Application of the Atonm 900E Double-Sheet Material Sensor in Three-Piece Can Automated Production

Three-piece cans commonly consist of a body, bottom and lid. The body typically has a longitudinal seam, and because these cans are usually produced from tinplate, they are also called tinplate cans. Tinplate cans are widely used for food, beverages, powders, chemicals and aerosols.

These cans have been used for nearly 200 years. Although improved many times, they are fundamentally made from three metal panels and thus called "three-piece cans".

The shapes, sizes and manufacturing methods of the can bottom and lid are the same and are collectively called the lid.

Longitudinal seam sealing mainly uses soldering or welding. Historically, soldered cans were used but were phased out due to lead in solder. Welding and other advanced edge-joining methods such as laser welding and adhesive bonding have since been developed to reduce pollution and energy consumption, though equipment is more complex.

Can manufacturing process:

Body: cut plate → feed → form into cylinder → lap joint positioning → resistance welding → trimming → drying → flipping → ironing → necking (for beverage cans)

Painting → blanking → stamping lids → flange sealing → curing

Finally, inspect can bodies and lids for quality.

During processing of metal sheets for three-piece cans, double-sheet overlaps commonly occur due to material handling issues. The Atonm 900E Double-Sheet Detector is specifically designed for metal sheet single/double detection. In can production it can accurately identify single vs double sheets and output a double-sheet signal to the PLC so that the PLC can remove or bypass double sheets.