The core technology of cold chain temperature-controlled packaging is primarily thermal insulation and temperature control technology. Its main principle is to use high-performance insulation materials to slow down heat exchange between the packaging's interior and external environment, combined with ice packs, cold storage agents, or phase change materials to regulate the internal temperature, ensuring the product remains within the target temperature range as much as possible during the specified transportation time. In actual design, comprehensive calculations are needed based on the product's storage temperature, transportation duration, ambient temperature, packaging dimensions, and product load to rationally determine the insulation layer thickness and the amount and placement of cold storage materials. Insufficient cold storage material may fail to meet the temperature requirements throughout the transportation cycle; excessive material may cause localized excessively low temperatures, even leading to frostbite or freezing of some products. Therefore, cold chain packaging is not simply about adding insulation material, but requires heat transfer analysis, temperature distribution design, and optimization of the cold storage scheme to create a relatively stable temperature environment inside the packaging.
Another key technology is temperature monitoring, structural design, and transportation reliability control. For temperature-sensitive products such as pharmaceuticals, biological products, vaccines, and some high-value foods, it is difficult to determine whether the temperature remains within the specified range throughout transportation using only insulation materials. Therefore, temperature recorders, temperature tags, or intelligent temperature monitoring devices are typically used to record the internal temperature of the packaging in real time or throughout the entire process. Regarding packaging structure, the positional relationship between the insulation layer, cold storage materials, and the product needs to be rationally designed to avoid direct contact between the cold storage agent and the low-temperature sensitive product, while minimizing temperature dead zones within the packaging. In addition, factors such as drops, vibrations, stacking, and changes in ambient temperature during transportation must be considered. Strengthening the outer box structure and internal fixing structures improves the stability of the packaging during long-distance transportation and multiple loading and unloading processes. For high-requirement cold chain packaging, tests are also required for high and low temperature environments, transportation vibrations, drops, and insulation performance. These tests verify the packaging's temperature retention capabilities under different transportation conditions, thereby improving the safety and reliability of cold chain transportation.