D21 - Paper-making; Production of cellulose

More topics under "D21 - Paper-making; Production of cellulose" (197,038)
D21B - Fibrous raw materials or their mechanical treatment (6,881)
D21C - Production of cellulose by removing non-cellulose substances from cellulose- containing materials; Regeneration of pulping liquors; Apparatus therefor (29,117)
D21D - Treatment of the materials before passing to the paper-making machine (7,655)
D21F - Paper-making machines; Methods of producing paper thereon (43,899)
D21G - Calenders; Accessories for paper-making machines (11,814)
D21H - Pulp compositions; Preparation thereof not covered by subclasses ,; Impregnating or coating of paper; Treatment of finished paper not covered by class or subclass; Paper not otherwise provided for (94,172)
D21J - Fibreboard; Manufacture of articles from cellulosic fibrous suspensions or from papier-mâché (3,500)