Pinholes
Counted against light per square metre. They increase sharply below about 12 µm and depend on metal cleanliness and rolling practice.
Rolled flat products
Aluminium Foil Grades: 8011, 1235 & 8079
Aluminium foil is aluminium rolled thinner than about 0.2 mm, used wherever a light, formable and complete barrier to light, oxygen and moisture is needed: household wrap, food containers, blister packs, lids, cable wrap, battery electrodes and heat-exchanger fins. The main alloys are 1235, 8011, 8079 and 8021, with 3003 and 8006 for containers. Metline supplies plain and converter-ready foil rolls to EN 546 and ASTM B479 worldwide.
- Alloys
- 1235, 8011, 8079, 8021, 3003
- Gauge
- 6 – 200 µm
- Tempers
- O, H18, H22, H24
- Standards
- EN 546 · ASTM B479 · EN 602
What is aluminium foil?
Foil is the thinnest product a rolling mill makes. Standards put the upper limit at about 0.2 mm (200 µm); thicker material is sheet or strip. Household foil is typically 9 – 25 µm, while the thinnest converter foils go down to about 6 µm.
Foil is rolled from foil stock (usually 0.3 – 0.7 mm coil) through several passes on a foil mill. For the last pass, two strips are rolled together, which is why household foil has one bright side, that touched the polished rolls, and one matt side, that touched the other strip. The finished foil is slit and either annealed to soft O temper, which also burns off rolling oil, or left hard (H18) for applications that need stiffness, such as blister lids.
Rolled foil of about 17 µm and above is effectively impermeable to gases, water vapour and light. Thinner gauges may contain a small number of pinholes, which is why barrier laminates use foil with polymer layers and why alloy choice matters at thin gauges.
Foil alloys and what they are used for
| Alloy | Composition | Strengths | Typical uses |
|---|---|---|---|
| 1235 | ≥ 99.35 % Al | Very ductile, high conductivity | Household foil, laminates, cable wrap, battery foil |
| 1145 / 1100 | ≥ 99.45 % / ≥ 99.0 % Al | Pure and formable | Flexible packaging, insulation, fin stock |
| 8011 | Al-Fe-Si | Higher strength than 1235, good formability | Household and container foil, lids, pharmaceutical blisters, fins |
| 8079 | Al-Fe (low Si) | Very good ductility, low pinholes at thin gauges | Thin packaging foil, laminates, cigarette foil |
| 8021 | Al-Fe-Mn | High strength and puncture resistance | Cold-form blister (Alu-Alu), battery pouch laminates |
| 3003 / 8006 | Al-Mn / Al-Fe-Mn | Higher strength and stiffness | Semi-rigid food containers and trays |
Tempers and typical foil properties
| Temper | Condition | Typical tensile strength | Used for |
|---|---|---|---|
| O | Fully annealed, soft, clean and dry | 60 – 110 MPa (by alloy) | Household foil, laminates, containers, cold-form blister |
| H22 / H24 | Partially annealed | 100 – 150 MPa | Container foil, lids, fins |
| H18 / H19 | Full hard, as rolled | 150 – 200 MPa | Blister lidding, capacitor and battery foil, cable wrap |
Typical ranges for 1235 and 8011 foil around 20 – 50 µm; elongation is low at thin gauges and depends strongly on alloy. EN 546-2 gives the specified limits by alloy, temper and gauge.
Physical properties (1235)
- Density
- 2.705 g/cm³
- Thermal conductivity
- About 230 W/m·K
- Electrical conductivity
- About 61 % IACS
- Reflectivity
- Bright side reflects most visible light and infrared
Gauges, widths and roll formats
| Application | Typical gauge | Typical alloy and temper |
|---|---|---|
| Household foil | 9 – 25 µm | 8011-O, 1235-O |
| Flexible packaging laminate | 6 – 12 µm | 1235-O, 8079-O |
| Pharmaceutical blister lid (PTP) | 20 – 25 µm | 8011-H18, 8021-H18 |
| Cold-form blister (Alu-Alu) | 45 – 60 µm | 8021-O, 8079-O |
| Lidding and induction seals | 30 – 50 µm | 8011-O / H22 |
| Food containers | 30 – 200 µm | 8011, 3003, 8006 in O, H22, H24 |
| Battery current collector | 10 – 20 µm | 1060, 1070, 1235 in H18 |
| Air-conditioner fin foil | 90 – 200 µm | 8011, 1100, 3102 in H22 – H26 |
Roll formats
- Width
- Narrow slit rolls up to about 1600 mm jumbo rolls
- Core
- Aluminium or steel cores, commonly 76 mm (3 in) or 152 mm (6 in) inside diameter
- Surface
- One side bright / one side matt, or both sides bright
- Treatment
- Plain, lacquered, embossed, coloured, hydrophilic or primed for lamination
Foil area per kilogram is 1 / (gauge × density). One kilogram of 10 µm foil covers about 37 m²; one kilogram of 20 µm foil about 18.5 m².
Quality properties converters care about
Wettability
Annealed foil must be free of rolling oil so inks, lacquers and adhesives bond; checked with the water or alcohol brush wettability tests described in EN 546-4.
Gauge tolerance
Usually around ±5 – 8 % on thin foil, tighter for battery and capacitor foil.
Flatness and profile
Edge waves and centre buckles cause wrinkles on laminators and coaters.
Mechanical properties
Tensile strength, elongation and burst strength matter for blister, container and battery foil.
Surface
Free from oil stains, streaks, corrosion and roll marks; bright-side reflectivity for decorative uses.
Foil standards and food-contact rules
| Standard | Scope |
|---|---|
| EN 546-1 to -4 | Foil: technical conditions, mechanical properties, tolerances and special properties |
| ASTM B479 | Annealed and intermediate-temper aluminium foil for flexible barrier, food contact and other uses |
| ASTM B373 | Aluminium foil for capacitors |
| EN 602 | Chemical composition of wrought products for food contact |
| EN 573-3 | Chemical composition of wrought alloys |
Where aluminium foil is used
- Food packaging: household wrap, trays and containers, lids, chocolate and confectionery wraps
- Pharmaceutical: blister lidding, Alu-Alu cold-form packs, sachets and strip packs
- Flexible packaging: laminated pouches, coffee and snack packs, aseptic cartons
- Electrical and battery: lithium-ion cathode current collectors, pouch-cell laminates, capacitor and cable foil
- Thermal and building: air-conditioner fins, insulation facings, duct tape, roofing laminates
References and standards
- EN 546-2 – Foil: mechanical properties
- ASTM B479 – Annealed Aluminum and Aluminum-Alloy Foil for Flexible Barrier, Food Contact, and Other Applications
- EN 602 – Wrought products: chemical composition of semi-finished products used for articles in contact with foodstuff
- European Aluminium Foil Association (EAFA) – technical information on aluminium foil
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
Aluminium (aluminum) foil: frequently asked questions
What is the difference between 8011 and 1235 foil?
1235 is almost pure aluminium (at least 99.35 % Al) and is very soft and conductive. 8011 contains iron and silicon, which make it stronger and stiffer, so it is preferred for containers, lids and blister packs.
Why is one side of foil shiny and the other matt?
In the final pass two foils are rolled together. The sides touching the polished steel rolls come out bright; the sides touching each other are matt. Both sides perform the same.
What thickness is household aluminium foil?
Standard household foil is about 10 – 13 µm and heavy-duty foil about 18 – 25 µm.
Is thin aluminium foil a complete barrier?
Foil of roughly 17 µm and thicker is essentially pinhole-free and a complete barrier. Thinner foils may have a few pinholes, so they are laminated with plastic films for barrier packaging.
Which foil is used for lithium-ion battery cathodes?
Hard (H18) 1060, 1070 or 1235 foil about 10 – 20 µm thick, with tight gauge and surface cleanliness control, is used as the cathode current collector.
Can you supply foil in jumbo rolls for converters?
Yes. Foil can be supplied as jumbo or slit rolls on your core size, plain or treated, with a certificate for each lot.
Buying aluminium foil?
Send the alloy, gauge, width, temper and end use. We will reply with availability, certification and a delivered price.
