Aluminum foil composite film is a multi-layer flexible packaging material widely used to protect products from moisture, oxygen, light, and contamination. It is typically produced by laminating aluminum foil with plastic films such as PET, PE, PA, or CPP, and in some cases with paper. Each layer in the structure plays a specific role: the aluminum foil provides excellent barrier properties, the plastic films offer mechanical strength and heat-sealing performance, and the adhesive layers bond the materials together securely.The aluminum foil layer is the core functional element of the composite. It has extremely low permeability to gases and water vapor, making it ideal for packaging products that are sensitive to oxidation, humidity, or aroma loss. Its metallic surface also reflects light and heat, contributing to the protection of light‑sensitive and temperature‑sensitive contents. By combining different thicknesses of foil and plastic, manufacturers can tailor barrier levels to the needs of food, pharmaceuticals, chemicals, and high‑value consumer goods.The plastic film layers add flexibility, tear resistance, and processability. Polyester (PET) film often serves as a printing surface and outer protective layer because of its dimensional stability and resistance to abrasion. Polyethylene (PE) or cast polypropylene (CPP) are commonly used as inner sealing layers thanks to their good heat‑seal characteristics and compatibility with a wide range of filling and sealing machines. Polyamide (PA) can be included to improve puncture resistance and toughness for heavy or sharp‑edged contents.Production of aluminum foil composite film usually involves dry lamination, extrusion lamination, or solvent‑free lamination. These methods ensure that the layers are evenly bonded, without bubbles or delamination, even when the film is subjected to high‑speed packaging, folding, or sterilization processes. The final product can be supplied in rolls for form‑fill‑seal applications or converted into pre‑made pouches such as stand‑up pouches, three‑side‑seal bags, and vacuum bags.This type of composite film is widely applied in packaging coffee, tea, snack foods, dairy products, condiments, pet food, and ready‑to‑eat meals. In the pharmaceutical field, it is used for blister packs, sachets, and moisture‑sensitive formulations. Industrial uses include packaging electronic components, powders, and materials that must be stored in controlled conditions.In recent years, there has been growing attention to the environmental impact of aluminum foil composite films. Traditional multi‑layer structures are difficult to recycle because they combine metal and different plastics in a single material. As a result, research and development efforts are focusing on reducing material thickness, optimizing layer structures, and exploring recyclable or mono‑material alternatives while still maintaining the high barrier and protective performance associated with aluminum foil composites.