IPC 7 English version
D21-D21B00138

SECTION D – TEXTILES; PAPER


D 21PAPER-MAKING; PRODUCTION OF CELLULOSE


D 21 BFIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT


1/

00Fibrous raw materials or their mechanical treatment

1/

02.Pretreatment of the raw materials by physical or chemical means (removal of bark B27L)

1/

04.by dividing raw materials into small particles, e.g. fibres (breaking-up or cutting wood or the like by dry methods B27L; disintegrating peat C10F 7/02; obtaining fibres mechanically for spinning from rags, peat, or the like D01B)

1/

06..by dry methods

1/

08...the raw material being waste paper (chemical part D21C 5/02); the raw material being rags

1/

10....by cutting actions

1/

12..by wet methods, by the use of steam (beaters D21D 1/00)

1/

14...Disintegrating in mills (in general B02C)

1/

16....in the presence of chemical agents

1/

18....in magazine-type machines

1/

20.....with chain feed

1/

22.....with screw feed

1/

24.....of the pocket type

1/

26....Driving or feeding arrangements

1/

28....Dressers for mill stones, combined with the mill

1/

30...Defibrating by other means

1/

32....of waste paper

1/

34....Kneading or mixing; Pulpers

1/

36....Explosive disintegration by sudden pressure reduction

1/

38.Conserving the finely-divided cellulosic material