This industry comprises establishments primarily engaged in manufacturing pulp without manufacturing paper or paperboard. The pulp is made by separating the cellulose fibers from the other impurities in wood or other materials, such as used or recycled rags, linters, scrap paper, and straw. Cross-References. Establishments primarily engaged in-- ? Manufacturing both pulp and paper--are classified in Industry 32212, Paper Mills; and ? Manufacturing both pulp and paperboard--are classified in Industry 322130, Paperboard Mills.