ISO 812 Rubber, Vulcanized or Thermoplastic - Determination of Low Temperature Brittleness

The ISO 812 standard, published by the International Standards Organization (ISO), defines a test method for determining the lowest temperature at which rubber materials do not show brittle deterioration, or the temperature at which half of the test pieces used in a test fail when impacted under certain conditions. The temperatures determined in this way are not necessarily related to the lowest temperature at which the material can be used, as brittleness will be affected by test conditions and particularly the impact rate. Therefore, the data obtained with this test method are only used to predict the behavior of rubbers at low temperatures in applications where deformation conditions are similar to those specified in the test.

Three test methods are described in the ISO 812 standard:

• Procedure A: Determination of brittleness temperature
• Procedure B: Determination of brittleness temperature for 50 percent fracture
• Procedure C: Affecting the test piece at a certain temperature

Procedure C is used for classification of rubber materials and for specification purposes.

For the purposes of the ISO 812 standard,

• The brittleness temperature refers to the lowest temperature at which none of a set of test pieces breaks due to low temperature embrittlement when tested under the specified conditions.
• The expression 50 percent brittle temperature refers to the temperature at which 50 percent of a set of test pieces breaks due to low temperature embrittlement when tested under the specified conditions.
• The test velocity expression expresses the relative linear velocity at the moment of impact between the impact edge of the tester and a clamped test piece.
• Failure refers to any crack, hole, or complete breakup into two or more parts that are visible to the naked eye.

Briefly, the test method detailed in this standard is used to evaluate the brittleness of rubber materials or rubber-coated fabrics when subjected to low temperature flexing. The tests performed are used to determine the lowest temperature at which rubber compounds will not break or crack in the coating when exposed to specified conditions.

Among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, our organization also provides testing services for the determination of low temperature brittleness of rubber, vulcanized or thermoplastic materials, within the scope of ISO 812 standard, with its trained and expert staff and advanced technological equipment.