Aluminum is a metal second only to steel production, but aluminum has only been used as a packaging material for more than 30 years. In recent years, the amount of aluminum used in packaging has increased due to its series of excellent properties. It has a low density, only 1/3 of steel, and lighter weight; it has excellent workability and is easy to stamp into various complex shapes; it has strong corrosion resistance and will not rust; barrier properties, light-shielding properties, and fragrance retention properties Excellent, can effectively protect the product; high thermal conductivity, easy to sterilize aluminum cans; silvery white, beautiful color, and high reflectivity to light, easy to print, good printing effect; non-toxic, tasteless, and will not be caused by aluminum The ions escape and bring peculiar smell to the food inside; the waste aluminum container can be recycled and remelted, and there is no environmental pollution. Its main shortcomings are: soft material, low strength, easy to deform when impacted; poor welding performance, joints cannot be welded; poor corrosion resistance to acids and alkalis, not suitable for fruit food; high cost, etc.

Aluminum packaging materials mainly include pure aluminum plate, alloy aluminum plate and aluminum foil.

(1) Pure aluminum plate and alloy aluminum plate

The pure aluminum plate contains more than 99.9% aluminum, and the thickness is generally between 0.25 and 0.3 mm. It is soft and low in strength, so it is rarely used as a packaging material, but it is also used as a wine container.

Alloy aluminum plate is processed by adding a small amount of magnesium, manganese, and copper to aluminum. Commonly used aluminum alloys on packaging are aluminum-magnesium alloy and aluminum-manganese alloy, also known as anti-rust aluminum alloy. The strength and hardness of the alloy aluminum plate are obviously improved, the corrosion resistance is strong, the polishability is good, and the appearance remains bright after long-term storage.

Alloy aluminum plates are mostly used to make canned food containers. When used for canned fish and meat, they will not cause vulcanization and blackening like tinned cans; they are more used to package beverages, which will not cause the beverages to become muddy and flavor changes.

(2) Aluminum foil

Aluminum foil is made of pure aluminum with a purity of more than 99.5%, and the thickness is between 0.005 and 0.2mm. It is light and shiny, with strong reflection ability, and can be used as heat-proof and insulating packaging; good barrier properties, impermeable to gas and water vapor; easy to process, easy to process into various shapes; easy to print, glue, paint, color, Embossing, printing, etc.; strong adaptability to temperature, stable shape at high or low temperature; excellent shading and fragrance retention, etc. The major disadvantage of aluminum foil is that it is not resistant to acids and strong alkalis, cannot be welded, and has low tear resistance.

Aluminum foil is widely used in packaging. It can be used to package items individually; more often it is made into composite materials with paper, plastic film, etc., used for packaging of food, cigarettes, cosmetics, medicines, chemicals, etc., and can be made into retort pouches. , Packaging convenience foods and steamed foods, etc.