Structure and Materials of Heat Sealable Foil Pouches
This is a typical multi-layer composite structure, with each layer having a clear function:
1. Outer layer (protective/printing layer):
PET (Polyethylene terephthalate): Provides excellent mechanical strength, abrasion resistance and a high-gloss printing surface.
NY (Nylon): Offers outstanding puncture resistance and toughness, often used for contents with sharp edges.
2. Middle layer (core barrier layer):
AL (Aluminum foil): This is the "heart" of the bag, typically with a thickness ranging from 7μm to 12μm, providing ultimate barrier properties in all directions. The number of pinholes is a key indicator of quality.
3. Inner layer (heat seal layer):
CPP (Cast Polypropylene): Suitable for high-temperature environments, such as making high-temperature retort bags. It has good heat resistance.
PE (Polyethylene): Has good low-temperature heat seal performance and moisture resistance, is cost-effective, and is suitable for regular sealing.
4. Common examples of compound structures:
PET/AL/PE: General structure, suitable for moisture-proof packaging of milk powder, coffee, dry food, and electronic components.
PET/AL/CPP: Suitable for foods requiring high-temperature sterilization, such as soft canned food and meat products.
NY/AL/CPP: High-puncture-resistant structure, used for pet food, bone-in meat or heavy-duty hardware parts.
What are the Application Areas of Heat Sealable Foil Pouches?
The heat-sealable aluminum foil pouches, due to their superior protective performance, are widely used in fields where strict preservation conditions are required:
1. Food and Beverages:
High-temperature cooked foods: Military ready-to-eat food, soft-packaged canned food, sauce packets.
Foods highly sensitive to oxygen/light: High-end coffee beans/powder, infant milk powder, nuts, edible oil, seasonings.
Vacuum/Inflation-packaged foods: Meat, cheese, sausages, tea.
2. Medicine and Health Care:
3. Electronics and Industry:
Electronic components: IC chips, moisture-proof and anti-static packaging for circuit boards (often used as inner bags).
Chemical Products: Dyes, catalysts, rust-proof packaging for precision instruments.
4. Special Purposes:
What are the Advantages and Challenges of Heat Sealable Foil Pouches?
Advantages:
1. Top-notch comprehensive protection: It is one of the gold standards for barrier performance in flexible packaging.
2. Long shelf life: It can extend the shelf life of sensitive products to the greatest extent.
3. Air-tight sealing: Heat sealing provides the most reliable sealing method, suitable for vacuum and inflation packaging.
4. Wide functional adaptability: It can be customized to meet the demanding processing and storage conditions such as steaming, freezing, etc.
Challenge:
1. Higher cost: The use of aluminum foil material and the complex manufacturing process result in significantly higher costs compared to ordinary plastic packaging.
2. Limited flexibility, prone to pinholes: Aluminum foil is prone to cracking when repeatedly bent or impacted by sharp objects, thereby compromising its barrier integrity. The shape of the contents must be taken into account during design.
3. Non-visibility: It cannot display the contents and relies solely on external printing for marketing.
4. Special equipment required: A heat sealer must be used for sealing, which increases equipment and operational costs.
5. Environmental issues: The use of multi-layer heterogeneous materials makes recycling and reuse difficult, resulting in significant environmental pressure.
