ISO 17202:2002 テキスタイル—単紡績糸の撚りの測定—撚りを解く/撚り直す方法 | ページ 2

Foreword

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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 17202 was prepared by Technical Committee ISO/TC 38, Textiles, Subcommittee SC 23, Fibres and yarns.

Annex A of this International Standard is for information only.

Introduction

The direct twist method (see [1] and [2]) has, for a long time, been recognized as the most accurate method of twist determination but the much faster untwist/retwist method has long been used in industry in many countries. In the 1980s the hope was expressed by some Institutes that the untwist/retwist method would be suitable for the measurement of twist of open-end yarns that cannot be measured by the direct method. First experiments in the 1970s and later in the 1990s showed, however, that the untwist/retwist method is not suitable to OE yarns. The present method is therefore restricted to ring spun yarns.

1 Scope

This International Standard specifies a method for the determination of the direction of twist in single yarns and the amount of twist, in terms of turns per unit length, by the indirect untwist/retwist method.

This International Standard is applicable to single spun yarns.

This International Standard is not applicable to:

• a) open-end spun yarns;
• b) false twist and self twist yarns;
• c) air-jet yarns;
• d) yarns that stretch more than 0,5 % when the tension increases from 0,5 cN/tex to 1,0 cN/tex.

  NOTE Such yarns may be tested under special conditions of tension which are accepted by all parties interested in the test results.

• e) yarns that are too large to permit their being placed in the clamps of testing apparatus without crushing or distortion severe enough to affect the test results.

The method is designed primarily for yarns in packages, but by the application of special precautions the procedures can be used for yarns taken from fabrics.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.

3 Terms and definitions

For the purposes of this International Standard, the following terms and definitions apply.

Bibliography