Gas transmission rates of commercially available polyethylene and polypropylene films for modified atmosphere packaging
YaptengcoK.F.,Kim J.G. and Lim B.S.
Philippine Agricultural Scientist, 90(1) p.22-27, 2007.
2007
บทคัดย่อ
Oxygen transmission rates (OTR)of low-density polyethylene (PE) and polypropylene (PP) films were measured at 10,15 and 17 deg C using the whole-bag method of Moyls (2004) for unperforated films. PE films with the normal thickness of 30,40, 60 and 80 micro m (PE30, PE40,PE60, and PE80, respectively) were analyzed; thickness of the PP film was 40 micro m. Oxygen and CO2 transmission rates (CO2TR) of 35-microperforated polypropylene (MPP) were measured at 10, 15 and 17 deg C using the method described by Ozdemir et al. (Ozdemir I, Monnet F., Gouble B. 2005 Postharvest Bio Tech 36:209-213). Temperature effects on unperforated PE and PP films followed Arrhenius Kinetics (R20.970). Activation energy (E sub a)of the PE film had a range of 28.1-35.0 KJ/mol; for the PP film, E sub a was 38.1 KJ/mol. In general E sub a of PE film increased as film thickness (t sub F) increased Q sub 10 Tr values at 10-20 deg C for PE and PP were 1.50-1.66 and 1.74, respectively.Temperature had no definite effect on OTR and CO2TR of MPP. Mean OTR and CO2TR for MPP were 10,848 and 9,554 mL/sq m/d, respectively. The average perforation diameter (D sub mp) and density (d sub mp) was 41.0 micro m and 125 perforations per sq m, respectively, for a 20 cm x 28 cm bag. Comparisons with published data showed the sample film to have gas transmission rates at the lower end of the range for such types of packaging film.