8079 aluminum foil is a thin, high-ductility foil from the Al-Fe-Si family, and its main purpose is to provide a light, flexible and essentially impermeable barrier at the lowest practical gauge. Double-zero foil rolled from 8079, commonly between 0.005 mm and 0.009 mm, is used wherever a converter needs a pinhole-resistant web that can be laminated, lacquered, printed or coated without cracking. In practice that means food packaging first, pharmaceutical packaging second, and flexible protective packaging for electronics and other moisture-sensitive goods third.
Composition: Why Iron and Silicon Matter
8079 contains no magnesium or manganese additions to speak of. Its properties come from a carefully balanced iron and silicon content, with iron deliberately kept higher than silicon so that fine iron-bearing dispersoids form during casting and rolling.
| Element | Typical range (wt %) | Why it is controlled |
|---|---|---|
| Fe | 0.70 - 1.30 | Raises strength, improves high-temperature creep resistance |
| Si | 0.05 - 0.30 | Kept low relative to iron for ductility and pinhole control |
| Cu | 0.05 max | Low copper for food contact and corrosion |
| Mn | 0.05 max | Residual |
| Mg | 0.05 max | Residual |
| Zn | 0.10 max | Residual |
| Ti | 0.05 max | Grain refinement |
| Al | Balance | Matrix |
Because the dispersoids remain stable at annealing temperature, 8079 foil keeps useful strength in the soft O temper instead of fully collapsing. That is the property converters rely on when they run very thin foil through high-speed lacquering, printing and lamination lines.
Main Uses by Sector
| Sector | Typical product | Why 8079 is selected |
|---|---|---|
| Food and beverage | Lidding for dairy cups and ready meals, chocolate and confectionery wrap, laminated pouches, sachet stock | Light, grease resistant, heat sealable in laminate form |
| Pharmaceutical | Blister pack backing foil, strip packs, powder sachets | Moisture, light and oxygen barrier with good forming behaviour |
| Electronics | Moisture-barrier bags and laminates for components, shielding layers | Thin, flexible, electrically conductive and impermeable |
| Industrial | Insulation and vapour-barrier facing, cable and duct wrapping | Reflective surface and low vapour transmission |
| Tobacco and premium goods | Inner liners and decorative wraps | Smooth surface for printing, dead-fold behaviour |
The food and pharmaceutical applications dominate consumption because they combine the two properties 8079 is chosen for: total opacity from about 0.006 mm upward, which blocks light, and a barrier against moisture, oxygen, grease and aroma that a polymer film cannot match at the same weight.
Barrier Performance and Pinhole Control
Aluminium foil is inherently impermeable, so the practical barrier question is not permeability but pinhole population. A bare foil with an excessive pinhole count behaves like a sieve regardless of its nominal thickness, which is why foil specifications pair a gauge tolerance with a maximum pinhole count per square metre. In a sound laminate the measured water-vapour transmission rate falls to negligible levels, and converters commonly specify a limit below 0.1 g per square metre per 24 hours for the finished structure.
| Property | Typical performance |
|---|---|
| Thickness range | 0.005 - 0.009 mm for double-zero foil |
| Light transmission | Fully opaque at 0.006 mm and above |
| Water-vapour barrier | Effectively impermeable when pinhole-free |
| Oxygen barrier | Effectively impermeable in a sound laminate |
| Grease and aroma barrier | Complete |
| Dead-fold behaviour | Excellent, holds a crease without springback |
Production Route, Temper and Thickness
8079 foil begins as direct-chill cast rolling slab, is hot rolled to coil, cold rolled down to intermediate gauge, and then finished on foil mills where two webs are rolled together and separated afterwards to reach the thinnest gauges. Annealing and surface treatment follow, with degreasing and controlled wettability the usual finishing steps before despatch.
Temper O: fully soft, maximum elongation, used for lidding, wrap and demanding forming operations.
Temper H18: hard rolled, higher stiffness, used where foil acts as a structural or insulation facing layer.
Thickness: 0.005 mm to 0.009 mm for barrier packaging; heavier gauges for semi-rigid containers and trays.
Standards: foil products are commonly ordered to the general aluminium foil specification covering dimensions and tolerances, or to the annealed-foil specification used for flexible barrier applications, with composition controlled under the relevant wrought aluminium composition standard.
Selection Notes: 8079 Against 8011 and 1235
| Grade | Character | Best fit |
|---|---|---|
| 8079 | High iron, high ductility, low pinhole count | Thinnest barrier foils, food and pharma laminates |
| 8011 | Higher silicon and manganese tolerance, greater strength | Slightly thicker lidding, closures, fin stock |
| 1235 | Near-pure aluminium, softest and most conductive | Insulation facing, cable wrap, low-strength laminates |
Where the requirement is the lowest possible weight per square metre with reliable barrier, 8079 is the default. Where extra strength or stiffness at a slightly heavier gauge is acceptable, 8011 usually costs less. Where electrical or thermal conductivity matters more than strength, a near-pure foil such as 1235 is the better fit.
Frequently Asked Questions
Q: What is the main purpose of 8079 aluminum foil?
Its main purpose is lightweight barrier packaging. It is used for food and beverage packaging, pharmaceutical blister and sachet structures, flexible laminates and protective packaging for electronics.
Q: What thickness is 8079 aluminum foil supplied in?
Barrier packaging typically uses 0.005 mm to 0.009 mm double-zero foil, while thicker gauges are used for semi-rigid trays and container applications.
Q: Does 8079 aluminum foil resist corrosion?
Yes. With low copper, manganese and magnesium residuals, the foil forms a stable oxide layer and remains stable in normal packaging and storage environments.
Q: How is 8079 aluminum foil produced?
It is cast, hot rolled, cold rolled to intermediate gauge and then finish rolled on foil mills, followed by annealing, degreasing and surface treatment to meet the converter's requirements.
Q: What are the advantages of 8079 aluminum foil?
High ductility that allows very thin gauges, a low pinhole count, complete opacity, an excellent moisture and grease barrier, good dead-fold behaviour and reliable performance on high-speed converting lines.
Q: Can 8079 foil be laminated with paper or film?
Yes. It is routinely laminated with paper, polyethylene and other polymers, and in that structure it supplies the barrier while the partner material supplies sealability and mechanical support.
