Multilayer Co-extruded Cross-Linked Shrink Film
is a novel high-shrinkage biaxially oriented shrink film developed on
the basis of POF shrink film. It is produced by irradiating multilayer
co-extruded PE shrink film with high-energy electron beams, inducing
cross-linking between PE molecules. This process transforms the
molecular structure from a linear chain into a three-dimensional
network, significantly altering the physical and mechanical properties
of the material. Through customized formulation designs and controlled
cross-linking degrees, products with tailored performance
characteristics can be manufactured to meet the requirements of various
packaging equipment and applications.

The most common form of cross-linking for flexible packaging materials is radiation cross-linking.
This method utilizes electron beams that generate high-energy β-rays.
During irradiation, molecular bonds within the film cross-link,
resulting in:

• Enhanced Puncture Resistance:
  Cross-linking improves puncture resistance, enabling the use of thinner
  films while maintaining strength. Thinner films offer advantages such
  as cost savings, better transparency, faster sealing, and quicker
  shrinkage.

• Higher Seal Strength:
  The weakest point in shrink packaging is often the seal seam.
  Cross-linked shrink films achieve stronger seals compared to standard
  shrink films, reducing packaging damage and ensuring product integrity.

• Reduced Residue:
  Over time, shrink films can leave residue on seal wires or blades.
  Cross-linked films minimize residue buildup, reducing maintenance
  frequency and downtime for high-speed automated machinery.

• Improved Clarity:
  The ability to use thinner films without sacrificing strength enhances
  clarity. Radiation cross-linked shrink films also exhibit lower haze,
  further improving visual appeal.

Key Advantages of Cross-Linked Films vs. POF Films:

• Higher Shrinkage Rate: Bidirectional shrinkage exceeds 70%, compared to ~60% for POF films.

• Lower Shrinkage Temperature: Reduces energy consumption and risk of product damage.

• Superior Heat Seal Strength: Wider heat seal temperature range for robust packaging.

• No Delamination: Avoids layer separation issues common in POF films.

• Dimensional Stability: Lower natural shrinkage during aging and storage.

• Uniform Thickness: Better consistency compared to non-cross-linked films.

• Enhanced Stiffness and Hardness: Improved resistance to mechanical scratches.

• Customizable Properties: Special formulations enable high shrinkage with low shrinkage force, a feature not achievable with POF films.

• Gentle Shrinkage Process:
  Lower initial shrinkage temperature allows slower, more controlled
  shrinking, reducing the risk of product deformation or damage.

These
properties make cross-linked shrink films ideal for demanding packaging
applications where durability, clarity, and efficiency are critical.