The aluminum foil inner bag is an inner packaging product focusing on high barrier protection. It is mainly suitable for the inner layer of outer bags such as FIBCs (Flexible Intermediate Bulk Containers) and woven bags, providing refined protection for various sensitive materials. Its most prominent advantage lies in the five-layer composite structure adopted for the inner lining. This special structure endows the bag with extreme protective performance—it is not only highly moisture-proof and light-proof, firmly blocking the invasion of moisture, but also effectively isolating light irradiation, fundamentally avoiding the deterioration, oxidation, discoloration and other problems of the raw materials inside the bag caused by moisture and light exposure.