Oriented Polypropylene
OPP
Available in coextruded heat-sealable and non heatsealable/high gloss
a) Metallised for light and barrier performance.
b) White solid for multipack applications or voided/pearlized for confectionery
c) Anti-fog for produce packing
d) Low-sealing for high speed applications
e) Matt for enhanced visual appearance
f) Coated films – acrylic, PVdC or LTS for enhanced machineability and barrier performance
Non-heatsealable/plain OPP has high gloss and low haze for visual applications and more specifically in recent times as a PET replacement film to achieve ‘PP mono-film laminates’ in conjunction with a CPP sealing layer. Applications include;
a) PP mono-film laminates
b) Greetings cards
c) Flower wrap
d) Adhesive tapes
e) Over-lamination films – wet and thermal
f) Pressure sensitive adhesive applications
g) Label films for cut and stack, IML, wrap-around suitable for ink-jet and laser printing
h) Synthetic papers
Oriented Polyester
OPET
Biaxially oriented polyester film is primarily used in the packaging and graphics industry. OPET is temperature resistant and suitable for deep-freeze, retort, medical sterilisable, micro-wave and conventional thermal ovens. OPET is used in both single-ply and laminate applications. Thickness range is 8 to 250um and variants include;
a) Corona treated
b) Chemically treated
c) Post-consumer waste, PCR (30-100%)
d) Metallised
e) Matt
f) White
g) Isotropic for lidding application such as yoghurt
h) Heat-sealable to multiple materials
i) Peelable
j) Anti-fog
k) PE replacement
l) Barrier coated
m) Coloured and ‘gold’ metallised
Applications for food packaging include fresh, chilled and frozen for bakery, salads, fruit, confectionery, snacks, fish and meat.
Cast Polyester
cPET
A new product used in thermal lamination to paper and paper mulch as a moisture/liquid barrier for environmental and recycling issues. Unlike OPET, cPET is readily thermoformable and available in thicknesses 25 to 150um dependent on the depth of draw. Available in transparent and white.
Twist Films
TWIST
Used primarily in confectionery;
Twist PVC: a very versatile film with good dead-fold and twistability and good test retention. Available in transparent, white, coloured and metallised and will run on most machines for which cellulose film is used. Normally used at 26um.
Twist PP: this film is used on most newer machines developed to run PP and is available in transparent, white, coloured and metallised. Typically used at 30 and 35um.
Twist PET: this is an oriented PET film with specific orientation to achieve good twist retention and environmental requirements. The film is available with up to 30% PCR with stiffness and runs well on older machines. Thicknesses available are 18, 22 and 26um and transparent, white and metallised.
Metallised Films
METAL
Metallised films enhance the moisture, gas and light barrier of packaging films. This prolongs the shelf-life of food products being packed and is environmentally friendly by reducing food waste. The enhancement of barrier is directly related to the smoothness of the film surface and amount of aluminium deposited on the film.
The thickness of metal layer is incredibly thin and compliant to OPRL specifications on recycling and on-line measurement of optical density is continuously monitored and controlled and is directly related to film thickness. Target optical density of metal is usually 2.0 to 2.3.
Metallised films available include;
Oriented Polyester
Oriented Polypropylene
Cast Polypropylene
Polyethylene
Oriented Nylon/Polyamide
OPA
Oriented Nylon has the benefit of enhanced gas barrier over standard PET and capable of providing sufficient oxygen barrier for cheese packing without the necessity of a coating thereby saving cost. OPA has excellent inherent strength and is capable of taking heavier product weights than PET. Thicknesses available are 12 and 15um
