How Aluminum Beverage Cans Are Made: Complete Manufacturing Process

Step 1: Aluminum Coil Preparation

Manufacturing begins with aluminum coils, typically 3104-H19 alloy for body stock and 5182-H48 for end stock. These alloys provide the perfect balance of formability and strength.

• Coils arrive at the factory
• Chemical composition verified
• Surface cleaned and lubricated

Step 2: Cupping

The aluminum strip is fed into a cupping press that forms circular blanks into shallow cups. This process reduces the width while creating the initial can shape.

• Multiple cups punched from strip
• Each cup is the diameter of the finished can
• High-speed process: thousands per minute

Step 3: Drawing & Ironing

Cups are transferred to the draw-and-iron (D&I) press, where they are drawn through a series of rings to reduce wall thickness while increasing height. This creates the iconic tall can profile.

• Wall thickness reduced from 0.3mm to 0.08mm
• Can height increases dramatically
• Multiple ironing rings create smooth walls
• Base remains thicker for pressure resistance

Step 4: Trimming

The drawn can has a slightly irregular top edge that must be trimmed to exact height. Rotary trimmers cut the open end to precise specifications.

Step 5: Cleaning & Coating

Cans are thoroughly cleaned and dried before applying internal and external coatings.

• Internal coating: Sprayed on to protect product (BPA-NI or epoxy)
• External coating: Base lacquer for print adhesion
• Curing ovens bake coatings at 200°C

Step 6: Printing

External decoration is applied using offset lithography, typically in 6-8 colors. The printed can passes through a varnishing station for protection.

• CMYK process colors + spot colors
• Decoration wraps around entire can
• UV or thermal curing
• Gloss, matte, or tactile finishes

Step 7: Necking

The open end of the can is necked in—a process that gradually reduces the diameter to accept the easy open end. Multiple necking rings create the tapered profile.

• Diameter reduced to accept end (200, 202, or 206)
• Typically 3-5 necking steps
• Precise tolerances critical for sealing

Step 8: Flanging

The necked end is flanged outward to create the sealing surface where the end will be attached during filling.

Step 9: Quality Testing

Every can undergoes rigorous quality control:

• Pressure burst testing (minimum 6.2 bar)
• Dimensions verified (diameter, height, neck)
• Coating thickness measurement
• Visual inspection for defects

Step 10: Packaging & Shipping

Finished cans are packed in export-grade cartons with protective materials. Pallets are stretch-wrapped and containerized for shipping.

• 3,600-4,800 cans per carton
• Interleaved for protection
• Sealed and labeled