Alu Alu foil vs PVC and PVDC blisters: which barrier does your product need?
How the three most common blister structures compare, and a simple way to decide between them.
Business Land Trading,
Every blister pack has two parts: a forming web that makes the cavities and a lidding foil that seals them. The lidding is almost always aluminium PTP foil. The real decision is the forming web, and it comes down to three options in Pakistan: rigid PVC, PVC coated with PVDC, and Alu Alu cold form foil.
How each structure protects the product
Rigid PVC is clear, cheap and forms quickly with heat. It lets a measurable amount of moisture and oxygen through, which is fine for stable tablets but not for hygroscopic ones.
PVC/PVDC adds a PVDC coating, usually 40, 60 or 90 gsm, on top of the PVC. The coating cuts moisture transmission many times over while the film still thermoforms like PVC and stays transparent.
Alu Alu foil is a laminate of OPA, aluminium and PVC that is cold formed. Because the aluminium layer is continuous around the cavity, moisture, oxygen and light barrier is close to total.
Side-by-side comparison
| PVC | PVC/PVDC | Alu Alu | |
|---|---|---|---|
| Moisture barrier | Low | Medium to high | Very high |
| Light barrier | None (clear) or partial (amber) | None or partial (amber) | Complete |
| Product visible | Yes | Yes | No |
| Material cost | Lowest | Medium | Highest |
| Pack size for same tablet | Smallest | Smallest | Larger (cold forming needs wider cavities) |
| Forming method | Heat | Heat | Cold punch |
A simple way to choose
- Stable product, cost-sensitive market: PVC with PTP foil.
- Moderately moisture-sensitive product or hot, humid distribution: PVC/PVDC, with the coat weight set by stability data.
- Highly hygroscopic, light-sensitive or long shelf-life product: Alu Alu foil with PTP lidding.
Stability data always has the final word. Run accelerated stability on the shortlisted packs, and choose the lowest-cost structure that passes.
What to send us for a recommendation
Send the product name and strength, tablet or capsule size, your blister machine model and web width, and the markets you sell in. We will suggest the structure and send rates for the forming film and matching blister foil.
