Presentation on theme: "1 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Barrier Films : Co-extruded EVOH film and Polyester-Metallised film for Bag-In-Box application."— Presentation transcript:
1 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Barrier Films : Co-extruded EVOH film and Polyester-Metallised film for Bag-In-Box application
2 Structure of EVOH Poly Ethylene (PE) (CH 2 ()m)m )n)n CHCH 2 OH Ethylene Vinyl Alcohol Copolymer (EVOH) Poly Vinyl Alcohol (PVA) ExtrudabilityGas Barrier : C : O : H CH 2 ()m)m )n)n CHCH 2 OH ( Smurfit Bag-in-Box Comparison of EVOH & PETMET Films
3 Smurfit Bag-in-Box Coextruded EVOH Film Manufacture Binding (PE based) agent Polyethylene EVOH Binding agent (PE) Polyethylene Bubble Heating Blowing Reels of coextruded film
4 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Structure & Manufacture of Metallised Polyester (METPET ) - First Part: Metallization - Aluminium vaporization under vacuum Cooling cylinder Reel of Polyester/polyethylene (Co-extruded film) Reel of Polyethylene Metallised polyester
5 Comparison EVOH & METPET Smurfit Bag-in-Box Structure & Manufacture of Metallised Polyester (METPET ) -2nd Part: lamination Adhesive agent Binding Cylinder Reel of Polyethylene Film Reel of Polyethylene Metallised Polyester Film laminated with Polyethylene Film Binding Cylinder Reel of Polyethylene film Reel of Polyester Metallised Polyéthylène
6 Comparison EVOH et METPET Films Smurfit Bag-in-Box 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 CHARACTERISTICS OF BARRIER FILMS FOR BAG IN BOX Dynamic perforation resistance Food contact agreement TemperatureResistance AntistaticProperties ElongationProperties Multilayer FlavourBarrier Oxygen Barrier after transport OxygenBarrier Comparison EVOH et METPET Films Smurfit Bag-in-Box Sliperiness Seal Strength SealingProperties
8 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Mechanical characteristics No transport After 400 Gelboflexes (= 400km)
9 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. Smurfit Bag-in-Box
10 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Influence of Gelbo Flexing on Oxygen Transmission Rate (100 Cycles = 80 km)
11 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 Influence of different barrier Films on SO2 Levels (No transport) Free SO2 Total SO2
13 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box Influence of different barrier Films on SO2 Levels (With transport) SO2 Libre SO2 Total
14 Comparison of EVOH & PETMET Films Smurfit Bag-in-Box 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 Various
15 Comparison EVOH et METPET Films Smurfit Bag-in-Box 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. 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