Zipper Bag Process Introduction
Zipper Bag Process Introduction
The application of zipper bags in soft packaging composites is becoming more widespread, but customer requirements vary, with some even exceeding industry standards. Therefore, when producing zipper bags, it is essential to have an in-depth understanding of the process requirements and ensure proper process control. If you are looking to purchase high-quality, low-cost zipper bags, please contact China LIJIE Factory.
Types of Zipper Bags
Zipper bags can be classified based on the material of the fabric as follows:
1. Flexible Material Zipper Bags: Made of BOPP and matte film.
2. Rigid Material Zipper Bags: Made of PET or NY materials.
3. Degradable Zipper Bags: Made of PBAT or other degradable materials.
4. PE Material Zipper Bags: Made of PE material.
If classified by the middle layer, they mainly include VMPET, aluminum foil, PET, and NY zipper bags. If classified by the inner layer material, they mainly include PE, CPP, and PLA inner layer zipper bags. Zipper types can be classified into regular single-track and double-track zippers.
Different material structures and zipper types involve different processes and pre-production designs, so it's important to pay attention to key process control points.
Key Points for Producing Zipper Bags with Different Fabrics
1. BOPP or Matte Film Zipper Bags
- Printing Process: Use heat-resistant inks and avoid using ordinary light packaging inks. It’s best to leave a transparent edge of at least 2mm on the design and consider the white background design.
- Lamination Process: Use heat-resistant adhesives, and avoid using adhesives for ordinary light packaging materials, as they may cause delamination at the zipper head area due to high temperatures.
- Base Material: Choose low-temperature materials to ensure compatibility with the low-temperature characteristics of BOPP or matte films.
2. PET or NY Rigid Material Zipper Bags
- These materials have good heat resistance and excellent heat-sealing properties, but it is still necessary to use heat-resistant inks and adhesives. The heat-sealing temperature range is wide, making it suitable for various temperature settings.
3. Zipper Bags with Middle Layers of VMPET, Aluminum Foil, NY, PET, etc.
- Pay special attention to the lamination strength of aluminum PET layers. Too strong a bond may cause the aluminum layer to transfer, while too weak a bond will affect the heat-sealing performance. Choosing heat-resistant polyurethane adhesives and proper curing processes is crucial.
4. PBAT and Other Degradable Material Zipper Bags
- These bags require strict control of the heat-sealing process, particularly the heat-seal strength of PLA zippers. Improper heat-sealing temperature control may lead to material brittleness or zipper issues.
5. PE Material Zipper Bags
- Due to the stretchability and melting characteristics of PE, bag-making processes can be challenging. It is necessary to modify PE materials to improve their heat resistance and ensure that the heat-sealing temperature matches the low-temperature characteristics of the zipper.
Key Points for Heat Sealing Zipper Bags
During the production of zipper bags, customers often require the zipper head area to be airtight to ensure convenience and sealing. Sealing is a critical control point. Below are common heat-sealing issues:
1. Unstable Heat Sealing at the Zipper Head: This leads to air or liquid leakage.
2. Zipper Head Damage: High temperatures can damage the surface layer, causing leakage.
3. Single-Track Zipper Heat Sealed Incorrectly: Incorrect zipper direction may result in the bag bursting.
4. Weak Internal Bite Force: This can cause difficulties in sealing or internal bursting.
5. Weak External Bite Force: Affects the stability of the bag's opening.
6. Double-Track Liquid-Seal Zipper Bags Leaking: Excessive pressure can puncture the bag material, causing leakage of contents.
In conclusion, producing every composite soft packaging zipper bag requires strict process control, detailed procedures, and material matching to ensure stable quality. Different materials and zipper types require different control points and technical treatment. Stable processes and material management are key to ensuring product quality and enhancing the competitiveness of the business.
