting creases and wrinkles. This is especially true when it is dry rather than wet. It is easy to remove wrinkles in wool with steam pressing.
- Resilient and durable
Wool fibers can bend back on themselves more than 20,000 times without breaking – this makes it resistant to wear and tear. Wool fabrics can last for a long time. The wool fibers have a natural crimp and they hold onto other fibers strongly which makes the fabric aslo very strong. It resists abrasion and tearing, making it wear well.
As a natural textile, wool is non-allergenic in its natural state. If it has special finishing applied to it the story is different. Mothproofing chemical is one such chemical added which can turn wool to a super allergy-inducing fabric
- Beautiful Looks
Wool fabric has a natural luster, a gloss or sheen which is very desirable. It takes dye well and can retain colours for a long time . The colour will not fade easily unless exposed to direct sunlight. Well tailored wool drapes beautifully on the body especially thin wool like wool batiste and wool challis.
- Sustainable fabric
As concerns for the environment is big nowadays the fact that wool is renewable and can be obtained again and again from sheep and other animals is one big thing in its favour. It is a biodegradable fiber that will degrade completely in soil rather than remain as it is like synthetic fabrics. Learn more about other eco-friendly sustainable fabrics like wool
- Natural fire-retardant property
Natural wool can resist flame to a degree, more so than cotton or synthetic textiles.
- Resists static, dirt and dust and even mildew
Lint, dirt, and dust are not attracted to wool because it repels static. As said it even resists spills
- Natural mildew and mold resistance.
Because its fibers can let moisture pass through it without retaining it resists mildew.
Care & maintenance
Unless it is specifically mentioned “dry clean only” you can hand wash woolen garments at home – just be wary of hot water. Heat does not agree well with wool – remember heat and agitation leads to felting of wool. Other things to take care of are hot iron, alkali-based stains, and moths. Know more about wool care here
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