|  | D |
SECTION D — TEXTILES; PAPER

PAPER

|  | D21 |
PAPER-MAKING; PRODUCTION OF CELLULOSE

|  | D21C |
PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR

|  | D21C |
Note(s) Processes using enzymes or micro-organisms in order to: liberate, separate or purify a pre-existing compound or composition, or to treat textiles or clean solid surfaces of materials are further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [5]

|  | D21C |
Subclass index
PRODUCTION OF CELLULOSE |
Pretreatment of raw material | 1/00
Pulping | 3/00
Other processes | 5/00
Digesters | 7/00
AFTER-TREATMENT | 9/00
REGENERATION OF PULP LIQUORS | 11/00

|  | D21C 1/00 |
Pretreatment of the finely-divided materials before digesting (of waste paper Fulltext... Hierarchy... Expanded...D21C 5/02)

|  | D21C 1/02 |
· | with water or steam

|  | D21C 1/04 |
· | with acid reacting compounds

|  | D21C 1/06 |
· | with alkaline reacting compounds

|  | D21C 1/08 |
· | with oxygen-generating compounds

|  | D21C 1/10 |
· | Physical methods for facilitating impregnation

|  | D21C 3/00 |
Pulping cellulose-containing materials (digesters Fulltext... Hierarchy... Expanded...D21C 7/00)

|  | D21C 3/02 |
· | with inorganic bases or alkaline reacting compounds, e.g. sulfate processes

|  | D21C 3/04 |
· | with acids, acid salts, or acid anhydrides

|  | D21C 3/06 |
· · | sulfur dioxide; sulfurous acid; bisulfites

|  | D21C 3/08 |
· · · | calcium bisulfite

|  | D21C 3/10 |
· · · | magnesium bisulfite

|  | D21C 3/12 |
· · · | sodium bisulfite

|  | D21C 3/14 |
· · · | ammonium bisulfite

|  | D21C 3/16 |
· · | nitrogen oxides; nitric acid

|  | D21C 3/18 |
· | with halogens or halogen-generating compounds (bleaching cellulose pulp Fulltext... Hierarchy... Expanded...D21C 9/12)

|  | D21C 3/20 |
· | with organic solvents

|  | D21C 3/22 |
· | Other features of pulping processes

|  | D21C 3/24 |
· · | Continuous processes

|  | D21C 3/26 |
· · | Multi-stage processes

|  | D21C 3/28 |
· · | Prevention of foam

|  | D21C 5/00 |
Other processes for obtaining cellulose, e.g. cooking cotton linters (obtaining fibres for spinning Fulltext... Hierarchy... Expanded...D01C)

|  | D21C 5/02 |
· | Working-up waste paper (mechanical part Fulltext... Hierarchy... Expanded...D21B 1/08, Fulltext... Hierarchy... Expanded...D21B 1/32)

|  | D21C 7/00 |
Digesters

|  | D21C 7/02 |
· | Rotary digesters

|  | D21C 7/04 |
· | Linings

|  | D21C 7/06 |
· | Feeding devices

|  | D21C 7/08 |
· | Discharge devices

|  | D21C 7/10 |
· | Heating devices

|  | D21C 7/12 |
· | Devices for regulating or controlling

|  | D21C 7/14 |
· | Means for circulating the lye

|  | D21C 7/16 |
· | Safety devices

|  | D21C 9/00 |
After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters

|  | D21C 9/02 |
· | Washing

|  | D21C 9/04 |
· · | in diffusers

|  | D21C 9/06 |
· · | in filters

|  | D21C 9/08 |
· | Removal of fats, resins, pitch, or waxes

|  | D21C 9/10 |
· | Bleaching

|  | D21C 9/12 |
· · | with halogens or halogen-containing compounds (Fulltext... Hierarchy... Expanded...D21C 9/16 takes precedence) [4]

|  | D21C 9/14 |
· · · | with ClO2 or chlorites

|  | D21C 9/147 |
· · | with oxygen or its allotropic modifications (Fulltext... Hierarchy... Expanded...D21C 9/16 takes precedence) [4]

|  | D21C 9/153 |
· · · | with ozone [4]

|  | D21C 9/16 |
· · | with per compounds

|  | D21C 9/18 |
· | De-watering (de-watering in general Fulltext... Hierarchy... Expanded...F26B)

|  | D21C 11/00 |
Regeneration of pulp liquors

|  | D21C 11/02 |
· | of sulfite lye

|  | D21C 11/04 |
· | of alkali lye

|  | D21C 11/06 |
· | Treatment of pulp gases; Recovery of the heat content of the gases

|  | D21C 11/08 |
· · | Deodorisation

|  | D21C 11/10 |
· | Concentrating spent liquor by evaporation (evaporators Fulltext... Hierarchy... Expanded...B01D)

|  | D21C 11/12 |
· | Combustion of pulp liquors

|  | D21C 11/14 |
· · | Wet combustion