Tpu bag

TPU (Thermoplastic Polyurethane) is superior due to its eco-friendly nature (biodegradable), high elasticity, and exceptional abrasion resistance. Unlike PVC, TPU is BPA-free and phthalate-free, making it safer for food-contact or medical applications. It also maintains flexibility at low temperatures (down to -30°C), whereas other plastics may crack.

For 100% waterproof requirements, buyers must specify High-Frequency (HF) Welding or Ultrasonic Welding rather than traditional stitching. Ensure the bag utilizes IPX6 to IPX8 rated airtight zippers or a roll-top closure system. Request a hydrostatic pressure test report to verify the material can withstand specific water depths.

For the US market, ensure compliance with California Proposition 65 and CPSIA (especially for bags intended for children). For the EU, REACH (SVHC) and RoHS certifications are mandatory to ensure no hazardous chemicals are present. If the bag is for cosmetics or food, verify FDA or EU Food Grade compliance.

Focus on the tensile strength and tear resistance of the TPU film (measured in MPa). Check the thickness (typically 0.2mm to 1.0mm); thicker isn't always better, as the TPU coating density on the base fabric (like 420D or 840D Nylon) determines the puncture resistance. Inspect the weld seams for bubbles or unevenness, which indicate weak points.

Standard TPU is prone to oxidation. Buyers should specifically request Anti-UV grade TPU (Level 4-5) or Aliphatic TPU from suppliers on Made-in-China.com. This is crucial for high-end retail products to prevent the material from turning yellow or becoming brittle during sea freight transit or warehouse storage.

Focus on tooling costs and MOQ. Custom TPU bags often require custom molds for HF welding. Negotiate for a refund of the mold fee once the cumulative order volume reaches a certain threshold (e.g., 5,000 units). Additionally, ask for a 5% - 10% discount on bulk raw material purchasing if you can commit to a yearly forecast.

Define a clear Acceptable Quality Limit (AQL 2.5/4.0). Explicitly state that the odor level must be minimal (low VOCs). Ensure the packaging includes silica gel desiccant packets to prevent moisture buildup and 'sticking' of the TPU surfaces during the high-humidity environment of ocean freight.

Always utilize Secured Trading Services provided by Made-in-China.com to protect your payment until the goods pass inspection. Conduct a third-party factory audit to verify the supplier actually owns High-Frequency welding machinery, as many 'manufacturers' are actually trading companies outsourcing the specialized welding process.