1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22641-1 SANS 10815-2:2009 Edition 1 ISO 815-2:2008 Edition 1SOUTH AFRICAN NATIONAL STANDARD Rubber, vulcanized or thermoplastic Determinat
4、ion of compression set Part 2: At low temperatures This national standard is the identical implementation of ISO 815-2:2008 and is adopted with the permission of the International Organization for Standardization. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pre
5、toria 0001 Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This standard may only be used and printed by approved subscription and freemailing clients of the SABS. SANS 10815-2:2009 Edition 1 ISO 815-2:2008 Edition 1 Table of changes Change No. Date Scope National foreword This South A
6、frican standard was approved by National Committee SABS TC 45, Rubber and rubber products, in accordance with the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in April 2009. This standard may only be used and printed by approved subsc
7、ription and freemailing clients of the SABS.INTERNATIONAL STANDARD ISO 815-2 First edition 2008-02-01 Reference number ISO 815-2:2008(E) ISO 2008 Rubber, vulcanized or thermoplastic Determination of compression set Part 2: At low temperatures Caoutchouc vulcanis ou thermoplastique Dtermination de la
8、 dformation rmanente aprs compression Partie 2: basses tempraturesSANS 10815-2:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 815-2:2008(E) ii ISO 2008 All rights reserved PDF disclaimer This PDF file may contain embedded typefaces. In
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11、 printing. Every care has 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 2008 All rights reserved. Unless othe
12、rwise specified, no part 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 copyrigh
13、t office Case postale 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 SANS 10815-2:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 815-2:2008(E) ISO 2008
14、 All rights reserved iii Contents Page 1 Scope 1 2 Normative references 1 3 Principle 1 4 Apparatus . 2 5 Test pieces . 4 6 Test conditions 6 7 Procedure . 6 8 Expression of results 7 9 Precision . 7 10 Test report 8 SANS 10815-2:2009This standard may only be used and printed by approved subscriptio
15、n and freemailing clients of the SABS.ISO 815-2:2008(E) iv ISO 2008 All rights reserved Foreword 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 carried out
16、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 coll
17、aborates 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 International St
18、andards. 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 elements
19、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 815-2 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis. Together with ISO 815-1, ISO 815-2 canc
20、els and replaces ISO 815:1991, as well as Technical Corrigendum ISO 815:1991/Cor.1:1993, which have been technically revised. The main modifications concern changes in tolerances to improve the precision of the test method. In addition, a new compression assembly has been specified which makes it po
21、ssible to perform all measurements inside the low-temperature cabinet without moving the test pieces or opening the cabinet door. ISO815 consists of the following parts, under the general title Rubber, vulcanized or thermoplastic Determination of compression set: Part 1: At ambient or elevated tempe
22、ratures Part 2: At low temperatures SANS 10815-2:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.INTERNATIONAL STANDARD ISO 815-2:2008(E) ISO 2008 All rights reserved 1 Rubber, vulcanized or thermoplastic Determination of compression set Pa
23、rt 2: At low temperatures WARNING Persons using this part of ISO 815 should be familiar with normal laboratory practice. This part of ISO 815 does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety
24、and health practices and to ensure compliance with any national regulatory conditions. CAUTION Certain procedures specified in this part of ISO 815 may involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be mad
25、e to appropriate documentation on safe handling and disposal after use. 1S c o p e This part of ISO 815 specifies a method for the determination of the compression set characteristics of vulcanized and thermoplastic rubbers at low temperatures. The method is intended to measure the ability of rubber
26、s of hardness within the range 10 IRHD to 95 IRHD to retain their elastic properties at specified temperatures after prolonged compression at constant strain (normally ) under one of the alternative sets of conditions described. For rubber of nominal hardness 80 IRHD and above, a lower compression s
27、train is used: for a nominal hardness from 80 IRHD to 89 IRHD and for a nominal hardness from 90 IRHD to 95 IRHD. NOTE When rubber is held under compression, physical or chemical changes can occur that prevent the rubber returning to its original dimensions after release of the deforming force. The
28、result is a set the magnitude of which depends on the time and temperature of compression as well as on the time and temperature of recovery. At low temperatures, changes resulting from the effects of glass hardening or crystallization become predominant and, since these effects are reversed by rais
29、ing the temperature, it is necessary for all measurements to be undertaken at the test temperature. 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 late
30、st edition of the referenced document (including any amendments) applies. ISO 4287, Geometrical Product Specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parameters ISO 23529:2004, Rubber General procedures for preparing and conditioning test pieces for phys
31、ical test methods 3 Principle A test piece of known thickness is compressed at standard laboratory temperature to a defined strain, which is then maintained constant for a specified time at a fixed low temperature. The compression is released and the test piece is allowed to recover at this temperat
32、ure. The thickness is measured either at intervals after the 25 % 15 % 10 % SANS 10815-2:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 815-2:2008(E) 2 ISO 2008 All rights reserved release of the strain (so that an assessment of compre
33、ssion set characteristics can be obtained by plotting recovery against time at the low temperature) or a specified time after the release of the strain. 4 Apparatus 4.1 Compression apparatus, consisting of compression plates, spacer(s) (optional), a thickness gauge, a temperature sensor and a device
34、 for applying a specified pressure for thickness measurements. The measurement pressure for thickness measurements is the same as that specified in ISO 23529. The compression apparatus shall be capable of applying the compression and maintaining it during the whole duration of the test, and it shall
35、 be possible to keep the apparatus in a low-temperature cabinet at the specified test temperature. Care shall be taken to ensure that there is as little influence on the test as possible by the conduction of heat away from the test piece, for example through metal parts which are connected with the
36、outside of the low-temperature cabinet. The part of the apparatus with the compression plates and the test piece shall be within the low-temperature cabinet during the whole of the test, but the thickness gauge may be located outside the cabinet. An example of a compression apparatus is shown in Fig
37、ure 1. It shall be possible to release the compression of the test piece without opening the low-temperature cabinet. An example of a quick-release mechanism for this purpose is shown in Figure 2. 4.1.1 Compression plates, comprising a pair of parallel, flat, highly polished chromium-plated steel or
38、 highly polished stainless-steel plates, between the faces of which the test piece is compressed. The finish of the surface of the compression plates shall be not worse than from the mean line of the profile (see ISO 4287). The plates shall be sufficiently rigid to ensure that, with a test piece und
39、er load, no compression plate bends by more than ; of sufficient size to ensure that the whole of the test piece, when compressed between the plates, remains within the area of the plates. 4.1.2 Steel spacer(s), to provide the required compression, if necessary. Whether spacer(s) will need to be use
40、d or not will depend on the design of the compression apparatus. If used, the spacer(s) shall be of such size and shape that contact with the compressed test piece is avoided. The height of the spacer(s) shall be chosen so that the compression applied to the test piece isfor hardnesses below 80 IRHD
41、;for hardnesses between 80 IRHD and 89 IRHD;for hardnesses of 90 IRHD and higher. 4.1.3 Thickness gauge, with an accuracy of , exerting a pressure of for solid rubber of hardness equal to or greater than 35 IRHD or a pressure of if the hardness is less than 35 IRHD. The thickness gauge shall have a
42、device for applying a pre-load by means of a deadweight or load-cell system so that it exerts the specified pressure. The thickness measurement may also be done using the compression plates. For comparative purposes, the same dimensions of the circular foot shall be used. NOTE When using a digital g
43、auge, a resolution of is needed to obtain the required accuracy. 4.1.4 Temperature measurement device, inserted in one of the plates, measuring the temperature directly with an accuracy of . Ra 0,4 m 0,01 mm (25 2) % (15 2) % (10 1) % 0,01 mm 22 kPa 5 kPa 10 kPa 2 kPa 0,001 mm 0,5 C SANS 10815-2:200
44、9This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 815-2:2008(E) ISO 2008 All rights reserved 3 Key 1s c r e w 2 thickness measurement gauge 3 rubber lid 4 insulating lid 5 aluminium lid 6 linear bearing 7 compression plates 8 spacers (option
45、al) 9 test piece 10 temperature sensor 11 weight for pre-loading test piece Figure 1 Example of a compression apparatus SANS 10815-2:2009This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 815-2:2008(E) 4 ISO 2008 All rights reserved 4.2 Low-te
46、mperature cabinet, capable of maintaining the compression apparatus and test pieces at the test temperature within the tolerance limits specified in 6.2. The low-temperature cabinet may be mechanically refrigerated or it may be cooled directly by dry ice or liquid nitrogen. The cabinet shall be desi
47、gned so that it is possible to release the test pieces and carry out the subsequent thickness measurements without direct contact, e.g. by means of hand-holes fitted with gloves or a remote- handling device. The cabinet shall be capable of maintaining the temperature within the specified limits whil
48、e these operations are being carried out. The time to reach a steady-state temperature depends on the type of cabinet and the overall heat capacity of the compression apparatus. To obtain test results which can be compared with each other, it is necessary, in the case of a test, to reach the steady-
49、state temperature, within the specified limits, in the interior of the test pieces in not more than . 4.3 Timing device, for measuring the recovery time, with a precision of . 5 Test pieces 5.1 Dimensions The test pieces shall be one of two sizes, designated type A and type B: type A: a cylindrical disc of diameter and thickness ; type B: a cylindrical disc of diameter and thickness . These two types do not necessarily give the same values for compression set, and comparison of results obtaine
