Heat Sealable PET Film: Structure, Technology, Benefits & Applications

Heat-sealable-pet-film

Heat-sealable-pet-film

Heat Sealable PET Film: Structure, Technology, Benefits & Applications

What is Heat Sealable PET Film?

Heat Sealable PET Film is a high-performance biaxially oriented polyester film (BOPET) engineered with a special heat sealable layer that enables direct sealing under heat and pressure without the need for adhesives.

By combining the strength and thermal stability of PET with low-temperature sealing capability, this film is widely used in food packaging, beverage containers, and lidding applications.


Origin of Heat Sealable PET Film Technology

Heat sealing technology originated with the development of thermoplastic polymers such as PET in the mid-20th century. As packaging industries evolved, traditional sealing methods (adhesives or mechanical sealing) were gradually replaced by thermal sealing systems.

With advancements in:

  • Co-extrusion technology
  • Multi-layer film design
  • High-speed packaging equipment

Heat sealable PET film has become a key material in modern packaging, especially for food safety and high-efficiency production.


Manufacturing Process of Heat Sealable PET Film

The production of heat sealable PET film is similar to standard BOPET film but includes multi-layer co-extrusion technology.

Main Process Steps:

  • Melt extrusion (single-layer or multi-layer co-extrusion)
  • Casting (sheet formation)
  • Longitudinal stretching (MD orientation)
  • Transverse stretching (TD orientation)
  • Heat setting
  • Winding and slitting

This process ensures:

  • High mechanical strength
  • Excellent dimensional stability
  • Superior thermal performance

Structure of Heat Sealable PET Film (A/B/C Design)

Heat sealable PET film is typically produced as a three-layer co-extruded structure (A/B/C structure):

A Layer – Heat Seal Layer

  • Made from amorphous copolyester
  • Acts as the heat sealable surface
  • Thickness: 10%–20% of total film thickness
  • Enables sealing at lower temperatures

B Layer – Core Layer

  • Biaxially oriented PET (BOPET)
  • Provides:
    • Strength
    • Rigidity
    • Heat resistance

C Layer – Back Surface

  • Usually corona treated
  • Ensures:
    • Excellent printability
    • Good ink adhesion

Heat Seal Strength

  • Typical range: 5 – 8 N / 15 mm
  • Can be adjusted based on application requirements

Heat Sealing Principle

Heat sealing works through thermal activation of the seal layer:

  1. The heat seal layer softens or melts at a specific temperature
  2. Pressure brings surfaces into close contact
  3. Cooling solidifies the bond

Result:
A strong, uniform, and leak-proof seal formed by molecular bonding.


Why Use Heat Sealable PET Film?

✔ Reliable Sealing Performance

  • Strong and consistent seals
  • Excellent leak-proof capability

✔ High Temperature Resistance

  • Suitable for freezer-to-oven applications
  • Ideal for ready meals

✔ No Adhesives Required

  • Cleaner process
  • Safer for food packaging

✔ High Processing Efficiency

  • Compatible with high-speed automatic packaging lines

✔ Wide Compatibility

  • Can seal to:
    • APET / CPET
    • PETG
    • BOPET
    • Coated paper / paperboard
    • Metal and glass

Key Benefits of Heat Sealable PET Film

Ideal for Food & Beverage Packaging


Excellent Thermal Performance

  • Resistant to high and low temperatures
  • Suitable for microwave and oven use

Superior Printability

  • Corona-treated surface
  • Supports high-quality branding

Strong Mechanical Properties

  • High tensile strength
  • Excellent dimensional stability

 Good Barrier Properties

  • Aroma retention
  • Moisture resistance

Sustainability & Environmental Advantages

Heat sealable PET film aligns with modern eco-friendly packaging trends:

1. Recyclable PET Structure

  • Supports mono-material recycling systems

2. Reduced Material Consumption

  • High strength allows thinner films

3. No Chemical Adhesives

  • Cleaner recycling process
  • Reduced environmental impact

4. Energy Efficiency

  • Faster sealing = lower energy usage

Helps brands meet global sustainability regulations and ESG goals


Main Applications

Food Packaging

Beverage Packaging

  • Aluminum laminiation for food can
  • Tin plate lamination for food can
  • Bottle and container lidding
  • Dairy and liquid packaging

Industrial Applications


Conclusion

Heat Sealable PET Film is an advanced packaging material that integrates:

  • Co-extrusion technology
  • Multi-layer structure
  • Efficient sealing performance

With its advantages in:

  • Strength
  • Heat resistance
  • Seal reliability
  • Sustainability

it has become a preferred solution for modern food and beverage packaging.


Get Technical Support & Samples

Looking for:

  • Heat Sealable PET Film
  • Lidding films for trays and containers
  • Custom sealing solutions

Contact us for TDS, samples, and expert support

Heat sealable pet film