1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication BS ISO 8942:2010 Rubber compounding ingredients Carbon black Determination of individual pellet crushing strengthBS ISO 8942:2010 BRITISH STANDARD National foreword This Briti
2、sh Standard is the UK implementation of ISO 8942:2010. The UK participation in its preparation was entrusted to Technical Committee PRI/50, Rubber - Raw, natural and synthetic, including latex and carbon black. A list of organizations represented on this committee can be obtained on request to its s
3、ecretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2010 ISBN 978 0 580 59054 2 ICS 83.040.20 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard
4、was published under the authority of the Standards Policy and Strategy Committee on 30 November 2010. Amendments issued since publication Date Text affectedBS ISO 8942:2010Reference number ISO 8942:2010(E) ISO 2010INTERNATIONAL STANDARD ISO 8942 First edition 2010-11-01 Rubber compounding ingredient
5、s Carbon black Determination of individual pellet crushing strength Ingrdients de mlange du caoutchouc Noir de carbone Dtermination de la force dcrasement des granules individuels BS ISO 8942:2010 ISO 8942:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes
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8、as been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2010 All rights reserved. Unless otherwise specified, no pa
9、rt 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 at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale
10、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 2010 All rights reservedBS ISO 8942:2010 ISO 8942:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references
11、1 3 Terms and definitions .1 4 Principle .1 5 Method A 1 6 Method B 2 6.1 Apparatus.2 6.2 Sampling and selection of pellets for use as test pieces3 6.3 Procedure.3 6.3.1 Manual procedure3 6.3.2 Automatic procedure 4 6.4 Calculation and expression of results 4 7 Test report4 Annex A (informative) Pre
12、cision and bias5 Bibliography7 BS ISO 8942:2010 ISO 8942:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carr
13、ied 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 organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
14、ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare Internat
15、ional 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 least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the e
16、lements 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 8942 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber
17、industry. It cancels and replaces ISO/TR 8942:1988, which has been technically revised. BS ISO 8942:2010 ISO 8942:2010(E) ISO 2010 All rights reserved vIntroduction Carbon black for the rubber industry is generally pelletized to reduce dust and facilitate handling. The property of individual pellet
18、crushing strength, among several other properties, may have an influence on the dispersion of carbon black in polymers, on bulk handling and on conveying properties. For these purposes, carbon black is mostly pelletized to around 1 mm in diameter, but the pellet size can reach 1,7 mm. Therefore, in
19、most of the existing test methods used to measure the individual pellet crushing strength, the pellets are selected in sizes ranging from 1 mm to 1,7 mm. The individual pellet crushing strength is the force necessary to crush one pellet, and the value measured is absolute (i.e. neither per unit volu
20、me nor per unit surface area of the pellet). The value varies with the size of the pellet. Therefore, a narrower size range in the sample generally gives a narrower distribution of the measured individual pellet crushing strength. This International Standard provides two methods for determining the
21、individual pellet crushing strength of carbon black: Method A, specified in ASTM D5230, which uses a test sample of a certain pellet size range that is widely used in the industry for typical grades, prepared by passing a sample through a sieve that has an aperture of 1,4 mm to 1,7 mm. Method B, whi
22、ch uses a test sample prepared using a sieve that has an aperture of 1,0 mm. This method is used when a more precise result is required, such as in process control or in order to meet a customers specification. BS ISO 8942:2010BS ISO 8942:2010 INTERNATIONAL STANDARD ISO 8942:2010(E) ISO 2010 All rig
23、hts reserved 1Rubber compounding ingredients Carbon black Determination of individual pellet crushing strength 1 Scope This International Standard specifies two methods for the determination of the individual pellet crushing strength of carbon black for use in the rubber industry: method A: using pe
24、llets of size ranging from 1,4 mm to 1,7 mm; method B: using pellets of size 1 mm. 2 Normative references 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
25、 referenced document (including any amendments) applies. ISO 565, Test sieves Metal wire cloth, perforated metal plate and electroformed sheet Nominal sizes of openings ISO 1124, Rubber compounding ingredients Carbon black shipment sampling procedures ASTM D5230, Standard Test Method for Carbon Blac
26、k Automated Individual Pellet Hardness 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 individual pellet crushing strength force required to crush (i.e. fracture) a carbon black pellet under specified conditions 4 Principle A number of pellet
27、s within the diameter range 1,4 mm to 1,7 mm (method A) or of diameter 1,0 mm (method B) are selected by sieving a carbon black sample (in method B, this is achieved by selecting only those pellets which, during sieving, become lodged in the apertures of a 1,0 mm aperture sieve). The pellets selecte
28、d are placed one at a time between two parallel plates of a device capable of applying a force. The force which is being applied when the pellet fractures is recorded. 5 Method A Testing is carried out in accordance with ASTM D5230. BS ISO 8942:2010 ISO 8942:2010(E) 2 ISO 2010 All rights reserved6 M
29、ethod B 6.1 Apparatus Usual laboratory apparatus, plus the following: 6.1.1 Manual pellet hardness tester. Required is a device capable of applying a force at a constant rate and of measuring the force at which the pellet fractures. The device shall: have two parallel plates (a baseplate and a force
30、-application plate) which remain horizontal throughout the whole of the test; be capable of applying a force which increases at a constant rate of between 5 cN/s 1)and 25 cN/s; possess a means of measuring this force with an accuracy of 1 cN; be capable of being calibrated using deadweights or a for
31、ce-measuring device that verifies the accuracy of the equipment over the range being used for the test. The baseplate and force-application plate shall be firmly fixed in order to prevent the pellet from rolling, or otherwise moving, before the start of the test. Simple, accurate bench dial scales h
32、aving a 50 g or 200 g dial and with the force-application plate positioned above the scale pan may be used. 6.1.2 Automatic pellet hardness tester 2) , capable of measuring the crushing force to an accuracy of 0,4 cN and having the following characteristics: the ability to load a pellet automaticall
33、y on to the plate from the pellet feed device; the ability to apply the crushing force at a constant rate; a control unit which takes the instrument through the test cycle which comprises crushing the pellet under controlled conditions, measuring the crushing force and storing the result and, finall
34、y, cleaning the pellet fragments from the plate surface before starting the next cycle; an algorithm for detecting the end-point of each individual test, i.e. the maximum force reached before the first occurrence of a reduction in force; a software programme for calculating the data required in 6.4
35、for a specified number of pellets. 1) 1 cN = 1,019 gf. 2) The following automatic pellet hardness testers are available commercially: AS 2000 from Asahisouken Co. Ltd., 3-13-3 Meikeshinmei chuo-ku, Niigata City, Niigata 950-0943, Japan; Individual Pellet Hardness Tester from Jaron Technologies LLC,
36、2338 Duncan St., Pampa, TX 79065, USA (formerly Titan Specialties); IPHT from HITEC Luxembourg, 5 rue de lglise, L-1458 Luxembourg. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of the instruments named. BS ISO 894
37、2:2010 ISO 8942:2010(E) ISO 2010 All rights reserved 36.1.3 Sieve shaker. 6.1.4 Sieve, complying with the requirements of ISO 565, preferably having a nominal aperture size of 1,0 mm. A sieve with an aperture size of 1,4 mm or 1,7 mm (or some other value) may, however, be used by agreement between t
38、he interested parties. NOTE There is a marked tendency for larger particle sizes to have a higher individual crushing strength. The use of a 1 mm sieve to isolate pellets of diameter 1 mm, as described in 6.2.3 and 6.2.4, is intended to avoid this problem. 6.1.5 Bottom-receiver pan. 6.1.6 Sieve cove
39、r. 6.1.7 Sample splitter, single-stage riffle type. 6.1.8 Shallow container, e.g. a dish approximately 300 mm long. 6.2 Sampling and selection of pellets for use as test pieces 6.2.1 Take samples in accordance with the requirements of ISO 1124. 6.2.2 Pass a sufficient quantity of carbon black throug
40、h the sample splitter (6.1.7) to obtain a representative sample of approximately 100 g. 6.2.3 Assemble the bottom-receiver pan (6.1.5) and sieve (6.1.4) correctly. Transfer the 100 g sample of the riffled carbon black to the sieve, place the sieve cover (6.1.6) on the sieve and transfer the assembly
41、 to the sieve shaker (6.1.3). Shake the sieve assembly for 10 0 60 + s with the minimum of energy input so as to avoid pellet breakdown. If a hammer-type mechanical shaker is used, the hammer shall be at rest. 6.2.4 Remove the pellets left on the sieve by turning it upside-down. Then hold the sieve
42、upside-down over a shallow container (6.1.8) and tap the sieve gently so that the pellets lodged in the apertures fall into the container. Repeat these operations until about 50, 100 or 150 1 mm pellets, depending how many it is intended to test (see 6.2.5), have been obtained. With these pellets at
43、 one end of the container, slightly tilt and gently shake the container so that the most spherical pellets roll to the opposite end. Choose 20, 50 or 100 (see 6.2.5) of the most spherical of these pellets. 6.2.5 The number of pellets tested is 20 for normal applications, although, by agreement betwe
44、en the interested parties, either 50 or 100 pellets may be tested if a more precise result is required. 6.3 Procedure 6.3.1 Manual procedure 6.3.1.1 Select one pellet and, using a soft brush, position it in the centre of the baseplate, just under the force-application plate (see 6.1.1). 6.3.1.2 Care
45、fully bring the force-application plate into contact with the pellet. Exercise great care when testing soft pellets which tend to fracture prematurely due to impact on initial contact. 6.3.1.3 Apply force at a constant rate of 25 cN/s until the pellet fractures. Record the force required. 6.3.1.4 Cl
46、ean the baseplate and force-application plate. 6.3.1.5 Repeat the operations in 6.3.1.1 to 6.3.1.4 until all 20 (or 50 or 100) pellets have been tested. BS ISO 8942:2010 ISO 8942:2010(E) 4 ISO 2010 All rights reserved6.3.2 Automatic procedure Use an automatic pellet hardness tester operated in accor
47、dance with the manufacturers instructions. Allow the machine to continue operating until all 20 (or 50 or 100) pellets have been tested. 6.4 Calculation and expression of results 6.4.1 Irrespective of the number of pellets tested, calculate and report the average value, in centinewtons, of the force
48、s recorded in 6.3.1 or 6.3.2, rounded to the nearest millinewton (i.e. the nearest 0,1 gf). Report, in addition, the maximum value, in centinewtons, of the forces recorded in 6.3.1 or 6.3.2. 6.4.2 When 50 or 100 pellets have been tested, the following may also be reported, in centinewtons, rounded t
49、o the nearest whole number: the average value of the five highest forces recorded in 6.3.1 or 6.3.2; the average of the highest 10 % of the individual forces recorded in 6.3.1 or 6.3.2. 7 Test report The test report shall include the following information: a) all details necessary for complete identification of the sample; b) a reference to this International Standard (i.e. ISO 8942:2010); c) the method used (A or B); d) details of the sieve apparatus used; e) if method B was used,
