Training day on program SML

1
Training day on program SML

• Exercises
• 5.12.2007

2
Exercise 1

• Additive migration from a monolayer sheet
• Goal searching data base, understanding
  temperature effect, introduction to partition
  coefficient

3
Packaging geometry and layer properties
Packaging LDPE, monolayerV 1000 cm3 S 6 dm2
thickness 0.5 mmconc. 1000 ppmMW 531 Da
Additive Octadecyl 3-(3,5-di-ter-butyl-4-hydroxyp
henyl)propionate CAS 002082-79-3
4
Problems

1. Approximate the diffusion coefficient at 20, 40
   and 80 C
2. Calculate the time tc to reach the SML of 6 mg/kg
3. What is the apparent effect of the partition
   coefficient K on tc (compare K 1 and K 10)

5
2
3
1
6
4
7
(No Transcript)
8
K10
9
Solutions
High K (low solubility in food) increases time to
reach SML
10
Exercise 2

• Soft drink contamination by a pigment degradation
  product
• Goal apprehend untypical geometry with
  surface/volume ratio

11
C.I. Pigment Red 53
Extrusion at temperature gt 150C produces
b-naphtol
12
Measured concentrations
article
concentration
1 mg/kg
closure HDPE
b-naphtol
190 mg/kg
masterbatch HDPE

1. Define the simulation geometry for a 1 litre
   bottle
2. Approximate D at 20C (MW 144 g/mol)
3. Calculate the concentration of contaminant after
   100 days
4. Concentration in soft drinks was measured at 0.3
   mg/kg conclusion ?

13
2
Closure diameteris 3 cm
3
1
Surface of closure is onlyone part of package
total surface !!
14
1
thickness of closure
2
b-naphtol is quite soluble in water
3
Approximate the diffusion coefficientfor a MW of
144 Da in HDPE
15
Select experimental T
Define MW
Selectpolymer
D is automatically calculated
16
(No Transcript)
17
Solution Q4
The measured concentration of 0.3 mg/kg cannot be
reached with a concentration of 1 mg/kg in the
closure. To get such a concentration in soft
drink, the starting concentration of ß-naphtol
should be gt 200 mg/kg in the HDPE closure. This
indicates that the closures that contaminate the
soft drinks were more contaminated than the ones
that were measured. The HDPE closures and
masterbatch were sent by the producer months
after the soft drink analysis. Probably,
ß-naphtol was lost during this storage time
(volatility of the molecule).
18
Exercise 3

• Degradation of a clarifying agent in
  polypropylene
• Goal designing multilayer packaging, defining
  temperature profile

19
in polymer 2000 ppm
in food (fresh ananas pieces in juice) 200 ppb ?
cherry taste from 100 ppb
20
Simulation parameters

• Geometry spherical segment (H5, R3, D7, d4
  cm)
• Multilayer PP-EVOH-PP (thickness 90, 10 and 200
  µm)
• DPP Ea 48.6 kJ/mol, D0 0.4 cm2/s
• DEVOH approximate as PA (polyamide) (MW
  tolualdehyde 121 Da)
• Assumption tolualdehyde is 10X more soluble in
  EVOH than in PP
• Concentration in the food contact layer (200µm)
  is 20 mg/kg

21
Problems

1. Estimate migration in food for a 3 days shelf
   life at 5C
2. Compare multilayer and monolayer packaging
3. Estimate effect of hot filling (100C, 10 min
   cooling to 5C) on the migration

22
(No Transcript)
23
2
Define layers thickness, diffusant concentration
in each layer and partition coefficient for each
interface
4
1
Enter the Arrhenius parameters for the two PP
layers
3
24
5
4
25
3 layers 3 days at 5C ? migration is 0.146
mg/kg 1 layer (PP, 200 µm) 3 days at 5C ?
migration is 0.151 mg/kg
26
(No Transcript)
27
3 layers Hot filling 3 days at 5C ? migration
is 0.150 mg/kg 1 layer (PP, 200 µm) Hot filling
3 days at 5C ? migration is 0.163 mg/kg