Closing of metal cans is performed by a can seamer. This machine seals the can bottom and lid to the can body. The seam that is formed in this process is leak-proof.
The metal food can is more than 200 years old. Today it remains one of the most economical, environmentally friendly and, above all, safest packaging forms.
It all started in 1809 when frenchman Nicholas Appert had the idea of packing food into bottles, like wine. It was only in the early 1900s that double seaming was first applied.
The first modern cans were three-piece soldered cans. In 1963 the first two-piece cans were introduced and were received with enthusiasm because they typically used less steel. Today, grocery shoppers today can select from an array of easy-to-use and convenient metal packages, including: containers with twist-top, resealable lids, easy-open cans with pull-tab lids made with steel, aluminum or plastic and even distinct, easy-to-grasp metal cans shaped like bowls, kettles and even squares.
Environmental and nutritional benefits:
Environmental conscious consumers can rejoice because the food can is 100 percent recyclable. They’re recycling rate is more than two-and-a-half times higher than that of most other packaging options. Steel food containers can be recycled again and again without losing strength or quality. Once the cans are sealed and heat processed, the food maintains its high quality for more than two years.
The seam is made by mechanically overlapping the two layers to form a hook. Different parameters of the hook are measured and monitored to check the integrity of the seam under different conditions. The shape of the double seam is determined by the shape of the seamer roll profile and the relative position. During the can seaming process, the seamer chuck holds the can while the rolls rotate around it. Initially, the first operation roll folds the lid (end) and then the second operation rolls tightens the resulting seam. The first operation seam is critical to avoid problems like wrinkles (tightness issues) and leaks. The shape of the seam is determined by the shape of the first operation roll, the second operation roll, their relative positions and distances, lifter height, lifter pressure.