ISO 132:2017 pdf download

ISO 132:2017 pdf download.Rubber, vulcanized or thermoplastic — Determination of flex cracking and crack growth (De Mattia)
1 Scope
This document specifies a method of test intended for use in comparing the resistance of vulcanized or thermoplastic rubbers to the formation and growth of cracks, when subjected to repeated flexing on the De Mattia type machine. For determination of crack growth, an artificial cut is made in the test piece to initiate cut growth.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.
ISO 18899:2013, Rubber — Guide to the calibration of test equipment
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
3  Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Apparatus
4.1  De Mattia type machine, the essential features of which are as follows. The machine has stationary parts, provided with grips for holding one end of each of the test pieces in a fixed position, and similar but reciprocating parts for holding the other end of each of the test pieces. The travel is 57 , mm and is such that the maximum distance between each set of opposing grips is 75 mm (see Figure 1). The reciprocating parts are so arranged that their motion is straight and in the direction of, and in the same plane as, the common centreline of each opposing pair of grips. The planes of the gripping surfaces of each opposing pair of grips remain parallel throughout the motion.The eccentric which actuates the reciprocating parts is driven by a constant-speed motor to give 5,00 Hz ± 0,17 Hz, with sufficient power to flex at least six, and preferably 12, test pieces at one test. The grips hold the test pieces firmly, without undue compression, and enable individual adjustment to be made to the test pieces to ensure accurate insertion. It is useful to arrange the test pieces in two equal groups, so that one group is being flexed while the other group is being straightened, thus reducing the vibration in the machine. For testing at elevated or subnormal temperatures, the machine can be enclosed in a chamber with temperature control near the centre of the test piece to ±2 °C, if necessary, by using an air circulator.