CHEMICAL OR BIOLOGICAL TREATMENT OF NATURAL FILAMENTARY OR FIBROUS MATERIAL TO OBTAIN FILAMENTS OR FIBRES FOR SPINNING

**Definition:** This place covers:

Chemical or biological treatment of natural filamentary or fibrous materials to obtain filaments or fibres that are subsequently used for spinning, i.e. the recovery of the fibres and/or filaments from natural materials. It also covers the carbonisation of rags and other fibrous materials to recover animal fibres. Please note that in this context "carbonisation" does not mean that carbon fibres are produced, but only that vegetable impurities are removed from the fibres, usually by an aqueous acidic treatment.

**Glossary:** - Fibre: a relatively-short, elongated member of natural or artificial material; - Filament: an endless or quasi-endless, elongated member of natural or artificial material - Yarn: a unitary assembly of fibres, usually produced by spinning; - Thread: an assembly of yarns or filaments, usually produced by twisting