The identiPol OIT
UK designed & manufactured
What is it?The lifetime of a plastic component is mainly governed by its ability to withstand oxidation and degradation. When exposed to the oxygen in the air that we breathe, plastics age and degrade over time, losing mechanical strength and leading eventually to component failure.
The lifetime of a plastic can be increased by appropriate polymer chemistry or by adding additives (antioxidants) to the plastic during processing. Generally, the lifetime is greater for materials having a higher molecular weight, although performance of lower specification plastics can be enhanced with anti-oxidants. However, as these additives are more expensive than the plastic granules, a balance is sought between cost and performance. The OIT test is frequently used as an indication of sufficient molecular weight, but in such cases it must be clear whether materials are tested with or without anti-oxidants.
The identiPol OIT is designed to provide unskilled staff with a simple tool to measure the oxidative stability of a plastic using the internationally recognised Oxidative Induction Time/Oxidative Induction Temperature (OIT) method. The system has been specifically designed to conform to approved standards (ASTM D3350, D3895-07, DIN EN 728, ISO 11357-6) and be operated alongside the production line by semi-skilled staff.
What does it do?There are two modes of operation for the identiPol OIT:
Oxidative Induction Time
In this mode a sample of plastic is heated in an inert atmosphere (typically nitrogen), to a given temperature appropriate for the type of plastic. (For example, PE would be heated to 210°C). The temperature is held constant and when the temperature reaches a stable value, the gas is switched automatically from nitrogen to air. The time elapsed from the switch in gases to the moment the plastic starts to oxidise and decompose defines the Oxidative Induction Time.
Oxidative Induction Temperature
In this mode a sample of plastic is heated in an atmosphere of air, at a constant heating rate, until the plastic starts to oxidise and decompose. The onset of this decomposition reaction defines the Oxidative Induction Temperature.
How does it work?When a plastic material undergoes oxidative degradation, heat is evolved. By measuring the temperature of the plastic and comparing it to the temperature of its nearby surroundings, a temperature difference can be measured when the plastic starts to oxidise.
Test samples are first moulded within the identiPol OIT to produce a consistent sample for measurement. The test sample is then heated up while the temperature difference of the sample is compared to an inert reference temperature. The temperature difference is then measured as the plastic is heated or held at a constant temperature.
Either the heating stops at a given temperature to measure Oxidative Induction Time, or continues to measure the Oxidative Induction Temperature. A rapid increase in the temperature difference between the plastic sample and the reference is used to indicate the onset of oxidation and decomposition.
At the end of the measurement the plastic sample is discarded and the built-in software calculates and stores all relevant information. A certificate of OIT conformance can be printed and used as part of your, or your customer's, quality control process.
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We will test your samples and one of our team will contact you to arrange a demonstration.
Download the OIT brochure
- Prevent incorrect material entering production
- Reduce scrap and wastage
- Both Oxidative Induction Time and Oxidative Induction Temperature determined automatically
- Simpler to use than a Differential Scanning Calorimetry (DSC) for unskilled operators
- Eliminate the need for expensive DSC equipment
- Reduce expensive additives whilst maintaining product quality
- Air is used avoiding the risk and cost involved with using oxygen
Secure your reputation
- Provide material that conforms to international standards
- Confirm formulation prior to moulding or dispatch
- Provide 'Certificate of Conformance' to your customers