Increased Shelf-Life with aTULC Liner

October 17, 2022

While accessibility and aesthetics are important for brand development, the most critical consideration when choosing your packaging option is product-to-package compatibility. This is determined by the interaction between ingredients and the specifications of the can, particularly the liner.

Why are cans coated?

In order to protect the integrity of the beverage and the can itself through limiting potential chemical interactions between the two with internal coating. This maintains the stability of the product within the container for an extended period of shelf-life time and protect the packaging metal from corrosion due to high-acidity ingredients found in the beverage mixture.

What are they coated with?

Traditionally, pre-formed cans are sprayed internally at a rate of 400 cans per minute with either epoxy or BPA-non-intent(BPANI). Epoxy, being the longest standing coating option, is commonly used as it adheres easily to the metal and provides a good protective layer from the beverage.

BPANI lining has grown in popularity as some states have deposit laws concerning the use of BPA in food and beverage packaging products. Thus, BPANI linings, while still epoxy-based, were created to comply with these concerns.

What does that mean for corrosion?

Some beverages contain potentially corrosive ingredients for aluminum cans. There are many factors that go into the viability of your beverage packaged in a can regarding corrosion, including pH levels, the type of acid used, alcohol percentage, volumes of CO2, and filling and preservation methods. The liner protects the can from these factors having a detrimental effect on the packaging practice.

For example, it has been determined for can packaging that when pH is high and Cl concentration is low, corrosion is less likely to occur. Conversely, beverages with high organic acids content (acetic acid, lactic acid, etc) or high salt concentrations may be prone to more rapid corrosion.

How is aTULC lining different from traditional?

aTULC uses a pre-coated raw aluminum sheet, rather than sprayed on a preformed can, during the manufacturing process. This provides a higher resistance to potential issues of flavor absorption and corrosion, inside and out of the can. This process, along with vigorous metal exposure testing throughout production, ensures greater consistency of application of the lining, greatly reducing the risk of an internal defect of the lining.

Regarding flavor absorption, the lining is slightly thicker than traditional epoxy and BPANI, allowing more protection from metal compounds interacting with your product. The same quality applies to the can being protected from your product’s corrosive properties. It also means the can is additionally lined on the outside, giving further protection against external corrosion caused by product coming in contact with the exterior walls of cans stacked and stored below a potentially punctured one.

How to determine which option is best for your beverage?

Test your beverage prior to can packaging for a range of potential problem areas. Labs are able to prove pH levels, acidic ingredients, coloring additives, etc. in addition to your knowledge of the production of your beverage to give credible accounts of how it will potentially interact with an aluminum can.