1. Material Barrier Properties: Aluminum foil (AL) layers offer superior oxygen and moisture barrier performance (common structures include PET/NY/AL/PE or NY/PE); high-barrier films without aluminum (such as EVOH co-extruded films) rank second, while standard PE bags offer the weakest barrier protection.
2. Sealing Mechanism: Permanent heat seals rely on seal strength (typically requiring ≥7N/15mm); resealable closures depend on the fit of the zipper or the airtightness of the spout cap, with spouted pouches generally offering better sealing integrity than standard zipper bags.
3. Bag Structure: Flat-bottom pouches (such as eight-side seal or stand-up pouches) provide excellent structural support, reducing the risk of stress cracking; conversely, three-side seal bags are prone to air leakage if the heat-sealed edges are subjected to pressure.
