First, the iron plate is cut into rectangular iron pieces, the blank is rolled into a cylindrical shape, and the joints at both ends are longitudinally soldered to form a cylindrical shape. One end of the cylinder and the round end cap are rolled and sealed by a mechanical method, and the other end is put into a finished can lid to form a tinplate can. The container is divided into three parts: a can body, a can lid and a can bottom, so it is called a three-piece can.
Generally, three-piece cans are used for iron cans. Aluminum cans use two-piece can technology. The patch uses offset printing technology. Such three-piece jars are not easy to hold candles. It is easy to leak. If it is necessary, it is recommended to apply coating glue (excluding tax) to prevent wax leakage. Usually such three-piece cans also need to prevent rust on the outer surface, and still need to be printed.
Note in making three-piece cans: cut corners and cutouts before the end-folding process; during the soldering process, scrape the solder chips at the soldering place, turn the edges after cooling, and complete the can body.
→ Cooling → Flanging → Can body is complete.
The process of processing the can lid is as follows: cutting and tinning of the tinned sheet → oiling → punching → crimping → gluing → drying → can lid processing is completed.
The processing process for forming an empty can by combining the can body and the can lid is as follows: can body feeding → adding can lid → double crimping sealing → empty can processing is completed.