GB/T 15256-2014Rubber or thermoplastic rubber, vulcanized -- Determination of low-temperature brittleness (multiple test piece method) (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This Standard replaces GB/T 15256-1994 "Rubber, vulcanized -- Determination of low-

temperature brittleness (multiple test piece method)". Compared with GB/T 15256-

1994, the main technical differences in this Standard are as follows:

- Add the WARNING;

- Add a test procedure to the scope (see Chapter 1 of this Edition);

- Add a movement mode of the impact head when impacting the test piece (see 4.1.3

of this Edition);

- Add the requirements for the test device (see 4.2, 4.3, 4.4, 4.5, 4.6, 4.7 of this

Edition);

- Add device verification (see Chapter 5 of this Edition);

- Add a test procedure during the test (see Chapter 8 of this Edition);

- Modify the number of test pieces (see 8.1.2 of this Edition, 7.1.1.2 of Edition 1994);

- Add the part of precision (see Chapter 9 of this Edition);

- Add Annex B and Annex C.

This Standard uses translation method to identically adopt ISO 812:2011 "Rubber,

vulcanized or thermoplastic - Determination of low-temperature brittleness".

The Chinese documents that have consistent correspondence with the international

documents cited in this standard are as follows:

- GB/T 2941-2006, Rubber -- General procedures for preparing and conditioning

test pieces for physical test methods (ISO 23529:2004, IDT).

The following editorial modifications have been made to this Standard:

- Change the standard name to "Rubber, vulcanized or thermoplastic - Determination

of low-temperature brittleness (multiple test piece method)".

This Standard was proposed by China Petroleum and Chemical Industry Federation.

This Standard shall be under the jurisdiction of Subcommittee on General Test Methods

of National Technical Committee on Rubber and Rubber Products of Standardization

Administration of China (SAC/TC 35/SC 2).

Rubber, vulcanized or thermoplastic - Determination of low-

temperature brittleness (multiple test piece method)

WARNING -- Persons using this Standard should be familiar with normal

laboratory practice. This standard 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 and health practices and to ensure compliance with

any national regulatory conditions.

IMPORTANT -- Certain procedures specified in this Standard might involve the

use or generation of substances, or the generation of waste, that could constitute a

local environmental hazard. Reference should be made to appropriate

documentation on safe handling and disposal after use.

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 applies to the determination of low temperature brittleness of vulcanized

rubber 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 behavior 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.

punched from sheet using a suitable sharp die. Alternatively, type A test pieces can be

prepared using sharp, parallel double-bladed cutters, in a single stroke. The strip so

formed is then cut to the correct length.

7 Time interval between manufacture and testing

Unless otherwise specified, the time interval between the date the material was formed

and testing shall be in accordance with ISO 23529.

8 Procedure