In cold chain logistics, extreme temperature and humidity are key factors affecting the quality of goods. Aluminum foil composite paper has become an important packaging material with its unique properties, but it also faces many challenges and needs to adopt effective strategies to deal with them.
The extreme temperature and humidity environment of cold chain logistics is complex and harsh. In terms of low temperature, the transportation temperature of frozen food is usually maintained at -18℃ or even lower, and the cold chain transportation of medicines may be as low as -70℃. At such low temperatures, packaging materials tend to become brittle, resulting in decreased mechanical properties, cracking, delamination and other problems. High humidity environments are equally tricky. In refrigerated environments, water droplets are easily condensed on the surface of goods and packaging, and the humidity can reach more than 90%, which will accelerate the aging and mildew of packaging materials and reduce their barrier properties. For example, ordinary paper packaging in a high humidity environment will become soft due to water absorption in a short time and lose its protective effect on the goods. If electronic products, precision instruments, etc. are transported, short circuits and damage may also occur due to water vapor infiltration.
The characteristics of aluminum foil composite paper itself give it certain advantages in cold chain transportation. Aluminum foil has excellent barrier properties and has strong barrier properties against oxygen, water vapor and light. Data shows that the water vapor permeability of aluminum foil with a thickness of 0.01mm is almost zero, and the oxygen permeability is also extremely low, which can effectively prevent external moisture and oxygen from entering the packaging, and prevent the goods from oxidation, moisture and deterioration. Aluminum foil composite paper combines aluminum foil with paper, combining the flexibility and printability of paper, which is convenient for printing various logos and information, and can also give play to the barrier advantages of aluminum foil. In addition, aluminum foil has good thermal conductivity, which can quickly transfer heat during cold chain transportation, help the goods to cool down evenly and keep the temperature stable.
In order to cope with extreme low temperatures, the low-temperature toughness of aluminum foil composite paper can be enhanced. In the production process, by adding special plasticizers, cold-resistant agents and other additives, the low-temperature performance of paper and composite layers can be improved, and their flexibility and impact resistance can be improved. For example, adding a low-temperature modifier to the composite adhesive can keep the composite layer at low temperatures. Good bonding strength still avoids stratification. A multi-layer composite structure can also be used to add a buffer layer between the aluminum foil and the paper, such as EVA (ethylene-vinyl acetate copolymer) film, using its good elasticity and flexibility to absorb external impact and reduce the risk of rupture caused by low-temperature embrittlement.
In the face of high humidity environment, it is crucial to optimize the moisture-proof structure of aluminum foil composite paper. On the one hand, strengthen the composite process of aluminum foil and paper, and adopt more advanced dry composite, extrusion composite and other technologies to ensure that the composite layer is tightly combined and reduce the water vapor penetration path. On the other hand, a waterproof coating is applied on the surface of the aluminum foil composite paper, such as nano-silicon dioxide waterproof coating, which has super-hydrophobic properties and can make water droplets roll off the surface, greatly reducing the chance of contact between water vapor and packaging materials. For some goods with extremely high moisture-proof requirements, desiccant can also be placed in the package, and vacuum packaging can be used to further reduce the internal humidity.
Although aluminum foil composite paper has certain advantages, there are still problems in actual cold chain transportation. In an environment with frequent changes in extreme temperature and humidity, the thermal expansion coefficients of aluminum foil and paper are different, which can easily lead to tiny gaps in the composite layer and affect the barrier performance. Moreover, in a low temperature and high humidity environment for a long time, electrochemical corrosion may occur on the surface of the aluminum foil, reducing its barrier effect. In addition, the cost of aluminum foil composite paper is relatively high. For some cold chain products with small profit margins, companies will have concerns when choosing packaging materials.
In order to further improve the performance of aluminum foil composite paper in cold chain transportation, it is imperative to develop new materials and processes. In the future, we can explore the application of nanotechnology in aluminum foil composite paper, and enhance its barrier performance and corrosion resistance through nano coatings, nano composite materials and other methods. The development of degradable aluminum foil composite paper materials is also an important direction, which can not only meet the packaging needs of cold chain transportation, but also reduce pollution to the environment. At the same time, we should strengthen the cooperation between industry, academia and research, promote the collaborative innovation of aluminum foil composite paper manufacturers, cold chain logistics companies and scientific research institutions, and jointly solve the problems encountered in practical applications.
Although aluminum foil composite paper faces challenges in extreme temperature and humidity environments during cold chain logistics and transportation, it can effectively respond to these challenges by continuously optimizing material properties, improving production processes, and strengthening research and development innovations, playing a greater role in the field of cold chain packaging and providing strong support for ensuring the quality and safety of cold chain goods.
