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 978-0-626-19235-8 SANS 5867:2008Edition 2SOUTH AFRICAN NATIONAL STANDARD Preparation of samples of vulcanized rubbers for testing Published by SABS
4、Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 5867:2008 Edition 2 Table of changes Change No. Date Scope Foreword This South African standard was approved by National Committee SABS TC 45, Rubber and r
5、ubber products, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in November 2008. This document supersedes SABS SM 867:1976 (first edition). SANS 5867:2008 Edition 2 1 Preparation of samples of vulcanized
6、rubbers for testing 1 Scope This standard specifies the procedure for the preparation of samples of vulcanized rubbers for testing. 2 General 2.1 Test specimens should, if possible, be obtained from samples of the product that is to be tested. If the shape or dimensions (or both) of the product rend
7、er preparation of test specimens for the assessment of compliance with any requirement impracticable, sample sheets of the appropriate thickness from an unvulcanized compound of the same formulation should be prepared and vulcanized under the same conditions as that used for the product. 2.2 Due to
8、the natural aging that occurs in vulcanized rubbers, the results of tests cannot be deemed to be representative of the initial values if the time-lapse between vulcanization and testing is more than three months. NOTE If a product that has been stored for a period of more than three months requires
9、testing, it should be deemed to have originally complied with the requirements of this standard if a) the samples are found to comply with all the requirements of this standard other than for tensile strength, elongation at break, hardness and tear strength; b) the values obtained for hardness do no
10、t differ by more than 5 IRH degrees from the specified value; and c) the values obtained for tensile strength, elongation at break, and tear resistance do not differ by more than 10 % from the specified values. 3 Preparation of samples cut from products 3.1 Removal of textiles combined with the rubb
11、er Preferably avoid the use of a solvent which causes swelling. If this is not possible, a non-toxic solvent that has a low boiling point may be used to wet the contacting surfaces. Avoid stretching the rubber when removing the fabric. 3.2 Buffing When it is necessary to reduce the thickness of a sa
12、mple to a specific value or to remove surface irregularities (such as fabric impressions), buff the sample, using a grinder with a motor-drivenSANS 5867:2008 Edition 2 2 abrasive wheel (that is based on aluminium oxide or silicon carbide) that is equipped with a slow-feed mechanism that enables very
13、 light cuts to be made. Ensure that the wheel runs true, without vibration, and that the abrasive surface is true and sharp. Avoid overheating of the rubber. Do this by using cuts of depth not exceeding 0,2 mm. 4 Preparation of samples from unvulcanized compounds 4.1 Milling Pass the unvulcanized co
14、mpound 10 times through the rolls of a laboratory mill (set in tight nip) without banding or rolling the compound. Adjust the clearance between the rolls to 1,5 mm, band the compound on the slow roll, make three three-quarter cuts each way, and sheet the compound from the mill to the required thickness. 4.2 Vulcanizing Fill the cavity of the appropriate mould with slabs of suitable size cut from the milled sheet and vulcanize in a press under the same conditions of pressure, temperature and time as were used in the manufacture of the product. SABS
