Metal Food Cans have a proven history of successfully preserving food for long term storage. They are durable, reliable, stack well, and are capable of enduring vibrations, temperature, and pressure variations to a greater degree than any other packaging method. Metal packaging materials are an excellent barrier against the transfer of gases, light, and moisture. Metal containers are ideal for the stresses and heat required in preserving and canning foods. And Metal Food Cans will accept adhesive labels, can be painted directly on the can, or even shrink wrap labels. They can easily be manufactured into a variety of shapes and sizes, and are 100% recyclable!
A Brief History of Metal Food Cans - The invention and use of metal food cans has had a key role in the history and in the improvement of the basic life-style of humankind. The ability to preserve and store food safely and reliably has allowed adventures to take longer, extended expeditions. Allowed soldiers to be fed in our armies. Provided ways for families to preserve long term food storage in their homes. And finally, has enabled safe, and reliable mass production and transportation of large quantities of food.
The first metal food cans were manufactured from “tinplated, wrought-iron canisters”. And were opened with whatever one had on hand really. Like a chisel, or knife and hammer.
The invention of the can opener suddenly made it possible for anyone to easily open a metal food can for normal folk.
It was during World War II that manufacturers began to line the insides of the metal food cans with plastic polymer liners better preserve the taste, quality, and shelf-life of the packaged product within the cans.
Though originally made from tin plated iron. Today’s modern food cans are made from thinner, lighter, yet stronger steel that is much more resistant to corrosion. And you can choose from lined or unlined cans as well as going with the easy-open lids when making a purchase. Today’s metal food cans are safer, stronger, and easier to use!
Advantages - Metal food cans have many advantages, including:
Preservation and Protection - Metal is an excellant barrier against light, moisture, and gases. Which can be improved even more with the addition of a polymer coating or lacquer liner.
Structurally Durable – Metal Cans are strong, and durable. Resisting scratches, abrasions and punctures during transit and storage. They are also easy to stack without worry. Paneling rarely happens to metal cans.
Temperature and Pressure - Due to its natural strength and durability, metal food cans are capable of withstanding high temperatures, and pressures. Thus, making them ideal for canning, pasteurization, and sterilization.
Recyclable – Metal Cans are 100% recyclable. And, unlike plastic, they can be recycled over and over again without quality degradation.
Inexpensive - The costs for manufacture, packaging, and transportation are relatively lower than other, commonly used materials.
Adaptability – Metal containers can be produced in a wide variety of shapes, sizes, and styles.
Long-Term Storage – Metal Food Cans are capable of maintaining the freshness of the food product for up to 5 years. (Though many foods can be kept longer. 5 years is considered the safe limit) And because canned product requires no refrigeration, it’s among the most cost-effective and reliable ways to transit food long distances.
Most Commonly Packaged Products - The natural and excellent barrier that metal containers provide against light, gas and moisture, paired with their ability to withstand high-heat preservation and canning temperatures, make Metal Food Cans ideal for food products:
Snacks and Candy - Mixed nuts, wasabi peas, pretzels, brittles and other dry salt and sweet snacks are commonly packaged into Metal Food Cans. Preserved from moisture and sunlight. Such canned snacks can last for years.
Fruits and Vegetables – The naturally acidic nature of canned fruits and vegetables can lead to corrosion of the metal can. However, choosing to use a protective coating, or “liner” will inhibit corrosion of the can, improve the quality of the final product, and increase storage shelf life.
Shellfish and Sea Food – Seafood like crab, shrimp, and fish all do well when canned. Particularly due to excellent long-term shelf life and storage, as well as for package durability for world-wide distribution.
Meats – When properly preserved and sealed in Metal Food Cans, Meats are capable of staying fresh and tasty for years without the need of refrigeration. This alone has changed the ability for millions of people who do not have the ability to refrigerate their food. Enabling them to have access to the proteins and vitamins available in meat products.
Coffee and Tea – Ground coffee and tea was most often packaged in metal food cans. Though nowadays, most coffee and tea are packaged in special, hybrid cans of aluminum, cardstock and polymer.
Metal Food Can Structure and Materials - Tin plate, tin free steel and polymer coated steels are the most commonly used materials for the manufacture of Metal Food Cans.
Tin Plate – Tin plate is usually sheet metal with a layer of tin electroplated to either side of the metal to help prevent corrosion and the transfer of metals into the food product. Electroplating tin to the sheet metal (as apposed to hot-dipping), allows for absolute control over the desired thickness of the tin plating. Tin plate is relatively inexpensive, highly durable, magnetic, and is recyclable. However, the layer of electroplated tin onto the metal of the can sometimes does react with the contents. Especially highly acidic foods such as fruits and vegetables. This can be remedied by applying a polymer lining.
Polymer Coated Steel – Basically, steel cans that have been coated in a specific, plastic polymer, such as polyvinylidene fluoride (PVDF), perfluoro alkoxy alkane (PFA), polyethylene terephthalate (PET), and polypropylene (PP) as protective coatings. Metals are not inert to food products. Especially, the more acidic fruits and vegetables. For this reason, polymer coated steels provide additional protection from interaction with the product, and against corrosion of the can. Thereby improving the preservation of freshness and taste.
Stainless Steel – Stainless steel is extremely corrosion resistant, and even chemically inert. Which makes it ideal for packaging food products. However, stainless steel is expensive. And is typically only used for larger, bulk containers (such as beer and wine kegs).
Hybrid Containers – A newer technology that provides the lighter weight and versatility of high-barrier plastic with the stability and strength of aluminum. (Collapsing of the container walls, known as "paneling", is rare on Hybrid containers) Hybrid containers can be microwaved, have long shelf-lives, and present excellent barrier capabilities against light, gases, and moisture.
Two Piece, or Draw Redraw (DRD) Cans – These cans are manufactured as two parts. The body and the lid. The body is created by pressing or stamping a sheet of metal into a pre-formed shape via a machine called a “cupping press”. The only seam is at the top end. Where the lid will be pressed and crimped on after the can has been filled with product.
Three Piece, or Welded Seam Cans – A three piece, welded seam can consists of the “body”, made from a sheet of metal that is rolled into a tube till the ends meet. Which are then welded together. The bottom end is pressed and crimped onto one end of the tube, and hermetically sealed. The other end of the new can is given a flange to the rim to allow for the customer to crimp on the lid once the can has been filled with product. Three piece cans are relatively simple to manufacture at any height and diameter. And are generally cheaper to manufacture.
Protective Coatings & Liners - Because most metals are not inert, and do interact to some degree to food products, using a polymer coating or a lacquer or enamel liner can dramatically improve the freshness, taste, and storage life of food packaged in said metal cans. Polymer Coatings and Lacquer Liners are applied to the metal during the manufacture of the metal can.
Polymer Coated Cans – Typically, sheet steel is coated in a specific plastic polymer (usually sprayed on) prior to being formed into cans. Thereby creating an effective barrier against the transfer of light, moisture, and gases. Additionally, the polymer coating helps eliminate the possibility of the metal interacting with the natural acids of food products like tomatoes and pineapples, improving taste. As well as helping to prevent against corrosion of the metal. Polymer coatings can be applied to both interior and exterior surfaces of the metal food can.
Lacquer/Enamel Lined Cans – Similar to polymer coatings, only a different material. Like polymer coatings. Lacquer/enamel liners provide an effective barrier between the metal and the product stored within. They are applied (usually via rollers directly to the metal plates) and baked in large ovens till a dry, hard film of resin is left covering the metal. Lacquer/Enamel lined cans provide additional protection from interaction with the product, against corrosion of the can, as well as resisting damage from outside sources. (Dents, scratches, abrasions). Lacquer/Enamel liners can be used internally and externally. And can be tinted with color.
Are Polymer Coatings and Lacquer/Enamel Liners Safe? – Some of the sealants used today contain small amounts of Bisphenol A (BPA). Yes, it is possible that some of the BPA may leach from the liner into the food product. The FDA is aware of BPA and has been conducting an ongoing safety review into BPA and canned foods. As of the writing of this blog, the FDA research indicates the amounts of BPA found in cans and absorbed by foods Is SAFE for humans to consume. The FDA's National Center for Toxicological Research (NCTR) have shown no effects of BPA from low-dose exposure.
If you would like to learn more, we have a link to the FDA website for you to follow at the end of this blog. However, if you are STILL worried about BPA content in metal can liners, here are some simple practices that you can do to help reduce the amount of possible BPA being absorbed by the contents of any metal can.
Store canned foods in cool, dry places. Do not cook the product in the cans. (It’s a CAN not a cook pot. It’s not designed for that.) And once you’ve opened the can, do not use it as a leftover container. These simple practices will help you limit the amount of BPA entering your food.
Best Ways to Store Canned Food Products - Follow these guidelines to keep your canned food, safe, healthy, and delicious.
• Store Metal Food Cans in a cool, dark, dry place.
• Rotate the cans so that older ones are used first.
• Canned meats and seafood can be considered Safe if used within 3 years of the date on the package.
• Canned low-acid fruits and juices can be considered Safe within 3 years of the date on the package. However, high-acid foods like fruit, pickles and tomatoes should be used within 2 years of the date on the package.
You may safely consume food from cans stored longer than the maximum suggested time of 5 years, provided you have confirmed that the cans are not damaged, bloated, or corroded. But it’s likely that the foods may have started to lose their color, nutritional value, and taste.
Have more questions? - If you would like more information, give us a call! Our support team is standing by during regular business hours to help. Please contact our customer service team
Resources – Sources and links for more information.
More detail on the structure of metal cans: link
The delicious history of the tin can – Amanda Haffeler: link
FDA U.S. Food & Drug Administration website – BPA research: link
