Characterizing plastics and composites under varying temperature degrees can be a demanding task. When pushed to the limits of their service temperature range, the performance of plastics and composites becomes less predictable and reliable in certain applications.
Image Credit: ZwickRoell GmbH Co. KG
Additionally, they become rigid and less ductile in low temperature environments and can become either soft or too brittle in high temperature environments.
The right test setup is critical for testing plastics and composites. Many companies and universities looking for a solution are initially not aware of how important it is to use a high-performance video extensometer that can be completely integrated into a well-engineered temperature chamber. The right equipment can greatly improve measurement accuracy and reliability of the test results.
Dr. Mehdi Dargahi, Regional Sales Manager for Canada., ZwickRoell in North America.
What are the key factors contributing to precise and dependable test results when characterizing plastics and composites?
The Temperature Chamber Must Facilitate Error-free Integration of the Extensometer without Impacting the Precision of the Measurements and Resolution of the Extensometer
ZwickRoell’s innovative air-feed system ensures excellent airflow and consistent temperature distribution throughout the whole chamber, with only ±1°C of temperature deviation in the entire testing area.
This ensures optimization of the measurement resolution and class accuracy when ZwickRoell extensometers are utilized with the temperature chamber.
Mounting the Extensometer Must be Performed in such a Way that it has a Direct view into the Test Area, with No Obstructions
ZwickRoell’s videoXtens extensometer is mounted on the chamber’s side, providing a considerable advantage over test setups where the extensometer is positioned at the front of the door, meaning each time the chamber is opened, the device must be moved.
In such instances, front mounting of the extensometer leads to a field of view (FOV) that is constantly shifting perspective. This can result in measurement inaccuracies and potentially damage the equipment.
By way of comparison, ZwickRoell’s extensometers follow the specimen via the connection to the crosshead at half crosshead speed, maintaining automatic focus of the testing operation, providing optimum FOV and making best use of the measuring range.
The Extensometer Needs to Possess a High Accuracy Class and Resolution at Various Testing Temperatures
Testing per standards such as ISO 527-1 demands a high resolution (e.g., <1 µm) for strain measurement.
ZwickRoell’s extensometers, such as videoXtens 2-120 HP, are some of the only extensometers that are in total compliance with these requirements and provide a unique resolution of 0.4µm at +250°C, generating considerably more accurate test results in contrast to traditional video extensometers with a low resolution of 5µm or below.
When combined with ZwickRoell’s temperature chamber, videoXtens is an exceptional choice for composites and plastics testing necessitating a level of accuracy that cannot be matched by other non-contact extensometers.
Testing with both typical and atypical specimens means testing under varying temperature ranges does not have to be complicated when using the right test equipment.
Temperature chambers from -80°C to +250°C
Video Credit: ZwickRoell GmbH Co. KG
This information has been sourced, reviewed and adapted from materials provided by ZwickRoell GmbH Co. KG .
For more information on this source, please visit ZwickRoell GmbH Co. KG