LINK TO THE ORIGINAL PAGE  CACHED IMAGE 22/10/2007  SAFE FOOD PACKAGING PORTAL 
getting started notations list of inputs parameter form FV MONOLAYER FV MULTILAYER
QSPRMS WEBSERVER
MULTILAYERS: 1D DESORPTION SIMULATION STANDARD FINITE FORMULATION FOR MULTI GEOMETRIES (v. 1.05)
Notations: (dimensionless equations are detailed here)
NAME  DESCRIPTION 

_F or layer 0

food or food simulant 
_Pi

layer i of plastics or polymer (layer 1 is in contact with F) 
_FP 
ratio in F and in P 
M

migrant or diffusant 
0

initial 
slab

sheet or planar packaging (most common) 
cylindrical

cylinder (L_FP gives the internal radius) 
spherical

sphere (L_FP gives the internal radius) 
List of input parameters (geometry, thermodynamics, transport, initial concentration, contact time)
NAME  PHYSICAL PROPERTY / UNITS / MAIN ASSUMPTION / SAFE VALUE 

l_Pi

thickness of the layer i [ SI unit = m)]  ONE SINGLE SIDE CONTACT No safe value (must be measured) 
L_FP

mass dilution factor [SI unit: kgF/kgP)]  NO
SIDE EFFECT (1D TRANSPORT) No safe value (must be measured) >>3D»1D approximations 
rho_ 
density [SI unit: (kg/m³)  since ratios of density are used, other units are also possible]
 NB: k_ and rho ARE USED AS k_/rho_ No safe value (must be measured) 
k_F k_Pi 
phenomenological coefficient (Henry like coefficients, such that the partition coefficient between i and j is
K_ij = kj /ki [SI unit: (kgM/kgj)/(kgM/kgi)]
Safe choice = k_Pi>1000.k_F (almost complete extraction at equilibrium) >>How to handle uncertainty on k values 
D_Pi

diffusion coefficient in Pi [SI unit: m²/s]  THE FOOD/SIMULANT DOES NOT INTERACT WITH THE POLYMER Safety value = must be [over]estimated or measured at a temperature higher than the conditions of use. 
Bi

dimensionless mass Biot number [no unit]  EXTERNAL
MASS TRANSFER RESISTANCE DUE TO FOOD TEXTURE/ABSENCE OF STIRRING/MASS TRANSFER IN FOOD Safety value = 1000 (almost no external mass transfer resistance) 
C0_Pi

initial concentration in Pi [SI unit: kgM/kgP]  ASSUMES AN HOMOEGENOUS AND UNIFORM INITIAL CONCENTRATION IN THE LAYER _Pi Safety value = 5000 ppm >>maximum recommended concentrations 
t

contact time [SI unit s]  NO REACTION AND NO MASS LOSSES DURING DESORPTION Default value = 10 days (use the maximum shelf life combined with the maximum storage temperature) 
©2007 by INRA\Olivier Vitrac