1、BRITISH STANDARD BS ISO 10716:1994 Implementation of ISO 10716:1994 Paper and board Determination of alkali reserveBS ISO10716:1994 This British Standard, having been prepared under the directionof the Sector Board forMaterials and Chemicals, waspublished under the authorityof the Standards Boardand
2、 comes into effect on 15 May 1995 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PAI/11 Draft for comment 93/303463 DC ISBN 0 580 24231 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Tech
3、nical Committee PAI/11, Methods of test for paper, board and pulps, upon which thefollowing bodies were represented: British Carton Association British Fibreboard Packaging Association British Printing Industries Federation British Textile Confederation Envelope Makers and Manufacturing Stationers A
4、ssociation Her Majestys Stationery Office Institute of Paper Conservation Pira International Post Office The Paper Federation of Great Britain University of Manchester (Institute of Science and Technology) Coopted members Amendments issued since publication Amd. No. Date CommentsBS ISO10716:1994 BSI
5、 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword iii Text of ISO 10716 1BS ISO10716:1994 ii BSI 11-1999 National foreword This British Standard reproduces verbatim ISO 10716:1994 and implements it as the UK national standard. This British Standard is p
6、ublished under the direction of the Sector Board for Materials and Chemicals whose Technical Committee PAI/11 has responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interest
7、s informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include
8、 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 confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i
9、and ii, theISO title page, pages ii to iv, pages1 to 3 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.ISO10716:1994(E) ii BSI 11-1999 Contents Page Foreword iii In
10、troduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle 1 5 Reagents 1 6 Apparatus 1 7 Sampling and preparation of sample 1 8 Test procedure 2 9 Calculation 2 10 Precision 2 11 Test report 3 Table 1 Precision data 2ISO10716:1994(E) BSI 11-1999 iii Foreword ISO (the International
11、Organization for Standardization) 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 esta
12、blished has the right to be 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 standardiza
13、tion. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an InternationalStandard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO 10716 was prepared by Technical Committee
14、ISO/TC 6, Paper, board and pulps.iv blankISO10716:1994(E) BSI 11-1999 1 Introduction Papers produced to be stable for long time periods normally contain some alkaline filler, such as calcium carbonate, as an alkali reserve to prevent attack from acid substances in ambient air or formed by deteriorat
15、ion of substances in the paper. Specifications for paper permeance may require a minimum alkali reserve. This ISO Standard is intended for checking the amount of alkali reserve present. Normally, the required alkali reserve is obtained by adding some form of calcium carbonate to the paper furnish, b
16、ut other substances can also be used for the purpose. By expressing the test result in moles per kilogram of alkaline substances and not as a calcium carbonate content, no confusion arises when alkaline substances other than calcium carbonate are used. 1 Scope This International Standard specifies a
17、 method for the determination of the alkali reserve of papers and boards. It is intended for products that contain alkaline pigments or other alkaline material, added in order to improve their resistance to acid attack (degradation). This International Standard is not applicable to laminated, printe
18、d or otherwise processed grades that will not disintegrate completely by the procedure described. The result obtained will include alkaline pigments contained in the coating of a coated paper. NOTE 1Such alkaline coating will protect the core of the paper from acid substances in ambient air, but its
19、 effect on acid substances generated in the base paper itself is uncertain. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO10716. At the time of publication, the editions indicated were valid. All stan
20、dards are subject to revision, and parties to agreements based on this part of ISO 10716 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 186:
21、, Paper and board Sampling to determine average quality 1) . ISO 287:1985, Paper and board Determination of moisture content Oven drying method. 3 Definitions For the purposes of this International Standard, thefollowing definition applies. 3.1 alkali reserve (in paper and board) compound, such as c
22、alcium carbonate, that neutralizes acid that might be generated as a result of natural ageing or from atmospheric pollution, determined as specified in this InternationalStandard 4 Principle Digestion of the sample in water containing a measured amount of hydrochloric acid. Heating of the slurry to
23、boiling and titration of unreacted hydrochloric acid with sodium hydroxide solution. 5 Reagents During analysis, use only reagents of recognized analytical grade, and freshly distilled water or water of equivalent purity. 5.1 Hydrochloric acid, standard reference solution, c(HCl)=0,10 mol/l 0,001mol
24、/l. 5.2 Sodium hydroxide solution, titrant, c(NaOH)=0,1mol/l. 5.3 Methyl red, indicator solution for acidometric titration. Dissolve 0,2g of methyl red2-4-(dimethylamino)-phenylazobenzoic acid in 100 ml of ethanol. 6 Apparatus Ordinary laboratory equipment. 7 Sampling and preparation of sample Ensur
25、e that the sample is representative of the lot to be tested. Where applicable, follow the instructions given in ISO 186. Select from the sample enough test pieces to provide for the testing to be done, ensuring that these pieces are representative of the whole sample. Tear the pieces into smaller pi
26、eces, about 15 mm 15mm, and split thick board pieces. Wear protective gloves when handling the sample. 1) To be published. (Revision of ISO 186:1985)ISO10716:1994(E) 2 BSI 11-1999 8 Test procedure Carry out this procedure in duplicate. Weigh about1g of sample to the nearest 0,001g. At the same time
27、weigh a separate sample portion for dry matter content determination in accordance with ISO 287. Transfer the test portion to a clean250ml or 300ml conical flask. Add about 100ml of distilled water (or more if required to soak the sample portion) and boil the mixture gently for5min. Allow the mixtur
28、e to cool somewhat. With a pipette, add 20,0ml of hydrochloric acid (5.1). NOTE 2The amount of acid, 20ml or 2mmol, is sufficient to neutralize an alkali reserve of up to 2mol/kg 10% (m/m) CaCO 3 . If the paper contains more than1,5 mol/kg alkali reserve7,5% (m/m) CaCO 3 , use a smaller test sample
29、or a larger volume of hydrochloric acid. Bring the mixture to boiling again and allow it to cool for at least 15min. Titrate with the sodium hydroxide solution (5.2) to the first lemon-yellow, using three drops of the methyl red solution (5.3) as the indicator. If less than5ml of the sodium hydroxid
30、e solution are required to reach the end-point, repeat the procedure with a smaller test sample or with a larger volume of hydrochloric acid. If a trace of pink indicator remains adsorbed in the surface of the fibres, boil the slurry briefly to desorb the pink colour. Usually a further drop of sodiu
31、m hydroxide solution will restore the lemon-yellow colour. Carry out a blank determination by the same procedure, but omit the sample. NOTE 3If the sample is dyed so that the end-point cannot readily be detected, an electrometric titration may be used. However, glass electrodes are sensitive to the
32、presence of suspended matter. If interference from suspended matter is observed, the suspension should be filtered before titration. If such a modification to the test procedure has been carried out, this shall be stated in the test report. 9 Calculation Calculate the alkali reserve, X, expressed in
33、 moles per kilogram, from the expression where NOTE 4The expression above is obtained by combining the equation for the blank titration V 0 c(NaOH) = V 2 c(HCl) with that for the sample titration V 1 c(NaOH) = V 2 c(HCl) Xm and solving for X. Duplicate determinations should agree within0,07mol/kg. I
34、f this is not the case, repeat theprocedure with two more sample portions. Calculate the mean result and round it off to the first decimal place. NOTE 5The alkali reserve, as defined by this InternationalStandard, represents moles per kilogram of an alkali in which the cation is monovalent. One mole
35、 of acid is equivalent to0,5mol of calcium carbonate, or 50g of CACO 3 . One per cent of calcium carbonate thus gives an alkali reserve of0,2 mol/kg. 10 Precision In an interlaboratory study conducted within ISOTC 46/SC 10/WG 1, the alkali reserve of a range of printing and writing papers was tested
36、 by laboratories in different countries. The procedure used was similar to that described in this International Standard. Some of the results (in moles per kilogram) are quoted in Table 1. The data were obtained under reproducibility conditions. Table 1 Precision data V 0 is the volume, in millilitr
37、es, of sodium hydroxide solution used in the blank titration; V 1 is the volume, in millilitres, of sodium hydroxide solution used in the sample titration; V 2 is the volume, in millilitres, of hydrochloric acid used (normally 20 ml); X V 0 V 1 V 0 - V 2 c (HCl) m - = c(HCl) is the concentration of
38、the hydrochloric acid solution (5.1), in moles per litre; m is the mass, in grams, of the oven-dry sample. Sample No. Number of participating laboratories Mean of the results Standard deviation of reproducibility 1 2 3 4 5 6 7 8 9 12 12 12 12 12 12 11 9 9 3,48 3,18 2,81 1,85 0,50 0,27 0,36 0,08 0,04
39、 0,54 0,18 0,17 0,07 0,06 0,06 0,06 0,02 0,03ISO10716:1994(E) BSI 11-1999 3 11 Test report The test report shall include the following particulars: a) a reference to this International Standard; b) date and place of test; c) all information necessary for complete identification of the sample tested;
40、 d) the mean alkali reserve, expressed in moles per kilogram to the nearest0,1 mol/kg; e) any departure from the procedure described in this International Standard, or any other circumstances that may have affected the test results.BS ISO 10716:1994 BSI 389 Chiswick High Road London W4 4AL BSIBritis
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