In recent years, the flexible packaging is growing rapidly all over the world. In our daily life, it have been the indispensable part. Try to imagine the food from the shop to your hand without any packaging, will you think it’s hygienic? Or when you bought the drug from the drugstore without any protective packaging, will you suspect the it have been polluted? We all cannot imagine these issues. And in daily flexible packaging area, we may find the foil packaging is one of the most popular material.
On the market, the foil packaging is always made of three or four layers materials, mainly including Alu foil, PET film, PA film, PE film, CPP. Etc.
Construction: PET+AL+PE or PET+NY+AL+PE (Regular packaging)
PET+NY+AL+CPP (High temperature cooking packaging)
These single layer materials have both advantage and disadvantage, due to its performance:
| Barrier material | Advantage | disadvantage |
| PET | Rigidity、Good flatness、Water and oxidation resistance | – |
| NY | Good flexibility, gas resistance | Bad water resistance |
| AL | Strong barrier，light-proof, oil-resistant、 retaining performance | Easy to tear |
| PE | Low temperature resistance, heat sealing | Be soften at high temperature |
| CPP | High temperature resistance, heat sealing | Be fragility at low temperature |
PET (polyester):
It’s widely used due to the chemical molecular structure is symmetric and stable, the plane of the molecular chain is so good and tightly stacked, that easy to crystallize. These performances make the PET film have the good flatness and water-tightness. It is always used as the surface layer of foil packaging materials to protect and print.
NY(nylon):
This is the materials with obvious advantage and disadvantage. Gas resistance, toughness and ductility, temperature resistance is its strength. But the poor water vapor barrier and strong water absorption make NY film not to used as the surface layer or single layer. And it is always used to laminate other high barrier material.
AL Foil:
Good barrier materials with oxygen and water resistance. Besides, because of the heat resistance, good reflective and gloss, the al foil is suitable for the boiling resistance up to 125℃. But at the same time, it is also very brittle, poor acid resistance, no heat sealing and other weakness. So it’s used as the middle layer of the foil packaging material.
PE(polyethylene):
With the excellent heat sealing, people always select the PE film as the inner layer of foil laminated materials to seal. When the packaging item is stored at room or low temperature, the packaging material PET+NY+AL+PE is more suitable. Because the PE film will be softened at 65°C.
So PE film is unsuitable for the inner layer of boiling resistance material.
CPP(cast polypropylene)
Contrary to the PE film, the CPP is more used as the inner layer of boiling resistance material. Because it will be brittle at low temperature.
From the information above, we may learn the single material couldn’t be used in flexible packaging industry, but laminated other materials with different advantage, which will be a better packaging material with these advantages as below:
(1). Strong barrier, oxidation proof, waterproof, moisture proof.
(2). Excellent mechanical properties, high blasting resistance, puncture resistance and tear resistance.
(3). High temperature resistance up to 121℃, low temperature resistance down to -50℃, oil resistance and fragrance keeping.
(4). Non-toxic and tasteless,
(5). Good heat sealing and flexibility.
Comparing with other regular packaging materials, foil packaging material has its distinct advantages, so that to be the unique one. In pharmaceutical packaging field, foil packaging could help to protect the drug or isolate from the pharmaceutical wastes. In chemical field, taking use of the light barrier of materials, to prevent the chemicals from lose or degrade some of its own features. In food field, the foil packaging material with good light barrier and strong moisture resistance could ensure the food not go bad. In electronics field, the foil packaging with anti – static & anti – shielding could protect the digital item from damaging.
If the foil flexible packaging keep the strength and stabilize its market share, it’s important and necessary to explore the functions and more possibility. Separating the products and environment like heat, air and light effectively is the most obvious feature of foil packaging materials. As the manufacturer, keep it and exploit more features, to adapt to the changing tastes and market needs in customers’ market, and expand the use of foil packaging materials in more industries.
