The packaging bag for frozen dumplings is not just a simple plastic bag. It is a high-performance composite packaging material specially designed for frozen food. Its main function is to protect the dumplings from various damages during storage, transportation and sales, ensuring their quality, safety and deliciousness. Its multi-layer composite structure collectively provides four core functions: barrier, protection, information and convenience. It is an indispensable key link in ensuring the quality, safety and deliciousness of frozen dumplings.
1. Outer layer (printing layer/protective layer):
Material: Usually BOPP (biaxially oriented polypropylene) or PET (polyester) is used.
Function: It has good printing adaptability, making the packaging patterns bright and beautiful; provides mechanical strength, resistant to wear and scratch; has certain moisture-proof properties.
2. Middle layer (barrier layer):
Material: Commonly aluminum foil (AL) or aluminum-coated film (VMPET). High-end products use aluminum foil, while ordinary products mostly use aluminum-coated film.
Function: This is the "core technology" of the packaging. It can efficiently block oxygen, water vapor, light and odors. Prevent dumplings from deteriorating due to oxidation (off-flavor), avoid moisture loss leading to cracking and poor taste, and block quality deterioration caused by light exposure.
3. Inner layer (heat sealing layer/contact layer):
Material: Mainly CPP (extruded polypropylene) or PE (polyethylene) is used.
Function: Directly contacts the food, requiring the material to meet food hygiene and safety standards. Has good low-temperature heat sealing performance, easy to make bags and seal, and resistant to freezing, good flexibility, and not prone to cracking at low temperatures.
Examples of common composite structures: BOPP/AL/CPP or PET/VMPET/PE. This "sandwich" structure combines the advantages of each layer of material, providing comprehensive protection.
High barrier property: Prevents oxygen from entering and water from evaporating, which is the core for maintaining the freshness of dumplings.
Excellent low-temperature resistance: Can maintain physical properties stable in a frozen environment (-18℃ to -30℃), without brittling or cracking.
Good heat-sealing strength: The seal is firm, preventing bag rupture due to squeezing or dropping during transportation and handling.
Anti-puncture property: The edges and corners of dumplings may be sharp, so the packaging bag needs sufficient strength to resist punctures and prevent air leakage.
Easy-tear property: Many packages are designed with easy-tear openings (cuts or dotted lines), facilitating consumers to open them easily and enhancing the usage experience.
High transparency window design: Some packages will have a transparent window (using high transparency materials), allowing consumers to directly see the real shape of the dumplings, increasing purchasing confidence.
