Last updated on September 22nd, 2023 at 09:46 pm
The vegetable matter is removed by chemical means; the process is called wool carbonizing. The method is comparatively simple. The wool to be carbonized is placed in tanks containing solutions of some strong acid like chloride of aluminum, hydrochloride, or sulphuric acid. Here it remains for a period of twelve hours, during which it is stirred several times. The acid, if it is not too strong, does not affect the woolen fibres. But attacks all vegetable matter and causes it to crumble.
At the end of twelve hours the wool is taken out of the acid tanks and placed in a woven to dry. The temperature is raised to about 160o or 170o Fahrenheit, not as warm as seriously to harm the woolen fibres, but warm enough to cause the acid to eat or burn up the vegetable matter. When dried, the vegetable matter will be found reduced to a crisp and, on shaking the wool, will fall out easily in the form of dust. Even large burrs, straw, seeds etc., can be removed in this way, but the risk in the use of acids and heat is such that the process is generally used only for disposing of the finer particles that the burr pickers and other machines cannot get at. The chemical carbonizing process came into use in the wool manufacturing industry about 1880.
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