Scouring and cleaning of raw wool:

Wool is composed with Keratine (approx. 33%), Dirt (Aprrox. 26%), Suint (Dry perspiration: 28%), Fat/grease (12%), Burr (Vegetable matter: 2-10%), Mineral matter (aprox. 1%) and Colouring matter (0.5 to 1%).

1. Wool grease can be removed by scouring. These Grease/waxes are comprised of a variety of monocarboxylic, dicarboxylic and hydrocarboxylic acids as well as steroidal alcohols. It has been determined that unscoured wool contains an unoxidized fraction of wool grease and other contaminants that is easily removed and readily recoverable 

2. Suint is usually considered to be a variable composition of water-soluble materials that is readily removed by scouring. 

3. The dirt that is removed from the scoured wool consist of both inorganic and organic materials.

4. Dirt: It is held by adhesive action of suint and wool fat. It removed during the scouring and washing processes.

5. Burrs: It is vegetable fragments consisting of dried grass, straw, sticks etc. These vegetable fragment come on the body of sheep during grazing and scratching the body against bush or tree to relive itching. It is remove using Carbonizing process. Following is the process of removal of Burrs:

i) Wool is resistant to acid. Burr being a vegetable matter is not resistant to acid.

ii) This property is used for the removal of burr.

iii) In this case wool is treated with 5-7% Sulphuric acid for 2 hours followed by hydro-extraction and then drying at 80-90oC for 20-30 minutes. 

iv) Carbonized burr is removed by washing with mechanical agitation.