BS ISO 10376-2011 Pulps Determination of mass fraction of fines《纸浆 细粉质量分数的测定》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 10376:2011Pulps Determination of mass fraction of finesBS ISO 10376:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 10376:2011.

2、 The UK participation in its preparation was entrusted to TechnicalCommittee PAI/11, Methods of test for paper, board and pulps. A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions

3、 of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 66121 1 ICS 85.040 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31

4、May 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 10376:2011Reference numberISO 10376:2011(E)ISO 2011INTERNATIONAL STANDARD ISO10376First edition2011-04-15Pulps Determination of mass fraction of fines Ptes Dtermination de la fraction massique des fines BS ISO 10376:2011I

5、SO 10376:2011(E) COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO

6、 at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 10376:2011ISO 10376:20

7、11(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle .2 5 Apparatus.2 6 Reagents and material 3 7 Sampling 3 8 Procedure.4 8.1 Disintegration 4 8.2 Screening .4 9 Calculations .5 10 Test report5 Annex A

8、 (informative) Precision6 Annex B (informative) Comparison between McNett classifier and fibre classifier (BDDJ) .7 Bibliography8 BS ISO 10376:2011ISO 10376:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national

9、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

10、 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 g

11、iven in the ISO/IEC Directives, Part 2. 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 leas

12、t 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 patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 10376 was prepared by Technical Committee ISO/TC 6, P

13、aper, board and pulps, Subcommittee SC 5, Test methods and quality specifications for pulps. BS ISO 10376:2011ISO 10376:2011(E) ISO 2011 All rights reserved vIntroduction This International Standard has been prepared to make it possible to determine the fines mass fraction of mechanical and chemical

14、 pulps. The greater tendency of the fines fraction to pass through the wire during sheet formation and to be recycled leads to an accumulation of fines in the headbox. The extent of this buildup is an indication of the retention performance of the machine and affects, for example, drainage, felt fil

15、ling and save-all loading. The fines mass fraction in the pulp has also very often an effect on the properties of the end product, e.g. paper or board. NOTE This International Standard involves a more precise determination, i.e. a lower coefficient of variation of repeated determinations is achieved

16、 (see Annex B), compared to the use of a McNett apparatus in which the fines mass fraction is obtained from the difference between the total mass and the sum of the fibre fractions (see Reference 3 in the Bibliography). BS ISO 10376:2011BS ISO 10376:2011INTERNATIONAL STANDARD ISO 10376:2011(E) ISO 2

17、011 All rights reserved 1Pulps Determination of mass fraction of fines 1 Scope This International Standard describes the procedure for determining the fines mass fraction of all kinds of pulp by means of a perforated metal plate or a single-screen fibre classifier (Dynamic Drainage Jar or similar).

18、The screening procedure is the same for all pulps, although the mass of the test portion and the total volume of water for screening are not the same. NOTE The procedure is also applicable for most kinds of paper samples, provided that it is possible to fully disintegrate the sample. 2 Normative ref

19、erences The 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 4119, Pulps Determination of stock co

20、ncentration ISO 5263-1, Pulps Laboratory wet disintegration Part 1: Disintegration of chemical pulps ISO 5263-2, Pulps Laboratory wet disintegration Part 2: Disintegration of mechanical pulps at 20C ISO 5263-3, Pulps Laboratory wet disintegration Part 3: Disintegration of mechanical pulps at 85C ISO

21、 7213, Pulps Sampling for testing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fines fraction of a pulp which passes a screen (nominal aperture of 76 m) or a perforated plate (holes of 76 m) NOTE There is no significant difference in the r

22、esults obtained using a perforated plate and a wire screen in the fibre classifier, see Annex B. WARNING If the sample contains mineral fillers, the filler particles will normally appear in the fines fraction. BS ISO 10376:2011ISO 10376:2011(E) 2 ISO 2011 All rights reserved4 Principle The pulp samp

23、le is disintegrated using tap water. The pulp suspension is screened through a plate with round holes, or through a wire screen. The material retained on the screen and that which passes the screen are dried and weighed separately. The fines mass fraction is calculated and reported as a percentage o

24、f the oven-dry mass of the test portion. NOTE 1 The mass of the test portion and the volume of water are different for mechanical pulps and chemical pulps. NOTE 2 The screening effect results from the turbulence and the pressure developed by a stirrer with a three-blade propeller. NOTE 3 The mineral

25、 (fillers and pigment) content in the fines fraction can be calculated from the mass of the residue on ignition (the ash) of this fraction, provided that the ash content of the mineral and the pulp are known. 5 Apparatus 5.1 Disintegrator, as described in ISO 5263-1, ISO 5263-2 and ISO 5263-3, depen

26、ding on which part of the standard is relevant. 5.2 Fibre classifier, of BDDJ type (Britt Dynamic Drainage Jar) or similar (an example of a suitable device is shown in Figures 1 and 2). A cylindrical sample holder with an internal diameter of (100 10) mm, provided with 3 or 4 vanes on the inside, th

27、e vanes having a square section with (6,0 1,0) mm sides, and equipped for the insertion of a bottom screen and a bottom chamber beneath the screen. The bottom chamber shall have an outlet located centrally in its base with a diameter of (6,5 1) mm and the outlet shall be equipped with a device for c

28、losing the outlet. NOTE The water flow rate has a minor influence on the result when determining the fines mass fraction. Figure 1 Sketch of the fibre classifier BS ISO 10376:2011ISO 10376:2011(E) ISO 2011 All rights reserved 3Key A bottom chamber with outlet D plug for outlet B gaskets E supporting

29、 plate C sample holder F screen, hole diameter (76 4) m Figure 2 Key of the different parts of the classifier 5.3 Stirrer, a shaft that carries a three-bladed (5 mm 1 mm 1 mm 0,1 mm) propeller. The blades shall be circular, (17,5 2) mm in diameter with a pitch of (30 3). The stirrer shall be well ce

30、ntred in the jar and the distance between the propeller and the screen shall be (3,5 0,5) mm. The rotation direction of the motor shall be such that the pressure of the propeller blades is downward toward the screen and the speed of the propeller shall be (12,5 0,8) s1. 5.4 Screen, a perforated meta

31、l plate with circular holes, each hole with a diameter of (76 4) m or a wire screen having a nominal aperture size of (76 4) m (see ISO 3310-1 2). 5.5 Filter paper, grammage about 90 g/m2e.g. Whatman No. 41)or equivalent. The recommended diameter is 120 mm for the fibre fraction and 90 mm for the fi

32、nes. 5.6 Balance, accurate to 1 mg. 6 Reagents and material 6.1 Tap water. 7 Sampling If 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 type of sample, report the source of the sample and, if possible, the sampl

33、ing procedure used. Make sure that the test portions taken are representative of the pulp sample. 1) Whatman No. 4 is an example of a suitable product available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of this

34、 product. BS ISO 10376:2011ISO 10376:2011(E) 4 ISO 2011 All rights reserved8 Procedure 8.1 Disintegration Using tap water (6.1) and a disintegrator (5.1), disintegrate the pulp as described in the relevant part of ISO 5263. Use ISO 5263-3 for mechanical pulps exhibiting latency. Determine the concen

35、tration of the pulp suspension as specified in ISO 4119. 8.2 Screening Carry out the screening procedure in duplicate. From the well-stirred, disintegrated pulp suspension, take a test portion having a mass as specified in Table 1. The total volume of screening water to be used is also specified in

36、Table 1. Table 1 Mass of test portion and total volume of screening water to be used in the test Pulp grade Oven-dry mass of test portion g Total volume of water ml Sample with low fines mass fraction: 10 % (e.g. chemical pulp) 5,0 0,5 5 000 Sample with high fines mass fraction: 10 % (e.g. mechanica

37、l pulp) 0,5 0,1 2 500 NOTE 1 In this International Standard, chemi-thermo-mechanical pulps (CTMP) and pulps with a high fines mass fraction, such as semi-chemical pulps and recycled pulps, are regarded as mechanical pulp. NOTE 2 For chemical pulps, a mass of 5 g has been chosen to guarantee good pre

38、cision, even for pulps with low fines mass fraction. NOTE 3 The content of dissolved and colloid substances can, for example, be obtained by determination of the total dry matter content of the sample, i.e. concentration by evaporation. Then calculate the difference between the total dry matter cont

39、ent and the concentration determined using a pre-weighed filter paper. Dilute the weighed test portion with 1 000 ml of tap water (6.1) and transfer it to the sample holder (5.2) of the fibre classifier with the bottom outlet closed. Set the stirrer above the screen as described in 5.3 and start the

40、 stirrer. Open the outlet. Allow the contents of the jar to drain into a beaker. When the level in the jar is within 1 mm to 5 mm above the screen, add an additional portion of tap water (6.1), e.g. 1 000 ml, and allow the contents to drain into the beaker. Continue this procedure until the total vo

41、lume of tap water (6.1) for screening, as specified in Table 1, has been used. Collect all that passes through the screen into the same beaker. After the final addition of screening water, continue until the water in the jar has disappeared. Filter the fibre fraction and the fines fraction separatel

42、y using pre-weighed filter papers (5.5). Dry and weigh the filter papers with the mat of fibres and the mat of fines. Calculate separately the oven-dry mass of the fibre fraction, m2, and of the fines fraction, m1. BS ISO 10376:2011ISO 10376:2011(E) ISO 2011 All rights reserved 59 Calculations Calcu

43、late the fines mass fraction, as a percentage, using Equation 1: 112100 mwmm=+(1) where w is the fines mass fraction , expressed as a percentage; m1is the oven-dry mass of the fines fraction, in milligrams; m2is the oven-dry mass of the fibre fraction, in milligrams. Calculate and report the mean fi

44、nes mass fraction as a percentage with three significant figures. 10 Test report The test report shall include the following information: a) a reference to this International Standard; b) all information for complete identification of the sample; c) date and place of testing; d) the fines mass fract

45、ion, as a percentage; e) any departure from this International Standard or any circumstances or influences regarded as optional that could have affected the results. BS ISO 10376:2011ISO 10376:2011(E) 6 ISO 2011 All rights reservedAnnex A (informative) Precision A.1 Repeatability Seven pulp samples

46、were tested in one laboratory according to this International Standard. Five parallel determinations were made in each case. The results are shown in Table A.1. Table A.1 Repeatability Parameter Bleached CTMP Bleached kraft hardwoodBleached kraft softwood Bleached bagasseTMP Bleached kraft softwood,

47、 unrefined Bleached kraft softwood,refined Fines mass fraction, % 18,7 5,80 2,53 7,68 22,6 2,89 4,99 Standard deviation, sr0,72 0,19 0,23 0,10 0,22 0,09 0,12 Repeatability, r 2,0 0,52 0,64 0,28 0,61 0,25 0,32 Coefficient of variation, % 3,9 3,2 9,1 1,3 0,98 3,1 2,3 A.2 Reproducibility Four pulp samp

48、les were tested in five different laboratories according to this International Standard. The results are shown in Table A.2. Table A.2 Reproducibility Parameter Bleached CTMP Bleached kraft hardwoodBleached kraft softwood Bleached bagasseFines mass fraction, % 18,9 6,92 3,03 9,41 Standard deviation,

49、 sR2,8 1,3 0,38 1,1 Repeatability, R 7,9 3,5 1,04 3,0 Coefficient of variation, % 15,0 18,3 12,4 11,6 BS ISO 10376:2011ISO 10376:2011(E) ISO 2011 All rights reserved 7Annex B (informative) Comparison between McNett classifier and fibre classifier (BDDJ) This comparision study is based on the work published as SCAN-method in SCAN-CM 66:05 4. In a laboratory study, results from the determination of the fines content (mass fraction) using the fibre classif