Stock code: 601677
Stock code: 601677
The choice of aluminium alloy for Cold Formed Pharmaceutical Blister Foil directly determines packaging reliability.
Unlike traditional heat‑sealed blisters, cold forming uses mechanical pressure at room temperature to shape the foil into cavities – no heating involved. This places two strict demands on the substrate:
– Exceptional ductility – to survive deep drawing without cracking.
– Uncompromised barrier integrity – even after significant stretching.
Among all available alloys, 8021 aluminium foil has emerged as the preferred substrate for this demanding application, thanks to its unique balance of properties.
This is one of the most frequent questions during material selection. Each alloy serves a distinct purpose:
– 8011 – Al‑Fe‑Si alloy with balanced performance. Good deep‑drawability and tensile strength, covering most standard blister needs.
– 8021 – Higher tensile strength and elongation than 8011. Typical elongation ≥3% (often 3.2–3.8%), allowing deep stretching without cracking. Cup value ≥1.8 mm ensures consistent cavity formation. Spring‑back ≤2% guarantees dimensional precision. Ideal for multi‑cavity, odd‑shaped tablets, and large capsules.
– 8079 – Higher iron content gives the best barrier and the lowest pinhole count, even at ultra‑thin gauges (e.g., 0.025 mm), while retaining formability.
The takeaway is straightforward:
> For general use → choose 8011.
> For complex forming → choose 8021.
> For maximum barrier → choose 8079.
For deep‑drawn cold‑formed blisters, 8021 delivers the best compromise between formability and protection.
Packaging engineers pay closest attention to these four parameters:
The typical thickness range for cold‑formed pharmaceutical foil is 0.04–0.065 mm. Three common 8021‑O gauges serve distinct applications. The table below summarises their differences:
|
Thickness |
Best Suited For |
Key Advantage |
|
0.05 mm (50 μm) |
Standard blisters for regular tablets and capsules |
Balanced formability and cost, adequate for most routine drugs |
|
0.058 mm (58 μm) |
Deep cavities (depth > 6 mm) and multi‑cavity formats |
Extra 8 μm significantly reduces thinning – prevents pinhole formation during stretching |
|
0.065 mm (65 μm) |
Highly moisture‑sensitive drugs or tropical‑market shipments |
Highest safety margin – even after 50% local thinning, residual thickness stays above 0.03 mm |
The rule is simple: the deeper the cavity, the more sensitive the drug, or the harsher the environment – the thicker the starting gauge should be.
8021 cold‑formed foil is widely used for packaging:
– Moisture‑sensitive drugs (antibiotics, probiotics, etc.)
– Light‑sensitive drugs (vitamins, cardiovascular medications)
– Heat‑sensitive drugs – the cold‑forming process requires no heating, protecting thermo‑labile ingredients
– High‑end prescription drugs and export medicines (meeting FDA, EU, and other international standards)
– Large‑size or irregularly shaped dosage forms (softgels, odd‑shaped tablets)
The typical multilayer structure for cold‑formed blisters is nylon (OPA) / aluminium foil / PVC (or VC), with the foil substrate often made from 8021 or 8079 alloy. This construction ensures reliable protection even under extreme temperature variations.
High‑grade 8021 cold‑formed foil must meet a series of international standards and pass rigorous quality checks:
– Complies with FDA 21 CFR 175.300, EU 10/2011, and GB/T 25591 (China)
– Heavy metal content ≤0.25 ppm
– 100% ultrasonic inspection and microbial testing
– Grade‑A wetting test – confirms zero pinhole penetration
These requirements guarantee safety and consistency when the foil is in direct contact with pharmaceutical products.
With over two decades of dedicated production, Mingtai Aluminum supplies 8021 cold‑formed foil in 0.05, 0.058, and 0.065 mm thicknesses, all manufactured to global compliance standards.
For reliable aluminium substrates that perform consistently in Cold Formed Pharmaceutical Blister Foil applications, Mingtai Aluminum is a partner you can trust.
Q: What is the main difference between 8021 and 8011 for cold forming?
A: 8021 offers higher elongation and puncture resistance, making it better for deep‑cavity and complex‑shape blisters.
Q: What is the standard thickness for cold‑formed pharmaceutical foil?
A: Common thicknesses are 0.05 mm, 0.058 mm, and 0.065 mm, depending on cavity depth and drug sensitivity.
Q: Does 8021 foil effectively block oxygen and moisture?
A: Yes, it blocks 99.9% oxygen, has WVTR ≤0.1 g/(m²·24h), and provides 100% light protection.
Q: How does cold forming differ from heat sealing?
A: Cold forming shapes the foil at room temperature using mechanical pressure, without heating – ideal for heat‑sensitive drugs; heat sealing uses heat to bond layers.
