ISO 812-2017 pdf free download

ISO 812-2017 pdf free download.Rubber, vulcanized or thermoplastic Determination of low-temperature brittleness
Caoutchouc vulcanisé ou therinoplastique — Determination de Ia fragilité a basse tern pérature.
8.1.1 Bring the bath or test chamber to a temperature below the expected lowest temperature of non-failure. In the case of a liquid heat-transfer medium, place sufficient liquid in the bath to ensure approximately 25 mm depth or more of the liquid over the test piece(s). Pre-cool the test piece clamp by immersing it in the cooled bath or test chamber.
8.1.2 Quickly mount the test piece(s) in the test piece clamp and immerse them for 5 mm at the test temperature when using a liquid medium or for 10 mm when using a gaseous medium (see also
ISO 23529).
NOTE 1 For very soft materials, it might be necessary to use a device to support the test piece horizontally until just before the striker is released.
‘[he free length of the test piece(s) shall be greater than 19 mm.
Test five type A or type B test pieces. If the available striking energy has the minimum value specified in 4.1.2. they may all be tested at the same time.
Proper tightening of the clamp is of the utmost importance. The clamp shall be tightened so that each test piece is held with approximately the same clamping torque.
NOTE 2 It has been reported that the temperature at which a test piece fails can be affected by the clamping torque. Clamping to a torque of 0,15 Nm to 0,25 Nm is suggested.
8.1.3 After immersion for the specified time at the test temperature, record the temperature and deliver a single impact blow to the test piece(s).
8.1.4 Remove the test pieces from the test piece clamp and allow them to reach standard laboratory temperature. Examine each test piece to determine whether or not it has failed. Failure is defined as any crack, fissure or hole visible to the naked eye or complete separation into two or more pieces. Where a test piece has not completely separated, bend it to an angle of 90° in the same direction as the bend caused by the impact. Then, examine it for cracks at the bend.ISO 812-2017 pdf free download.