Source: Link Testing Instruments Co.,Ltd.
I. What is the pinhole density of pharmaceutical aluminum foil?
Pharmaceutical aluminum foil (usually PTP aluminum foil, means Press Through Pack) is a key material for pharmaceutical blister packaging. It is primarily used to seal pharmaceuticals (tablets, capsules, etc.), protecting them from moisture, oxygen, light, and microorganisms.
Pinholes are micron-sized, through-holes created during the production or subsequent processing of aluminum foil due to its material, process, or external forces. These pinholes are a critical flaw in the foil's barrier properties.
Pinhole testing uses specialized instruments to quantitatively measure the number and size of pinholes per unit area of aluminum foil. It is a core and mandatory inspection for evaluating aluminum foil quality and ensuring the safety of pharmaceutical packaging.
The LTZK-02 aluminum foil pinhole tester, developed by Link Testing Instruments Co.,Ltd, strictly complies with the Chinese Pharmacopoeia 4055 and YBB00152002-2015 standards, providing a scientific and efficient testing solution for pharmaceutical packaging quality control. The following is an explanation of the expertise behind this equipment:
II.Significance and Necessity of Testing
As the core material for blister packaging (PTP), pharmaceutical aluminum foil must possess high airtightness to prevent moisture, oxidation, and microbial contamination of pharmaceutical products. The presence of pinholes can significantly reduce barrier properties, leading to drug failure or safety hazards.
According to the Chinese Pharmacopoeia (e.g., Pharmacopoeia 4055) and national standards (YBB00152002-2015), the density and size of pinholes in aluminum foil must strictly comply with limits. For example:
Pinholes with a diameter greater than 0.3mm: Not permitted;
Pinholes with a diameter between 0.1 and 0.3mm: ≤ 1 per square meter;
Pinholes that are densely packed, continuous, or periodically distributed: Immediately deemed unqualified.
III. Technical Principles and Detection Methods
Optical transmission technology utilizes the light transmittance of pinholes in aluminum foil to observe the number and size of pinholes under specific lighting conditions.
Transmitted light intensity: The transmitted light intensity is typically required to be stable at 1000 Lux, with ambient light controlled at 20-50 Lux (in a darkroom environment).
Auxiliary tools: High-transmittance glass backing, magnifying glass, or microscope (resolution 0.01mm) for precise measurement of pinhole size.
Optical transmission method: The most commonly used method involves observing pinholes with the naked eye or a microscope. It is suitable for laboratory and production line spot checks.
Current breakdown method: This method uses current to detect pinhole continuity, offering higher accuracy (capable of detecting pinholes as small as 0.01mm), but at a higher cost.
IV. Standardized Testing Process
V.Technical Advantages
The LTZK-02 Aluminum Foil Pinhole Tester utilizes optical transmission technology, utilizing a stable 1000 Lux transmitted light source and 20-50 Lux ambient light adjustment to ensure accurate pinhole detection. Equipped with an 80x high-definition objective lens and 0.01mm resolution, it can accurately identify pinholes as small as 0.1mm, meeting the strict pharmacopoeia requirements of "zero tolerance" for pinholes with diameters greater than 0.3mm and "≤1 pinhole per square meter" for pinholes between 0.1-0.3mm. The device complies with multiple standards, including GB/T3198-2010 and GB/T22638.2-2008, making it suitable for both laboratory and production line scenarios.
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