Page:Paper and Its Uses.djvu/22

10 loosening the fibres, and allowing dirt to come away. The second and smaller cylinder is employed as a washing drum. It is covered with wire gauze, through which the water passes, and as the drum revolves the dirty water passes into the interior, where a number of bucket compartments carry the water and pass it through the axis of the drum to the waste pipe. When the rags are filled into the beating engine clean water is run in, the beating roll is kept out of contact

with the bottom knives, and the rags are kept in circulation. The washing cylinder is in action, and the roll being gradually lowered the dirt is eliminated. When this stage is reached the washing drum is lifted, the beating roll lowered, and the rags are gradually reduced in size until they attain a state of fibrous pulp, being known technically as "half-stuff." In most instances the next process is bleaching. There are special drawing papers, of which "O.W." and "Unbleached Arnold" are examples, which are the colour of the original rags, no bleaching having taken place. But