1. Inspect the material structure
High-quality aluminum foil bags typically use a three-layer composite structure of PET/AL/PE. Using a magnifying glass to examine the cross-section, the aluminum foil layer should exhibit a uniform metallic luster with no light-transmitting holes. Inferior products often cut corners by using aluminum-coated film instead of genuine aluminum foil, which will show light-transmitting spots under strong light.
2. Test the seal strength
Fill the bag with 3/4 of its volume with water, vacuum-seal it, and suspend it for 30 minutes. Qualified products should have no water leakage at the seal and no bulging or deformation of the bag body. Bags with poor seals are prone to air leakage during transportation, leading to food spoilage.
3. Testing Barrier Performance
Place a desiccant inside the bag, seal it, and weigh it after 48 hours. High-quality aluminum foil bags should have a water vapor transmission rate of ≤1.0g/(m²·24h). Poor-quality bags with defective barrier layers will cause significant weight gain in the desiccant. This method is more scientific than simple light transmission testing.
4. Verifying Temperature Resistance Performance
Pour boiling water into the aluminum foil bag, seal it, and suspend it for a weight-bearing test. Genuine products can withstand 100°C high temperatures for one hour without rupturing and maintain good sealing properties after cold water immersion. Food-grade materials certified by the FDA are safer and do not release harmful substances.
It is recommended to prioritize manufacturers with SC food production license certification. Such companies have comprehensive quality management systems from raw material procurement to production processes. High-quality aluminum foil bags typically cost 20%-30% more than ordinary products but can extend food shelf life by 3-6 months, making them more cost-effective in the long run.
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