IPC 2013 : D21H 27/16 : Pure paper, i.e. paper lacking or having low content of contaminants (after-treatment of cellulose pulp D21C 9/00).

IPC2013 > D > D21 > D21H > D21H 27/00 > D21H 27/16[1] > Pure paper, i.e. paper lacking or having low content of contaminants (after-treatment of cellulose pulp D21C 9/00).
D SECTION D — TEXTILES; PAPER.
D21 PAPER-MAKING; PRODUCTION OF CELLULOSE.
D21H PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C, D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR.
D21H 27/00 Special paper not otherwise provided for, e.g. made by multi-step processes.
D21H 27/16 · Pure paper, i.e. paper lacking or having low content of contaminants (after-treatment of cellulose pulp D21C 9/00).