Effect of Materials and Assembly Methods on Gas Selectivity of Blow® Device

In the present paper, the effect on gas selectivity using different materials of the patented Blow® device is described. Blow® is an innovative device that allows the bidirectional gas exchange across a sealed package. The device results particularly useful for managing the atmosphere in the package headspace of fruit and vegetables packed in modified atmosphere, with a high level of carbon dioxide or low level of oxygen. The latest device version is produced by assembling two different parts; preliminary tests showed that the device’s material and the assembly procedure affects the gas selectivity of the device. To evaluate the effect of material and welding system on the breathable characteristics of the device, three plastic- (PP, LDPE, ABS) and bio- (Mater-Bi®) based materials and three different levels of welding pressure were used for comparative tests. For each material and test condition, the diffusion of oxygen (O2) and carbon dioxide (CO2) has been measured by the pressure discharging time measured in the range from 400 to 10 Pa of differential pressure from inside to outside of the package.