BS ISO 699-2015 en_9495 Pulps Determination of alkali resistance《纸浆 耐碱性的测定》.pdf

1、BSI Standards Publication BS ISO 699:2015 Pulps Determination of alkali resistanceBS ISO 699:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 699:2015. It supersedes BS 4499:1984 which is withdrawn. The UK participation in its preparation was entrusted to

2、 Technical Committee 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 of a contract. Users are responsible for its correct a

3、pplication. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 86893 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

4、 Committee on 30 April 2015. Amendments issued since publication Date Text affectedBS ISO 699:2015 ISO 2015 Pulps Determination of alkali resistance Ptes Dtermination de la rsistance aux solutions dhydroxyde de sodium INTERNATIONAL STANDARD ISO 699 Third edition 2015-04-01 Reference number ISO 699:2

5、015(E)BS ISO 699:2015ISO 699:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying

6、, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO 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-m

7、ail copyrightiso.org Web www.iso.org Published in SwitzerlandBS ISO 699:2015ISO 699:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principle 1 5 Reagents 1 6 Apparatus . 2 7 Preparation of the test sample . 2 8 Procedure. 3 8.1 Test portion 3 8.

8、2 Determination . 3 9 Expression of results 4 9.1 Method of calculation and formula . 4 9.2 Precision and expression of results 4 10 Test report . 4 Bibliography 5 ISO 2015 All rights reserved iii Contents PageBS ISO 699:2015ISO 699:2015(E) Foreword ISO (the International Organization for Standardiz

9、ation) 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

10、 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. The procedures used t

11、o develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of t

12、he ISO/IEC Directives, Part 2 (see www.iso.org/directives). 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. Details of any patent rights identified d

13、uring the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the

14、 meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information. The committee responsible for this document is ISO/T

15、C 6, Paper, board and pulps. This third edition cancels and replaces the second edition (ISO 699:1982), of which it constitutes a minor revision.iv ISO 2015 All rights reservedBS ISO 699:2015ISO 699:2015(E) Introduction The object of both this International Standard and ISO 692, Pulps Determination

16、of alkali solubility, is to permit the study of the behaviour of pulps in the presence of alkali solutions, but their fields of application are different. While this International Standard describes the gravimetric determination of the alkali insoluble constituents of the pulp and applies to all cat

17、egories of pulps, ISO 692 describes the volumetric determination of the alkali soluble constituents of the pulp and is applied preferably to the control of bleached pulps. ISO 2015 All rights reserved vBS ISO 699:2015BS ISO 699:2015Pulps Determination of alkali resistance W AR NIN G Th e m e t h o d

18、 sp ecif i e d in t his I n te rna t i o nal S t an dard in v o l v e s t h e us e o f hazard o us chemicals. Appropriate precautions are to be taken to ensure the proper use and disposal of these chemicals. 1 Scope This International Standard specifies a method for the determination of the alkali-i

19、nsoluble fraction of pulps using sodium hydroxide solution of fixed concentration. The sodium hydroxide concentrations most frequently used are 18, 10, and 5 % (m/m). The method is applicable to all kinds of pulp. 2 Normative references The following documents, in whole or in part, are normatively r

20、eferenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 638, Paper, board and pulps Determination of dry matter content Ov

21、en-drying method ISO 4793, Laboratory sintered (fritted) filters Porosity grading, classification and designation 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 R-value alkali resistance; the insoluble fraction expressed as a percentage b

22、y mass of the oven-dry pulp 3.2 R 18, R 10, R 5 , or R c R-values in which the indices 18, 10, 5, or c refer to the chosen concentration in grams of sodium hydroxide per 100 g of solution 4 Principle Defibreing of the pulp under specified conditions in sodium hydroxide solution of chosen concentrati

23、on. Filtering of the insoluble fraction, washing with sodium hydroxide solution of the same concentration, and temperature as that used for defibreing and acidification, washing, drying, and weighing. 5 Reagents Use only reagents of recognized analytical grade and only distilled water or water of eq

24、uivalent purity. 5.1 Sodium hydroxide, solution of known concentration containing less than 1 g of sodium carbonate per litre (see the notes), for example: (5,39 0,03) mol/l solution, containing (18,0 0,1) g of sodium hydroxide per 100 g of solution ( 20= 1,197 2 g/ml), equivalent to (215,5 1,0) g o

25、f sodium hydroxide per litre; INTERNATIONAL ST ANDARD ISO 699:2015(E) ISO 2015 All rights reserved 1BS ISO 699:2015ISO 699:2015(E) (2,77 0,03) mol/l solution, containing (10,0 0,1) g of sodium hydroxide per 100 g of solution ( 20= 1,108 9 g/ml), equivalent to (110,9 1,0) g of sodium hydroxide per li

26、tre; (1,31 0,03) mol/l solution, containing (5,0 0,1) g of sodium hydroxide per 100 g of solution ( 20= 1,053 8 g/ml), equivalent to (52,7 1,0) g of sodium hydroxide per litre. NOTE 1 The sodium hydroxide solution can be conveniently prepared as follows: dissolve a quantity of solid sodium hydroxide

27、 in an equal mass of water and allow the suspended sodium carbonate to settle. Decant the supernatant liquid and dilute with carbon dioxide-free water to the appropriate concentration. Check by titration with standard acid solution. NOTE 2 Although sodium hydroxide solution generally possesses the m

28、aximum dissolving power at a concentration of about 10 % (m/m), certain pulps show maximum solubility at some lower or higher alkali concentration. If the R-value of an unknown pulp or of a new type of pulp is to be determined with the sodium hydroxide solution of maximum dissolving power for this p

29、ulp, it is necessary to establish a solubility diagram using several different concentrations in order to determine the sodium hydroxide concentration of maximum dissolving power. 5.2 Acetic acid, 1,7 mol/l solution, corresponding to 100 ml of CH 3 COOH ( 20= 1,055 to 1,058 g/ml) per litre. 6 Appara

30、tus 6.1 Beaker, of capacity 250 ml, flat-bottomed, made of alkali-resistant material. 6.2 Stirring rod, of diameter 15 mm, with a flat end, made of a non-brittle alkali-resistant material, preferably hard plastics. 6.3 Filtering device, of capacity 80 to 100 ml, internal diameter about 30 mm, with a

31、 bottom made of sintered glass, of porosity grade P 250 (porosity 0) in accordance with ISO 4793. 6.4 Weighing bottle, with a lid. 6.5 Constant temperature bath, capable of maintaining a temperature of (20 0,2) C. 7 Preparation of the test sample If the pulp is in slush form, remove the water by suc

32、tion taking precautions to avoid the loss of fine fibres, press between blotters, and dry at a maximum temperature of 60 C. If the pulp is in the form of wet sheets or rolls, dry the sample at a maximum temperature of 60 C. Tear the sample into pieces of size approximately 5 mm x 5 mm. If the pulp i

33、s difficult to defibre, split the sample by means of tweezers (see Note 1). Check that the pulp contains not more than 0,1 % ash (see Note 2). Before weighing, condition, the sample for not less than 20 min in the atmosphere near the balance. NOTE 1 Dry disintegration, for example with a Wiley-mill,

34、 or wet disintegration, for example with a high-speed stirrer, are not permitted. NOTE 2 If the pulp to be tested contains more than 0,1 % ash, determine the ash content of the alkali-insoluble fraction. Calculate the R-value on the basis of the ash-free pulp and the ash-free insoluble fraction.2 IS

35、O 2015 All rights reservedBS ISO 699:2015ISO 699:2015(E) 8 Procedure 8.1 Test portion Weigh, to the nearest 1 mg, about 2,5 g of the test sample. Then immediately weigh two separate test portions for the determination of the dry matter content in accordance with ISO 638. 8.2 Determination Transfer t

36、he test portion to the beaker (6.1), add 25 ml of the sodium hydroxide solution (5.1) adjusted to (20 0,2) C (see 5.1, Note 1 and Note 2), place the beaker in the constant temperature bath (6.5), and allow the pulp to swell for 3 min. Thoroughly defibre the pulp by stirring and macerating with the s

37、tirring rod (6.2) for at least 3 min, macerating at a rate of two strokes per second. Add another 25 ml of the sodium hydroxide solution at 20 C, stir until the suspension is uniform, and dilute by adding 100 ml of the sodium hydroxide solution at 20 C. Cover the beaker with a watch-glass and leave

38、in the constant temperature bath. 60 minutes after the first addition of the sodium hydroxide solution, stir the fibre suspension again and transfer it to the filtering device (6.3) fitted on a dry suction flask, adjusted to a temperature of (20 0,2) C in the constant temperature bath. Apply suction

39、 only as long as the fibre mat is still covered with liquid in order that no air is sucked through the mat. Use the filtrate for rinsing the beaker and filter again through the slightly pressed fibre mat in order to collect all fibres. Finally, apply full suction briefly. The time for filtering and

40、washing shall not exceed 20 min. Compact the fibre mat, especially at the edges, cover with the acetic acid (5.2) and allow 200 ml to pass through slowly without suction. Drain completely and wash with hot water until the filtrate is free from acid. Cover the filtering device with the hand during th

41、e last washing in order that a vacuum is formed above the fibre mat. Then quickly release the vacuum in the suction flask in order to lift the fibre mat. Transfer the fibre mat together with any remaining fibres adhering to the filtering device by means of stainless steel tweezers to the weighing bo

42、ttle (6.4). Place the open weighing bottle together with its lid in a drying oven and dry to constant mass at a temperature of (105 2) C (normally for 6 h). Allow the closed weighing bottle to cool in a desiccator and determine the mass of the alkali-insoluble fraction to the nearest 1 mg, after bri

43、efly raising the lid to allow equalization of pressure. Carry out at least two parallel determinations on each test sample. NOTE 1 In certain cases, for example, straw pulps, it is advisable to add initially only 15 ml or 20 ml of the sodium hydroxide solution to the pulp in order to facilitate defi

44、breing. The volume of alkali for the second addition has then to be increased to 35 ml or 30 ml respectively. The solubility in 18 % (m/m) sodium hydroxide solution is not affected by variations of a few degrees in temperature. At this concentration, the temperature may be kept at (20 2) C. The solu

45、bility in sodium hydroxide solution of lower concentration (for example, 10 % (m/m) is much more dependent on temperature. At this lower concentration, the temperature should be kept at (20 0,2) C. ISO 2015 All rights reserved 3BS ISO 699:2015ISO 699:2015(E) 9 Expression of results 9.1 Method of cal

46、culation and formula The alkali resistance, R c , expressed as a percentage by mass, is given by the formula m m (1) where m 0 is the mass, in grams, of the test portion calculated on an oven-dry basis; m 1 is the oven-dry mass, in grams, of the alkali-insoluble fraction. 9.2 Precision and expressio

47、n of results The results of the parallel determinations should agree to within 0,3 %. Report the mean alkali resistance to one decimal place using the symbols R 18 , R 10 , etc. NOTE For pulps containing less than 0,1 % ash, and other noncarbohydrate materials, the value (100 - R c ) approaches the

48、value (S c ) determined by the method for alkali solubility of pulps described in ISO 692. 10 Test report The test report shall include the following particulars: a) a reference to this International Standard, i.e. ISO 699; b) the results and the method of expression used; c) any unusual features no

49、ted during the determination; d) any operation not specified in this International Standard, or regarded as optional.4 ISO 2015 All rights reservedBS ISO 699:2015ISO 699:2015(E) Bibliography 1 ISO 692, Pulps Determination of alkali solubility ISO 2015 All rights reserved 5BS ISO 699:2015ISO 699:2015(E) ISO 2015 All rights reserved IC S 85.040 Price based on 5 pagesThis page deliberately left blankBSI is the national body responsible for preparing British Standa