Raw wool is sometimes bleached by steeping, but the use of the continuous woolscouring machine is now more common. The bleach bath is usually run on the acid side and the bowls are lined with lead. Best results in this type of wool bleaching are obtained by keeping the peroxide bath at a pH of about 4.4 by the addition of small amounts of iron-free sulfuric acid to the peroxide bowl. The natural alkalinity of the water and the alkali brought in by the wool will affect this pH, which is best maintained by adding small amounts of acid at regular intervals as the peroxide in the bath is replenished. The pH can be measured by use of pH papers or other accepted means. Peroxide concentration should be maintained at 0.38 to 0.45% or approximately 1.25 to 1.50 volumes.
地址：山东省烟台市开发区南昌大街48号
