BS ISO 23713-2005 Pulps - Determination of fibre coarseness by automated optical analysis - Polarized light method《纸浆 用自动光学分析测定纤维粗度 偏振光法》.pdf

1、BRITISH STANDARDBS ISO 23713:2005Pulps Determination of fibre coarseness by automated optical analysis Polarized light methodICS 85.040g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38

2、g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 23713:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 21 October 2005 BSI 21 October 2005ISBN 0 580 46433 4National forewordThis British Standard reproduces verbatim ISO 23713:2005 and implements

3、it as the UK national standard.The UK participation in its preparation was entrusted to Technical Committee PAI/11, Methods of test for paper, board and pulps, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary.Cross-ref

4、erencesThe British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards

5、Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the respon

6、sible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the

7、 ISO title page, pages ii to iv, pages 1 to 8, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsINTERNATIONALSTANDARDISO23713First edition2005-07-01Reference

8、numberISO 23713:2005(E)Pulps Determination of fibre coarseness by automated optical analysis Polarized light methodPtes Dtermination de la grosseur de fibre par analyse optique automatise Mthode de la lumire polariseBS ISO 23713:2005iiiiiContents Page1 Scope 12 Normative references 13 Terms and defi

9、nitions 14 Principle 25 Apparatus and materials . 26 Sampling and preparation of specimen 37 Measurement and verification procedures 58 Calculation and expression of results . 59 Test report 7Bibliography . 8BS ISO 23713:2005ivForewordISO (the International Organization for Standardization) is a wor

10、ldwide federation of national standards bodies(ISO member bodies). The work of preparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subject for which a technical committee has beenestablished has the right to be represented on th

11、at committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in acc

12、ordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standardsadopted by the technical committees are circulated to the member bodies for voting. Publication as anInternational Standard require

13、s 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 document may be the subject of patentrights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 23713 was prepared by Technical Com

14、mittee ISO/TC 6, Paper, board and pulps, Subcommittee SC 5, Testmethods and quality specifications for pulps.BS ISO 23713:20051Pulps Determination of fibre coarseness by automated optical analysis Polarized light method1ScopeThis International Standard specifies a method for determining fibre coarse

15、ness using polarized light.The method is applicable to all kinds of pulp that polarize light. However fibrous particles shorter than are not regarded as fibres for the purposes of this International Standard and therefore are not to be included inthe results.2 Normative referencesThe following refer

16、enced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO 638, Pulps Determination of dry matter contentISO 4119, Pulps Deter

17、mination of stock concentrationISO 5263-1, Pulps Laboratory wet disintegration Part 1: Disintegration of chemical pulpsISO 5263-2, Pulps Laboratory wet disintegration Part 2: Disintegration of mechanical pulps at 20 CISO 5263-3, Pulps Laboratory wet disintegration Part 3: Disintegration of mechanica

18、l pulps at W 85 CISO 5269-1, Pulps Preparation of laboratory sheets for physical testing Part 1: Conventional sheet-formermethodISO 7213, Pulps Sampling for testingISO 16065-1, Pulps Determination of fibre length by automated optical analysis Part 1: Polarized lightmethod3 Terms and definitionsFor t

19、he purposes of this document, the following terms and definitions apply.3.1unpolarized lightlight composed of light waves whose planes of vibration are randomly oriented3.2polarizermaterial which only transmits that component of a light wave which is vibrating in a particular direction, thedirection

20、 of polarization of the material0,2 mmBS ISO 23713:2005BS ISO 23713:200523.3plane polarized light light composed of light waves which all vibrate in the same plane3.4crossed polarizers pair of polarizers placed in a light path such that the direction of polarization of one is at right angles to the

21、direction of polarization of the other, thus resulting ideally in none of the light which has passed directly from one polarizer to the other being transmitted through this second polarizer3.5birefringence property of certain materials, such as cellulose fibres, which have a crystalline structure th

22、at results in the refractive index varying with the direction of polarization of the lightNOTE This has the effect of rotating the direction of polarization of a plain polarized beam of light resulting in light which has passed through this material being transmitted through the second polarizer of

23、a crossed pair.3.6total fibre lengthtotal length of all fibres in the test portionSee Equation (4)3.7fibre coarseness oven-dry mass of fibres in the test portion divided by the total fibre length of the same test portionSee Equation (5).3.8fines particles shorter than 4PrincipleA known mass of fibre

24、s, suspended in water, is passed through a fibre orienting cell (FOC). The projected lengths of individual fibres are measured automatically. A crossed-polarizer set-up is used to discriminate between birefringent material like fibres with oriented cellulose molecules and non-birefringent material l

25、ike air bubbles and filler particles, which do not rotate the plane of polarization. The total fibre length and the mean fibre coarseness of the pulp are calculated.5 Apparatus and materialsOrdinary laboratory equipment and the following are required.5.1 Fibre length analyzer, as described in ISO 16

26、065-1, consisting of a measurement section and a sample transport system.5.2 Disintegrator, as described in ISO 5263-1, ISO 5263-2 or ISO 5263-3.5.3 Sheet former, as described in ISO 5269-1.5.4 Balance, with accuracy.5.5 Balance, with a capacity exceeding and with accuracy.5.6 Vials, for storing tes

27、t portions, volume , with caps and labels.LT0,2 mm 0,1 mg5kg 0,1 g50 mlBS ISO 23713:200535.7 A reference pulp1).6 Sampling and preparation of specimen6.1 SamplingIf the test is being made to evaluate a pulp lot, the sample shall be selected in accordance with ISO 7213. If the test is made on another

28、 type of sample, report the source of the sample and, if possible, the sampling procedure used. From the sample received, select specimens so that they are representative of the whole sample.6.2 Disintegration6.2.1 Sample in dried formFor samples in dried form, take at least oven-dry mass and soak f

29、or a minimum of in water. Tear the pieces, do not cut into pieces as this will cause fibre shortening. Disintegrate the pulp according to ISO 5263-1, ISO 5263-2 or ISO 5263-3, depending on the pulp.Determine the concentration of the disintegrated pulp according to ISO 4119.6.2.2 Sample in never-drie

30、d formDisintegrate the pulp according to ISO 5263-1, ISO 5263-2 or ISO 5263-3, depending on the pulp.Determine the concentration of the disintegrated pulp according to ISO 4119.NOTE It is preferable to measure never-dried pulps with minimal disintegration, because excessive disintegration maygenerat

31、e fines and reduce fibre length in some pulps.6.3 Removal of fines and preparation of test portion6.3.1 Removal of finesPlace approximately oven-dry mass of the disintegrated pulp into a laboratory sheet former and form awet sheet as described in ISO 5269-1.NOTE 1 Forming a oven-dry laboratory sheet

32、 ensures that most fines are washed out.Visually inspect the wet laboratory sheet for debris (i.e. shives, fibre bundles, contaminants). If debris is found (e.g. in recycled pulp, in mechanical pulps), then carefully remove (approx. oven-dry) of wet pulp from parts of the wet sheet that do not conta

33、in debris. Any debris removal shall be mentioned in the test report.NOTE 2 Debris introduces inaccuracy in the mass measurement, which in turn causes inaccuracy in the final coarseness result.Place the debris-free wet pulp into a tared vial (5.6) and determine the mass of the wet pulp to an accuracy

34、 of .1) Reference pulp is available, for example, from the National Institute of Science is the mass of the fibres and water mixture in the container, in grams.Tare a clean beaker, to within . The beaker, or other container, should conform to the manufacturersrequirements.NOTE 2 Typically a beaker i

35、s used.Calculate the mass ( ), expressed in grams, of the fibre/water mixture to be transferred to the beaker usingthe equation(2)whereis the final, total suspension mass in the beaker, in grams;is the gravimetric concentration as specified by the manufacturer of the analyzer, in milligrams pergram.

36、NOTE 3 Typically for softwoods the fibre concentration , and for hardwoods . Treatmixed stocks as hardwood samples. depends on the beaker volume. For example: the value of for a beakerwould be up to .Place the empty tared beaker on the balance.=m14C2C0,1 g4 500 ml=m2cAcA=m1m2m1m20,1 g600 mlm3m3=cBMc

37、AMcBcB= 0,002 4 mg/g cB= 0,001 0 mg/gMM600 ml600 gBS ISO 23713:20055Ensure that the fibres in the fibre/water mixture are well dispersed when drawing a test portion for testing. Drawthe test portion and fill the beaker on the balance with the amount of fibre/water mixture needed ( ) to within. Recor

38、d the mass of fibre/water mixture in the beaker to an accuracy of , and calculate the mass ofoven-dry fibre in the beaker:NOTE 4 A recommended procedure is to pour the fibre/water mixture rapidly back and forth, without splashing, betweentwo clean 5 litre containers. After the last transfer and befo

39、re the fibres have a chance to settle, add a mass of about ofthe mixture to the beaker.Calculate and record the mass of oven-dry fibre in the beaker ( ), expressed in milligrams, using the equation(3)Prepare at least two more beakers, using the remainder of the fibre/water mixture in the 5 litre con

40、tainer, asdescribed above. The test portions should be tested soon after preparation.7 Measurement and verification procedures7.1 Measurement procedureFor the most precise results, all fibres in each test portion shall be detected and analysed.Add water to the fibre/water mixture in the beaker until

41、 the correct mass ( ) of the suspension in the beaker isreached, so that the concentration is equal to or less than that required by the manufacturer for coarsenesstesting (cf. concentration ). Follow the instructions to enter the oven-dry mass of the test portion into theanalyzer and then start the

42、 test.7.2 Verification procedureCheck the performance of the analyzer regularly using a reference pulp and always after cleaning. A verificationprocedure shall include a calibration check every week, and a performance check every month. Follow theprocedures as presented in ISO 16065-1.8 Calculation

43、and expression of results8.1 Total fibre length The total length of fibres in the test portion , expressed in metres, is calculated using the equation(4)where is the length of the th fibre, in metres.8.2 Fibre coarsenessThe fibre coarseness of the test portion , expressed in milligrams (oven-dry mas

44、s) per metre, is calculatedusing the equation(5)m310 % 0,1 gm3m4m4=cAm3McBLTLT=summationdisplayliliiCkCk=m4LTBS ISO 23713:20056whereis the fibre coarseness of the th test portionis the mass of the oven-dry fibres in the test portion (from Equation (3), in milligramsCalculate the mean fibre coarsenes

45、s , using the equation(6)where is the number of test portions tested.8.3 Precision8.3.1 GeneralA precision statement for this International Standard is based on work published in a peer reviewed journal(see reference 3). The estimates of precision are based on hardwood and softwood reference pulps a

46、vailablefrom NIST.There is no indication that the precision should be different between chemical and mechanical pulps, becausethe fines are washed out in 6.3.1 (see reference 3).Eleven laboratories participated with 17 instruments representing the different manufacturers whose apparatusmet the appar

47、atus specifications of ISO 16065-1.8.3.2 RepeatabilityThe hardwood and softwood pulps were tested in 11 different laboratories according to this InternationalStandard. The pooled repeatability was determined and the results are shown in Table 1.8.3.3 ReproducibilityThe hardwood and softwood pulps we

48、re tested in 11 different laboratories according to this InternationalStandard. The results are shown in Table 2.Table 1 Pooled repeatability for determination of mean fibre coarsenessSample Mean fibre coarseness Coefficient of variationHardwood 0,085 4,3Softwood 0,140 4,0Table 2 Reproducibility for

49、 determination of mean fibre coarsenessSample Mean fibre coarseness Coefficient of variationHardwood 0,085 10,5Softwood 0,140 5,1CkKm4CC =summationtextCknnmg/m %mg/m %BS ISO 23713:200579 Test reportThe test report shall give the following information:a) reference to this International Standard;b) the date and place of testing;c) all information for complete identification of the sample;d) the type of instrument used;e) the total amount of fibres;f) the total fibre length (the other measures, length-weighted and mass-w