1、Rubber, raw natural Determination of plasticity retention index (PRI)BS ISO 2930:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Rubber, raw natural Determination of plasticity retention index (PRI)Caoutchouc naturel brut Dtermination de lindice de rtent
2、ion de plasticit (PRI)INTERNATIONAL STANDARDISO2930Fifth edition2017-08Reference numberISO 2930:2017(E)National forewordThis British Standard is the UK implementation of ISO 2930:2017. It supersedes BS ISO 2930:2009, which is withdrawn.The UK participation in its preparation was entrusted to Technic
3、al Committee PRI/50, Raw materials (including latex) for use in the rubber industry.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
4、 correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 89101 4ICS 83.040.10Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and
5、Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 2930:2017 ISO 2017Rubber, raw natural Determination of plasticity retention index (PRI)Caoutchouc naturel brut Dtermination de lindice de rtention de plasticit (PRI)INTERNAT
6、IONAL STANDARDISO2930Fifth edition2017-08Reference numberISO 2930:2017(E)BS ISO 2930:2017ISO 2930:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or uti
7、lized otherwise in any form or by any means, electronic or mechanical, including photocopying, 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 copyrig
8、ht officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 2930:2017ISO 2930:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwi
9、se specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address bel
10、ow or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgISO 2930:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Prin
11、ciple 25 Apparatus . 26 Procedure. 36.1 Preparation of test pieces 36.2 Ageing . 36.3 Determination of plasticity. 37 Expression of results 48 Precision . 49 Test report . 4Annex A (informative) Air change in oven for PRI determination . 5Annex B (informative) Precision statement for plasticity rete
12、ntion index 7Bibliography 9 ISO 2017 All rights reserved iiiContents PageBS ISO 2930:2017ISO 2930:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is norma
13、lly 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 organizations, governmental and non-governmental, in liaison with ISO, also take part in th
14、e work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the
15、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 the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this documen
16、t 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 during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/p
17、atents).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 voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information ab
18、out ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex
19、) for use in the rubber industry.This fifth edition cancels and replaces the fourth edition (ISO 2930:2009), which has been technically revised.The main changes compared to the previous edition are as follows: the normative references have been updated; a duration of 30 min has been added in Clause
20、4; the tolerance value for oven temperature has been changed to 0,5 C in 5.5; the description for lightweight aluminium tray and dishes in 5.6 has been modified; a new Annex A on the air change in oven for PRI determination has been added; Table B.1 has been updated, following the interlaboratory te
21、st programme conducted in 2014.iv ISO 2017 All rights reservedBS ISO 2930:2017ISO 2930:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried
22、 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. ISO
23、 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different a
24、pproval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the 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 th
25、e subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during 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
26、 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 voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs ad
27、herence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use i
28、n the rubber industry.This fifth edition cancels and replaces the fourth edition (ISO 2930:2009), which has been technically revised.The main changes compared to the previous edition are as follows: the normative references have been updated; a duration of 30 min has been added in Clause 4; the tole
29、rance value for oven temperature has been changed to 0,5 C in 5.5; the description for lightweight aluminium tray and dishes in 5.6 has been modified; a new Annex A on the air change in oven for PRI determination has been added; Table B.1 has been updated, following the interlaboratory test programm
30、e conducted in 2014.iv ISO 2017 All rights reserved INTERNATIONAL STANDARD ISO 2930:2017(E)Rubber, raw natural Determination of plasticity retention index (PRI)WARNING Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the
31、 safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.1 ScopeThis document specifies a method for determining the plasticity retention index (PRI) o
32、f raw natural rubber.The PRI is a measure of the resistance of raw natural rubber to thermal oxidation. A high resistance to thermal oxidation is shown as a high value of the index. PRI is not an absolute value and cannot give an absolute classification of plasticity number of different natural rubb
33、er after oxidation.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced d
34、ocument (including any amendments) applies.ISO 1795, Rubber, raw natural and raw synthetic Sampling and further preparative proceduresISO 2007, Rubber, unvulcanized Determination of plasticity Rapid-plastimeter methodISO 2393, Rubber test mixes Preparation, mixing and vulcanization Equipment and pro
35、ceduresISO 23529:2016, Rubber General procedures for preparing and conditioning test pieces for physical test methods3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the fol
36、lowing addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp3.1plasticity numbermeasure of plasticity, based upon the height of a test piece after being subjected to deformation under specified conditions of compressive
37、 force, time and temperature3.2plasticity retention indexratio of the plasticity number (3.1) measured after air-oven ageing for 30 min at 140 C to the plasticity number before oven ageing ISO 2017 All rights reserved 1BS ISO 2930:2017ISO 2930:2017(E)4 PrincipleThe rapid plasticity numbers of unaged
38、 test pieces and test pieces aged by heating in an oven at 140 C for 30 min are determined using a parallel-plate plastimeter with a platen of diameter 10 mm, following the procedure specified in ISO 2007.The PRI is the ratio of the rapid plasticity numbers before and after the heating multiplied by
39、 100.5 Apparatus5.1 Parallel-plate plastimeter, with a platen of 10 mm diameter, as specified in ISO 2007.5.2 Punch, capable of compressing a portion of the material being tested to a thickness of approximately 3 mm and cutting out a disc of approximately 13 mm in diameter for the preparation of tes
40、t pieces, as specified in ISO 2007.5.3 Thickness gauge, having a scale graduated in unit divisions of 0,01 mm, fitted with a flat contact of 10 mm diameter and operating with a pressure of (20 3) kPa.5.4 Laboratory mixing mill, in conformity with the requirements of ISO 2393, but with the following
41、characteristics: roll diameter: 150 mm to 250 mm; linear speed of back (fast) roll: (14,6 0,5) m/min; roll speed ratio: 1:1,4; temperature: (27 3) C; roll length between guides: (265 15) mm.5.5 Oven, meeting the following requirements at 140 C. The temperature in the vicinity of the test pieces shal
42、l be controllable to within 0,5 C over a period of 30 min. Following insertion of the tray plus dishes into the oven, the temperature of the oven shall recover, and that of the tray plus dishes increase, to within 1 C of the set temperature within 5 min. The air shall be changed 10 times per hour. A
43、lternatively, the air flap of the oven can be set as semi-open.NOTE Additional information on the air change in an oven is given in Annex A.5.6 Lightweight aluminium dishes and tray, with a low thermal capacity.A suitable size of tray and/or dishes should be used depending on the size of the oven.5.
44、7 Tissue paper, as described in ISO 2007, or cigarette paper of 22 g/m2to 26 g/m2cut into two equal pieces (approximately 30 mm 45 mm).2 ISO 2017 All rights reservedBS ISO 2930:2017ISO 2930:2017(E)4 PrincipleThe rapid plasticity numbers of unaged test pieces and test pieces aged by heating in an ove
45、n at 140 C for 30 min are determined using a parallel-plate plastimeter with a platen of diameter 10 mm, following the procedure specified in ISO 2007.The PRI is the ratio of the rapid plasticity numbers before and after the heating multiplied by 100.5 Apparatus5.1 Parallel-plate plastimeter, with a
46、 platen of 10 mm diameter, as specified in ISO 2007.5.2 Punch, capable of compressing a portion of the material being tested to a thickness of approximately 3 mm and cutting out a disc of approximately 13 mm in diameter for the preparation of test pieces, as specified in ISO 2007.5.3 Thickness gauge
47、, having a scale graduated in unit divisions of 0,01 mm, fitted with a flat contact of 10 mm diameter and operating with a pressure of (20 3) kPa.5.4 Laboratory mixing mill, in conformity with the requirements of ISO 2393, but with the following characteristics: roll diameter: 150 mm to 250 mm; line
48、ar speed of back (fast) roll: (14,6 0,5) m/min; roll speed ratio: 1:1,4; temperature: (27 3) C; roll length between guides: (265 15) mm.5.5 Oven, meeting the following requirements at 140 C. The temperature in the vicinity of the test pieces shall be controllable to within 0,5 C over a period of 30
49、min. Following insertion of the tray plus dishes into the oven, the temperature of the oven shall recover, and that of the tray plus dishes increase, to within 1 C of the set temperature within 5 min. The air shall be changed 10 times per hour. Alternatively, the air flap of the oven can be set as semi-open.NOTE Additional information on the air change in an oven is given in Annex A.5.6 Lightweight aluminium dishes and tray, with a low thermal capacity
