1、BRITISH STANDARD BS 7463-5: 1991 ISO 9184-5: 1990 Fibre furnish analysis of paper, board and pulps Part 5: Method of test by Lofton-Merritt stain (Wisbar modification)BS7463-5:1991 This British Standard, having been prepared under the directionof the Paper and PrintingStandards Policy Committee, was
2、 published under the authority of the Standards Board and comes into effect on 28June 1991 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference PAM/11 Draft for comment 88/45953 DC ISBN 0 580 19829 4 Committees responsible for this British Standard The pr
3、eparation of this British Standard was entrusted by the Paper and Printing Standards Policy Committee (PAM/-) to Technical Committee PAM/11, upon which the following bodies were represented: British Fibreboard Packaging Association British Paper and Board Industry Federation (PIF) British Printing I
4、ndustries Federation British Telecommunications plc Envelope Makers and Manufacturing Stationers Association Her Majestys Stationery Office Man-made Fibres Producers Committee Ministry of Defence Pira (the Research Association for the Paper and Board, Printing and Packaging Industries) Post Office S
5、ociety of British Printing Ink Manufacturers University of Manchester Institute of Science and Technology Amendments issued since publication Amd. No. Date CommentsBS7463-5:1991 BSI 08-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative reference
6、 1 3 Principle 1 4 Reagents 1 5 Procedure 1 6 Expression of results and test report 1 Annex A (informative) Bibliography 3 Table 1 Colour chart for Lofton-Merritt stain 2 Publication(s) referred to Inside back coverBS7463-5:1991 ii BSI 08-1999 National foreword This Part of BS 7463 has been prepared
7、 under the direction of the Paper and Printing Standards Policy Committee. It is identical with ISO9184-5:1990 “Paper, board and pulps Fibre furnish analysis Part 5: Lofton-Merritt staining test (modification of Wisbar)”, published by the International Organization for Standardization (ISO). A Briti
8、sh 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 confer immunity from legal obligations. Cross-reference International Standard Correspon
9、ding British Standard ISO 9184-1:1990 BS 7463 Fibre furnish analysis of paper, board and pulps Part 1:1991 General method (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4, an inside back cover and a back cover. This standard has been
10、 updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS7463-5:1991 BSI 08-1999 1 1 Scope This part of ISO 9184 specifies the preparation, use and colour reactions of Lofton-Merritt stain in fibre furnish analy
11、sis. It should be used in conjunction with ISO 9184-1 and, if necessary, with other staining tests defined in ISO 9184-2. The Lofton-Merritt staining test is applicable to the qualitative and quantitative differentiation of the following pulps: unbleached and bleached softwood chemical pulps; unblea
12、ched kraft and sulfite in softwood pulps; unbleached semi-chemical kraft and sulfite pulps. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this part of ISO9184. At the time of publication, the edition indicated was val
13、id. All standards are subject to revision, and parties to agreements based on this part of ISO9184 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
14、ISO 9184-1:1990, Paper, board and pulps Fibre furnish analysis Part 1: General method. 3 Principle Fibres are stained with Lofton-Merritt stain and examined under the microscope. 4 Reagents CAUTION Some of the components used in preparing this stain are toxic. The stain should be prepared and handle
15、d in keeping with safe laboratory practice. Use only reagents of recognized analytical grade and distilled water or water of equivalent purity. 4.1 Fuchsine, solution, about 1% (m/m). Add 1 g of fuchsine monohydrochloride (C 20 H 20 N 3 Cl) (C.l. 42510 C.l. basic violet14) in small portions to50ml o
16、f boiling water in a250ml beaker, with vigorous stirring. Dilute to100ml. 4.2 Malachite green, solution, about2% (m/m). Take 2 g of malachite green (C 23 H 25 N 2 Cl) (C.l.42000 C.l. basic green 4) and proceed as described for the fuchsine solution. 4.3 Hydrochloric acid, solution, about0,5% (m/m).
17、Dilute5ml of a37% (m/m) solution of hydrochloric acid (HCl) to400ml. Store in brown reagent bottles. The solutions (4.1 to4.3) are stable. 4.4 Lofton-Merritt stain Mix 4,4 ml of the fuchsine solution (4.1); 2,2 ml of the malachite green solution (4.2); 20,0 ml of the hydrochloric acid solution (4.3)
18、. Pipette the required volume of each solution, given above, into a100ml glass cylinder and dilute to100ml. Store in a brown reagent bottle and keep in the dark when not in use. Shake before use. NOTE 1Adjustment of the stain mixture by the addition of malachite green or fuchsine solution is require
19、d to attain the colours given inTable 1. Test the fresh mixture with known samples containing unbleached softwood sulfate and sulfite pulp, and mechanical pulp. If the fibres of unbleached kraft pulp and/or mechanical pulp yield a reddish colour, add malachite green solution. If the fibres of unblea
20、ched sulfite pulp exhibit a bluish or greenish colour, add fuchsine solution. The stain mixture is stable. However, it is preferable to check it with known fibres every2months. More distinct staining is obtained with a fresh mixture. 5 Procedure 5.1 Staining Draw a specimen from the moist filtered f
21、ibre pad (see ISO9184-1) into a test tube, add5ml to10ml of the Lofton-Merritt stain mixture (4.4) and boil from1min to2min, stirring all the time with a glass rod. Pour the suspension into a sieve or a glass filter, and rinse with small amounts of water until the filtrate is colourless. Draw a smal
22、l quantity of the stained fibres on to a slide, add2 or3 drops of water, and with dissecting needles distribute the fibres into a uniform network. Apply a cover glass, tilt the slide and blot edgewise. The fibre slide can also be made from a diluted suspension of the stained fibres in accordance wit
23、h ISO9184-1, using water instead of stain. 5.2 Determination Place the stained fibre slide under the microscope and examine using a magnification of 40 to 120. Identify and count the fibres in accordance with ISO9184-1 on the basis of the colours developed by the Lofton-Merritt stain (seeTable 1). 6
24、 Expression of results and test report Express and report the results in accordance with ISO9184-1.BS7463-5:1991 2 BSI 08-1999 Table 1 Colour chart for Lofton-Merritt stain Type of pulp Colour a Softwood chemical pulp Unbleached kraft Unbleached sulfite Bleached kraft and sulfite Semi-bleached kraft
25、 Greenish or greyish-blue b Red-violet bcd Colourless Light pink or colourless Hardwood chemical pulp Unbleached kraft and sulfite Semi-bleached or bleached kraft and sulfite Light greenish or light violet (weak colours or colourless) Mostly colourless Softwood and hardwood semi-chemical pulp Unblea
26、ched kraft Unbleached sulfite Bluish-green Dark blue-violet Mechanical pulp Bright blue a The colours obtained using fuchsine and malachite green from different manufacturers and from different batches, differ slightly from each other. The above-mentioned colours are obtained using basic fuchsine of
27、 National Aniline Division and malachite green of Fluka AG. Diamant fuchsine of Merck give about the same colours. b The intensity of the colour diminishes with increasing degrees of delignification. c In the Lofton-Merritt staining test, the central part of the bordered pits is often stained strong
28、 violet. This “eye formation” is most distinct in slightly stained fibres of sulfite pulps. Kraft fibres never display staining of the bordered pits, and consequently such staining can be interpreted as a specific test for unbleached sulfite pulp. This phenomenon is generally encountered when staini
29、ng fibres with alkaline stains. d The pitch content of ray cells is stained bluish-green by Lofton-Merritt stain, which often is an indication of softwood sulfite pulp.BS7463-5:1991 BSI 08-1999 3 Annex A (informative) Bibliography 1 SCHULZE, B.: Die mikroskopische Unterscheidung von ungebleichtem Na
30、tron = (Sulfat =) und Sulfitzellstoff nach Lofton und Merritt. Wochenbl. fr Papierfabr. 64 (1933):9, pp. 159160. 2 LOFTON, R.E. and MERRITT, M.F.: Method for differentiating and estimating unbleached sulfite andsulfate pulps in paper. U.S. Department of Commerce, National Bureau of Standards, Techn.
31、 Papers 189 (1921). Techn. Assoc. Papers 3 (1920):1, pp. 117. 3 GRAFF, J.H.: A Color Atlas for Fiber Identification. The Institute of Paper Chemistry, Appleton, WI,1940, Plate IV.4 blankBS7463-5:1991 BSI 08-1999 Publication(s) referred to See national foreword.BS 7463-5: 1991 ISO 9184-5: 1990 BSI 38
32、9 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 Charter. Revisions BritishStandards are update
33、d by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishSta
34、ndard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editi
35、ons of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have
36、been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also av
37、ailable which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and oth
38、er benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the internationalstandardization bodies. Except as permitted under the Copyright, Designs and Patents
39、 Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary de
40、tails such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
