Cooperative Patent Classification

CPC Definition - Subclass B29K

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Last Updated Version: 2016.11
Definition statement

This place covers:

In accordance with the Note to B29 and the corresponding notes to the subclasses B29B, B29C and B29D, the Indexing Codes of this subclass provide information concerning moulding materials, materials for reinforcements, fillers or preformed parts, e.g. inserts. It further provides Indexing Codes for mould materials.

Moulding materials include the materials being applied in the processes as provided in the subclass B29B, e.g. the making of granules, the recovery of plastics.

This subclass provides further an indexing scheme B29K 2995/00 concerning the properties of moulding materials, reinforcements, fillers, preformed parts and moulds.

Relationships with other classification places

The Indexing Codes B29K follow the same structure as C08L, e.g. C08L 71/00 refers to the composition of polyethers as such. B29K 2071/00 refers to the use of polyethers as moulding material, B29K 2271/00 refers to the use of polyethers as reinforcement, B29K 2471/00 refers to the use of polyethers as filler, B29K 2671/00 refers to the use of polyethers as preformed parts, e.g. inserts and B29K 2871/00 refers to the use of polyethers as mould material

In the same way, for compositions of polyureas and polyurethanes as defined in C08L 75/00, corresponding Indexing Codes B29K 2075/00, B29K 2275/00, B29K 2475/00, B29K 2675/00 and B29K 2875/00 are provided.

Special rules of classification

It is desirable to apply the Indexing Codes provided in this subclass to identify any additional information complementing the invention information in the subclasses B29B, B29C and B29D, mentioned in the claims or in the unclaimed disclosures, if it is useful for search purposes.

The classifier should therefore identify additional information that is neither implicit from the allocated B29B, B29C or B29D classification symbols, nor implicit from the applied technology as such. The mere identification of materials or their properties by extensive lists does not necessarily imply that this information is useful for search purposes. The selection of non-obvious materials or the application of materials or the selection of material properties, which have some relation with the alleged invention are considered to be useful for search and should be identified by the allocation of the corresponding Indexing Code or codes provided in B29K, as long as they are not implicit from the allocated B29B, B29C or B29D classification symbols or from the applied technology as such.

Example : the manufacture by resin transfer moulding of a wind turbine blade is described using fibres of carbon, glass or aramid and a thermoplastic matrix, such as PE, PVC, PP, PS or PEEK. In this case, the Indexing Code for fibres will give no information of use for searching, the applied technology, namely shaping composites, implies already the use of a reinforcement. Glass, carbon and aramid fibres are further the main used fibres in composite material. The mere mention of these three types of fibres as alternative in an application is, therefore, not considered as additional information useful for search purposes, and the Indexing Codes are not required. The list of matrix material also consists of common polymers which have no particular claimed effects and/or characteristics in regards to the manufactured product. The allocation of the general Indexing Code for thermoplastic materials B29K 2101/12 is sufficient.

Reference is further made to the special rule of classification in the field of B29B 17/00.

Glossary of terms

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


a structure in the form of fibres, wires, rods, bars, sections, plates or blocks, which improves the strength of an article


a relatively inert substance in the form of particles, powder, beads, flakes or spheres, which improves the physical properties or increases the bulk or weight of an article

Preformed part

a part made of any material, being completely shaped to have a determined form and which is not used as areinforcement, e.g. wires or nets forced only into the surfaceof an article


a preformed part incorporated in an article during moulding; the insert can be incorporated completely or partially, e.g. only its edge or its surface