IPC Classification

Class code (prefix) Descriptions Number of results
D21D 1/00 Methods of beating or refining; Beaters of the Hollander type
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
D21D 1/20 Methods of refining
D21D 1/22 Jordans
D21D 1/24 Jordan rolls
D21D 1/26 Jordan bed plates
D21D 1/28 Ball or rod mills
D21D 1/30 Disc mills
D21D 1/32 Hammer mills
D21D 1/34 Other mills or refiners
D21D 1/36 Other mills or refiners with vertical shaft
D21D 1/38 Other mills or refiners with horizontal shaft
D21D 1/40 Washing the fibres
D21D 5/00 Purification of the pulp suspension by mechanical means; Apparatus therefor
D21D 5/02 Straining or screening the pulp
D21D 5/04 Flat screens
D21D 5/06 Rotary screen-drums
D21D 5/08 Rotary screen-drums combined with a rocking movement
D21D 5/10 Rotary screen-drums combined with a rocking movement of the tank
D21D 5/12 Rotary screen-drums combined with a rocking movement of the screen
D21D 5/14 Rotary screen-drums combined with a rocking movement of the tank and the screen
D21D 5/16 Cylinders and plates for screens
D21D 5/18 Purification of the pulp suspension by mechanical means; Apparatus therefor with the aid of centrifugal force
D21D 5/20 Purification of the pulp suspension by mechanical means; Apparatus therefor with the aid of centrifugal force in apparatus with a horizontal axis
D21D 5/22 Purification of the pulp suspension by mechanical means; Apparatus therefor with the aid of centrifugal force in apparatus with a vertical axis
D21D 5/24 Purification of the pulp suspension by mechanical means; Apparatus therefor with the aid of centrifugal force 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