The metamorphosis of aluminum ingots into high-performance foil containers represents a feat of materials engineering and precision manufacturing. This process bridges metallurgical science, industrial automation, and food safety compliance to create sustainable, high-barrier packaging solutions.

Section 1: Raw Material Selection & Metallurgical Foundations

• Alloy Specifications

  Alloy Series	Key Elements	Application Suitability
  8000-series	Fe 0.5-1.0%, Mn <0.3%	Food containers (pH>4.0)
  3000-series	Mn 1.0-1.5%, Mg 0.8-1.3%	High-strength trays

• Ingot Quality Control

  • Hydrogen content: <0.15 ml/100g Al

  • Inclusion size: ≤20 μm

Section 2: Precision Rolling – From Slab to Foil

• Hot Rolling Process

  • Temperature: 480-520°C

  • Thickness reduction: 600mm → 6mm in 5 passes

• Cold Rolling Critical Parameters

  Stage	Entry Thickness	Exit Thickness	Reduction %
  Breakdown	6 mm	0.7 mm	88%
  Finishing	0.7 mm	0.05-0.2 mm	71-93%

• Annealing Protocols
  Batch annealing at 340-380°C for 8-12 hours to restore ductility

Section 3: Container Forming Technologies

• Mechanical Pressing

  • Force range: 200-800 tons

  • Stroke speed: 30-70 cycles/minute

• Impact Extrusion

  • Pressure: 1,500-2,500 bar

  • Wall thickness tolerance: ±5%

• Critical Tooling Specifications

  • Tool steel hardness: 58-62 HRC

  • Surface finish: Ra ≤0.2 μm

Section 4: Quality Assurance & Performance Testing

• Barrier Property Validation

  Test	Standard	Requirement
  Water Vapor Transmission	ASTM E96	<0.01 g/m²/day
  Oxygen Permeability	ASTM D3985	<0.05 cc/m²/day

• Mechanical Strength Testing

  • Stacking resistance: ≥150 kg for 24h

  • Edge crush resistance: ≥180 N

Section 5: Surface Engineering & Coatings

• Lacquer Application Systems

  Coating Type	Thickness	Acid Resistance
  Epoxy-phenolic	3-5 g/m²	pH ≥3.0
  Polyester	4-6 g/m²	pH ≥2.5

• Corrosion Protection
  Chromating treatment: 10-50 mg/m² Cr⁶⁺