In the pharmaceutical industry, blister packaging is a common solution for solid medications. Among these, cold-form blisters are preferred for high-end drug packaging due to their superior barrier properties and forming capabilities. Among cold-forming foils, 8021-O aluminum foil is one of the most commonly used and well-established materials.
About 8021-O Aluminum Foil
8021 is an aluminum alloy in the 8xxx series, primarily composed of aluminum, iron, and silicon. It offers excellent barrier properties, ductility, and corrosion resistance. The “O” temper indicates that it is in the annealed state, providing outstanding softness and formability, ideal for deep-drawing cold forming.
Cold-Form Blister Packaging Structure
Cold-form blister packs usually adopt a three-layer composite structure that ensures high barrier performance, excellent formability, and secure sealing.
Outer Layer: 8021-O Aluminum Foil
Middle Layer: Nylon (PA)
Inner Layer: PVC or PP
Specifications
| Alloy | 8021 |
| Temper | O |
| Thickness | 0.04–0.06 mm |
| Width | 60–1600 mm |
| Length | Customizable |
| Core ID | 76 mm / 152 mm |
| Surface Finish | Bright / Matte / Embossed (customizable) |
| Surface Quality | Oil-free, no black spots, no scratches, no pinholes |
| Applications | Tablets, capsules, granules, etc. |
Features of 8021-O Aluminum Foil for Cold-Forming Blister Packaging
1.High Barrier Performance
Blocks moisture, oxygen, and UV light effectively—preserving medication stability.
2.Excellent Mechanical Properties
High resistance to bursting, puncturing, and tearing—suitable for complex packaging processes and mechanical stress.
3.Safe and Non-Toxic
Clean, smooth surface with no oil residue; compliant with pharmaceutical safety standards, odorless and tasteless—safe for direct contact with medicines.
4.Wide Applicability
Ideal for solid medications (tablets, capsules, granules), especially suited for high-end cold-forming blister lines.
The core difference between cold aluminum blister packaging and heat-sealed blister packaging
1. Difference in molding process
Cold aluminum blister: It adopts cold stamping molding (no heating is required), and the aluminum foil is directly deformed by mechanical pressure, which is suitable for temperature-sensitive drugs.
Heat-sealed blister: It needs to be heated to soften plastic sheets such as PVC/PVDC before vacuum forming. High temperature may affect the stability of drugs.
2. Materials and structure
Cold aluminum blister: It uses 8021 aluminum foil as the base material, composite nylon (BOPA) and PVC to form a multi-layer high barrier structure.
Heat-sealed blister: It is mostly single-layer or double-layer PVC/PVDC plastic sheet, relying on aluminum foil (tropical aluminum) with heat-sealing coating to seal.
3. Barrier performance comparison
Cold aluminum blister: The water vapor/oxygen barrier is more than 60 times that of PVC, and it is completely light-proof, suitable for extreme environments.
Heat-sealed blisters: Barrier properties depend on the quality of the heat-sealed edge, and moisture-proof effects are easily affected by heat-sealed temperature and pressure fluctuations.
4. Applicable scenarios
Cold aluminum blisters:
Highly sensitive drugs (such as antibiotics, controlled-release drugs);
Drugs in hot and humid areas or that need to be stored for a long time.
Heat-sealed blisters:
Drugs that are not sensitive to temperature, such as conventional tablets and capsules;
Cost-sensitive packaging needs.
5. Other differences
Environmental protection: Cold aluminum can be 100% recycled, and heat-sealed PVC is more difficult to degrade.
Appearance design: Cold aluminum blisters can achieve complex shapes through molds, while heat-sealed blisters are mainly transparent.
Summary: Cold aluminum blisters are significantly better than heat-sealed blisters in terms of barrier properties and safety, but the cost is higher; the heat-sealed blister process is mature and suitable for large-scale conventional drug packaging.
MC Aluminum is a professional aluminum foil manufacturer for pharmaceutical packaging, producing 8011 aluminum foil, 8021 aluminum foil, 8079 aluminum foil, ptp aluminum foil, ALU-ALU Foil and other products. The product quality is stable, the manufacturer sells directly, exports overseas, provides samples, and customers can visit the factory.