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United States Department of Agriculture

Agricultural Research Service

Film Permeability
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1 - Film Index
2 - Film Table
3 - References
Film Table
 
Table 1. Mass transfer and sorption coefficients for fumigants diffusing through plastics at 20 °C, measured using triplicate static permeability cells ± standard error of the estimate. Values for α and kp in parenthesis are determined independently using Eq. 16 and 17; values of h in parenthesis are determined by nonlinear regression with these values of α and kp fixed.
 
  Methyl Bromide Propargyl Bromide Chloropicrin
1-mil HDPE
h (cm h-1) 0.37±0.02 1.48±0.08 0.65±0.06
α (h-1) 0.5±0.4 0.4±0.2 0.9±0.3
kp (cm) 0.3±0.1 1.2±0.02 1.8±0.2
4-mil black HDPE
h (cm h-1) 0.14±0.01 0.48±0.02 0.25±0.03
α (h-1) 0.21±0.09 0.13±0.04 0.32±0.06
kp (cm) 1.3±0.2 1.3±0.2 3.8±0.3
silver mylar†
h (cm h-1) <4.4×10-6 <1.3×10-5 <2.3×10-4
α (h-1) 2.1±0.9 1.2±0.4 0.8±0.3
kp (cm) 1.09±0.07 5.2±0.4 11±2
 
†No permeation through the film detected; reported h is based on detection limit and Eq. 18. Regression to model to determine α and kp fixed h at the detection limit and C0 at 100%.
 
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Last Modified: 11/4/2009
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