Mylar bag

Thickness is measured in mils (1 mil = 1/1000 inch). For long-term food storage (5-20 years), you should prioritize bags with a thickness of at least 5.0 to 7.0 mils per side. Thinner bags (under 3.5 mils) are prone to pinhole leaks and are only suitable for short-term packaging. Heavier items like grains or pasta with sharp edges require thicker laminate layers to prevent punctures.

Since Mylar bags are primarily used for consumables, ensure the supplier provides FDA-approved food-grade materials and is BPA-free. For the European market, compliance with EC 1935/2004 is mandatory. Always request Migration Test Reports to ensure that no harmful chemicals leach from the metallic layer into the food products.

The core function of a Mylar bag is its Oxygen Transmission Rate (OTR) and Water Vapor Transmission Rate (WVTR). High-quality bags utilize a multi-layer structure (typically PET/AL/PE). Ensure the aluminum foil layer is genuine foil rather than just metalized film if you require a total light and oxygen barrier. For maximum shelf life, use these bags in conjunction with Oxygen Absorbers (O2A) of appropriate CC ratings.

For retail packaging, look for features like tear notches, hang holes, and resealable ziplocks. If the product is for long-term bulk storage, a stand-up pouch (Doypack) design is less critical than a heavy-duty flat bag that can be vacuum-sealed or heat-sealed. For light-sensitive products, ensure the bag is 100% opaque to prevent photo-oxidation.

The inner layer is usually LLDPE (Linear Low-Density Polyethylene), which facilitates heat sealing. Ask the supplier for the recommended sealing temperature and dwell time. A high-quality Mylar bag should maintain a hermetic seal even under pressure. You can test this by performing a burst test or a vacuum retention test on samples before placing a bulk order.

Mylar bags, especially thinner ones, can develop micro-pinholes if folded or creased excessively during transit. Instruct your supplier to ship bags flat in reinforced cartons with internal padding. Avoid suppliers who fold large bags to fit smaller boxes, as this compromises the aluminum barrier integrity.

Pricing is heavily influenced by material weight and order volume. Request a breakdown of the price per gram or square meter. For large-scale procurement, leverage Made-in-China.com to compare 'Diamond Combined' suppliers who offer tiered pricing. You can often achieve a 15-20% cost reduction by increasing the order to a full container load (FCL) to save on shipping overhead.

Always use Secured Trading Services provided by platforms like Made-in-China.com. Never wire full payments directly to private accounts. Utilize Escrow-based payment terms where the balance is released only after you receive the Bill of Lading (B/L) or a successful Pre-shipment Inspection (PSI) report from a third-party agency like SGS or Intertek.

Mylar bags are relatively heavy and dense. For small batches, Air Express (DHL/FedEx) is fast but expensive. For bulk commercial orders, Sea Freight (LCL or FCL) is the most economical. Ensure the supplier provides a Packing List with accurate G.W. (Gross Weight) and CBM (Cubic Meters) to avoid unexpected 'dead freight' charges at the destination port.