This lining constitutes a thin layer of protection against corrosion by coming in between the metal surface and the contents of a can. Aluminum and steel, widely used in many beverage and food cans, have a tendency to corrode, especially when coming into contact with foods and beverages that are acidic in nature, such as soda, juice, and tomatoes. These acids combine with metals to cause corrosion that will weaken not only the structural integrity but also contaminate foods with metallic ions.
The liner is usually of epoxy resin and some other BPA-free coating materials such as polyester or acrylic coatings applied as a thin coating on the inside surface of the can. This layer stops corrosive reactions caused by the direct contact between the metal and the content. For example, most beverages are acidic and have a pH of up to 2.5, which aggressively corrodes aluminum after some time. The lining withstands these acidic levels, thereby increasing the life of the can and preserving the quality of the product. A lining applied well can, therefore, increase the shelf life by as much as two years or more depending on the nature of the product in terms of acidity and storage conditions.
Other factors that contribute to this corrosion in unlined cans are temperature fluctuations and high carbonation. This lining acts as a barrier that is able to stabilize the pressure and temperature changes, ensuring the integrity of the can even when the environment is not ideal for storage. According to Food and Beverage Packaging Magazine, linings in cans reduce cases of corrosion by over 70%, hence maintaining the safety of the product.
In addition, the durability of the can linings provides a mechanism for maintaining the integrity of the cans during transportation. Impact-resistant linings ensure protection against corrosion throughout the lifecycle of a product in case of slight dents on the can or temperature changes that may cause any damage to the barrier.
High-quality lining materials for aluminum can lining are not only an important safety factor in the product but also a durability factor, as they maintain the can's structure and prevent chemical reactions that would affect either the taste or safety of the contents. Such linings are an industry-standard solution whereby canned goods become a reassuring, long-lasting, safe packaging choice.