barrier film.ppsx

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)

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

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

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

Typical barrier film applications Deep-draw packages for: meat sausage cheese fish bakery products etc. ,[object Object]

Deep-drawing film (base film, tray film)‏

Sealing layer, sealing layer properties,[object Object]

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

barrier film.ppsx

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