Barrier films protect packaged products from: 1) Moisture exchange which can cause drying out or absorption of moisture. 2) Oxygen permeation which can cause microbiological spoilage through oxidation. 3) Exchange of carbon dioxide and aroma compounds which can affect the protective gas environment or smell of the product.

1. Barrier films protect against Exchange of moisture- Protection against drying up (e.g., bakery products)- Protection of hygroscopic products (e.g., milk powder) Oxygen permeation- microbiologic spoilage (oxidation of greases, flavors, etc e.g., bakery products, nut products, ready-to-serve meals) Emerging of CO2- change of protective gas type- undesired vacuum effect (e.g., with bakery products, meat products) Exchange of aroma- loss of aroma from the product packaged- assuming a different smell (e.g., coffee, spices, washing agents)

2. Oxygen Permeability of different Polymers Standard konditions 23°C, dry

3. Oxygen Permeability of EVOH Verbund: PE/ HV/ EVOH/ HV/ PE

4. EVOH = Ethylen Vinyl Alkohol Copolymer Handelsname: Soarnol (Nippon Gohsei), EVAL (Kuraray)‏ Gas Barriere Resin ( z.B.: O2, CO2...)‏ High Oil- Resistance High Transparency Charakteristic is the ethylen content of EVOH 104 103 Oxygen Permeability (cm3 20µm/ m2 24 h Pa)‏ 102 101 100 10-1 100 0 Ethylen content [%] Ethylen content [%] Improvement of processability Function of ethylen: Improvement of water resistance

5. Structure of Barrier Films

6. 5- Layer- Barrier Films

8. Deep-drawing film (base film, tray film)‏

9. Shrink, reshrink

11. Heat-Sealing of Deep-Drawing Films Sealing heat is applied from above ! standard: 130 -140 °C ( 1,5 sec)‏ faster: 140 -150 °C (<1,5 sec)‏ PA HV PE Lid film (70-120 µm)‏ A temp. difference at the melt.point isrequired to prevent film sticking tothe sealing jaw ! Barrier layer Sealing layer (LDPE, LLDPE, EVA, mPE, Surlyn)‏ asymmetric ! PE HV PA HV PE Tray film (150-350 µm)‏ Symmetric structure possible, since forming part issilicone coated ! Silicone coated

12. Barrier film for foam trays Barrier lid film Seal Legend:A - heat-resistant layerB - tie layerC - gas barrierB - tie layerD - sealing layer Barrier tray

13. CONTACT US Express Plaspack (Thailand) Co.,Ltd 1480 Moo 9 Old Train Road, Teparuk, Muang, Samutprakarn, 10270, THAILAND Tel. (66 2) 755-0778, 755-0757, 757-9099 Fax. (66 2) 755-0730 Email : sales@expressplaspack.com