MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER, NOT PROVIDED FOR IN SUBCLASSES B31B OR B31C (manufacture by dry processes of articles made from particles or fibres consisting of wood or other lignocellulosic or like organic material B27N; making layered products not composed wholly of paper or cardboard B32B; making articles from cellulosic fibrous suspensions, e.g. wood pulp, D21J)

Description

B31D covers the manufacture of paper and cardboard articles through processes and techniques not specifically classified in other B31 subclasses. This residual category encompasses specialized or novel paper-working methods, unconventional article shapes, and emerging technologies applied to cellulose-based or analogous fibrous materials. It serves as a catch-all for paper-related inventions that fall outside the defined scope of subclasses B31B (making articles of paper or cardboard by folding or bending), B31C (corrugated or laminated paper), and B31F (working of paper or material worked analogously to paper). Examiners use B31D for genuinely novel manufacturing approaches, hybrid processes, or articles that do not fit the more specific technical definitions of neighboring classifications.