Temperature Retraction Testing
Temperature retraction testing with ASTM D1329 gives you valuable information about crystallization and the viscoelasticity of your product at low temperatures. The method quickly evaluates these properties through a temperature retraction procedure.
What happens during a temperature retraction test? During this test method, a sample is elongated, then locked into the elongated position for testing. Then, the sample is frozen to a state of reduced elasticity. Then, the frozen sample is released and allowed to retract on its own, as the temperature rises steadily. Then, ACE measures the length of the sample at regular intervals as it retracts and thaws.
Finally, we calculate the percentage retraction from the obtained data. Two of the most important calculated measures in this test method are TR10 and TR70, which help with the determination of the temperatures which correspond to ten percent and seventy percent retraction.
The tendency of a sample to crystallize
ACE will provide expert recommendations based on years of expertise related to your product’s properties, informed by the data collected by temperature retraction testing.
The information you learn from ASTM D1329 is especially useful when analyzed alongside other cold test methods, like ASTM D746 and ASTM D2137–also available at ACE.
Brittleness Point Testing
ASTM D746 and ASTM D2137
Brittleness point testing examines the flexibility of materials at low temperatures through a prespecified and specific impact. These methods determine the lowest temperature at which your rubber vulcanizate or rubber-coated fabric will not fracture or crack when the samples are exposed to particular impact conditions.
Here’s how it works: ACE’s expert rubber testing laboratory technicians subject your rubber sample to a single impact. This same impact occurs under specific cold-temperature conditions, which is raised until no failures occur. This point is considered the brittleness temperature for your material.
Several test methods can be achieved with these standards, including:
- What is the lowest temperature at which rubber vulcanizates will not fracture or crack?
- What is the lowest temperature at which rubber-coated fabrics will not fracture or crack?
- At what temperature do fifty percent of samples fail? (50% brittleness temperature)
- Brittleness testing of materials from a supplier for classification and specification purposes.
However, these test methods do not necessarily determine the lowest point at which a product may be used. Instead, they are popular for research and development purposes. They are also useful for compliance testing: ACE can perform a simple pass/fail brittleness test at a specified temperature.