From family-size to institutional-size, metal food cans of all sizes can be found in most commercial kitchens. Boasting benefits like long-term food quality, product shelf life, and safety in packaging, food cans are a pivotal force in the way that consumers shop, cook, and eat – providing safe, economical, and nutritional food options. Want to learn more about these everyday essentials? Read on!
It's no secret that the vast majority of Americans need to eat more fruits and vegetables; and, these foods, in their fresh or frozen form, tend to be much more expensive than in their canned form. But, did you know that, according to food industry experts, canned fruits and vegetables are on par nutritionally with fresh or frozen varieties, and in some cases, may even be healthier? Whereas fresh fruits and vegetables lose nutritional value each day, and frozen products lose it via oxidation, canned foods are canned at the peak of ripeness and typically retain their nutritional attributes for far longer.
Perhaps the greatest impact the can has had is its effect on the environment. Long before the cry for eco-smart and eco-friendly was the norm, can manufacturers were quietly committed to sustainability by providing a virtually effortless way to go green: cans are infinitely recyclable. Below are some fun facts from the Can Manufacturer's Institute and The Aluminum Association:
- An aluminum beverage container can be recycled and back on the shelf in 60 days
- Steel food containers can be recycled multiple times without losing strength or quality
- The recycling rate of the steel food can is more than 2.5 times higher than other packaging options
- Recycling one aluminum can saves enough energy to listen to a full album on an iPod
- Every ton of recycled steel saves 2,500 pounds of iron ore, 1,000 pounds of coal and 40 pounds of limestone
- Aluminum is one of the most recycled -- and most recyclable -- materials on the market today. Nearly 75 percent of all aluminum produced in the U.S. is still in use today
With so many immediate and long-term benefits, the can has certainly left its mark throughout history – and with constant recycling, will continue to do so.
Dimensional Food Can Standards
Most recipes will specify a can size rather than a volume amount. Knowing the sizes and capacities of the most common cans on the market is imperative when planning meals in the food service industry: restaurants, cafeterias, day care centers, and more rely on canned goods as a quick, economical way to serve their patrons.
In the United States, metal cans are measured prior to seaming on the packers' end. These dimensions are nominal in nature and, while they may be expressed in inches, the custom is to use a conventionalized method in which three-digit numbers are used to express each dimension.
The first digit indicates the number of whole inches in a dimension, and the second and third digits indicate the fractional inches as sixteenths of an inch.
The first three-digit number indicates the diameter measured across the outside of the chime on the seamed end. The second three-digit number indicates the overall height of the can. Thus:
- 303 x 406 means 3 3/16 x 4 6/16 inches
- 307 x 512 means 3 7/16 x 5 12/16 inches
- 603 x 700 means 6 3/16 x 7 inches
Types of Food Cans
Aside from sizing, it's important to understand how the cans you purchase are produced. From a manufacturing standpoint, food cans can be assembled from two or three pieces of metal, and they are classified as either made from aluminum or steel, depending on the can-body material.
Two-piece metal food cans consist of:
- a body integrated with a bottom lid and
- a lid with a lip
These types of cans are made using a drawing process, in which a coil of coated rolled steel or aluminum is fed into a press and formed into a cup shape object, complete with a flat, round bottom and cylindrical side walls.
The cups then go through another drawing phase (the redraw) to achieve the final shape (DRD, draw and redraw cans), or they may go through a wall ironing phase (DWI, draw and wall ironing cans), which results in the cup walls being stretched and ironed to a predetermined height. Regardless of the can being redrawn or ironed, the final step is to trim the cup into a finished container before filling and sealing on the top lid via "double seaming".
Three-piece metal food cans feature:
- a bottom lid,
- a cylindrical body, and
- a top lid
These cans are made with a rectangular, flat sheet of food-grade steel that's shaped into a cylinder and closed with a vertical side seam. The bottom end is then attached via "double seaming" to create a hermetic seal. Once filled, the can is sealed closed at the top with a similar seal to the bottom. Three-piece cans can either be assembled via soldering or welding, depending on the manufacturer.