PETpla.net Insider 09 / 2020

INSPECTION 49 PETplanet Insider Vol. 21 No. 09/20 www.petpla.net High throughput OTR testing High throughput is always a dominant consideration when test- ing permeation, especially in the QA/QC environment. However, OTR testing of bottles presents some unique challenges. Due to the intricacy of the sensors in the testing instrument, room air and any residual oxygen must be swept out of the bottle before testing can begin. This process can be lengthy without a proper high-flow purge phase. Additionally, traditional permeation measurement devices typically have only two test cells. Based on other testing in the bever- age industry, a much larger sample size is required for QA/QC pro- cesses. Finally, depending on the barrier level of the bottle, OTR tests can take several days to a week to reach equilibrium. Fortunately, instruments are available that offer high-flow purge with eleven bottle stations. Unfor- tunately, the time to equilibrium of any type of OTR test can only be reduced by increasing the tem- perature. While this may be an option in R&D applications, it isn’t an accepted alternative in QA/ QC processes. It is possible how- ever, to reduce the test time and, in conjunction with a high-flow purge and 11-cell instrument, significantly increase throughput. While it is impossible to acceler- ate equilibrium time, with a proper protocol development the time bot- tles are in test may be shortened. During a batch quality OTR analysis, most bottle outliers should manifest in the beginning to middle of the test. However, in order to deter- mine the appropriate amount of time required and to better understand the bottle behaviour, a protocol development study should be con- ducted. This type of study should involve a variety of bottles tests including but not limited to: stand- ard test with high purge (to evacu- ate residual O 2 from the inside the bottle), modified test with extended purge on inside and outside (to evacuate all oxygen from both inside the bottle and within the materials), and standard test with high purge on bottle with known defects. Data from this development study can be used to determine optimal test time for a quality system protocol, insur- ing confidence in the accuracy of the desired bottle parameters. As beverage products continue to diversify, the capacity to measure oxygen ingress, rather than carbon dioxide levels, will become increas- ingly important as an indication of shelf life. Rigorous and accurate testing, along with careful protocol development, will ensure products maintain their quality without jeop- ardising plant productivity. Authored by Michelle Ste- vens, a 24-year veteran and globally recognised technical expert in the barrier packaging industry. Michelle has spent her career working for and consult- ing with many major companies and trade and testing organisa- tions throughout the industry. For the last three years she has lent her expertise exclusively to the technical and sales teams at Systech Illinois. Systech Illinois is an Industrial Physics brand. Systech Illinois offers an 11-cell, high-purge OTR testing system, the 8700 Oxygen Permeation Analyser. The 8700 can measure 11 samples simultaneously - individually started, stopped or delayed. Fixed platens and Turbopurge technology allow for rapid OTR testing of multiple bottles. Systech Illinois’ scientists can aid in developing an 8700 test protocol to create an industry-leading, high- throughput OTR analysis system for QA/QC of beverage bottles. www.industrialphysics.com