ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 38, Textiles, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 248, Textile and textile products, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO 1833-1:2006), which has been technically revised. It also incorporates the Technical Corrigendum ISO 1833-1:2006/Cor 1:2009.

The main changes compared to the previous edition are as follows:

A list of all parts in the ISO 1833 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Methods for the quantitative analysis of fibre mixtures are based on two main processes, the manual separation and the chemical separation of fibres.

It is preferable to use the method of manual separation, which is given in Annex B, whenever possible since it generally gives more accurate results than the chemical method. It can be used for all textiles whose component fibres do not form an intimate mixture, for example in the case of yarns composed of several elements each of which is made up of only one type of fibre, or woven fabrics in which the fibre of the warp is of a different kind to that of the weft, or knitted fabrics capable of being unravelled made up of yarns of different types.

In general, the methods described in the different parts of ISO 1833 are based on the selective dissolution of an individual component. After the removal of a component, the insoluble residue is weighed, and the proportion of soluble component is calculated from the loss in mass. This document gives the information which is common to the analyses, by this method, of all fibre mixtures, whatever their composition. This information is intended to be used in conjunction with the other parts of ISO 1833; these parts contain the detailed procedures applicable to particular fibre mixtures. Where, occasionally, an analysis is based on a principle other than selective dissolution, full details are given in the appropriate part.

Mixtures of fibres obtained during processing and, to a lesser extent, in finished textiles can contain non-fibrous matter, such as fats, waxes or dressings, or water-soluble matter, either occurring naturally or added to facilitate processing. Non-fibrous matters are removed before analysis.

A method of pre-treatment for removing oils, fats, waxes and water-soluble matter is given in Annex A.

Dye in dyed fibres is considered to be an integral part of the fibre and is not removed.

In addition, textiles can contain resins or other matter added to bond the fibres together or to confer special properties, such as water-repellence or crease-resistance. Such matter, including dyestuffs in exceptional cases, can interfere with the action of the reagent on the soluble component and/or it can be partially or completely removed by the reagent. This type of added matter can also cause errors and are removed before the sample is analysed. If it is impossible to remove such added matter, the methods of analysis are no longer applicable.

Most textile fibres contain water, the amount depending on the type of fibre and on the relative humidity of the surrounding air. Analyses are conducted on the basis of dry mass, and a procedure for determining the dry mass of test specimens and residues is given in this document.

The result is therefore obtained on the basis of clean, dry fibres.

Provision is made for recalculating the result on the basis of

In some methods, the insoluble component of a mixture can be partially dissolved in the reagent used to dissolve the soluble component. Where possible, the reagents that have been chosen are those that have little or no effect on the insoluble fibres. If loss in mass is known to occur during the analysis, the result is corrected; correction factors for this purpose are given. These correction factors have been determined in several laboratories by treating, in the appropriate reagent as specified in the method of analysis, fibres cleaned by the pre-treatment.

These correction factors apply only to undegraded fibres, and different correction factors might be necessary if the fibres have been degraded during processing.

The procedures given apply to single determinations; at least two determinations on separate test specimens are made, both in the case of manual separation and in the case of chemical separation, but more may be carried out if desired.

Before proceeding with any quantitative analysis, it is assumed that all the fibres present in the mixture have been identified. For this purpose, ISO/TR 11827 may be used.

For confirmation, unless it is technically impossible, it is recommended that use be made of alternative procedures whereby the component that would be the residue in the standard method is dissolved out first.