Detail of GB/T 15256-2014

Introduction of GB/T 15256-2014

1 Scope This standard specifies a method for determining the lowest temperature at which rubber materials do not exhibit brittle failure or the temperature at which half of the test pieces used in a test fail when impacted under specified conditions. This standard is applicable to the determination of low-temperature brittleness of vulcanized or thermoplastic rubber. The temperatures thus determined do not necessarily relate to the lowest temperature at which the material can be used since the brittleness will be affected by the conditions of test and especially by the rate of impact. Data obtained by this method should, therefore, be used to predict the behaviour of rubbers at low temperatures only in applications in which the conditions of deformation are similar to those specified in the test. Three procedures are described. Procedure A, in which the brittleness temperature is determined; Procedure B, in which the brittleness temperature for 50% failure is determined; Procedure C, in which the test piece is impacted at a specified temperature. Procedure C is used in the classification of rubber materials and for specification purposes. Note: A similar test for rubber-coated fabrics is described in ISO 4646, Rubber- or Plastics-coated Fabrics — Low-temperature Impact Test. 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 referenced document (including any amendments) applies. GB/T 25269-2010 Rubber — Guide to the Calibration of Test Equipment (ISO 18899:2004, IDT) ISO 23529 Rubber — General Procedures for Preparing and Conditioning Test Pieces for Physical Test Methods 3 Terms and Definitions For the purposes of this document, the following terms and definitions apply. 3.1 brittleness temperature lowest temperature at which none of a set of test pieces fractures due to low-temperature embrittlement when tested under the specified conditions 3.2 50% brittleness temperature temperature at which 50% of a set of test pieces fracture due to low-temperature embrittlement when tested under the specified conditions

Contents of GB/T 15256-2014

Foreword II 1 Scope 2 Normative References 3 Terms and Definitions 4 Apparatus and Materials 5 Calibration 6 Test Pieces 7 Time Interval between Manufacture and Testing 8 Procedure 9 Precision 10 Testing Report Annex A (Informative) Speed Calibration of a Solenoid-actuated Low-temperature Impact Tester Annex B (Normative) Calibration Procedure Annex C (Informative) Precision