Coated FIBC (Laminate Moisture-Barrier Bulk Bag)

Coated FIBC bulk bags add a continuous polypropylene film layer to the woven fabric, sealing the open weave that defines a standard bag. The result is a moisture barrier, a dust stop, and a washable surface — the three properties that moisture-sensitive and fine-powder products actually need.

Coating matters when the product itself is the risk: lithium battery cathode and anode powders degrade with humidity exposure, cement and lime escape as fugitive dust through every gap in the weave, and food powders demand a surface that cleans out completely between lots. A plain woven bag, no matter how well constructed, cannot solve any of those three problems on its own.

How the Coating Works

The laminate is a thin PP film — typically 1 to 3 mil (25 to 75 microns) — heat-sealed or extrusion-coated directly onto the inner face of the woven fabric before or after panel construction. The fabric carries the load; the film does the separating.

Inner Coating vs Double Wall

Inner coating is the standard configuration: film on the inside face only, outside stays the familiar woven texture for stacking friction and label adhesion. It blocks moisture ingress and powder migration at a cost of 8–15% over uncoated fabric.

Double-wall construction weaves the product layer between two fabric plies, or seals film to both faces, giving the strongest possible barrier. Double-wall is the correct answer for high-value hygroscopic materials (battery chemistries, specialty chemical powders) and for bags that will be washed, sterilized, or reused across customers. Our PE liners and coatings comparison covers when a removable liner beats a bonded coating.

Why Plants Switch to Coated Bags

• Moisture control: the film keeps ambient humidity out of the product. On ocean legs through tropical ports, the difference between a coated and uncoated bag is the difference between passing and failing a water-content spec at the destination lab.
• Dust containment: fine powders (under 100 µm) pass through open weave readily. A coated surface stops migration at the fabric, cutting filling-area fugitive dust and housekeeping cost.
• Discharge recovery: powder that clings to an open-weave fabric stays in the bag. Coated surfaces shed cleanly — recovery above 99% is routine with a valve or spout discharge, versus 95–97% typical on uncoated bags.
• Cross-contamination control: a sealed, washable surface supports lot-to-lot changes without product carryover, which is the requirement that makes a coated bag re-usable at all.

Construction Options

Coated FIBCs are built on standard 4-panel or baffle geometry in 140–230 gsm woven polypropylene with 1–3% UV stabilization for outdoor stock.

Capacity Classes

SWL class	Typical size	Use case
500 kg	80×80×100 cm	Specialty powders, battery precursors
750 kg	90×90×120 cm	Detergent and food-grade powders
1000 kg	100×100×120 cm	Cathode/anode powders, cement, minerals
1500-2000 kg	110×110×140 cm	High-density granules and pellets

Anti-Static Compatibility

For products that generate electrostatic charge during pneumatic transfer — battery materials, plastic powders, reactive chemicals — the coating pairs with a conductive or static-dissipative fabric system. Note that the laminate itself is insulating, so the anti-static path must run through the fabric construction and loops, not the coating. Our Type B, C, or D comparison works through the selection logic, and the coating types guide covers film options in detail.

Discharge

Bottom-open is common for construction and mineral products; valve discharge is the standard for fine, high-value powders where recovery and dust control at the destination decide the economics. See the filling and discharge design guide for sizing.

Applications by Product

• Lithium battery cathode and anode powders — the defining 2026 application: hygroscopic, fine, valuable. Coated double-wall construction with static-dissipative fabric; see FIBC packaging for lithium battery materials and a real export deployment.
• Cement, lime, mineral powders — high-volume dusting applications where the coating pays back in housekeeping and recovery.
• Sugar, salt, starch, flour, premixes — food-grade PE laminate, washable surface, lot-change discipline.
• Fine chemical and polymer powders — moisture barrier plus, where needed, Type C conductive or Type D dissipative construction.
• Plastic pellets and granules — outdoor stock durability, UV-stabilized, moisture protection over multi-month storage.

Specifying a Coated FIBC

Three numbers drive the quotation: film thickness (1, 2, or 3 mil), wall configuration (inner vs double-wall), and the fabric system (plain, Type C, or Type D). Everything else — capacity, closure, discharge, printing — follows the standard FIBC spec. If you are packaging a moisture-sensitive or fine-powder product and your current bags are uncoated, ask for a side-by-side recovery and water-content comparison before the next order: on battery-grade materials, the coated bag usually earns its premium in the first container.