Key Production Points of Zipper Bags for Different Fabric Types
1）BOPP or Matte Film Zipper Bags
1.Printing: Use heat-resistant ink rather than regular light packaging ink. Design the layout to leave a 2mm clear border at the edge if possible. For full-page designs, add a white ink layer under the color ink.
2.Lamination: Whether using solvent-based or solvent-free adhesives, select heat-resistant types to avoid delamination near the zipper during high-temperature sealing.
3.Bottom Layer Material: Choose a low-temperature material for both the zipper and bottom layer to better match the heat sensitivity of
BOPP or matte OPP fabric.
2）PET or NY Rigid Zipper Bags
As rigid materials, PET and NY are naturally heat-resistant, especially for edge sealing. However, choose heat-resistant inks and adhesives to maintain lamination strength during heat sealing. The material’s heat resistance also allows for a wider range of zipper heat-sealing temperatures.
3）Zipper Bags with VMPET, Aluminum Foil, NY, or PET Intermediate Layers
These structures pose unique production challenges. Achieving strong adhesion between the aluminum-coated PET and surface layers without causing aluminum transfer is crucial. Excessive adhesive strength can cause aluminum transfer, while insufficient strength can weaken the heat-sealing performance.
Glue Selection: Choose a specialized aluminum adhesive with high temperature tolerance.
Curing: Typically use lower temperatures and longer curing times. Adhesives vary by supplier, so adjust processes accordingly.
4）Degradable Zipper Bags with PBAT Fabric
The bottom layer should match the degradable nature of the top layer, ideally using PLA zippers as well. Since this type of bag is uncommon, there are still challenges with heat-sealing degradation.
Heat Sealing: Control the temperature carefully to prevent rapid brittleness in the PLA zipper due to high temperatures, which can weaken the zipper’s strength over time.
5）PE Material Zipper Bags
Ink and Adhesive Requirements: The requirements for inks and adhesives are similar to those for PET zipper bags.
1.Production Process Specifics: PE-based composite zipper bags have unique challenges in the bag-making process. Initially, when using PE//PE material structures, even creating a three-side-sealed bag posed significant challenges. This difficulty arises due to PE’s inherent stretchability and melting characteristics, which complicate the bag-making process.
2.Surface Layer Modification: Modifications to the outer PE layer improve its heat resistance, rigidity, and high-temperature shrinkage, bringing its heat resistance closer to that of BOPP. Ideally, the PE outer layer should melt at a higher temperature, while the bottom heat-seal PE layer should have a low melting point. Using a low-temperature zipper provides an optimal match among the three layers.
3.Matching Materials: If these three elements are not well-matched, issues can occur during the bag-making process, such as poor heat-seal integrity, crushing of the PE surface layer, or even piercing of the inner PE layer. Additionally, stretching deformation along the seal edges may occur, complicating the bag's stability.
