Aluminum blister foil is a thin, flexible packaging material used primarily in the pharmaceutical and food industries. It forms the backing layer in blister packs, holding tablets, capsules, or small items in sealed cavities. When a user presses a tablet through, the foil breaks cleanly — that’s the key property that sets it apart from other foil types.
This material combines three qualities in one sheet: barrier protection, breakability, and printability. It blocks moisture, oxygen, and light while remaining easy to push through by hand.
Alloy Options: 8011 vs 8021 vs 8079
Three aluminum alloys dominate blister foil production. Each has a different composition that affects softness, formability, and barrier performance.
| Alloy | Key Character | Best Use |
|---|---|---|
| 8011 | Good formability, cost-effective | General pharmaceutical blister |
| 8021 | High elongation, softer feel | Cold-form blister, alu-alu foil |
| 8079 | Excellent barrier, fine grain | High-barrier drug packaging |
8011 Aluminum Blister Foil
8011 is the most widely used alloy in standard blister packs. It offers reliable formability and works well with printing inks and lacquer coatings. Cost is lower than 8021 or 8079, making it a common choice for high-volume pharmaceutical lines.
8021 Aluminum Blister Foil
8021 has higher elongation than 8011. This means it stretches more before tearing, which makes it suitable for cold-form blister packaging — where the foil is pressed into deep cavities without heat. It is also the alloy most often used in alu-alu (OPA/Alu/PVC) laminate structures.
8079 Aluminum Blister Foil
8079 Aluminum Blister Foil contains a slightly different iron and silicon balance. The result is a finer grain structure and a tighter surface finish. This helps it achieve very low pinhole counts, which matters when packaging moisture-sensitive drugs.
Temper Comparison
Temper affects how stiff or soft the foil is. Blister foil is typically supplied in three temper states.
| Temper | Hardness Level | Typical Thickness | Application |
|---|---|---|---|
| O (Annealed) | Softest | 0.02–0.065 mm | Cold-form, alu-alu blister |
| H14 | Semi-hard | 0.025–0.05 mm | Tropical blister, push-through |
| H18 | Full hard | 0.02–0.03 mm | Standard push-through blister |
O temper foil is fully annealed — it bends without cracking and forms deep pockets. H18 is work-hardened and snaps cleanly when pressed. H14 sits in between and is used where moderate stiffness is needed.
Aluminum Blister Foil Thickness Range and What It Means
Aluminum Blister Foil Thickness is one of the most important specs to define early. It controls barrier performance, breakability, and weight.
| Thickness (microns) | Thickness (mm) | Typical Role |
|---|---|---|
| 20 µm | 0.020 | Lightweight push-through, standard tablets |
| 25 µm | 0.025 | General pharmaceutical blister |
| 30 µm | 0.030 | Improved barrier, standard drugs |
| 40 µm | 0.040 | Cold-form base layer |
| 45 µm | 0.045 | OTC blister with extra stiffness |
| 60 µm | 0.060 | Alu-alu cold-form blister |
| 65 µm | 0.065 | High-barrier deep-draw applications |
Thinner foil (20–25 µm) is easier to push through but offers slightly lower moisture protection. Thicker foil (60–65 µm) is used in cold-form blisters where the pack must protect sensitive drugs in tropical climates.
Full Technical Specifications
| Parameter | Value |
|---|---|
| Alloy | 8011 / 8021 / 8079 |
| Temper | O, H14, H18 |
| Thickness | 0.015–0.080 mm |
| Width | 100–1,600 mm |
| Form | Coil |
| Surface | Mill finish |
| Standards | ISO, SGS, ASTM, ENAW |
Product Types by Structure
Blister foil is not a single product. It comes in several laminate and coating configurations depending on the end use.
Plain Aluminum Blister Foil
This is uncoated, mill-finish foil in a single layer. It is used as a raw input for converters who apply their own coatings. Alloys: 8011, 8079. Thickness: 20–30 µm.
Heat-Seal Lacquer Coated Foil
One side is coated with a heat-seal lacquer (HSL). This allows the foil to bond to a PVC or PVDC base film under heat and pressure. This is the most common form of finished blister lidding foil.
- Lacquer weight: typically 3–6 g/m²
- Bonding temp: 140–200°C depending on lacquer type
- Used on: standard tablet blister lines
Printed Blister Foil
The outer surface of Aluminum Blister Foil can carry printed text, branding, batch numbers, or expiry dates. Printing is done by gravure or flexo methods before the lacquer coat. This version is common for branded pharmaceutical products.
Cold-Form Blister Foil (Alu-Alu)
This is a laminate: OPA (oriented polyamide) / Aluminum / PVC. The aluminum layer is typically 8021-O at 45–65 µm. It forms into cavities without heat. This type offers the highest moisture and oxygen barrier of all blister formats.
- No PVC required on the lid side
- Suitable for humidity-sensitive APIs
- Heavier and more expensive than standard blister
Tropical Blister Foil
A variant designed for markets with high heat and humidity. The lacquer and coating layers are selected for performance at 40°C / 75% RH (ICH Zone IV conditions). Often uses H14 temper at 25–30 µm.
Key Properties at a Glance
- High barrier: blocks moisture, oxygen, and light
- Breakable: clean push-through without jagged edges
- Printable: accepts gravure and flexo inks
- Heat-sealable: bonds to PVC, PVDC, and PE films
- Sterilization compatible: works with gamma and EtO processes
- Chemically inert: does not react with most drugs
Aluminum Blister Foil Application Areas
Aluminum Blister Foil is used across multiple industries, though pharmaceutical packaging accounts for the largest share.
Pharmaceutical
- Tablet and capsule blister packs
- Unit-dose packaging for hospitals
- Veterinary drug packaging
- Cold-form alu-alu blister for moisture-sensitive drugs
Food & Nutraceuticals
- Vitamin and supplement blisters
- Chewing gum strips
- Single-serve condiment packaging
- Confectionery display packs
Consumer & Industrial
- Battery cell packaging
- Small hardware items (screws, hooks)
- Cosmetics and personal care samples
- Electronic components protection
Alloy-by-Alloy Comparison for Blister Use
| Feature | 8011 | 8021 | 8079 |
|---|---|---|---|
| Elongation | Moderate | High | Moderate-High |
| Pinhole resistance | Good | Good | Excellent |
| Formability | Good | Excellent | Good |
| Cold-form suitability | Limited | Best | Good |
| Printability | Good | Good | Good |
| Cost level | Low | Medium | Medium-High |
For standard push-through Aluminum Blister Foil packs, 8011 is the cost-efficient default. For cold-form or alu-alu applications, 8021 in O temper is the industry standard. For the tightest barrier requirements, 8079 is worth the premium.
Aluminum Blister Foil Thickness vs. Barrier Performance
| Thickness | WVTR (approx.) | Oxygen Barrier | Typical Pack Type |
|---|---|---|---|
| 20 µm | ~0.5 g/m²/day | Moderate | Standard blister |
| 25 µm | ~0.3 g/m²/day | Good | General pharma |
| 30 µm | ~0.1 g/m²/day | Good | Improved barrier |
| 45 µm | ~0.02 g/m²/day | Excellent | Cold-form base |
| 60–65 µm | <0.01 g/m²/day | Highest | Alu-alu blister |
WVTR = water vapor transmission rate. Lower is better for moisture-sensitive drugs.
Typical Product: 8021 Aluminum Blister Foil
The 8021 alloy in O temper is the most requested specification for blister packaging globally. Here are its standard parameters:
| Parameter | Value |
|---|---|
| Alloy | 8021 |
| Temper | O |
| Thickness | 0.040–0.065 mm |
| Width | 100–1,600 mm |
| Surface | Mill finish |
| Key application | Cold-form blister, alu-alu packaging |
How Blister Foil Is Made
Understanding the process helps with quality evaluation.
Rolling and Annealing
Aluminum ingot is rolled down to target thickness in multiple passes. For O temper, the foil goes through a final annealing oven to relieve work hardening and maximize softness and elongation.
Surface Treatment
Mill finish means the surface is left as-rolled without additional polishing. Some grades receive a cleaning pass to reduce residual rolling oil before coating.
Slitting
Wide master coils (up to 1,600 mm) are slit to customer-specified widths. Tolerance on width is typically ±1 mm. Edge quality matters for machine feeding on blister lines.
Coating and Printing
Converters apply heat-seal lacquer, print layers, and primer coats depending on the final specification. The foil supplier typically delivers plain or primed coils for converter processing.
Frequently Asked Questions
What Is the Difference Between Blister Foil and Regular Aluminum Foil?
Regular household or industrial foil is made for heat transfer, cooking, or wrapping. Blister foil is engineered specifically for pharmaceutical packaging. It has tighter thickness tolerances, lower pinhole counts, and is produced under cleaner conditions. It is also coated for heat-sealing in most end-use forms.
Which Alloy Is Best for Cold-Form Blister?
8021 in O temper is the standard choice. Its high elongation allows forming into deep cavities. 8079 is sometimes used when an even tighter barrier is needed. 8011 is generally not recommended for cold-form due to lower elongation.
What Thickness Should I Use for Tropical Markets?
For ICH Zone IV climates (40°C / 75% RH), a minimum of 25–30 µm push-through foil with high-barrier PVDC base film is common. For the most sensitive drugs, cold-form 60–65 µm alu-alu blister eliminates the need for a polymer base entirely.
Can Blister Foil Be Printed?
Yes. The outer surface can be printed with batch numbers, expiry dates, product names, and dosage instructions. Gravure printing is standard for long runs. The print is applied before heat-seal lacquer coating so it is protected inside the laminate structure.
What Width Is Available?
Standard production widths run from 100 mm to 1,600 mm. Most blister lines use slit coils in the 100–300 mm range. Wide coils are supplied to converters who slit them to final width.
What Standards Does This Foil Comply With?
Production follows ISO quality systems. Material testing is done under ASTM standards. European supply meets ENAW designations. SGS third-party testing is available on request for chemical composition, thickness, and mechanical properties.
How Is Blister Foil Shipped?
Foil is wound onto paper or plastic cores and wrapped for moisture protection. Coils are packed in cartons or on pallets. Shipping in a humidity-controlled environment is recommended for O temper grades to avoid surface oxidation.
What Is the Minimum Order Quantity?
MOQ varies by supplier and specification. For standard alloys and tempers (8011-H18, 8021-O), smaller trial orders are usually available. Custom widths or special coating specs typically require larger minimum quantities.
Why Aluminum Is the Material of Choice for Blister Packaging
Several competing materials exist — paper, PVDC, and various polymer films — but aluminum remains dominant in pharmaceutical blister for clear reasons.
- It provides a complete barrier to moisture and oxygen at thicknesses above 25 µm
- It is chemically inert and does not interact with drug compounds
- It is easy to print, lacquer, and laminate
- It breaks cleanly on push-through without leaving sharp edges
- It is recyclable, which supports sustainability goals
Polymer-only blister packs offer some advantages in forming depth and weight, but they cannot match aluminum’s barrier performance at equivalent cost.
Selecting the Right Specification
Use this quick-reference guide when choosing between options:
| Requirement | Recommended Spec |
|---|---|
| Standard tablet, dry climates | 8011-H18, 20–25 µm |
| Standard tablet, humid climates | 8011-H14, 25–30 µm |
| Cold-form alu-alu blister | 8021-O, 45–65 µm |
| Highest barrier, tropical | 8079-O, 60 µm |
| OTC retail blister, printable | 8011-H18, 25 µm, printed + HSL |
| Nutraceutical blister | 8011-H14, 25–30 µm |
