The quality of mailing bags can be judged from the following aspects:
1. Material quality
Material type: high-quality mailing bags are usually made of LDPE (low-density polyethylene), HDPE (high-density polyethylene), co-extruded film or recyclable materials, which are flexible and not easy to break.
Thickness: Measure the thickness of the bag (generally 35-90 microns). Too thin bags are easy to break, affecting transportation safety.
Gloss: Good quality plastic bags have a smooth and shiny surface; inferior bags may be dark and rough.
2. Load-bearing and tensile strength
Tensile test: Gently pull the two ends of the bag. High-quality bags have a certain toughness and are not easy to tear or deform.
Load-bearing capacity: You can put a certain weight of items (such as books or goods) in the bag to test whether it can bear a certain weight without breaking.
3. Sealing and waterproofness
Sealing strip: Check whether the sealing strip of the bag opening is evenly coated and whether it has strong adhesion after tearing to prevent secondary use.
Waterproof test: Pour a small amount of water into the bag to observe whether there is leakage. High-quality mailing bags should have good waterproof and moisture-proof properties.
4. Tear resistance and impact resistance
Tear test: Try to tear the bag open by hand. Good-quality mailing bags will not tear quickly even if they are slightly damaged.
Puncture resistance: Gently press the bag with sharp objects (such as keys or pens). High-quality bags can better resist punctures and reduce the risk of damage.
5. Color and printing quality
Uniform color: Custom-colored mailing bags should have full colors, no color difference, no obvious fading or spots.
Clear printing: Printed patterns and texts should be clear, not blurred, and not faded to ensure the brand promotion effect.
6. Certification and environmental protection
Environmentally friendly materials: Some mailing bags are made of recyclable or biodegradable materials, which meet environmental protection requirements and can reduce pollution.
Certification standards: such as ISO9001, ISO14001, SGS test reports, etc., to ensure that the products meet industry standards and environmental protection requirements.
7. Other special features (based on demand)
Privacy protection: Black or opaque mailing bags provide better privacy protection and are suitable for important documents or e-commerce packaging.
Anti-tear design: Some bags are designed with anti-tear mouths, which cannot be restored once torn, ensuring the safety of express delivery.
Through the above methods, the quality of mailing bags can be judged more comprehensively to ensure that the right products are selected.
