1. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Barrier Films :
Co-extruded EVOH film and
Polyester-Metallised
film
for Bag-In-Box application

2. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Poly Ethylene (PE) (
CH2 )m )n CH OH
Ethylene Vinyl Alcohol Copolymer (EVOH)
Poly Vinyl Alcohol (PVA)
Extrudability
Gas Barrier
: C
: O
: H
Structure of EVOH

3. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Coextruded EVOH Film Manufacture
Reels of coextruded film
Binding
(PE based) agent
Polyethylene
Bubble
EVOH
Polyethylene
Blowing
Heating
Polyethylene
EVOH
Binding agent (PE)

4. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Structure & Manufacture of Metallised Polyester (METPET)
- First Part: Metallization -
Reel of Polyester/polyethylene
(Co-extruded film)
Reel of Polyethylene Metallised polyester
Cooling cylinder
Aluminium vaporization
under vacuum

5. Comparison EVOH & METPET
Smurfit Bag-in-Box
Comparison EVOH & METPET
Structure & Manufacture of Metallised Polyester (METPET)
-2nd Part: lamination
Reel of Polyethylene Film
Reel of Polyester Metallised Polyéthylène
Adhesive agent
Reel of Polyethylene Metallised Polyester Film laminated with Polyethylene Film
Binding Cylinder
Adhesive agent
Reel of Polyethylene film
Binding Cylinder

6. Comparison EVOH et METPET Films
Smurfit Bag-in-Box
Comparison EVOH et METPET Films
EVOH Film is made through a co-extrusion process that links the polyethylene,
the Tie Layer (modified PE) at the same time.
This means that the polyethylene and EVOH are extruded simultaneously.
Due to that, the cohesion of this two materials is excellent.
Metallised Polyester Film is made by lamination,
The process requires three stages. We need to get first three films made by extrusion
(2 polyethylene films and the polyester film independently)
Then we have the vacuum-metallization of the aluminium on the polyester layer.
This operation is very delicate because a very poor layer of aluminium is deposing
on the film. This thin deposit is very fragile and can break very easily.
The last stage consists of laminating these tree layers by sticking them together
with some adhesive: this operation is delicat and can be critical to the quality
of the film.

7. Smurfit Bag-in-Box Comparison EVOH et METPET Films
CHARACTERISTICS OF BARRIER FILMS FOR BAG IN BOX
Dynamic perforation resistance
Elongation
Properties
Food contact agreement
Oxygen
Barrier
Antistatic
Properties
Sealing
Properties
Flavour
Barrier
Oxygen Barrier after transport
Seal Strength
Temperature
Resistance
Multilayer
Sliperiness

8. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Mechanical characteristics
No transport
After 400 Gelboflexes
(= 400km)

9. Smurfit Bag-in-Box
EVOH film is a ‘flexible’ film. All the elements of the structure are polyethylene
and all therefore are ‘soft’ when compared to polyester. In addition, the oxygen
barrier of the film comes from an EVOH copolymer which is an extruded layer
in the film, rather than a layer of metal randomly deposited onto a film.
As a result of the ‘flexibility’ of the film and the manufacturing process of the
barrier layer, the film is very resistant to the rigours of transportation and
the ‘flex-cracking’ of the film which can result. It is this ‘flex-cracking of film
which at its worst leads to pinholing in the film and leakers.
Whilst the oxygen permeability rate of a piece of virgin EVOH may be slightly higher (say 1.2 cc compared to 1 cc/m²/day) than metallised polyester laminate,
laboratory tests, pallet vibration tests, transportation tests and many years
of experience show EVOH film to be more resistant to flex-cracking than
metallised polyester laminate, particularly over long distances.
Attached are two charts showing the results of some laboratory work which give
an indication of how EVOH film compared to metallised polyester laminate
when subjected to flex-cracking.

10. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Influence of Gelbo Flexing on Oxygen Transmission Rate
(100 Cycles = 80 km)

11. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
The following curves show the results of a study made by the « Institut coopératif du vin de Montpellier » and the Institut Œnologique de Champagne.
So2 Levels (Free & Total) has been analysed on bag-in-box made with the same inner ply, and a different outside linner (EVOH & PETMET) filled with red wine, either tranported or not.
These analyses reflects the level of the wine oxydation.
N.B.: You will notice that analyses made on transported are more heterogeneous due to mechanical alterations.

12. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Influence of different barrier Films on SO2 Levels
(No transport)
Total SO2
Free SO2

13. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Influence of different barrier Films on SO2 Levels
(With transport)
SO2 Total
SO2 Libre

14. Comparison of EVOH & PETMET Films
Smurfit Bag-in-Box
Comparison of EVOH & PETMET Films
Various
MET- PET:
1) Opacity/ metal aspect:
can protect un-packed bag-in-box from light
Can « hide » the product inside the bag
Can Give a « richer » aspect
2) Environment:
Waste can be incinerated, but it should be done in a smokeless (toxic gazes) incinerator to ensure complete combustion
Metal wastes in the ashes
EVOH:
1) Transparency:
No foreign body
No trapped air
Can check for discolouration and any quality defects in the product.
2) Environment:
Waste can be incinerated (No toxic gaz emission
No metal presence in the ashes

15. Comparison EVOH et METPET Films
Smurfit Bag-in-Box
Comparison EVOH et METPET Films
Point on Primary aromatic amines
(New 20001/62/EG Amendment to the 90/128/EG Directive)
Our Films in contact with the products fulfill the actual EEC/FDA regulations
N.B.:
Recent reports in the Danish Press has focus attention on the levels of Primary aromatic amines (PAAs) in multi-layer flexible laminates.
Aromatic amines (which seem to be linked to cancer) can be produced when any isocyanates (used in some Polyurethane based adhesive) react readily with moisture or any residual alcohol solvents from printing inks…
Sixth amendment (2001/62/EEC) to 90/128/EEC directive has introduced a limit of 20mg/kg foodsttuff for PAAs.
Polyurethane is never used in the process of co-extruded film (EVOH film)
 Some laminating Processes are using adhesive with high levels of isocyanates.