Types of wool Wool Grading
Methods of identifying wool Wool Shearing
Centers of Wool production Wool Washing
 
  Wool the proteinic fibers grown or sheep’s skin which due to easy availability and also its physical properties such as its curly nature and flexibility is employed as one of the main carpet-weaving materials. It is employed for carpet piles and in the case of tapestries such as tribal carpets, in addition to its application as pile it is also employed as wrap and weft.

Types of wool will be considered from three points of view :

1- From the viewpoint of shearing : 

Spring wool; sheared in the early parts of spring. Autumn wool : sheared in late autumn. To weave carpet and to supply worsted thread mainly his type of wool is used.

 

2- From the quality and color viewpoints :

 quality of wool depends on such factors as delicacy (fincness) of its fibers, thickness and length of fibers, strength, level of curlicue, employment of natural dyes, stainability, elasticity and collapsibiity of fibers. As an example the longer the length of fibers and the lesser their thickness, the higher the quality of wool produced of such fibers. Of course it is worth mentioning that such factors as gender and age of the sheep, climatic conditions, type of nutrition and season of shearing effectively influence the quality of wool. All parts of the sheep’s body are not covered with the same quality of wool and if all the wool sheared from different parts of the body are mixed up, due to discrepancies of color quality, as well as texture and delicacy the wool will lack uniformness and purity. Natural colors of wool include white, dark white, yellow, dark gray, brown and black. No doubt the more white and uniform the wool the more will be its quality and during the dyeing operations it will lead to better quality of the processed wool.

One of the characteristics of arid areas like Iran, is the diversiformity of its wool which gives it an elasticity property i.e. keeping its original condition and recoil quality. This quality, not very much suitable for cloth weaving however, is a very useful and important property in carpet-weaving. In this manner, the carpet piles in such conditions as compression, washing … will keep their original condition and do not become fetly.

3- From the view point of nature :
Two types of wool are available; natural and artificial.Artificial wool from the appearance point of view resembles natural wool however, based on durability, dye absorption, fineness and other attributes it has nothing in common with natural wool.

Methods of identifying natural wool 

A)    Once contacting the flame, natural wool burns smoothly, producing the characteristic smell of burnt hair and sulfur and at the end a fine powdery ash is left.

 

B)     Physical observation : Once observed under a microscope, wool, like pine stem, will represent alternative angles and scales.

 

      C)    Chemical procedure : Natural wool is very vulnerable to alkali and is not very reistant to reducing and oxydizing agents.

Important Centers of Wool Production

Amongst the most important wool production centers of Iran, one can point to such regions as Azerbijan, Isfahan, Khorasan, Fars, Kurdistan, Kerman, Kermanshah and Lorestan. “Makie” and “Moqani” races in Makou and Dasht Moqan, “Afshari” and “Kabud Shirazi” in Fars and “Qarahgol” and “Kurdish” races in Kurdistan are considered as the best sheep races of Iran.

Some of the characteristics of sheep wool obtained from different regions of Iran are as follows :
Urumieh : Mostly colored.
Khoy : Mainly white, with long, delicate and transparent fibers.
Dasht-e-Moqan : Coarse.
Kerman : Like wool of Khorassan but thinner and finer than that of Kermanshah and with more fat.
Makou : Mostly white-colored, transparent, with long fibers and with coarse and rough sections.
Mahabad : Mainly colored.
Naein : Finer and thineer than the wool of other regions.

 

Wool Grading

For carpet yarn grading, metric system is emloyed which indicates the quality and thickness of woolen yarns which is equal to the length of onefold wool yarns in meter/one gram of wool.  Nm = L/W

The more this ratio, the finer will be the onefold wool yarn. The commonest metric numbers used in carpet-weaving are numbers 3-10.

Wool Shearing

Sheep wool should be sheard in a suitable time before, due to animal’s sweting it is contaminated to dust and dirt. This process is usually done during the two seasons of spring and fall once at the age of 6 months and the second time at the age of 9 months.

Shearing is done either using the hand shearing procedure by a scissor-like tool (shear) or instrumentally employing wool shearing machines. 

Wool Washing  

Following shearing, there comes the turn of wool washing. In the past, carpet weaver believed that wool should be valued, therefore they used to wash wool in pure, fresh and cold source water. This procedure involved putting wool in baskets and rinsing it several times so that part of its fat be washed up. This procedure has persisted to present. Usually today, soaproot (chubak) or wild plum leaf are employed for washing wool. It should be noticed that to wash wool, never alkali, especially strong ones, should be used. Another procedure for washing wool in workshops and factories is employment of mechanical and cleaning machines. Following the wool washing comes the turn of carding, i.e. separation of wool fibers glued together during the washing process and preparing them for spinning. Finally spinning operations are done and wool yarn is prepared. These operations are performed either by hand or employing machines.

In hand spinning procedure, work is done by hand, spinning wheel and right twist, while in instrumental method, the wool is spun by machine spindles, using two right and two left twists.