How to work wool: properties, uses and production of this material. What is it used for, how to work the yarn.
Wool is a natural textile fibre obtained from the fleece of sheep (and some types of goats), rabbits, camels and some types of llamas. It is obtained through the operation of shearing, or cutting the hair, which for sheep occurs in spring. The wool obtained is called virgin wool . Another method of obtaining wool is to recover it after the slaughter of the sheep itself. The wool obtained is called tanning wool . The industry also reuses the wool obtained from production waste ; in this case we speak of regenerated wool .
WOOL: TEXTILE LABELLING
Only fibres from specific animals are classified as wool . Below is a list of the animals from which it is produced, along with the corresponding code on the fabric label:
- WO sheep
- WP alpacas
- WL blade
- WK camel
- WS cashmere
- WM mohair
- WHAT ANGORA
- WG Vicuna
- WY yak
- WU guanaco
- WB beaver
- WT otter
- Cashgora toilet
WOOL: APPEARANCE AND PROPERTIES
Wool, once washed to clean and degrease it, has a color that ranges from ivory to white. Its shine is given by the circular section and the scales. In microscopic analysis, it can be noted that longitudinally the fiber presents characteristic scales that cover its external surface, while its section is circular.
The fibre, which is made up of a protein substance, keratin , has a length between 2 and 40 cm and a circular section; it is covered externally with scales and has numerous elastic undulations, which are the origin of the characteristic curl . This structure gives wool softness, elasticity, hygroscopicity and high thermal insulation, due to the air retained between the fibres. However, it has poor resistance to mechanical stress .
The fineness (or diameter of the fibres) is the most important element for evaluating the quality of a wool and, like the length of the fibre itself, depends on the area where the fleece is taken (flanks, belly, shoulders, etc.).
Among the technological properties, it is worth mentioning the wool’s aptitude for dyeing, its good workability and its ease of spinning. On the other hand, wool does not tolerate ironing and can felt, losing its softness.
TECHNICAL PROPERTIES
Wool is a warm fiber to the touch and has high thermal insulation . This last characteristic determines that garments woven with wool are thicker, with a consequent retention of a greater quantity of air.
Heat causes degradation in wool fibres . The first degradation, which manifests itself with an imperceptible yellowing, can begin at around 70°C; at 130°C the actual decomposition begins; at 170°C ammonia develops. However, wool can remain exposed for short periods without suffering degradation even at a temperature of 200°C: this property is exploited by industries for the heat-setting operation .
Wool is relatively flame resistant and, when burned, develops a burnt bone-like odor along with the formation of small black grains that, when touched, crumble to powder. Wool is also thermoplastic .
Wool fabric not only insulates from the cold but also from the heat ; some African populations use it during the day to protect themselves from the heat and in the evening from the cold.
WOOL: PRODUCTION AND USES
Wool is a fibre that is very easily dyed . This is due to the fact that wool has an amphoteric character , that is, it behaves like a base in the presence of acid dyes, while it behaves like an acid in the presence of basic dyes.
The transformation, which includes spinning, weaving and other related operations, has been a European prerogative for centuries, with England and Italy in the lead. Today, wool processing is seeing the rapid advance of Asian states. From the second half of the twentieth century, its production was first surpassed by cotton and other plant-based fibres, then by artificial and synthetic fibres. The largest wool producer in the world in 1980 was Australia, followed by: New Zealand, the Soviet Republics, China, Argentina, Uruguay and South Africa.
Due to its origin, wool is typically used for clothing , but it has mainly outlets in the market for furnishing fabrics and padding (cushions and mattresses). It is not used in technical and industrial fabrics. However, wool is often used in blends with other fibres. It can be found with silk, for finely crafted garments, with cotton and linen, for the production of underwear; with polyester, for summer garments, with acrylic fibres to produce knitwear yarns.
