Skip over navigation
FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
Definition statement
This subclass/group covers:

Preparation of fibrous raw materials (like wood, rags, waste paper, pulp bales) and their mechanical treatment to obtain mechanical pulp, particular for papermaking purposes and production of fibre board, cutting raw materials into small particles, pretreatment of raw materials before pulp preparation, pulp preparation by mechanical defibration (for example by grinding), pulpers and mixers for pulps, de-inking devices.

Relationship between large subject matter areas

Even if the focus is clearly on the mechanical side of pulp preparation, also processes including chemical aspects are classified herein, as long as the nature of the process is to be considered as mainly mechanical. Otherwise, D21C is the appropriate subclass.

References relevant to classification in this subclass
This subclass/group does not cover:
Removal of bark
Disintegrating peat
Pulp or chip refiners, beaters, methods of refining or beating
Informative references
Attention is drawn to the following places, which may be of interest for search:
Disintegration in mills
Dry sorting of waste
Flotation in general
Milling devices in general
Disposal of solid waste
Manufacture of articles made from particles or fibers consisting of wood or like organic material by dry processes
Fiberboard, manufacture of articles from cellulosic fibrous suspensions
Flotation of white water, recovering fibers from suspensions
Mechanical treatment of fibrous material to obtain fibers for spinning
Production of chemical pulps, pretreatments or processes of mainly chemical nature
Special rules of classification within this subclass

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.
Fibrous raw materials or their mechanical treatment
Pretreatment of the raw materials by chemical or physical means (removal of bark B27L)
Definition statement
This subclass/group covers:

Steaming or heating of wood chips.

[N: by chemical means]
Definition statement
This subclass/group covers:

Impregnation of wood chips with chemical or biological (enzymatic) substances.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Chemical aspects of pulp preparation
Defibrating by other means
Definition statement
This subclass/group covers:

Defibrating between cooperating rotating screw members in drums.

[N: using microwaves]
Definition statement
This subclass/group covers:

Ultrasound treatments.

This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013