Most exported food products, such as fresh meat and seafood, rely entirely on the cold chain throughout the entire distribution process. Low-temperature environments put the flexibility, adhesion, and resistance to brittle cracking of skin packaging films to the test. Ordinary skin packaging films tend to harden and crack under prolonged exposure to low temperatures, leading to packaging failure. Surlyn Skin Packaging Film is a commonly used material for skin packaging of cold-chain foods. Dongguan Promivision Packaging Manufactory conducted low-temperature environment testing specifically for cold-chain conditions to verify the film's stability during long-distance cold-chain transportation and low-temperature storage, thereby providing a basis for material selection in the packaging of fresh export products.
Key Challenges Posed by Low-Temperature Environments to Skin Packaging Films
Temperatures in cold chain environments are typically maintained between 0°C and -18°C, with storage temperatures for some quick-frozen products even lower. Prolonged exposure to low temperatures alters the physical properties of polymer films. Many conventional skin packaging films become stiffer and less flexible at low temperatures, making them prone to brittle fracture when subjected to jolts or compression. This reduces the adhesion between the film, the product, and the substrate, leading to localized delamination and air pockets. Cross-border cold-chain ocean freight involves greater temperature fluctuations; repeated temperature changes further increase the risk of packaging defects, directly affecting the freshness of food products.
Advantages of Surlyn Material Properties at Low Temperatures
Surlyn ionomer resin inherently possesses excellent low-temperature impact resistance. Compared to ordinary food-grade skin-tight films, it does not become brittle easily in low-temperature environments and retains good tensile and tear resistance. Even at freezing temperatures, the film continues to closely conform to the contours of irregularly shaped fresh produce without curling at the edges due to low-temperature shrinkage. Additionally, the film's heat-seal layer is highly stable; heat-sealed edges are less prone to leakage at low temperatures, and transparency remains consistent during prolonged exposure to cold, ensuring optimal shelf display.
Field Test Performance Under Cold Chain Transportation Vibrations and Temperature Cycling
Simulated cross-border cold chain transportation tests included multiple stages such as prolonged static storage at low temperatures, vibration and jolting, and temperature cycling. The tests focused on observing whether the Surlyn skin packaging film exhibited cracking, delamination, or seal failure. Test data shows that qualified Surlyn Skin Packaging Film can withstand typical cold chain vibrations. Even after multiple temperature cycling cycles, the decline in adhesion strength and seal strength is minimal. It is suitable for multimodal transport scenarios such as sea and land transport, significantly reducing the packaging damage rate of fresh produce during distribution and minimizing cargo loss.
Precautions for the Use and Selection of Cold Chain Packaging Accessories
When selecting Surlyn skin packaging film for cold chain packaging, it must be used in conjunction with a compatible Skin Pack Board or Skin Pack Tray. Additionally, the heat-sealing parameters of the skin packaging machine must be adjusted to prevent weak seals caused by low temperatures. It is also necessary to distinguish between refrigerated and frozen conditions based on product type; for quick-frozen products, prioritize models with higher low-temperature resistance ratings, while simultaneously verifying compliance with food contact standards. Relying solely on the film's performance is insufficient; the substrate, equipment parameters, and packaging process must work in concert to fully realize the cold chain protection capabilities of the entire skin packaging system.
Dongguan Promivision Packaging Manufactory offers Surlyn Skin Packaging Film, food-grade skin packaging film, skin packaging board, skin packaging trays, and corresponding skin packaging machine solutions. To meet the cold chain export requirements for fresh produce, seafood, and frozen meat products, we provide low-temperature performance testing, sample prototyping, and production line process guidance. This helps food companies consistently maintain packaging quality throughout the cold chain distribution process and meet the stringent packaging requirements of overseas supermarkets.
