Testing of plastics in compliance with current standards
In our laboratory, we can carry out measurements completely independently on test pieces made of plastic products and plastic compounds. Our laboratory facilities include a DSC device for determining OIT, transition temperatures, melting and crystallization phenomena. As part of a regular quality control or part of a (residual) lifetime study on PE (polyethylene) products, we can carry out the OIT measurement in accordance with NEN-EN-ISO 11357-6 entirely in-house and under accreditation.
The abbreviation OIT stands for oxidation induction time. An OIT measurement is a standardized test in which the time to oxidation at a constant temperature in the oxygen environment is determined on the basis of the heat released during oxidationreaction. DSC (differential scanning calorimetry) is a method to accurately perform a differential heat measurement per unit of time. The oxidation of PE material starts after the thermal stabilizer has been consumed. The period between switching from nitrogen environment to oxygen environment and the start of oxidation at the constant temperature, standard 200 °C, is the OIT value and is calculated from the DSC measurement curve.
An OIT measurement is carried out in our laboratory mainly on PE products such as tubes and geomembranes to determine (remaining) resistance to oxidation. In combination with exposure in water and air at elevated temperature, the measurement is used in other areas to determine the (residual) service life; for example, for validation of one hundred years. The OIT measurement gives a quick indication of the remaining stabilization against oxidation.
