WOOL FIBERS
a—Medium Wool; b—Camel's Hair; c—Diseased Fiber; d—Merino Wool; e—Mohair.
Scouring Wool
As it comes from the sheep, the wool contains many substances besides the wool fiber which must be removed before dyeing or spinning. This cleansing is called scouring. Before scouring, the wool is usually dusted by machines to remove all loose dirt. The scouring must be done by the mildest means possible in order to preserve the natural fluffiness and brilliancy of the fiber. The chief impurity is the wool grease or "yolk" which is secreted by the skin glands to lubricate the fiber and prevent it from matting.
ONE METHOD OF WOOL SORTING
1—The Best Grade; 2—Lowest Grade; 3—Fair; 4—Medium Grade.
Scouring Agents
In the scouring of wool, soap is the principal agent. Soft soap made from caustic potash is generally used as it is less harmful than ordinary hard soda soap. Potassium carbonate—"pearl ash"—is often used in connection with the soap. If the water for scouring is hard, it is softened with pearl ash. The temperature of wash water is never allowed to go above 120° F. The scoured wool weighs from a little over a half to one-third or less of the weight of the fleece.