Metallized films (or metalized films) are polymer films coated with a thin layer of metal, usually aluminum. They offer a metallic glossy appearance of aluminum foil with weight and reduced cost. Metallised films are widely used for decorative purposes and food packaging, as well as for specialized applications including insulation and electronics.
Video Metallised film
Producing
Metallization was performed using a physical vapor deposition process. Aluminum is the most common metal used for precipitation, but other metals such as nickel or chromium are also used. The metal is heated and evaporated under vacuum. It condenses on a cold polymer film, which is released near a metal vapor source. This layer is much thinner than a metal foil that can be made, in the range of 0.5 micrometers. This layer will not fade or change color over time. While oriented polypropylene and polyethylene terephthalate (PET) are the most commonly used films for metallisation, nylon, polyethylene and cast polypropylene are also used.
Maps Metallised film
Properties
Metallized films have a reflective silver surface similar to aluminum foil and are highly flammable. This layer also reduces film permeability to light, water and oxygen. The properties of fixed films, such as higher toughness, the ability to heat sealed, and lower densities at a lower cost than aluminum foil. This gives the metallization film several advantages over aluminum foil and aluminum foil laminate. It is thought that the metallization film will be a replacement for aluminum foil lamination, but the current film still can not match the foil retaining properties. Some very high barrier metallization films are available using EVOH, but have not been cost effective against laminate foil.
Usage
Decorations
First branded films are used for decorative purposes as Christmas bracelets, and continue to be used for items such as wrap and ribbons. The metallic helium novelty balloons are given as gifts made of a metallic PACKAGE and are often called Mylar balloons commercially.
Packaging
Both PET and PP plated metals have replaced foil laminates for products such as snacks, coffee and sweets, which require no superior aluminum barrier. Nylon and polyethylene coated metals are used in the meat export markets. Controlled permeability extends shelf life.
Metallised films are used as susceptor for cooking in a microwave oven. An example is a microwave popcorn bag.
Many food items are also packaged using metallized films only for appearance, as these produce packages with greater luster when compared to competing products using printed paper or polymer film.
Isolation
PET films have metals used in NASA's spacecraft to reflect heat radiation, keep astronauts warm, and deep? Clothes proximity? used by firefighters for protection from high amounts of heat released from fuel fires. The aluminized emergency blanket is also used to save the body heat of the shock victims. MPET has been used as an antistatic container for other heat and sound insulation materials used in aircraft, to prevent leakage insulation into the passenger cabin, but is not an isolator in that use.
Electronics
Metallised films are used as dielectrics in the manufacture of the type of capacitors used in electronic circuits, and as an ingredient in some types of antistatic bags.
See also
- Carbon dioxide transmission rate
- Cutting stock issues
- Insulated shipping container
- Humid steam transmission rate
- Permeation
- Popcorn bag
- Oxygen transmission rate
- PET movie (biaxial oriented)
- Sputter Deposition
- Vacuum thinning
References
Further reading
- Soroka, W, "The Basics of Packaging Technology", IoPP, 2002, ISBNÃ, 1-930268-25-4
- Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & amp; Children, 2009, ISBN 978-0-470-08704-6
Source of the article : Wikipedia
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