Oxygen permeation through plastic films can play an important role in many applications, for example for food packaging. Knowing the oxygen permeability of a polymer film/substrate is therefore crucial to prevent unwanted effects. However, oxygen permeability values found in literature vary a lot, as the permeability strongly depends on several factors such as polymer production and processing method, polymer orientation, temperature and the measurement setup applied. Therefore, there is a high demand of building custom measurement set-ups for the determination of oxygen permeability values.
PyroScience oxygen sensor spots are an ideal tool for the determination of polymer oxygen permeation, because they enable contactless measurement and therefore minimize contamination inside a measurement set-up from outside.
A possible measurement setup is shown in Fig.1. Here, a single cell is used with atmospheric oxygen pressure as feed pressure. The cell is flushed with e.g. nitrogen gas to decrease oxygen concentration inside the measurement cell and to generate a concentration difference across the polymer foil. After flushing, the oxygen increase caused by oxygen permeability of the polymer substrate is measured using PyroScience TROXSP5 trace oxygen sensor spots, optimized for measurements at low oxygen contents. The slope of the oxygen increase over time can then be used to calculate the oxygen permeability.
Applicable Sensor Types and Products
- Oxygen Sensor Spots (OXSP5) for contactless read-out