Aluminium Foil & Industrial Foil Stock

1. What is aluminium foil and foil stock?

Foil is produced by cold rolling aluminium strip through successive passes to the final gauge, often double-rolling two layers together for the thinnest gauges, which produces one bright and one matte side. "Foil stock" refers to the rolled product before converting, supplied as coils to laminators, container makers and fin-stock processors. Thicker gauges used for fins and containers are sometimes called light-gauge or thin strip.

2. Which product types are traded?

3. Which terms appear in foil specifications?

Alloy (for example 1xxx or 8xxx series), temper (O for annealed, H-series for strain-hardened), gauge (µm or mm), width, coil inner and outer diameter, core type, bright or matte side, wettability (often stated as a water-brush or dyne test), pinholes per area, tensile strength and elongation, burst or Mullen strength, rolling-oil residue, degreasing, surface defects (streaks, oil stains, roll marks), flatness and camber.

4. Who buys foil?

Flexible-packaging converters, pharmaceutical blister and lidding laminators, container and tray producers, insulation and construction-product manufacturers, cable makers, HVAC and automotive heat-exchanger producers, and battery cell and electrode manufacturers. Each starts from a different converting process and so ranks properties differently.

5. How do alloy and temper affect behaviour?

Commercially pure 1xxx alloys offer good formability and conductivity; 8xxx alloys (with iron and silicon) are widely used for thin packaging foil because they can reach higher strength and better pinhole behaviour at thin gauge. Annealing to O temper softens the foil for folding and laminating and also removes rolling oil; H tempers retain strength for fins and containers. The alloy and temper designations used in specifications refer to ANSI H35.1, as referenced by ASTM B479 (S1).

6. Which properties should be specified?

Alloy and temper; gauge and tolerance; width and tolerance; coil dimensions and core; surface condition and wettability; pinhole limit for the gauge; tensile strength and elongation (or burst strength for packaging); flatness; and, for battery foil, cleanliness and surface roughness. Each value should name its test method and sampling plan.

7. How does foil provide barrier?

Pinhole-free aluminium is essentially impermeable to gases, moisture and light, which is why foil laminates are used for oxygen- and moisture-sensitive products. In practice thin foils contain pinholes and can crack when flexed or creased, so barrier depends on the laminate: films on one or both sides bridge pinholes and protect the foil from flex cracking. Barrier must be confirmed on the finished laminate and pack, under the conditions the pack will see.

8. Why does surface condition matter?

Rolling oil remaining on the foil can weaken lamination bonds and coating adhesion. Annealed foil is usually degreased by the annealing cycle; hard-temper foil may need chemical cleaning. Wettability tests indicate whether adhesives and coatings will wet the surface. Bright and matte sides can bond differently, so laminating specifications should state which side faces the adhesive.

9. How is foil produced?

Foil is produced from hot- or continuously-cast and cold-rolled reroll stock that is rolled in several passes on foil mills, separated and slit to width, then annealed if a soft temper is required. Process control of rolling oil, roll condition, gauge and flatness determines pinholes, surface quality and coil shape.

10. Which converting processes use foil?

Adhesive or extrusion lamination to films and papers, coating with heat-seal lacquers or primers, printing, embossing, forming into containers or blister lids, fin pressing for heat exchangers, and coating of electrode slurries for batteries. Each process sets its own limits for gauge, flatness, surface and mechanical properties.

11. Which problems are common?

12. How should foil coils be stored?

Store coils dry and away from temperature swings that cause condensation, which leads to corrosion and white staining. Keep coils in original packaging, supported on cores or saddles, and allow them to reach room temperature before unwrapping. Record coil identification through converting.

13. Where is foil used?

Food, beverage and pharmaceutical flexible packaging; blister and cup lidding; trays and containers; household foil; insulation facings and vapour retarders; cable screening; heat-exchanger fins; and lithium-ion battery cathode current collectors.

14. Which requirements depend on the application?

Food- and pharmaceutical-contact uses require compliance documentation for the foil and the finished laminate in the target market; battery foil requires the cell maker's own specification and audit; construction facings may require fire and vapour-performance data for the assembled product. Define these requirements before comparing offers.

15. How should a buyer select candidates?

1. Describe the converting process, end use and current foil specification.
2. Fix alloy, temper, gauge, width and surface requirements with tolerances.
3. Ask manufacturers for offers against that specification, with test methods.
4. Run converting trials and finished-product tests.
5. Choose on yield, consistency and documentation, not only coil price.

16. How should a foil trial be run?

Run trial coils on your production line with the incumbent as a control. Record web breaks, bond strength, coating defects and pinholes or barrier on finished laminates; measure gauge and flatness on incoming coils. For battery foil, coat and calender electrodes and test cells per your qualification plan. Keep coil numbers linked to results.

17. Which documents should be requested?

Product specification naming alloy, temper and applicable standard; certificates of analysis per coil with chemistry, gauge and mechanical properties; pinhole and wettability results with method; food-contact or other compliance statements with scope; packaging and storage guidance; and change-notification commitments.

18. How does foil compare with metallised film?

See also High-barrier packaging materials.

19. How should cost be compared?

Compare cost per usable square metre of finished product: coil price adjusted for yield, web breaks, scrap from bond or coating defects, and the effect of gauge on area per tonne. A slightly thinner gauge with the same performance can reduce cost per pack, provided pinholes and flex performance remain acceptable.

20. What should a foil RFQ include?

• End use and converting process.
• Alloy, temper, gauge and tolerance.
• Width, coil inner and outer diameter, core and maximum coil weight.
• Surface condition, wettability and side orientation.
• Pinhole and mechanical requirements with methods.
• Compliance documentation needed.
• Annual quantities, call-off pattern and delivery location.

Prepare and submit these through the RFQ brief.

21. Which manufacturer qualification questions should be asked?

Rolling and finishing capability for the gauge and width; pinhole and surface control; certificates per coil; compliance documentation; experience with your converting process; manufacturing locations; and change control for alloy, rolling oil or annealing changes. PAXOMER does not confirm any manufacturer's capabilities on this page.

22. Which related pages should be read next?

• Guide: Aluminum can sheet and can stock
• Related page: High-barrier packaging materials
• Related page: Medical and pharmaceutical lidding films

Engineering and purchasing FAQs

Each answer is general technical information, not a specification or a quotation.

What is the difference between foil and sheet?

Why does thin foil have pinholes?

Which temper should I specify for laminating?

Can I use any foil for battery current collectors?

What documents should accompany each coil?

Can PAXOMER supply aluminium foil?

Technical References

References below were opened on the access date shown. A source supports only the statement it is cited for. Standards are cited by number and title from public catalogue entries; their full text was not read unless stated.

1. S1. ASTM B479-19 — Standard Specification for Annealed Aluminum and Aluminum Alloy Foil for Flexible Barrier, Food Contact, and Other Applications. ASTM International, 2019. store.astm.org/b0479-19.html (opens in a new tab) standard catalogue · accessed 2026-10-30
   Catalogue entry opened 2026-10-30 to confirm title and active edition. Scope details (98.00% minimum aluminium; reference to ANSI H35.1 designations) were taken from catalogue summaries; the standard text was not read.
2. S2. Aluminum can sheet and can stock (PAXOMER guide). PAXOMER Inc., 2026-10-30. /products/aluminum-can-sheet-can-stock/ technical literature · accessed 2026-10-30
   PAXOMER’s own guide; not an external source and not independently reviewed.

Regional manufacturing evidence

Company and trade publications cited in Manufacturing Regions & International Supply. Each supports only the statement it is cited for (checked 29–30 October 2026). Naming a company here does not state or imply a relationship with PAXOMER.

1. R52. UACJ to build battery foil plant in China (Japanese producer with three domestic battery-use aluminium plants; 10 September 2018). Argus Media. www.argusmedia.com/en/news/1750843-uacj-to-build-battery-foil-plant-in-china (opens in a new tab) checked 2026-10-30
2. R53. Member profile: LOTTE INFRACELL Co., Ltd (aluminium foil rolled products, Ansan plant, South Korea). Aluminium Stewardship Initiative. aluminium-stewardship.org/about-asi/members/LOTTE-INFRACELL-Co--Ltd (opens in a new tab) checked 2026-10-30