Plastic: The main material is usually polypropylene (PP), a durable, lightweight plastic material with good sealing properties. Sometimes other types of plastics, such as polyethylene (PE), are also used. Plastic cans have good chemical stability, resisting the effects of external environmental factors and protecting the quality of the milk powder.
Aluminum Foil: Aluminum foil is often used in the inner or inner layers of milk powder cans to enhance the ability to isolate oxygen and moisture, improving preservation. The aluminum foil layer also helps block light, preventing the nutrients in the milk powder from degrading due to photo-oxidation.
Metal: Many high-end brands of milk powder use metal cans, such as aluminum alloy or iron cans. Metal cans have excellent sealing properties, extending the shelf life of the milk powder. Metal cans can be further divided into different types, such as tin-plated tinplate, chromium-passivated tinplate, and chromium-free tinplate, with chromium-free tinplate being more popular due to its environmentally friendly characteristics.
Cardboard: Some milk powder cans use cardboard as the outer material, with plastic or aluminum foil layers inside to enhance moisture resistance and sealing. Cardboard cans are usually lighter but not as sturdy as metal cans.