A can seamer is a piece of equipment people use to close cans by affixing a cover and crimping to make a tight seal. The size of the machine can vary from a can seamer for home canning use that a person can operate by hand to an industrial-sized machine for an assembly line. Numerous manufacturers produce can seamers and related products, and people can purchase them new or used. It may also be possible to rent equipment for canning, for one-time use.
The can seamer works by deforming the edges of a metal plate around the ends of a can to compress them together, creating a tight seal. In addition to metal cans, companies can also use plastic or cardboard. The tightness of the seal depends on the materials and the machine. Some can seamers create a very reliable, tight seal to protect canned goods from oxidation and bacterial contamination. Others make a looser seal, and the can may leak in some situations.
Many can seamers are attached to a vacuum machine. This allows the worker to remove air from the can before sealing it to maintain the integrity of whatever is inside. A small machine may need to be cranked by hand to seal the can, while automated machines use hydraulic or mechanical systems to move the can seamer. Machines for sealing by hand tend to be less expensive to operate, but the number of cans that can be produced are limited by the abilities of the operator.
On the floor of a factor, workers regularly clean and inspect can seamers to make sure they are working properly. With food, it is critical to avoid bacterial contamination or other forms of spoilage, and keeping equipment in good working order is an important part of quality control. The cans may also need to be periodically inspected to confirm the reliability of the seal. If cans start to leak or develop other problems, they will need to be returned to the can seamer to see if the source of the problem can be determined.
Costs for this kind of equipment vary. Manual can seamers are much less expensive than machines designed for the assembly line. Sometimes buying used can seamers can be a cheaper option. People setting up a canning operation may want to look into lease or rental to get started.