What is the driving force for gas permeation?
Gas permeation is focused on the separation of gases by permeating selectively one component of the gas mixture. The permeate is also a gas phase and the driving force is achieved by the difference of pressures at both sides of the membrane.
How is OTR calculated?
OTR can be calculated by measuring the recov- ery speed of the dissolved oxygen (DO) in the vessel after sodium sulfite depletion. To further establish this as a proof of principle, we used the BioFlo 320 3 L glass vessel as the experimental device to define the parameters of the OTR.
What is permeability in food packaging?
In contrast to glass or metal packaging materials, packages made with plastic are permeable at different degrees to small molecules like gases, water vapour, and organic vapour and to other low molecular weight compounds like aromas, flavour, and additives present into food.
What is permeation rate?
Flux (or permeation rate) is the volumetric mass flow of fluid passing through the membrane per unit area of membrane and unit mass time.
What does a high permeability coefficient mean?
As given above, the coefficient of permeability is the rate at which fluid can flow through a porous membrane (lipid bilayer) under unit pressure and volume. Thus, for a high coefficient permeability, the rate of flow of fluid will be high.
What is the gas permeability rate?
The gas permeability rate is the volume of the gas which passes through unit area of specimen in a unit time; it is determined by the barrier property of the material and the partial pressure difference between two sides of the specimen.
What is the rate of transmission of gas?
Gas transmission rate: The volume of gas which, under steady conditions, crosses unit area of the sample in unit time under unit pressure difference and at constant temperature. The rate is usually expressed in cm 3 /m 2 ·d·atm. There are two descriptions of permeability parameters in GB/T 1038-2000:
What are the British Standards for gas permeability tests?
Although there are no British Standards for gas permeability tests, a method by which the flow of air is used to determine the intrinsic permeability of rock is available in ASTM Standard D 4525-85. [126] A permeameter similar to that shown in Fig. 16 can be used to carry out the steady state gas permeability test.
What is permeability of gas in plastic?
Gas permeability (P): Volume of gas passing through a plastic material of unit thickness, per unit area and unit time, under unit partial-pressure difference between the two sides of the material. P is expressed in mole metres per square metre second pascal [mol·m / m 2 ·s·Pa].