Basic Concepts

FIBC (Flexible Intermediate Bulk Container) is a large flexible packaging container made of polypropylene woven fabric, designed to carry bulk materials ranging from 500kg to 2000kg, such as chemicals, grains, and minerals. Its core functionality revolves around the unitized transportation concept, fundamentally transforming fragmented packaging models into integrated unit-load systems. By establishing standardized unitized containers, FIBC enables integrated lifting operations via cranes or forklifts, eliminating manual disassembly processes. For example, a truckload of cement traditionally requires hundreds of separate bags for manual handling, whereas FIBC systems accomplish full vehicle loading through single-lift operations, significantly improving efficiency.

Manufactured through polypropylene resin melting, filament drawing, fabric weaving, and sewing processes, FIBC maintains structural integrity under multiple times of rated load impacts during transit. Additional material modifications or structural enhancements enable specialized functions: moisture-proofing for grain storage to prevent mildew, anti-static liners for calcium carbide transportation to avoid explosions, and UV-resistant coatings for outdoor applications.

When empty, FIBCs can be compactly folded, reducing storage space. Reusable variants further enhance cost-effectiveness and environmental sustainability compared to single-use packaging. Serving as "flexible containers," FIBCs standardize bulk cargo handling across scenarios from port terminals to construction sites, resolving efficiency and cost challenges in loose material logistics through mechanized operations.

FIBC (Flexible Intermediate Bulk Container): The formal technical designation under international transportation regulations and quality certifications, systematically defining their flexible structure and intermediate-scale bulk handling characteristics.

Jumbo Bags: Derived from their massive and load-bearing capability, frequently used in maritime bulk cargo transport for commodities like ores and grains. The term "Jumbo" emphasizes their visually imposing design.

Space Bags: Highlights space-saving characteristics. Their collapsible design makes them prevalent in Southeast Asian export regions for optimal container space utilization during bulk cargo shipping.  

Bulk Bags: A generic term in European and American markets, directly denoting their primary application in transporting unpackaged materials (e.g., chemical powders, cereals), emphasizing functional purpose over structural specifics.

Ton Bags: Explicitly references the standardized weight capacity, commonly used in technical documentation and ISO standards to specify industrial-grade load specifications. 

The core distinctions between FIBCs and ordinary woven bags lie in load-bearing capacity, structural design, protective performance, and application scenarios. FIBCs typically have a load capacity range of 0.5–2 tons, with a structure primarily composed of outer polypropylene (PP) woven fabric. High-end variants incorporate inner liners such as polyethylene (PE) film or aluminum-plastic composite materials to enhance sealing properties, alongside integrated lifting loops and reinforced circular straps for compatibility with forklifts or cranes. In contrast, ordinary woven bags have a maximum load capacity of 50 kilograms, relying mainly on single-layer PP woven fabric strength, though some products may incorporate inner liners (e.g., HDPE, EVA) or surface coatings (PE, PVC) for basic moisture resistance.  

Regarding protective performance, FIBCs achieve specialized safeguards through UV-resistant masterbatch additives, aluminum-plastic composite layers, or conductive thread weaving techniques. Ordinary woven bags, however, are constrained by liner integrity and process costs, offering only basic protective capabilities.  

In application scenarios, FIBCs are designed for mechanized bulk material transport (e.g., mineral ores, lithium battery materials, hazardous chemicals), with high customization levels (e.g., internal tension straps for deformation resistance, aluminum foil oxygen barrier for freshness preservation). Ordinary woven bags, while suitable for small-batch chemical additives or construction materials, are incompatible with highly corrosive or precision-sensitive materials due to structural strength and sealing limitations.  

The design philosophies diverge significantly: FIBCs prioritize high load capacity, robust protection, and customizability, whereas ordinary woven bags emphasize cost efficiency, lightweight design, and incremental functional upgrades.

Primary Material: Polypropylene (PP). The core material of FIBCs is polypropylene (PP), accounting for over 90% of the composition. PP, a thermoplastic polymer, exhibits properties such as lightweight high strength, chemical corrosion resistance, and heat resistance (withstands 100℃ sterilization). During production, PP pellets undergo melting, filament extrusion, and weaving into base fabric, which is then cut and stitched into bag structures. To enhance outdoor weathering resistance, UV inhibitors are pre-blended into PP raw materials. High-quality PP pellets must exhibit uniform color, impurity-free composition, and pass tensile strength testing post-extrusion to meet manufacturing standards.  

Functional Additive: Calcium Carbonate Masterbatch. Calcium carbonate masterbatch serves as a cost-reducing filler in FIBCs, typically added at 3%–10%. By partially replacing PP, it lowers production costs while improving base fabric rigidity, dimensional stability, and processing fluidity. For instance, calcium carbonate addition reduces shrinkage and enhances surface smoothness. Modified calcium carbonate variants (e.g., titanium dioxide-coated variants) can reflect UV radiation, synergizing with UV-resistant agents. However, excessive calcium carbonate (e.g., >20%) compromises transparency, toughness, and thermal stability, necessitating coupling agents and lubricant pretreatment to ensure PP compatibility.  

Functional and Aesthetic Enhancement: Color Masterbatch. Color masterbatch, composed of pigments, dispersants, and PP carrier resin, enables FIBC color customization. Pigment concentrations typically range from 20% to 40%, requiring synchronized melting with PP base material to prevent color deviation. In food and chemical industries, masterbatches must comply with non-toxic and heat-resistant standards, while UV-resistant variants require validation via artificial accelerated aging tests.

1. By Shape

(1) Circular: No directional adjustment required during filling; ensures uniform load distribution post-filling, eliminates internal dead zones, and facilitates complete material discharge.  

(2) Square: Highest universality, optimizes space utilization for palletized transport and stacking, with flat surfaces enabling full display of printed content.  

(3) U-shaped: Hybrid structural design combining features of square and circular FIBCs.  

2. By Lifting Configuration  

(1) Top-lift: Lifting loops positioned at the top, suitable for vertical crane hoisting, requiring reinforced connection points between loops and the bag body.  

(2) Bottom-lift: Lifting rings integrated at the base, designed for forklifts or sling-based port cranes to lift from the bottom, commonly used in material dumping or warehouse turnover scenarios.  

(3) Pallet-free: Reinforced base design allows direct ground contact; bottom structure accommodates forklift tines for direct lifting. Ideal for powdered materials prone to caking.  

3.By Functional Features  

(1) Antistatic: Conductive fibers woven into the base fabric, critical for handling petrochemicals or explosive dust-prone materials.  

(2) Moisture-proof: Incorporates PE or aluminum foil inner liners to block moisture permeation, suitable for grains or pharmaceutical raw materials.  

(3) Food-grade: PE-coated or PE Liner provide microbial barriers, compliant with dairy or food additive packaging standards.  

(4) Drainage-type: High-tensile base fabric with enlarged mesh openings to drain excess moisture, optimized for river sand transport.

Material Strength  

Single-use: Typically employs base fabric ≤160g/m² with tensile strength ≥1470N/5cm, prioritizing cost efficiency.  

Reusable: Requires high-strength base fabric (170–210g/m²) with tensile strength ≥2000N/5cm, paired with heat-sealed seams for enhanced durability.  

Functional Design  

Single-use: Simplified structure for short-term transport; may include minimal UV stabilizers.  

Reusable: Enhanced UV resistance (e.g., hindered amine light stabilizers), moisture barriers (PE coatings, added liners), and reinforced stress points.  

Safety Factor  

Single-use: Minimum 5:1 safety factor (e.g., 1-ton rated FIBC withstands 5-ton destructive force).  

Reusable: Mandatory 6:1 safety factor with validated cycle testing (e.g., load retention after repeated use).  

Cost Structure  

Single-use: Lower unit cost but higher long-term expenses due to frequent replacement.  

Reusable: Higher initial investment but lower lifecycle cost through multiple reuse cycles.  

Environmental Impact

Single-use: Generates plastic waste; requires recycling (e.g., reprocessing into plastic pellets) to mitigate pollution.  

Reusable: Aligns with circular economy principles, reducing resource consumption; each reuse cycle lowers carbon footprint by 30%.  

PE Coating  

PE coating involves applying a layer of polyethylene (PE) film to the inner or outer woven fabric surface of an FIBC (Bulk bag/Jumbo bag). It enhances the moisture-proof and waterproof properties of outer layer, preventing water penetration while maintaining a certain level of breathability. It also improves the abrasion resistance and tear resistance of the outer layer, though its sealing performance is inferior to that of a separate liner. With lower cost, it is suitable for basic moisture-proof requirements. It is primarily used for powdered or granular materials with general moisture-proof needs (e.g., fertilizers, animal feed) in environments where strict sealing is not required.  

PE Liner

A PE liner is an independent polyethylene film inner bag placed inside the FIBC. It provides moisture-proof and leak-proof protection, preventing fine particle leakage, but cannot fully block gases or highly permeable substances. It is flexible and conforms easily to the shape of the contents but is susceptible to punctures by sharp objects. With moderate cost and high cost-effectiveness, it is suitable for products requiring leak prevention and moderate barrier properties, such as general chemical raw materials or food additives.  

Aluminum Foil Liner

An aluminum foil liner is composed of multi-layer composite materials, combining the barrier properties of aluminum foil with the heat-sealing properties of PE. It offers high barrier performance, protecting against moisture, oxidation, UV light, oxygen, water vapor, and light. However, aluminum foil is brittle and prone to tearing, requiring protection from the outer woven bag. With higher cost, it is ideal for high-value or sensitive materials. It is primarily used for products with stringent storage requirements, such as food (e.g., coffee, milk powder), pharmaceutical ingredients, or oxidation-prone chemicals.