1、BS EN ISO1890:2009ICS 59.100.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDReinforcement yarns Determination of twist(ISO 1890:2009)This British Standardwas published underthe authority of theStandards Policy andStrategy Committee on 30November 2009. BSI 200
2、9ISBN 978 0 580 65488 6Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 1890:2009National forewordThis British Standard is the UK implementation of EN ISO 1890:2009. Itsupersedes BS EN ISO 1890:1997 which is withdrawn.The UK participation in its preparation was entrusted to Techn
3、icalCommittee PRI/42, Fibre reinforced thermosetting plastics and prepregs.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct ap
4、plication.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 1890June 2009ICS 59.100.01 Supersedes EN ISO 1890:1997 English VersionReinforcement yarns - Determination of twist (ISO 1890:2009)Fils de renfort - Dtermina
5、tion de la torsion (ISO1890:2009)Verstrkungsgarne - Bestimmung der Drehungszahl (ISO1890:2009)This European Standard was approved by CEN on 30 May 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status
6、 of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A ver
7、sion in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denm
8、ark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATION
9、EUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 1890:2009: EBS EN ISO 1890:2009EN ISO 1890:2009 (E) 3 Foreword This document (EN ISO 1890:200
10、9) has been prepared by Technical Committee ISO/TC 61 “ Plastics“ in collaboration with Technical Committee CEN/TC 249 “Plastics”, the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endors
11、ement, at the latest by December 2009, and conflicting national standards shall be withdrawn at the latest by December 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for iden
12、tifying any or all such patent rights. This document supersedes EN ISO 1890:1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denm
13、ark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 1890:2009 has been approve
14、d by CEN as a EN ISO 1890:2009 without any modification. BS EN ISO 1890:2009ISO 1890:2009(E) ISO 2009 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Internation
15、al 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,
16、 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 2. The main task of technical comm
17、ittees 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 p
18、ossibility 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. ISO 1890 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13, Composites and reinforcement fibres. This
19、fourth edition cancels and replaces the third edition (ISO 1890:1997), of which it constitutes a minor revision. The main changes are as follows: the scope has been broadened to include all reinforcement-fibre yarns; the normative references have been updated; the reference to ISO 1886 which was in
20、the first footnote on page 3 has been removed (ISO 1886 has been withdrawn without replacement). BS EN ISO 1890:2009BS EN ISO 1890:2009INTERNATIONAL STANDARD ISO 1890:2009(E) ISO 2009 All rights reserved 1Reinforcement yarns Determination of twist 1 Scope This International Standard specifies a meth
21、od for the determination of twist in yarns made from textile glass, carbon, aramid or any other reinforcement fibres. The method applies to single yarns (one twist) and to folded or cabled yarns (two or more twists). For folded and cabled yarns, the method is generally applied only to the final twis
22、t step. This International Standard is applicable to package-wound yarns. If the measurement is carried out on yarns taken from a beam (or warp) or from a fabric, the result is of an indicative nature only. The method is not applicable to products made from staple fibres. 2 Normative references The
23、following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2:1973, Textiles Designation of the direction of
24、twist in yarns and related products ISO 291, Plastics Standard atmospheres for conditioning and testing ISO 1889, Reinforcement yarns Determination of linear density 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Z twist S twist twist in a p
25、roduct if, when it is held in a vertical position, the spirals or helices formed by the fibres or filaments around its axis incline in the same direction as the central portion of the letter Z or S, respectively NOTE See ISO 2:1973, Clause 2. BS EN ISO 1890:2009ISO 1890:2009(E) 2 ISO 2009 All rights
26、 reserved4 Principle The twist in a specimen of known length is removed by untwisting, i.e. by turning one of the ends of the specimen with regard to the other, until all the elements (yarns, filaments) constituting the specimen are parallel. The direction of twist in the yarn is noted and the value
27、 of the twist is expressed as the number of turns needed to eliminate the twist in 1 m of yarn. The determination of the twist must allow for the fact that the take-off system may have an influence on the result. Thus when the yarn is taken off tangentially, the degree of twist inserted by the twist
28、 frame is not changed. On the other hand, if the yarn is taken off over-end, the measured twist is modified depending on the circumference of the bobbin. It will increase or decrease depending whether the yarn is taken off from alternate sides of the package. The method specified in this Internation
29、al Standard is based on the tangential take-off system. If required, the over-end twist can be either measured or an approximate value calculated using the following equation: over-end tangential1TTD=where 1Dcorresponds to the twist induced by over-end take-off; D is the diameter, in metres, at the
30、place on the bobbin where the specimen is taken. 5 Apparatus 5.1 Twist tester, i.e. an apparatus which has two clamps, one moving horizontally, the other rotating, mounted on a bar. The twist tester shall satisfy the following conditions: It shall be capable of measuring the number of turns to the n
31、earest turn. The clamps shall grip the yarn without slipping and shall not damage the yarn. The tester shall include a device capable of measuring the length of the yarn between the clamps to an accuracy of 1 mm. It shall be possible to adjust the tension in the yarn between the clamps to a given va
32、lue calculated as a function of the nominal linear density of the yarn. In practice, however, particularly for single yarns (and the final twist step in folded or cabled yarns), this tension does not affect the result. For routine checks and also when the measurement of the elongation of the yarn re
33、sulting from untwisting is not required, this adjustment tension can be omitted, making sure, however, that the specimen is clamped so that it is just taut. The initial distance between the clamps shall be of 500 mm 1 mm. For carbon-fibre yarn with no twist or with a twist of less than 20 turns per
34、metre, the yarn specification or the person ordering the determination may stipulate that a stand with a fixed clamp be incorporated to make it possible to test a specimen of length L given by 4 m L 5 m. For the calculation of the twist, the actual length shall be measured to an accuracy of 0,05 m.
35、BS EN ISO 1890:2009ISO 1890:2009(E) ISO 2009 All rights reserved 35.2 Dissection needle or thin blade. 5.3 Magnifying glass, for examination of the specimen, used to facilitate the separation of the yarn. 6 Test specimens The determination is based on measurements carried out on three specimens take
36、n consecutively from an elementary unit 1)or laboratory sample 2). The yarn specification or the person requesting the determination may stipulate that the determination be performed on a (specified) higher number of specimens which are generally taken from adjacent positions in the elementary unit
37、or laboratory sample. Moreover, it may be stipulated that the determination be repeated at different places within the elementary unit or laboratory sample, either at given meterages or in the cylindrical part of the package if it is not all of this shape. 7 Conditioning and test atmosphere No condi
38、tioning is required. However, in cases of dispute, the determination shall be carried out in a standard atmosphere as defined in ISO 291. 8 Procedure 8.1 Single yarns 8.1.1 If required, adjust the tension in the yarn to 0,25 cN/tex 0,1 cN/tex. 8.1.2 If the linear density of the yarn is not known, de
39、termine it by the method specified in ISO 1889. 8.1.3 Ensure that the elementary unit or laboratory sample to be examined is free of external damage. If necessary, remove yarn from the elementary unit or laboratory sample to obtain undamaged yarn. 8.1.4 Take off yarn tangentially (perpendicularly to
40、 the bobbin axis) and bring it directly, without cutting it, to the twist tester, fixing it first to the rotating clamp, then to the sliding clamp. Make sure that, during these clamping operations, the yarn is just taut, first between the elementary unit or laboratory sample and rotating clamp, then
41、 between the two clamps. 8.1.5 Set the twist tester counter to zero. 8.1.6 Turn the rotating clamp in the direction which eliminates the twist until it becomes possible to insert a dissection needle or thin blade between the filaments from the sliding clamp up to the rotating clamp. If necessary, us
42、e a magnifying glass to assist in inserting the needle and also to verify that all twist has been removed. 8.1.7 Record the number of turns on the counter and also the twist direction (Z or S, as per ISO 2). 8.1.8 Repeat the measurement on the two other specimens. 1) The elementary unit is the small
43、est normally commercially available entity of a given product. 2) A laboratory sample is a part of the elementary unit from which the specimen(s) will be selected for the test. A laboratory sample is taken when it is impractical to bring the elementary unit into the test laboratory. BS EN ISO 1890:2
44、009ISO 1890:2009(E) 4 ISO 2009 All rights reserved8.2 Folded or cabled yarns The procedure described in 8.1 is also designed for the final twist step of folded and cabled yarns. If, after measuring the final twist step, the determination is also to be performed on the previous twist steps, proceed a
45、s follows: Immediately after measurement of the final twist step: cut out all the yarns constituting the specimen except one; reset the counter to zero and make sure that the specimen is under slight tension so as to keep it straight; determine the degree of twist, taking into account the actual len
46、gth of the specimen; if necessary (for cabled yarns), repeat the operation on the previous twist step. 9 Expression of results Calculate, for each specimen, the twist T, in turns per metre, using the equation NTL= where N is the number of turns necessary to untwist the specimen; L is the length, in
47、metres, under standard tension prior to untwisting. Calculate, from the measurements made on the three specimens, the average of the twist, T , in turns per metre. Report this value as the result of the determination. If more than three specimens were taken for the determination (see Clause 6), the
48、results obtained for the various specimens in each determination shall be dealt with in accordance with the referring yarn specification or as specified by the person ordering the determination. 10 Precision The precision of this test method is not known because interlaboratory data are not availabl
49、e. BS EN ISO 1890:2009ISO 1890:2009(E) ISO 2009 All rights reserved 511 Test report The test report shall include the following information: a) a reference to this International Standard; b) all details necessary for identification of the yarn examined; c) the sampling procedure used and the length of the specimens, if not 0,5 m; d) the result of the determination (direction of twist and value of twist) and, if required, the results for each specimen; e) details of any operation not specified in this Internationa
