NY/VMPET/PE Composite Liquid Packaging Bag

1. Material structure and composition
Outer layer (NY nylon)  
Material: Bi-directional stretch nylon film (BOPA).  
Characteristics: high mechanical strength, puncture resistance, impact resistance, good flexibility to prevent breakage in transport; also has a certain oxygen barrier (about 20-30 cm³/m²-24h-atm).  

Intermediate layer (VMPET aluminised film) 
 Material: polyester film (PET) aluminised.  
 Characteristics:  
    Barrier: The aluminium layer blocks oxygen (≤1.5 cm³/m²-24h-atm), water vapour (≤1.0 g/m²-24h) and UV rays, extending the shelf life of the food.  
    Reflection*: aluminium layer reflects light and heat, suitable for light-sensitive liquids (e.g. dairy products, fruit juices).  
      

Inner layer (food grade PE) 
  Material: Polyethylene (PE)  
  Characteristics: Good heat sealing, non-toxic, chemical resistant, direct contact with liquid food (in accordance with GB 4806 standard).  

2. Typical composite structure
Common collocation:  
  NY (15μm) / VMPET (12μm) / PE (50-80μm)  
 

4. Main application scenarios
  
 Aseptic fruit juice, vegetable protein drinks, high-end dairy products (such as UHT milk), wine (instead of glass bottles).  
Condiments: soy sauce, vinegar, edible oil (anti-oxidation and freshness preservation).  

5. Advantages over other packaging materials
| Characteristics | NY/VMPET/PE Bags | **Pure Aluminium Foil Bags** | Ordinary PE Bags |
|----------------|-------------------|-------------------|-------------------|
| Oxygen barrier | Excellent (close to aluminium foil) | Very good | Poor |
| Cost | Medium | High | Low | Oxygen barrier | Excellent (close to aluminium foil) | Very good | Poor
| Folding Resistance | Excellent (not easy to crack aluminium layer) | Poor (easy to break at crease) | Excellent |
| Transparency | Opaque | Opaque | Transparent |

Summary: NY/VMPET/PE composite liquid pouches have become the ideal choice for high-end liquid food products with high barrier, light weight and durability, especially suitable for products with long shelf life and light protection needs. The inner material formulation needs to be adjusted according to the specific contents (pH, fat content) to ensure compatibility.