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Variations in thickness along the sample

Variations in thickness along the sample
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Variations in thickness along the sample - 1

Variations in thickness along the sample Question: Our film may have some variations of thickness along If you're looking for a very good generic source of innate the sample. Is there any correction factor that can be transmission rate/permeability data, we recommend a taken into account, or should we use a micrometer to book that is published by the Plastics Design Library. cut out samples with the lowest variability http://www.ebook3000.com/Permeability-Properties-Is there a calculator where we could plug in the material of-Plastics-and-Elastomers--A-Guide-to- Packaging- and thickness and out comes the standard WVTR for and-Barrier-Materials-by-Liesl-K--Massey_127495.html that material? Permeability Properties eiI Hwiiiei ,um| Eio.'ilaners IOMvnav4mbiiB Uuurdi Second EdlliQD Recommendation: Recommendation from Joel Fischer MOCON's lab manager in our corporate office in Minneapolis, Minnesota. Innately, our testing measures the water vapor passing through the test material. We then normalize this to a standard sample area (m2 and 100in2 are the most popular). The thickness absolutely plays an important role in the transmission rate of the sample. I don't really know of a correction factor for materials that have uneven thicknesses. The best that can be done is to average the thickness of the sample that was analyzed and then normalize the transmission rate results to a standard thickness (usually 1 mil or 1mm, depending upon if you're using metric measurements or not). This normalized data is known as permeation data. As for a permeation calculator, there are some out there that can be Googled. They may or may not get you a "ballpark" estimate. I've seen issues with some theoretical models, because they focus upon molecule size, but do not account for permeant/polymer affinity/interaction. An example is that CO2 transmission rates are almost always 5X higher than oxygen transmission rates, even though CO2 is a larger molecule. It's the polar nature of CO2 (and likewise with H2O) and their higher solubility (i.e. absorption) within most materials, when compared to oxygen, that yield a higher net transmission rate. mocorr Minneapolis, MN 55428 USA Phone: 763.493.6370 Fax: 763.493.6358 www.mocon.com

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