Rubber, vulcanized or thermoplastic —
Determination of flex cracking and crack growth (De mattia)
Warning: the personnel using this standard shall have practical experience in regular laboratory work. This standard does not purport to address all of the safety problems. It is the responsibility of the user to establish appropriate safety and health practices and guarantee compliance with the appropriate national laws and regulations.
1 Scope
This standard specifies the test method for flex cracking and crack growth of vulcanized rubber or thermoplastic rubber by using Demesia type testing machine.
This Standard is applicable to the determination of the resistance of flex cracking and crack growth when subjected to repeated flexing of vulcanized rubber or thermoplastic rubber. For determination of the property of resistance of crack growth, an artificial cut is made in the test piece to initiate cut growth.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, 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 edition of the document referred to applies.
GB/T 2941 Rubber-Standard temperatures, humidities and times for the conditioning environmental and testing of test pieces (GB/T 2941-1991, eqv ISO 471:1983)
GB/T 9868 Rubber-General directions for achieving elevated or subnormal temperatures for test purposes (GB/T 9868-1988, idt ISO 3383:1985)
GB/T 9865.1 Rubber, vulcanized or thermoplastic-Preparation of samples and test pieces — Part 1: Physical tests (GB/T 9865.1-1996, idt ISO 4661-1:1993)
3 Apparatus
3.1 De Mattia type machine
The essential features of the De Mattia type machine are as follows:
Dimensions in millimeters
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Apparatus
4 Test pieces
5 Test conditions
6 Procedure
7 Expression of results
