Corner-Loop 4-Panel FIBC Bulk Bags

Corner-loop 4-panel FIBC bulk bags are the global industrial standard for medium-to-long distance bulk commodity transport. Constructed by sewing four separate flat fabric panels together to form a rigid square box, this architecture provides exceptional vertical load stability.

The four lifting loops are stitched directly along the vertical corner seams, extending downward into the main body fabric to create maximum structural anchorage. This design ensures that when lifting payloads of 1.0 to 2.0 tons, the upward crane or forklift tension is channeled directly parallel to the four corners, minimizing lateral fabric stress and reducing container deformation during maritime transit.

Core Technical Features

Four-panel orthogonal seam construction
Reinforced corner webbing attachment zones
Heavy-duty polypropylene (PP) high-denier lifting loops
Compatible with form-fit or tubular PE/Aluminum Foil inner liners
Customizable filling spouts, discharge spouts, and top skirts

Why Choose Corner-Loop 4-Panel Bags?

Balanced Weight Distribution

Stitched securely along the vertical corner seams, the loops absorb dynamic shocks evenly during forklift tracking over uneven factory floors or during vessel crane operations.

Standard Pallet Footprint Compatibility

The square cubic shape fits standard ISO pallets (1200×1000mmor1100×1100mm) without excessive edge overhang. This allows for clean grid-pattern tracking inside automated warehouses.

High Corner Integrity Against Sifting

The intersection of vertical seams provides a dual-layer fabric overlap, making it the ideal base for applying single or double sift-proof felt piping to secure ultra-fine chemical powders.

Cost-Efficient Payload Delivery

It offers a reliable compromise between production speed and dimensional stability, serving as the standard workhorse package for global chemical, plastics, and agricultural supply chains.

Product Specifications

Item	Specification
Product Name	Corner-Loop 4-Panel FIBC / Standard Four-Loop Big Bag
Material	100% Virgin Polypropylene (PP) / UV Stabilized
Body Construction	4 Flat Panels sewn with heavy-duty chain stitches
Lifting Loops	4 Corner-seam loops (Side-seam stitched or over-corner options)
Safe Working Load (SWL)	500 kg / 1,000 kg / 1,500 kg / 2,000 kg
Safety Factor (SF)	5:1 (Single-trip industrial) / 6:1 (Multi-trip UN rated available)
Fabric Density	160g/m² to 220g/m² based on load requirement
Handling Interface	Standard two-prong forklifts, overhead crane spreaders, or hoists

Industrial Applications

Plastics & Polymers: Wholesale transport of raw nylon granules, PVC chips, and masterbatch pellets into compounding hoppers. Chemicals & Additives: Packaging for technical flame retardants, industrial salts, and chemical stabilizers prone to static or leaking. Minerals & Construction Materials: Storing high-density silica sand, cement additives, dry mortar, and crushed mineral concentrates.

Corner-Loop 4-Panel Bags vs. Cross-Corner Bags

Design Metric	Corner-Loop 4-Panel FIBC	Cross-Corner Webbing FIBC
Loop Seaming Zone	Sewn directly into the 4 vertical panel corner seams	Sewn flat onto the face panels across the corner apex
Forklift Prong Interface	Loops may lay flat; requires manual adjustment or stiffeners	Loops naturally stand arched open for quick prong entry
Stress Distribution	Direct vertical pull aligned with the seam reinforcement	Distributed cross-panel radial tension across the base
Cost Profile	Standard manufacturing process; lower per-unit production cost	High sewing complexity; carries a premium manufacturing cost

Frequently Asked Questions

1. What is the difference between a side-seam loop and an over-corner loop on a 4-panel bag?

Side-seam loops are sewn along the single vertical seam where two flat panels meet. Over-corner loops span across the corner angle, with one leg stitched to panel A and the other leg stitched to panel B. Over-corner designs keep the loops slightly more accessible for forklift prongs, while side-seam styles offer direct vertical stress tracking along the seams.

2. Can 4-panel corner-loop bags handle fine powders without leaking?

Standard woven polypropylene has micro-gaps between the warp and weft tape yarns. For fine chemical additives or flame retardants, you must specify either laminated (coated) fabric or add sift-proof felt piping along the corner seams to seal the needle puncture tracks.

3. How do I match an internal barrier liner with a corner-loop bag?

For sensitive materials like lithium battery cathode powders or moisture-sensitive chemicals, we pre-install either standard PE liners or multi-layer aluminum foil liners. These liners can be tied, glued, or tabbed to the outer 4-panel bag corners to ensure they do not collapse during filling or discharging.

Request a Technical Layout Evaluation

If you are setting up a bulk logistics line but lack precise bag blueprints, provide your basic operational parameters below. Our engineering team will calculate the necessary fabric weights and dimensions:

What material will you be loading? (e.g., Nylon granules, flame retardant powders, chemical resins, sand)
What is your target cargo weight per bag? (e.g., 1,000kg, 1,500kg)
What are the dimensions of your standard facility shipping pallets?
Does your material require atmospheric isolation? (e.g., Protection from moisture or oxygen via an Aluminum Foil liner)

Our technical department will evaluate your parameters and provide a structural specification profile along with an estimated price quotation.

Email:[email protected]

Direct Line: +86 15232851009

Technical Consultation: Coordinating with the Engineering Team