CPC Definition - Subclass D21B
This place covers:
The preparation of fibrous raw materials, e.g. wood, rags, waste paper or pulp bales and their mechanical treatment to obtain mechanical pulp, in particular for paper-making and the production of fibreboard, comprises pretreating raw materials before pulp preparation, pulp preparation by dividing raw materials into small particles, e.g. by dry or wet methods of mechanical defibrating (cutting, grinding, kneading in mills or pulpers), conserving the obtained finely-divided cellulosic material (wood chips).
Subclass B27L covers process steps which take place before those steps provided for in subclass D21B. Examples of subject matter provided for in subclass B27L include debarking and removing vestiges of branches from trees or logs, splitting wood and manufacture of wood shavings, chips, powder and wood fibres.
Subclass D21B covers the treatment of raw materials, which may be wood, in preparation for paper-making or cellulose production.
Subclass D21C covers further processes resulting in cellulose pulp, usually by chemical means.
Subclass D21D covers further mechanical processing after initial pulp preparation to cellulose and before the resulting materials are passed to the paper-making machines.
Subclass D21F covers methods of producing paper.
Subclass D21H covers pulp compositions.
This place does not cover:
Splitting wood; Manufacture of veneer, wooden sticks, wood shavings, wood fibres or wood powder | |
Obtaining fibres from plant material (mechanical separation) | |
Hackling or heckling machines | |
Pretreatment of the finely-divided materials before digesting | |
Methods of beating or refining pulp | |
Purification of the pulp suspension by mechanical means |
Attention is drawn to the following places, which may be of interest for search:
Disintegration in mills; Milling devices in general | |
Flotation in general | |
Dry sorting of waste | |
Disposal of solid waste | |
Manufacture by dry processes of articles, with or without organic binding agents, made from fibres consisting of wood or other lignocellulosic or like organic material | |
Treatment of water from the processing of plants or parts thereof | |
Treatment of water from the paper or cellulose industry | |
Cellulose derivatives and their preparation | |
Macromolecular compounds derived from lignocellulosic materials | |
Disintegrating peat | |
Preparation of ethanol by fermentation or enzyme-using process of cellulosic material substrate | |
Preparation of polysaccharide by fermentation or enzyme-using process | |
Mechanical removal of impurities from animal fibres | |
Obtaining silk fibres or filaments | |
Chemical features in the manufacture of artificial filaments, threads, fibres, bristles or ribbons | |
Working-up waste paper (chemical part) | |
Methods of producing paper in paper-machines | |
Flotation of white water, recovering fibres from suspensions | |
Pulp compositions | |
Manufacture of articles from cellulosic fibrous suspensions |
Subgroups and main group
If a document concerns embodiments which are covered by several subgroups dependent on a higher hierarchy group, the following rules apply:
- the specific technical information relevant for some of the subgroups is classified in all said subgroups;
- if relevant, the structural association (e.g. the combination) of the elements covered by the subgroups is classified in the head group;
- analogously, if generic technical information common to all of the subgroups is disclosed and only schematic embodiments of the specific subgroup embodiments are represented, the documents is classified in the head group only.
In patent documents, the word/expression in the first column is often used instead of the word/expression in the second column, which is used in the classification scheme of this place:
lignocellulosic biomass materials | fibrous raw materials |
This place covers:
Impregnation of wood chips with chemical or biological (enzymatic) substances.
Attention is drawn to the following places, which may be of interest for search:
Chemical aspects of pulp preparation |
This place covers:
Defibrating by means not explicitly defined before, for example between cooperating rotating screw members in drums.
This place covers:
Defibrating by the use of microwaves, for example by ultrasound treatments.