Metal Packaging Wiki

Understand standard metal containers and rigid processing practices.

Why Metal Packaging

With outstanding barrier properties, mechanical strength and shelf appeal, metal packaging holds an important place in food, beverage and cosmetics. The main formats are beverage cans, three-piece cans, tin boxes and aluminum cans.

🛡️ Total Barrier

Blocks 100% of light, oxygen and water vapor — excellent shelf life

💪 High Strength

High mechanical strength; resists pressure, impact and puncture

♻️ Recyclable

100% recyclable — environmentally sustainable

✨ Premium Feel

A metallic look that lifts brand image

Types of Metal Packaging

🥫 Two-Piece Can (Beverage Can)

Body and base are drawn as one piece and only the end is added — the most advanced metal can format.

Material:

Aluminum alloy (3104), tinplate

Typical Uses:

Carbonated soft drinks, beer, energy drinks, ready-to-drink tea

Specs:

Wall thickness: 0.25-0.35 mm | Common volumes: 200-500 ml

Advantages:

Excellent seal integrity, high line speed, high material yield, low cost

🥫 Three-Piece Can

Assembled from body, end and base, allowing many sizes and shapes.

Material:

Tinplate, tin-free steel (TFS)

Typical Uses:

Canned food, dry goods, cosmetics, lubricants

Specs:

Wall thickness: 0.15-0.30 mm | Volume range: 100 ml-5 L

Advantages:

Flexible sizing, shaped cans possible, large print area

🥤 Aluminum Can

All-aluminum, light, high recycling value and well sealed — the mainstream for beverages.

Material:

Aluminum alloy 3104 (body), 5182 (end)

Typical Uses:

Carbonated soft drinks (cola, lemon-lime), beer, energy drinks

Specs:

Standard can: 330 ml (Ø66 mm × 115 mm high)

Advantages:

Light (13-15 g), 100% recyclable, chills quickly

🎁 Tin Box

A box-shaped pack made of tinplate, well suited to gifts and premium foods.

Material:

Tinplate (0.20-0.30 mm)

Typical Uses:

Tea, mooncakes, biscuits, confectionery, cosmetics

Shapes:

Square, round, shaped (heart, book and more)

Finishing:

Offset printing, foiling, embossing, holographic effects, windows

💨 Aerosol Can

A high-pressure sealed can with a valve and actuator, used for spray products.

Material:

Aluminum alloy, tinplate (wall thickness 0.30-0.40 mm)

Typical Uses:

Insecticides, air fresheners, sunscreen sprays, hairspray

Pressure Rating:

Working pressure: 0.6-1.2 MPa | Burst pressure: ≥1.5 MPa

Safety:

Must meet GB/T 14449, with pressure and leak testing

🥫 Food Can

A three-piece structure, retort sterilized for a long ambient shelf life.

Material:

Tinplate with an internal coating (corrosion and acid resistant)

Typical Uses:

Canned fruit, meat, seafood and beans

Sterilization:

Pasteurization (85°C) or retort sterilization (121°C)

Shelf Life:

2-3 years at ambient temperature with stable nutrient retention

Metal Packaging Materials

🔸 Tinplate

Definition: Low-carbon steel base with tin coating on both sides (1-12 g/m²)

Properties:

The tin layer provides corrosion resistance
Weldable and easy to print
Relatively low cost
Magnetic, so easy to sort for recycling

Specs: Thickness 0.15-0.50 mm

Applications: Food cans, tin boxes, cosmetic boxes

🔸 Aluminum and Aluminum Alloys

Common Alloys:

3104 — can body (balanced strength, good formability)
5182 — can end (high strength, good opening performance)
8011 foil — sealing gaskets

Properties:

Light weight (density 2.7 g/cm³)
Good corrosion resistance
100% recyclable
Chills quickly

Applications: Beverage cans, beer cans, energy drinks

🔸 Tin-Free Steel (TFS)

Definition: Tin Free Steel — chromium-coated steel

Coating: A metallic chromium layer plus a chromium oxide layer

Properties:

10-15% cheaper than tinplate
Good corrosion resistance
Excellent printability
Not weldable — must be bonded

Applications: Beverage cans, food cans, cosmetic cans

🔸 Internal Coating Systems

Purpose: Separates the metal from the contents, preventing corrosion and contamination

Coating Types:

Epoxy phenolic — general purpose (food, beverages)
Polyester — acid resistant (juices, carbonated drinks)
Acrylic — dedicated to beer
Fluoropolymer — high corrosion resistance (seafood, meat)

Thickness: 3-8μm

Metal Can Manufacturing

Two-Piece (Beverage) Can Production Flow

📋

Blanking & Cupping

Aluminum coil → blanks

🔨

Drawing & Ironing

Body and base formed as one

✂️

Trimming & Necking

Can mouth necked in

🎨

Printing & Coating

External print plus internal coating

🔐

Filling & Seaming

Double seaming

🖨️ Printing

• Body printing — offset or dry offset, 4-6 colors
• End printing — tab and end-panel printing
• Tin box printing — offset plus foiling and embossing
• Coding — production date and batch number

🔗 Closing Processes

• Double seaming — the standard beverage can closure
• Welding — the side seam of a three-piece can body
• Press-on lids — tin box closures
• Screw closures — threaded can caps

Quality Standards and Testing

🔍 Visual Inspection

• No scratches or dents on the surface
• Sharp printing with accurate color
• Complete seams with no gaps
• Dimensional tolerance ±0.5 mm

💧 Seal Integrity Testing

• Hydraulic pressure test (0.3-0.5 MPa)
• Vacuum test (-60 kPa)
• Leak detection (bubble method)
• Drop test (1.2 m)

🧪 Material Testing

• Tin coating weight
• Coating thickness
• Corrosion resistance
• Heavy metal migration

💡 How to Choose Metal Packaging

1. By product type:

Carbonated drinks → aluminum two-piece can (pressure resistant, well sealed)
Beer → aluminum or steel can (blocks light and oxygen)
Canned food → three-piece can with internal coating (withstands retort)
Cosmetics → tin box (premium feel, moisture protection)
Aerosol products → aluminum or steel aerosol can (high pressure rating)

2. Cost considerations:

Aluminum can > Tinplate can > TFS steel can
Two-piece cans run fast and are cheaper at high volume
Three-piece cans suit small runs and many SKUs

3. Sustainability requirements:

Aluminum cans have the highest recycling value — the greenest choice
Tinplate cans are 100% recyclable and magnetic, so easy to sort
Choose water-based internal coatings to cut VOC emissions

Factory Direct Custom Packaging & Prototypes

Need Production Quotes or Custom Sized Boxes?

TadaPack (www.tadapack.com) offers direct factory manufacturing for corrugated shipping cartons, mailer boxes, rigid gift boxes, and eco-friendly protective packaging with instant online quotes and free vector CAD dielines.

Visit TadaPack.com