Standard No.:	GB/T 11206-2009
English Name:	Standard test method for rubber deterioration - Surface cracking
Chinese Name:	橡胶老化试验 表面龟裂法
Chinese Classification:	G40    Rubber products in general
Professional Classification:	GB    National Standard
Source Content Issued by:	AQSIQ; SAC
Issued on:	2009-04-24
Implemented on:	2009-12-1
Status:	valid
Superseding:	GB/T 11206-1989 GB 11206-1989 Rubber vulcanized; The test method of deterioration surface cracking
Target Language:	English
File Format:	PDF
Word Count:	6000 words
Translation Price(USD):	150.0
Delivery:	via email in 1 business day

1 Scope This standard specifies test method and evaluation method for surface cracking of rubber specimens when deteriorating under static strain. It is applicable to the aging test of rubber under static strain or bending state in atmospheric environment or zone-containing medium. It is not applicable to test of electrical insulation or other rubber parts where high concentrations of ozone prevail due to electrical discharge, nor to test of hard rubber. 2 Normative references The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding corrections), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editions apply. GB/T 528 Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties (GB/T 528-1998, eqv ISO 37: 1994) GB/T 7762 Rubber, vulcanized or thermoplastic - Resistance to ozone cracking - Static strain test (GB/T 7762-2003, ISO 1431-1: 1989, MOD) ASTM D 4575 Standard test methods for rubber deterioration - Reference and alternative method(s) for determining ozone level in laboratory test chambers 3 Test methods 3.1 According to the actual use state of rubber or rubber products, the following methods may be selected for the test: a) strain method of rectangular specimen; b) bending test method of rectangular specimen; c) strain method of tapered specimen; d) strain method of dumb-bell shaped specimen. 3.2 Expose rubber specimens, held under strain or bending state by test block, to atmospheric environment or zone-containing medium for definite periods of time and evaluate their deterioration observed as evidenced by the appearance and growth of cracks on the surfaces. 3.3 Ozone concentration shall be determined in accordance with ASTM D 4575. 4 Test principle and application 4.1 When a rubber specimen is placed in an atmospheric environment or an ozone-containing medium for aging test under static strain or bending state, its surface will crack due to ozone and other factors. The direction of this crack is basically perpendicular to the stress direction of the specimen. The aging resistance of rubber may be relatively evaluated by observing the change of specimen surface cracking. 4.2 This standard is not suited for use in purchase specifications, not only because correlation with service life is uncertain, but because the testing results from duplicate specimens tested in different locations do not ordinarily give the same values. No exact relation between the testing results of the test and actual service is given or implied. This standard is principally used for comparisons of aging resistance between two or more rubber materials. 5 Apparatus for Method A - Strain method of rectangular specimen 5.1 Specimen mounting block

Foreword i 1 Scope 2 Normative references 3 Test methods 4 Test principle and application 5 Apparatus for Method A - Strain method of rectangular specimen 6 Specimen for Method A - Strain method of rectangular specimen 7 Procedures for Method A - Strain method of rectangular specimen 8 Test report for Method A - Strain method of rectangular specimen 9 Apparatus for Method B - Bending test method of rectangular specimen 10 Specimen for Method B - Bending test method of rectangular specimen 11 Test procedures for Method B - Bending test method of rectangular specimen 12 Test report for Method B - Bending test method of rectangular specimen 13 Apparatus for Method C - Strain method of tapered specimen 14 Specimen for Method C - Strain method of tapered specimen 15 Test procedures for Method C - Strain method of tapered specimen 16 Test report for Method C - Strain method of tapered specimen 17 Apparatus for Method D - Strain method of dumb-bell shaped specimen 18 Specimen for Method D - Strain method of dumb-bell shaped specimen 19 Strain condition for Method D - Strain method of dumb-bell shaped specimen 20 Test procedures for Method D - Strain method of dumb-bell shaped specimen 21 Inspection method of surface cracking 22 Evaluation method of the test result 23 Precision and bias Annex A (Informative) Comparison between clause numbers in this standard and those in ASTM D 518:1999 Annex B (Informative) Reference photo of specimen cracking grade