BS 5414-1976 Method of test for determination of elongation of netting yarns for fishing nets《渔网网纱伸长度测定的试验方法》.pdf

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1、BRITISH STANDARD BS 5414:1976 ISO 3790:1976 Method of test for Determination of elongation of netting yarns for fishing nets ISO title: Fishing nets Determination of elongation of netting yarns UDC 677.664.22:639.2.081.11:620.172.222BS5414:1976 This British Standard, having been prepared under the d

2、irectionof the Ropes, Cordageand Netting StandardsCommittee, was published underthe authority ofthe Executive Board on 29 October1976 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference RCT/8 Draft for comment74/36062 DC and draft for approval76/35287 IS

3、BN 0 580 09038 8 Cooperating organizations The Ropes, Cordage and Netting Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following organizations: British Ports Association British Railways Board British Tugowners Association Chai

4、n Testers Association of G.B. Cordage Manufacturers Institute* Department of Industry Department of Trade Federation of Soft Fibre Associations Health and Safety Executive Lloyds Register of Shipping Ministry of Agriculture, Fisheries and Food* Ministry of Defence The organizations marked with an as

5、terisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Man-Made Fibres Federation British Trawler Federation Ltd Department of Agriculture and Fisheries for Scotland Federation of British Traw

6、ler Owners Grimsby Net Manufacturers Association Herring Industry Board Scottish Fishermens Federation Scottish Inshore White Fish Producers Association Ltd Scottish Trawler Federation Individual experts Amendments issued since publication Amd. No. Date of issue CommentsBS5414:1976 BSI 11-1999 i Con

7、tents Page Cooperating organizations Inside front cover Foreword ii 1 Scope and field of application 1 2 References 1 3 Definitions 1 4 Principle 1 5 Apparatus 1 6 Sampling 1 7 Preparation of specimens 2 8 Requirements for testing 2 9 Number of tests 2 10 Procedure 2 11 Expression of results 2 12 Te

8、st report 2 Figure Holding grips for the testing of netting yarns without knots 4BS5414:1976 ii BSI 11-1999 Foreword This British Standard has been prepared under the authority of the Ropes, Cordage, and Netting Standards Committee. It is identical withISO3790 “Fishing nets Determination of elongati

9、on of netting yarns”. For the purposes of this British Standard, the text ofISO3790 given in this publication should be modified as follows. Terminology. The words “British Standard” should replace “International Standard” wherever they appear. Cross references. The references to other International

10、 Standards should be replaced by references to British Standards as follows. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself conf

11、er immunity from legal obligations. References to ISO Publications Appropriate British Standards ISO 139 Textiles Standard atmospheres for conditioning and testing BS 1051 Glossary of terms relating to the conditioning and testing of textiles ISO 858 Fishing nets Designation of netting yarns in the

12、Tex System BS 4406 Designation in the Tex System of netting yarns for fishing nets ISO 1805 Fishing nets Determination of breaking load and knot breaking load of netting yarns BS 4674 Methods for the determination of the breaking load and knot breaking load of netting yarns for fishing nets ISO 1806

13、 Fishing nets Determination of mesh breaking load of netting BS 4650 Method for the determination of the mesh breaking load of netting for fishing Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4 and a back cover. This standard has been updated

14、(see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5414:1976 BSI 11-1999 1 1 Scope and field of application This International Standard specifies a method of determining the elongation of netting yarns, from packag

15、es or from netting, in their final physical state. Tests may be carried out in both the dry and wet states but tests in the wet state are considered to be particularly appropriate in indicating the behaviour of the yarn in use. 2 References ISO 139, Textiles Standard atmospheres for conditioning and

16、 testing. ISO 858, Fishing nets Designation of netting yarns in the Tex system. ISO 1805, Fishing nets Determination of breaking load and knot breaking load of netting yarns. ISO 1806, Fishing nets Determination of mesh breaking load of netting. 3 Definitions 3.1 knot breaking load the breaking load

17、, equal to the maximum load observed during a breaking test on netting yarn with a weavers knot distinction is made between the dry knot breaking load; the wet knot breaking load. 3.2 elongation the increase in length of a specimen during a tensile test, expressed as a percentage of the nominal gaug

18、e length 3.3 elongation at half the knot breaking load the elongation after applying a pre-tension, produced on a specimen at half the knot breaking load (see3.1) 3.4 load/elongation curve a graphical representation, showing the relationship between the change in length of the pre-tensioned specimen

19、 and the magnitude of the applied stress 3.5 duration of testing the time in seconds taken to reach half the knot breaking load, measured from the moment of application of the force, after application of pre-tension 3.6 pre-tension the tension applied to straighten the specimen (see8.4) 3.7 nominal

20、gauge length the length of specimen between the faces of the upper and lower grips of the testing machine, after application of pre-tension 4 Principle A prescribed length of netting yarn in the dry or wet state without knot is extended under increasing tensile load until that load reaches half the

21、value of the corresponding dry or wet knot breaking load. The test is performed using a suitable apparatus that records the amount of elongation. 5 Apparatus 5.1 Tensile testing machine Either of the following types may be used: a) constant rate of elongation machine; b) constant rate of traverse ma

22、chine. Preference should be given to a constant rate of elongation machine, which shall always be used for arbitration purposes. 5.1.1 The testing machine shall include a pair of flat grips to hold the specimen without slipping or damage, to ensure an accurate specimen length and to allow the applic

23、ation of a pre-tension (seetheFigure). 5.1.2 The testing machine shall be capable of operating with a starting distance between grips of500mm. 5.1.3 The testing machine shall include facilities for producing different speeds of traverse in order to test specimens in the specified time for testing. 5

24、.1.4 The testing machine shall be equipped with an autographic recorder for the load/elongation curve. The dynamic response of any recorder must be sufficiently rapid that it will accurately record the steepest part of the load/elongation curve. 5.2 Equipment for producing and maintaining the standa

25、rd atmosphere for testing (see8.1). 5.3 Equipment in which specimens can be immersed in water preparatory to wet testing. 6 Sampling Sampling shall be carried out in accordance with recognized national standards or in a manner agreed between the interested parties.BS5414:1976 2 BSI 11-1999 7 Prepara

26、tion of specimens 7.1 The specimen shall be removed from its package or taken from the netting in such a manner that there is no alteration in the construction. 7.2 If the elongation of yarn taken from netting is to be tested, knots shall be undone to obtain pieces of netting yarn of at least600mm l

27、ength. Precautions shall be taken to avoid damage, stretching and change of construction of the specimens. 8 Requirements for testing 8.1 Atmosphere for testing All specimens to be tested in the dry state shall be exposed to the standard atmosphere for testing specified inISO139, until they have rea

28、ched equilibrium. For netting yarns of man-made fibres, a period of24h exposure is generally sufficient. Where it is not possible to carry out the tests in the standard atmosphere, the tests shall be carried out immediately after removal of the samples from the standard atmosphere. 8.2 Testing in th

29、e wet state 8.2.1 All specimens to be tested in the wet state shall be immersed in tap water, without wetting agents, at a temperature of20 2 C for a period of not less then12h. Surplus water shall be shaken off. 8.2.2 By agreement between the interested parties, a shorter wetting time, with the add

30、ition of a wetting agent at a temperature of20 2 C, may be used provided that it can be shown that the specimen is completely wetted. 8.3 Distance between grips The distance between the grips at the commencement of the test shall be500mm measured accurately. 8.4 Pre-tension The pre-tension shall cor

31、respond to the mass of250 25m of the netting yarn to be tested. If this pre-tension is not sufficient to remove kinks and to just straighten the specimen, a higher pre-tension shall be applied. This value shall be recorded specially in the test report, because of the influence on the elongation resu

32、lts. 8.5 Duration of testing The mean duration of all the tests shall be30 3s. It shall be determined by preliminary tests. Where this time cannot be obtained owing to limitations of the apparatus, the duration of the test shall be as near as possible to30s. The actual mean and the range of time sha

33、ll be recorded in the test report. 9 Number of tests At least10 single valid tests on specimens from each sample shall be carried out. If a distinct confidence interval for the mean value is prescribed, as many additional tests shall be carried out as are necessary to achieve this confidence interva

34、l. 10 Procedure 10.1 Before testing for elongation, determine the relevant mean knot breaking load (wet or dry) of the netting yarn as specified inISO1805 or, for netting yarns taken from netting, as specified inISO1806, sub-clause10.7. 10.2 Test wet specimens immediately after removal from the wate

35、r (see8.2). 10.3 Mount the specimen in the testing machine in such a manner as to prevent slippage and avoid damage to the specimen in the grips with the axis of the specimen parallel to and coincidental with the direction of the applied tensile force. 10.4 Apply a pre-tension (see8.4) to remove kin

36、ks and just straighten the specimen. 10.5 Check that the length of the specimen, under pre-tension, is accurately500mm between the grips. 10.6 Increase the tensile force continuously until, within the prescribed time, it corresponds to half the knot breaking load as defined inISO1805. 10.7 Discard a

37、ll observations obtained on specimens which slip between the grips or break completely or partially before reaching half the relevant knot breaking load. Record the number of observations so discarded. 11 Expression of results 11.1 Calculate the mean values of the elongations and express them in per

38、centages of the nominal gauge length under pre-tension. 11.2 If necessary, the coefficient of variation and the confidence interval may be calculated by recognized statistical methods. 12 Test report The test report shall include the following particulars: a) a statement that the tests were performe

39、d in accordance with this International Standard; b) the date of the test; c) a description of the material tested type, linear density and construction of the netting yarn (seeISO858) and any treatment; used or unused;BS5414:1976 BSI 11-1999 3 d) the type and capacity of testing machine used and th

40、e range of indication; e) the sampling method employed; f) the number of specimens tested; g) the number of invalid tests; h) the method and time of wetting (with or without wetting agents); i) the load/elongation curves corresponding to each test; j) the mean elongation at half the knot breaking lo

41、ad; k) the actual mean duration and the range of durations of the test; l) any deviation from the specified test procedure. If required: m) the coefficient of variation of the elongation and the confidence interval.BS5414:1976 4 BSI 11-1999 Figure Holding grips for the testing of netting yarns witho

42、ut knotsblankBS 5414:1976 ISO3790:1976 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal C

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