Aluminum Foil for Blister Packaging

Pharmaceutical blister (PTP) packaging is to place the drug in the pit (called blister) PTP) packaging is to place the drug in the pit (called blister or blister) of the blister-formed plastic hard sheet, and then use a piece of aluminum foil that has been gravure printed and coated with a protective agent to bond with it, thus making the drug safely protected.

The main materials of blister packaging are ptp foil, plastic hard sheet (polyvinyl chloride PVC) and adhesive. The surface of 8011 aluminum foil is flat, clean, of uniform color and free of spots and pinholes. It has excellent moisture-proof performance, shading and extremely high barrier capacity, strong mechanical properties, high blast resistance, strong puncture and tear resistance. So it is a main aluminum alloy foil for the ptp blister packaging.

In addition to the barrier function, the intermediate aluminum foil barrier layer used in cold stamping also has functions such as strength support and stamping resistance, so it is different from the general aluminum foil for flexible packaging composites. The aluminum foil used in cold stamping is an aluminium alloy foil with extremely high strength and good elongation.

With the development of society, the quality requirements of pharmaceutical aluminum foil are getting higher and higher. Now some high-end medicines mostly use cold-forming blister foil 8021. 8021 aluminum foil plays a key role as a barrier material. 8021 aluminum foil has excellent electrical conductivity and shading properties, high moisture resistance, gas barrier and taste retention, which can block any gas, water vapor and light, and can effectively protect the packaged objects.

8079 aluminum foil is an aluminum foil with high strength, good elongation and stretchability. It can provide an exceptionally good combination of strength and ductility. The combination of the 8079 alloy and H18 temper provides optimal performance in pharmaceutical foil. The price of 8079 aluminum foil is higher compared with 8011 and 8021 aluminum foil, so its applications is less. Haomei Aluminum can produces all these three types of aluminum foils.

Pinhole is a key index to evaluate the quality of aluminum foil, which mainly affects the barrier properties of packaging materials, especially for pharmaceutical aluminum foil. Pinhole is an unavoidable defect in the process of aluminum foil processing. According to the results of water vapor transmission test on the pinhole area of pharmaceutical aluminum foil, it can be proved that the impact of small pinholes (≤0.2mm) on the aluminum foil’s vapor barrier performance is negligible.

This is due to the "plugging" effect of the adhesive. Excessively large holes can easily break the adhesive coating and cause the hole to lose its barrier properties. Therefore, we usually use a three-permeability tester (moisture permeability tester, air permeability tester, and oxygen permeability tester) to test the pinhole degree.