1. CPC Sections
  2. CPC Section D
  3. CPC Class D21
  4. CPC Subclass D21D
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CPC
COOPERATIVE PATENT CLASSIFICATION
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D21D
TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE [2018-08]
WARNING

  • In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme.
D21D 1/00
Methods of beating or refining; Beaters of the Hollander type (knotter screens D21F) [2013-01]
D21D 1/002
.
{Control devices} [2013-01]
D21D 1/004
.
{Methods of beating or refining including disperging or deflaking} [2013-01]
D21D 1/006
. .
{Disc mills} [2013-01]
D21D 1/008
. . .
{Discs} [2013-01]
D21D 1/02
.
Methods of beating; Beaters of the Hollander type [2013-01]
D21D 1/04
. .
Beater rolls or bars [2013-01]
D21D 1/06
. .
Bed plates [2013-01]
D21D 1/08
. .
Beaters with means for driving the pulp quickly [2013-01]
D21D 1/10
. .
Beaters with means for regulating the pressure between the beater roll and the bed plate [2013-01]
D21D 1/12
. .
Beaters with means for continuous pulp discharge [2013-01]
D21D 1/14
. .
Beaters with one beater roll and with vertical stuff circulation canal [2013-01]
D21D 1/16
. .
Beaters with means for returning the pulp over the head of the beater roll [2013-01]
D21D 1/18
. .
Beaters with two or more beater rolls [2013-01]
D21D 1/20
.
Methods of refining [2013-01]
D21D 1/22
. .
Jordans [2013-01]
D21D 1/24
. . .
Jordan rolls [2013-01]
D21D 1/26
. . .
Jordan bed plates [2013-01]
D21D 1/28
. .
Ball or rod mills [2013-01]
D21D 1/30
. .
Disc mills [2013-01]
D21D 1/303
. . .
{Double disc mills} [2013-01]
D21D 1/306
. . .
{Discs} [2013-01]
D21D 1/32
. .
Hammer mills [2013-01]
D21D 1/34
. .
Other mills or refiners [2013-01]
D21D 1/36
. . .
with vertical shaft [2013-01]
D21D 1/38
. . .
with horizontal shaft [2013-01]
D21D 1/40
. .
Washing the fibres [2013-01]
D21D 5/00
Purification of the pulp suspension by mechanical means; Apparatus therefor (centrifuges, cyclones B04) [2013-01]
D21D 5/005
.
{Forming fibrous aggregates} [2013-01]
D21D 5/02
.
Straining or screening the pulp [2013-01]
D21D 5/023
. .
{Stationary screen-drums} [2013-01]
D21D 5/026
. . .
{with rotating cleaning foils} [2013-01]
D21D 5/04
. .
Flat screens [2013-01]
D21D 5/043
. . .
{Vibrating screens} [2013-01]
D21D 5/046
. . .
{Rotary screens} [2013-01]
D21D 5/06
. .
Rotary screen-drums [2013-01]
D21D 5/08
. . .
combined with a rocking movement [2013-01]
D21D 5/10
. . . .
of the tank [2013-01]
D21D 5/12
. . . .
of the screen [2013-01]
D21D 5/14
. . . .
of the tank and the screen [2013-01]
D21D 5/16
. .
Cylinders and plates for screens [2013-01]
D21D 5/18
.
with the aid of centrifugal force [2013-01]
D21D 5/20
. .
in apparatus with a horizontal axis [2013-01]
D21D 5/22
. .
in apparatus with a vertical axis [2013-01]
D21D 5/24
. .
in cyclones [2013-01]
D21D 5/26
.
De-aeration of paper stock [2013-01]
D21D 5/28
.
Tanks for storing or agitating pulp [2013-01]
D21D 99/00
Subject matter not provided for in other groups of this subclass [2013-01]