Skip to content
Search Classifications
Search for IPC and CPC classification codes or keywords
CPC Subclass Not Allocatable
D21J

FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE (manufacture of articles by dry processes B27N)

Description

D21J covers the production of fibreboard and manufactured articles formed from cellulosic fibrous suspensions, including papier-mâché. This classification encompasses manufacturing processes such as wet-laying, pressing, drying, and bonding of cellulose fibers to create composite board materials or molded products. It includes technologies for controlling fiber distribution, density, and mechanical properties of the resulting boards and articles. Related processes in paper-making chemistry and pulp preparation are classified elsewhere in D21, while finished paper products themselves fall under different classifications.

4 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

  • D21J 5/00 Manufacture of hollow articles by transferring sheets, produced from fibres suspensions or papier-mâché by suction on wire-net moulds, to couch-moulds
  • D21J 7/00 Manufacture of hollow articles from fibre suspensions or papier-mâché by deposition of fibres in or on a wire-net mould

Top Applicants

Top 10 applicants by patent filingsfor class D21, 2013–2023, worldwide · Source: EPO PATSTAT

  1. VOITH PATENT DE 1,857
  2. STORA ENSO FI 1,552
  3. KEMIRA FI 1,173
  4. KIMBERLY-CLARK CORPORATION US 1,107
  5. VALMET TECHNOLOGIES FI 965
  6. VALMET SE 943
  7. P&G (PROCTER & GAMBLE COMPANY) US 941
  8. OMYA INTERNATIONAL CH 821
  9. UPM-KYMMENE CORPORATION FI 512
  10. SEIKO EPSON CORPORATION JP 501