Common Misconceptions About Aluminum Foil Pouch Puncture Resistance
Puncture resistance testing evaluates a material's ability to withstand penetration by measuring the force required for a metal needle to pierce through its surface until rupture occurs. Key factors affecting puncture resistance include: Material composition, thickness, rigidity/flexibility.
For aluminum foil bags:
• 4-layer structures (PET/PA/AL/PE) demonstrate higher puncture resistance than 3-layer structures (PET/AL/PE)
• Increased thickness or rigidity typically yields higher puncture resistance values
Why do most manufacturers produce rigid foil bags?
1. PET is inherently rigid
2. Aluminum foil is a metallic material
3. Many manufacturers use stiffer PE base layers with varying bond strengths
However, this leads to a common misconception: higher puncture resistance automatically indicates better pouch performance and impact tolerance. This is incomplete and unscientific because:
Vacuum Packaging Risks: Rigid bags are prone to foil fracture at PCB corners during vacuum sealing, potentially puncturing the inner PE layer
Impact Vulnerability: Stiffer bags tend to be more brittle - the metallic foil layer cracks easily under sudden impact (illustrated by the Chinese idiom "木强则折" - rigid wood breaks easily)
After a decade of customer validation, we've confirmed that softer aluminum foil bags better protect contents and effectively reduce bag breakage. This is because softer aluminum foil bags have stronger composite strength, with a more flexible inner PE layer that better encapsulates the aluminum foil, making them less prone to cracking when folded and giving them better toughness. This situation can be described by the idiom: "柔能克刚" (softness can overcome hardness).
In summary, compared to rigid aluminum foil bags, softer ones have lower puncture resistance values. Therefore, puncture resistance should not be the main indicator for evaluating aluminum foil bag performance.
Note: Aluminum foil bags are also called metalized bags and are prone to cracking or damage when folded. Packaged products should be handled with care—avoid impacts, lift gently, and never handle roughly during loading/unloading.