CPC Definition - Subclass D21H

Last Updated Version: 2025.01
PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
Definition statement

This place covers:

Pulp compositions and preparation thereof including after-treatment not covered by subclasses D21B, D21C, D21D: (a) from cellulose or lignocellulose fibres of natural origin, (b) from synthetic cellulose or non-cellulose fibres or web-forming material, or (c) non-fibrous material added to the pulp.

Coated paper characterised by: (a) coating material, (b) paper substrate, or (c) comprising more than one coating.

Processes or apparatus for adding material to the pulp or to the paper (processes for making continuous lengths of paper D21F 11/00).

Treatment of finished paper not covered by class B31 or subclass D21G.

Special paper not otherwise provided for, i.e. paper with special properties or applications which are only partially or not at all provided for elsewhere in the classification, e.g. made by multi-step processes. Whenever possible, however, these papers are classified according to the criteria used in the other groups of this subclass.

Paper-impregnating material characterised by its constitution.

Relationships with other classification places

Subclass D21B covers further processes from the wood chips to the pulp, usually mechanical processes.

Subclass D21C covers further processes from the wood chips to the pulp, usually chemical processes.

Subclass D21D covers further mechanical processing of cellulose containing materials after initial pulp preparation to cellulose, and before processing it in paper-making machines.

Subclass D21F covers methods of producing paper.

Subclass D21G covers further treatment of finished paper, e.g. in calendars.

Class B31 covers making paper articles and working paper, where subclass B31B covers boxes, cartons, envelopes or bags, subclass B31C covers wound articles and subclass B31D covers other articles not covered by class B31, as well as subclass B31F covers mechanical working or deformation of paper or cardboard.

References
References out of a residual place

Examples of places in relation to which this place is residual:

Making paper articles; Working paper

B31

Processes from the wood chips to the pulp, usually chemical processes

D21C

Mechanical processing of cellulose containing materials after initial pulp preparation to cellulose, and before processing it in paper-making machines

D21D

Treatment of finished paper, e.g. in calendars

D21G

Informative references

Attention is drawn to the following places, which may be of interest for search:

Self-supporting filtering material

B01D 39/14

Applying liquids or other fluent materials to surfaces, in general

B05

Layered products

B32B

Printing processes to produce watermarks

B41M 3/10

Printing processes to produce security printing

B41M 3/14

Printing processes to produce particular kinds of wallpapers

B41M 3/18

Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity

B41M 5/50

Books, book covers, loose leaves, printed matter

B42D

Securities; Bank notes

B42D 25/29

Identification or security features, e.g. for preventing forgery

B42D 25/30

Decorative panels

B44C 5/04

Paperhanging

B44C 7/00

Wood grain effects

B44F 9/02

Packaging materials of special type or form

B65D 65/38

Adhesives

C09J

Adhesives in the form of paper or textile fabric

C09J 7/21

Chemical features in the manufacture of artificial filaments and fibres

D01F

Non-woven fabrics formed of relatively short fibres

D04H 1/00

Treating fibres with macromolecular compounds

D06M 15/00

Mechanical treatment of fibrous raw materials by dry methods

D21B 1/06

Methods of producing watermarking devices

D21F 1/44

Dryer section of machines for making continuous webs of paper

D21F 5/00

Complete machines for making continuous webs of paper

D21F 9/00

Processes for making continuous lengths of paper

D21F 11/00

Patterned paper prepared on the paper-making machines

D21F 11/10

Coated fibreboard

D21J 1/08

Anti-coiling photographic support

G03C 1/81

Testing valuable papers, e.g. banknotes, for genuineness

G07D 7/00

Special rules of classification

In groups D21H 11/00 - D21H 15/00, in the absence of an indication to the contrary, classification is made in the last appropriate place.

In groups D21H 17/01 - D21H 17/63, in the absence of an indication to the contrary, a material is classified in the last appropriate place.

In groups D21H 27/30 - D21H 27/42, layered products classified in this group are also classified in subclass B32B.

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

binder or binding agent

usually a macromolecular product used to bind the paper-making fibres together in order to give cohesion to the final paper sheet, e.g. starchy materials, latexes, etc.

coating

layer of material applied to the paper substrate. Although part of this material may penetrate through the substrate, a coated paper is characterised by the presence of said layer on its surface.

fibres

under paper-making fibres are meant short fibres (maximum length in the range of the mm). Papers also comprising long fibres or filaments are classified in D21H 15/00.

filler or pigment

usually designating fine particles added to the pulp (very often inorganic materials such as talc, kaolin, silica, calcium carbonate, etc.).

finished paper

paper after passing to the finishing process, creating a surface characteristic of a sheet created by either on-machine or off-machine papermaking processes. Popular text and cover finishes include smooth, vellum, felt, laid, and linen.

impregnation

application of a liquid material to a paper substrate wherein the liquid material penetrates substantially the substrate, e.g. by submerging the substrate into a bath containing the liquid material.

pulp

a dispersion e.g. an aqueous suspension comprising paper-making fibres and optional additives, which is to be processed, and covers the term "paper stock"; it also means dry paper-making fibres which are to be made into paper by either wet or dry processes.

sizing agent or hydrophobising agent

substances used during paper manufacture to reduce the paper's tendency when dry to absorb liquid, allowing inks and paints to remain on the surface of the paper and to dry there, rather than be absorbed into the paper or agent added in order to increase the hydrophobicity of the paper.

paper stock

term used to define pulp after mechanical (refining or beating) and/or chemical treatment (sizing, loading, dyeing, etc.) in the paper making process, e.g. the pulp ready to make paper.

{Transparent papers, e.g. paper treated with transparent-rendering compositions or glassine paper prepared from well-hydrated paper stock}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Printing processes to produce watermarks

B41M 3/10

Watermarking devices

D21F 1/44

Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
References
Limiting references

This place does not cover:

Pulp or paper containing any kind of synthetic fibres

D21H 13/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Pulp manufacturing

D21C

Pulp comprising secondary fibres

D21C 5/02

Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material (chemical features in the manufacture of artificial fibres D01F)
Relationships with other classification places

Paper comprising synthetic fibres (possibly up to 100% synthetic fibres) may be used for different purposes. Such paper claimed per se is classified in this group.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Filters, particle separators, etc

B01D, B01D 46/00

Glass fibres; manufacture of fibres from mineral materials

C03B 37/00

Synthetic fibres

D01D, D01F

Insulating papers; electrical papers

H01B 3/52

Batteries (separators, spacing elements)

H01M 50/409, H01M 50/48

Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
Definition statement

This place covers:

Paper comprising long fibres, filaments, flakes or special fibres, being defined by their configuration (geometry, curled fibres, filaments, etc) or by specific properties (e.g. composite fibres).

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Manufacture/treatment of fibres, filaments, flake from glass, mineral or slags

C03B 37/00

Fibres or filament composition

C03C 13/00

Use of fibres or whiskers characterized by shape

C08K 7/02

Synthetic fibres

D01D, D01F

Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
Definition statement

This place covers:

Substances added to the pulp or to the paper by impregnation, characterized by their nature. Macromolecular or non-macromolecular compounds, material of vegetable origin, inorganic materials, etc.

In principle substances to be added by coating are to be found in D21H 19/00, unless both groups are possible.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Other metals (beryllium, magnesium, aluminium, calcium, etc.)

C01F

Compounds containing metal

C01G

Particles morphology

C01P 2004/00

Physical properties of inorganic compounds

C01P 2006/00

Polysaccharides; derivatives thereof (preparations of cellulose, starch, amylose, etc.)

C08B

Use of inorganic ingredients

C08K 3/00

Use of prepared ingredients

C08K 9/00

Compositions of macromolecular compounds

C08L

Inorganic materials

C09C

Coating/impregnating compositions per se

C09D

Inks

C09D 11/00

Microorganisms or enzymes

D21C 5/005, C12N, C12R

Coated paper (coated fibreboard D21J 1/08); Coating material (recording sheets characterised by the coating used to improve ink, dye or pigment receptivity B41M 5/50)
Definition statement

This place covers:

This group covers paper which have been coated (i.e. by means of a coated process per se) as well as the coating material per se.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity

B41M 5/50

Polysaccharides; derivatives thereof (preparations of cellulose, starch, amylose, etc.)

C08B

Compositions of macromolecular compounds

C08L

Coating/impregnating compositions per se

C09D

Inks

C09D 11/00

Coated fibreboard

D21J 1/08

Where the coating is characterized by the filler/pigment used:

Other metals (beryllium, magnesium, aluminium, calcium, etc.)

C01F

Compounds containing metal

C01G

Particles morphology

C01P 2004/00

Physical properties of inorganic compounds

C01P 2006/00

Use of inorganic ingredients

C08K 3/00

Use of prepared ingredients

C08K 9/00

Inorganic materials

C09C

Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
Definition statement

This place covers:

In this group the substances added to the paper are classified according to the function (hydrophobic agents, biocidal agents, ignifugeants, agents improving the absorbency of the formed paper, wet-strength agents, etc.) or specific properties (size, geometry, etc.) of the substance.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

As to security paper:

Making microcapsules

B01J 13/00

Watermarking

B41M 3/10

Security printing

B41M 3/14

Printing plates

B41N 1/00

Banknotes, cheques, shares, bonds:

B42D 25/29

Identity card, cheque, etc

B42D 25/29

With moiré effects

B42D 25/342

With security threads

B42D 25/355

Watermarking devices

D21F 1/44

Testing paper currency or valuable paper for genuineness

G04D 7/00

Additives defined by length or shape: see references given in D21H 15/00, D21H 17/00, D21H 19/00 regarding the fillers/pigments or other additional materials

Methods or apparatus for disinfecting or sterilising materials

A61L 2/00

Fire extinguishing compositions

A62D 1/00

Organic dyes or closely-related compounds for producing dyes; mordants; lakes

C09B

Treatment of inorganic materials

C09C

Fire proof paints

C09D 5/18

Inks

C09D 11/00

Modification of pulp properties

D21C 9/001

Removal of fats, resins, pitch or waxes from the pulp

D21C 9/08

Processes or apparatus for adding material to the pulp or to the paper (applying liquids or other fluent material to surfaces, in general B05; processes for making continuous lengths of paper D21F 11/00)
Definition statement

This place covers:

Processes for adding a substance to the pulp (D21H 23/04 - D21H 23/20) or to the formed paper (D21H 23/22 - D21H 23/74).

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

General coating processes (i.e. applying liquids or other fluent material to surfaces)

B05

Papermaking per se: machines and methods

D21F

Calenders and accessories for papermaking

D21G

After-treatment of paper not provided for in groups D21H 17/00 - D21H 23/00
Definition statement

This place covers:

This group is concerned with treatment of the formed/finished paper (e.g. mechanical treatments, chemical treatments, physical treatments, etc.). Coating processes per se do not fall within the scope of this group.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

General coating processes (i.e. applying liquids or other fluent material to surfaces)

B05

Papermaking per se: machines and methods

D21F

Calenders and accessories for papermaking

D21G

Special paper not otherwise provided for, e.g. made by multi-step processes
Definition statement

This place covers:

Paper materials for a special use (release paper, tissue paper, packing paper, wallpaper, etc.) or having a multi-ply structure.

Relationships with other classification places

Layered products per se are classified in the subclass B32B.

References
Limiting references

This place does not cover:

Cigarette papers

A24D 1/02

Informative references

Attention is drawn to the following places, which may be of interest for search:

Medals or badges

A44C 3/00

Paper filter inlays for filters/strainers for coffee or tea makers

A47J 31/08

Toilet paper; paper towels

A47K 10/00

Absorbent pads, e.g. sanitary towel, swab or tampon

A61F 13/15, A61F 2013/16, A61L 15/00

Cosmetic

A61L

Filter paper (see also informative ref. given for D21H 13/00); made on papermaking machine

B01D 39/14, D21F 11/14

Embossing

B31F 1/07

Creping

B31F 1/12, B31F 1/16, B31F 1/18

Attaching together paper or cardboard sheets

B31F 5/00

By adhesive means

B31F 5/06

Layered products comprising a layer of paper

B32B 27/10

Printed wallpapers

B41M 3/18

Sheets temporarily attached together

B42F

Decorative sheet/papers

B44C 5/0469

Paperhanging

B44C 7/00

Labelling

B65C

Packing; packaging; containers

B65D

Paper support for adhesive film / pre-gummed wallpaper

C09J 7/21

Non-woven

D04H

Multi-ply papers made on papermaking machines

D21F 9/006

On the papermaking machine

D21F 11/006

Anti-coil photographic support

G03C 1/81

Labels, tag ticket

G09F 3/00

Embossed/patterned papers: