Overview of the Drying Process in Food Can Production

Overview of the Drying Process in Food Can Production

The main production process of food three-piece can bodies includes shearing, welding, welding seam repairing and coating drying, necking, flanging, beading, sealing, leak testing, overall coating and drying, and packaging. Today, we will focus on explaining the drying process:

Drying is essential to ensure that the overall coating material is dried and cured, forming a dense barrier that isolates the can body from its contents to prevent leakage.

The main components of the drying equipment include the furnace body, gas ignition device, box insulation layer, heating blower and duct, waste gas recovery blower and duct, cooling fan unit, conveyor mesh tensioning and transmission device, and electrical control system.

The drying furnace is divided into four sections: the heating zone, waste gas recovery zone, cooling zone, and outlet buffer zone. The key process parameters for drying are the temperature of the hot air in the heating zone and the mesh speed (which determines the baking time). The setting and stable operation of these two parameters directly affect the overall coating baking effect.

After spraying, the empty cans are required to be dried in the oven (generally set at 180~210°C for 3~5 minutes). After drying and curing, there should be no odor, and the inner wall should be free from foaming or yellowing. The curing of the coating is tested by a steaming test in a high-temperature sterilization pot (usually using steam or boiling water at 121°C for 30 minutes), and it should show no whitening, peeling, or detachment.