Coextruded
film is a multilayer film having peelable interfaces. The interfaces
after separation expose a clean non-stacky surface. These peelable
layers are created by multilayer polymer co extrusion. The structures
can be made on conventional film processing equipment. The peelable
interfaces can serve as renewable surfaces, removable coupons, tags, and
cards, carrier webs, opening mechanisms and labels. The multi layer co
extrusion can be designed for one or two side printing, post converting
operation compatibility or for functionality. The layers can be
pigmented or modified with other additives. The bond between the layers
can be adjusted from low to high.
History
In 1985, Golden Eagle introduced coextruded films to bulk bun bakers.
Replacing expensive cast films with co extrusions radically changed the
industry, offering increased shelf life, productivity, and
profitability. Co extrusions, designed to provide lower moisture vapor
transmission rates allow the bakery products to retain freshness longer.
Features
- Cost effective transparent or opaque films
- Have greater puncture resistance
- Reduced tear propagation
- Extra ordinary anti blocking and slip properties
- Excellent moisture resistance
- High seal integrity for longer shelf life
Science of Coextruded Films
Coextruded films use resin formulations for each layer to provide
specific characteristics. When combined with a laminated support, the
properties are magnified. A wide range of polymers like LDPE, LLDPE is
used for making these films and a wide array of specialty resins. The
most commonly used resins are:
- EVOH- High oxygen barrier
- Nylon- Strength plus oxygen barrier
- EVA- Flexibility and sealability
- Matallocene- Wide seal range
Resins with custom additives enhance film performance to fit the
end use as well as the needs of converting and packaging systems.
Applications: Coextruded Films for Packaging
Natural film for cigarette packaging. Performs well in general overwrap
applications. It is also used for bundling applications, surface print
and non-print applications requiring improved puncture resistance. It is
used as outer web in laminations for semi-free flowing products like
pasta, candy, nuts in the shell. Used as laminations for bakery, snack
and confectionery products. Some of the packaging products made using
coextruded films are as follows:
- Packaging pouch
- Packaging bags
- Food packaging laminates
- Pharma packaging products
