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CPC
COOPERATIVE PATENT CLASSIFICATION
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D21D
TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
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D21D 1/00
Methods of beating or refining; Beaters of the Hollander type (knotter screens D21F)
D21D 1/002
.
{
Control devices
}
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D21D 1/004
.
{
Methods of beating or refining including disperging or deflaking
}
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D21D 1/006
. .
{
Disc mills
}
D21D 1/008
. . .
{
Discs
}
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D21D 1/02
.
Methods of beating; Beaters of the Hollander type
D21D 1/04
. .
Beater rolls or bars
D21D 1/06
. .
Bed plates
D21D 1/08
. .
Beaters with means for driving the pulp quickly
D21D 1/10
. .
Beaters with means for regulating the pressure between the beater roll and the bed plate
D21D 1/12
. .
Beaters with means for continuous pulp discharge
D21D 1/14
. .
Beaters with one beater roll and with vertical stuff circulation canal
D21D 1/16
. .
Beaters with means for returning the pulp over the head of the beater roll
D21D 1/18
. .
Beaters with two or more beater rolls
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D21D 1/20
.
Methods of refining
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D21D 1/22
. .
Jordans
D21D 1/24
. . .
Jordan rolls
D21D 1/26
. . .
Jordan bed plates
D21D 1/28
. .
Ball or rod mills
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D21D 1/30
. .
Disc mills
D21D 1/303
. . .
{
Double disc mills
}
D21D 1/306
. . .
{
Discs
}
D21D 1/32
. .
Hammer mills
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D21D 1/34
. .
Other mills or refiners
D21D 1/36
. . .
with vertical shaft
D21D 1/38
. . .
with horizontal shaft
D21D 1/40
. .
Washing the fibres
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D21D 5/00
Purification of the pulp suspension by mechanical means; Apparatus therefor (centrifuges, cyclones B04)
D21D 5/005
.
{
Forming fibrous aggregates
}
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D21D 5/02
.
Straining or screening the pulp
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D21D 5/023
. .
{
Stationary screen-drums
}
D21D 5/026
. . .
{
with rotating cleaning foils
}
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D21D 5/04
. .
Flat screens
D21D 5/043
. . .
{
Vibrating screens
}
D21D 5/046
. . .
{
Rotary screens
}
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D21D 5/06
. .
Rotary screen-drums
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D21D 5/08
. . .
combined with a rocking movement
D21D 5/10
. . . .
of the tank
D21D 5/12
. . . .
of the screen
D21D 5/14
. . . .
of the tank and the screen
D21D 5/16
. .
Cylinders and plates for screens
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D21D 5/18
.
with the aid of centrifugal force
D21D 5/20
. .
in apparatus with a horizontal axis
D21D 5/22
. .
in apparatus with a vertical axis
D21D 5/24
. .
in cyclones
D21D 5/26
.
De-aeration of paper stock
D21D 5/28
.
Tanks for storing or agitating pulp
D21D 99/00
Subject matter not provided for in other groups of this subclass
This page is owned by Office of Patent Classification.
Last Modified: 04/16/2013 4:31:16 PM