I. Raw Material Pre-treatment: Laying the Foundation for the Tank Body
Raw Material Cutting: Shearing machines cut rolled tinplate into rectangular sheets that meet the dimensions required for the can body. This ensures straight edges and dimensional accuracy with an error margin of ≤0.1mm.
Coating and Printing: Apply a food-grade inner coating to rectangular panels (to prevent contents from corroding the can body). The exterior is printed with patterns according to product requirements. After printing, the panels undergo drying and curing in a drying oven to ensure coating adhesion.
Slitting strips: Using a slitting machine, printed sheets are cut into long, narrow strips matching the can body's circumference. Simultaneously, burrs along the strip edges are removed to prevent misalignment or weld defects during subsequent welding.
II. Tank Body Forming: Creating the Cylindrical Structure
Rolling into Cylinders: Feed the slit strips into the rolling machine to form cylindrical can blanks. Ensure uniform overlap at the cylinder joint (typically 0.3-2mm, adjusted based on welding method), with circumferential deviation ≤0.2mm, preparing for side seam sealing.
Side Seam Sealing (Core Process): Fusion Welding Sealing Using resistance welding or self-consuming wire electrode fusion welding machines, the tank body blanks are processed with a narrow overlap of 0.3-0.5mm. They are then heated to a temperature slightly below the material's melting point. Simultaneously, the overlap area is expanded through roll forging, forming a tight weld seam to achieve both fixation and sealing of the tank body side seams.
Weld and Coating Finishing: After welding, remove slag, spatter, or excess filler metal from the weld surface (using a weld slag scraper/deburring machine). Reapply protective coating to exposed metal surfaces at the weld to prevent corrosion or contamination of contents. Re-bake after reapplication.
III. Post-Processing of Tank Hulls: Structural Reinforcement and Adaptive Assembly
Cutting of Split Tanks: To enhance production efficiency, the initial rolled-formed long cylinders are designed to be split into 2-3 tank bodies. At this stage, a trimming shear machine cuts the long cylinders into individual tank bodies, ensuring consistent height dimensions across all units.
Reinforced Structure: To enhance the can body's compressive strength adapting to external pressure or internal vacuum environments in food cans, corrugations or ribs are formed on the can surface using corrugating equipment, creating structural reinforcements.
End Flanging Process: Feed both ends of the tank body into the end bending machine (flanging machine) to form flanges matching the end caps, ensuring subsequent assembly and sealing integrity with the tank lid and bottom.
IV. Assembly and Inspection: Final Product Completion
Can Bottom Sealing: The can bottom is rolled and sealed to the flanged edge of the can body using a flange rolling machine, ensuring leak-free joints with sealing strength meeting industry standards .
Finished Product Inspection: Conduct airtightness testing using hydrostatic or pneumatic pressure methods, weld quality inspection, and dimensional accuracy verification on the containers. Reject non-conforming items such as leaking containers and weld defects.
Palletizing and Storage: Qualified three-piece containers are neatly stacked onto pallets, secured with protective measures, and transported to the warehouse for subsequent filling operations.
Chengdu Changtai Intelligent Equipment Co., Ltd.- A automatic can equipment Manufacturer and Exporter, provides all the solutions for Tin can making. To know the latest news of metal packing industry, Find new tin can making production line, and get the prices about Machine For Can Making,Choose Quality Can Making Machine At Changtai.
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Tel:+86 138 0801 1206 +86 18943602128
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Email:llz@changtaizn.cn cdctzg@changtaizn.cn
Post time: Nov-28-2025