FIBC Glossary: 56 Bulk Packaging Terms Defined

Angle of repose — bulk mechanics

The steepest angle at which a granular material remains stable when piled. It determines how a powder behaves during filling and discharge: a low angle of repose (free-flowing, e.g. dry sand) needs a wider discharge spout, while a high angle (cohesive, e.g. damp clay) may need a larger opening or vibration to empty. Always quote it alongside bulk density when specifying a bag.

Antistatic — electrostatics

Material behaviour that limits the build-up of static charge rather than conducting it away. In FIBC terms, antistatic fabric is the basis of Type D bags, which suppress spark energy without requiring a ground connection. "Antistatic" is not a synonym for "conductive": conductive bags (Type C) must be earthed, antistatic bags (Type D) must not be.

ADR — regulation

The European Agreement concerning the International Carriage of Dangerous Goods by Road. It governs which UN-certified packaging may be used for which dangerous goods class on European road movements, and is the reference most European chemical buyers cite when asking for a "13H3" or "13H4" bag.

ATEX — regulation

The two EU directives covering equipment and workplaces in potentially explosive atmospheres. ATEX zone classification (Zone 20, 21, 22 for dust) determines whether Type C or Type D FIBCs are required at a filling or discharge point. If a buyer cannot state their zone, the correct next step is a hazardous-area assessment, not a bag quote.

Baffle bag — construction

An FIBC with internal panels (baffles) that pull the bag into a near-cubic shape as it fills, instead of letting it bulge into a barrel. Baffled bags — also called Q-bags — typically increase usable container payload by 15–25% for light cargo. They add fabric and sewing cost per bag but often reduce cost per tonne shipped.

Bag liner — component

A separate polyethylene film insert placed inside an FIBC to provide a moisture, oxygen, odour or contamination barrier. Distinct from a container liner, which lines the whole shipping container. Bag liners are specified by film type (LDPE, co-extruded EVOH, foil laminate), thickness in microns, and attachment method (loose, tabbed or welded).

BRCGS — certification

A Global Food Safety Initiative-recognised standard, originally British Retail Consortium. The Packaging Materials scope certifies a packaging manufacturer's food-safety management system, hygiene controls and hazard analysis. Increasingly required by retailers and food manufacturers of their packaging suppliers, not just of the filler.

Bulk bag — product term

A trade synonym for FIBC, dominant in North American usage. Structurally identical to a jumbo bag, super sack or big bag. Because the terms are interchangeable, a specification should always state load rating, construction type and certification rather than relying on the name.

Bulk density — bulk mechanics

Mass per unit volume of a material including the voids between particles, expressed in kg/m³. It is the single most useful number for sizing an FIBC: weight alone cannot tell a supplier whether the bag will be a third full or overflowing. A 1,000 kg load of iron oxide (≈2,500 kg/m³) and 1,000 kg of expanded clay (≈350 kg/m³) require completely different bag dimensions.

Circular FIBC — construction

A bag whose body is woven as a continuous tube, so it has no vertical body seam. Fewer stitch lines means better resistance to sifting of fine powders and a stronger seam profile. Slightly more expensive than a U-panel construction of the same fabric weight.

Coated fabric — material

Woven polypropylene with a laminated PP or PE film on one or both faces. The coating closes the weave and improves moisture resistance, print quality and sift-proofing. Coated fabric adds weight and cost; it reduces but does not eliminate the need for a liner in hygroscopic applications.

Conductive FIBC — electrostatics

An FIBC woven with interconnecting conductive threads that carry static charge to a grounding point. This is Type C. Conductive bags provide no protection unless they are properly earthed during filling and discharge — an ungrounded Type C bag performs like an ordinary Type A bag.

Container bag — product term

Another synonym for FIBC, common in Asian export markets. Also occasionally used loosely for container liners, which is a source of confusion in purchase orders. If a supplier's quotation says "container bag", confirm whether they mean an FIBC or a container liner before signing.

Container liner — product term

A large flexible liner fitted inside a standard dry shipping container so the container itself can carry bulk cargo — typically 20–24 tonnes of granular or powder product — without a bag. Container liners are specified by volume, film thickness, loading configuration (bulkhead or door-end) and discharge method. They are a separate product line from FIBCs and are often bought together.

CROHMIQ — material brand

A proprietary static-dissipative woven fabric used in Type D FIBCs, widely referenced in chemical and lithium processing because it needs no grounding. Branded fabrics of this kind are typically supported by third-party electrostatic test data — ask for the report rather than accepting the brand name as assurance.

Cyclic top lift test — test method

A test in which a filled FIBC is lifted and lowered repeatedly by its lifting loops to verify the loop and seam strength under repeated loading. It is one of the core performance tests behind ISO 21898 compliance and is the reason lifting loops are sewn through the bag body rather than only into the top hem.

Discharge spout — component

The outlet at the base of an FIBC through which product empties. Specified by diameter, length and closure type (tie, iris, petal, cone). Spout diameter must be matched to the product's flow behaviour: too narrow for a cohesive powder and the bag will not empty without intervention.

Drop test — test method

A test in which a filled FIBC is dropped from a specified height onto a rigid surface to verify that seams, fabric and discharge closure survive impact without loss of contents. Required under ISO 21898 and as part of UN approval for hazardous goods packaging.

Duffel top — component

A full-opening top with a skirt that is tied or cinched closed after filling, offering a wide aperture for fast filling of free-flowing product. Contrasts with a filling spout, which is narrower and better for dust control.

Type D — classification

The FIBC classification for static-dissipative bags that prevent dangerous charge build-up without a grounding connection. Used where grounding is impractical, unreliable or frequently skipped — remote mines, offshore installations, mobile filling. Requires an antistatic liner if a liner is fitted.

EVOH — material

Ethylene vinyl alcohol, a co-extruded barrier layer used in high-performance liners to block oxygen and aroma. Specified for coffee, nuts, sensitive food ingredients and some pharmaceutical powders where oxidation or odour transfer would spoil the cargo.

Fabric weight (gsm) — specification

Grams per square metre of woven PP fabric — the primary driver of strength and cost. Common bands: 120–140 gsm for light duty, 150–170 gsm for standard 1,000–1,250 kg export bags, 180–200 gsm for 1,500–2,000 kg mineral cargo, and 210–280 gsm for heavy-duty or sharp-edged product.

FDA 21 CFR 177 — regulation

The US regulation governing indirect food additives — polymers and materials permitted in contact with food. A supplier claiming "FDA approved" for an FIBC should be able to produce a declaration referencing this part, with the specific resin grades used.

FIBC — product term

Flexible Intermediate Bulk Container: a woven polypropylene container rated from 500 kg to 2,000 kg (heavy-duty designs to 4,000 kg), designed for filling from the top, lifting by loops, and discharging from the base. The standards term, defined in ISO 21898. Also called bulk bag, jumbo bag, super sack, big bag and container bag.

Filling spout — component

A tubular inlet at the top of an FIBC through which product is loaded. Diameter, length and closure (tie, iris, valve) are specified to match filling equipment. A spout that is too short for the filling head causes spillage and dust; too long and it interferes with the clamp.

Flexitank — product term

A large flexible bladder fitted inside a 20-foot container to carry non-hazardous liquids in bulk, typically up to 24,000–26,000 litres. A substitute for ISO tanks and drums on many routes, with lower repositioning cost. Distinct from an FIBC (dry cargo) and from a container liner (dry bulk in a container without a bag).

Form-fit liner — component

A liner manufactured to the exact internal shape of the FIBC, rather than a simple tube. Form-fit liners stay in place during filling, resist being drawn into the spout, and use less film for the same protection.

Four-panel FIBC — construction

A bag built from four separate body panels joined at the corners, producing a very square, dimensionally stable filled shape. Preferred where palletisation and container cube consistency matter, and where the bag must not rotate or lean in a stack.

Gusset — construction

A folded-in section of fabric that allows a flat-woven tube or panel to expand into a three-dimensional shape. Gussets determine the difference between a flat bag and a self-standing square FIBC body.

HACCP — certification

Hazard Analysis and Critical Control Points: a systematic food-safety methodology. In packaging manufacture it covers contamination risks from people, machinery, pests and materials. Often a prerequisite for BRCGS or FSSC 22000 certification rather than a substitute for it.

IBC — alternative packaging

Intermediate Bulk Container — in practice, a rigid reusable container such as a 1,000 litre plastic tote in a steel cage. IBCs compete with FIBCs for high-value, hazardous or liquid cargo where rigidity and reusability outweigh the weight and cost penalty. The choice between them is usually decided by cargo value, cleaning requirements and return logistics.

IEC 61340-4-4 — standard

The international standard defining electrostatic classification and test methods for FIBCs, and the technical basis for Type B, C and D designations. When a buyer asks for "Type C to IEC 61340-4-4", they are asking for test evidence, not just conductive threads.

ISO 21898 — standard

The international standard for FIBCs used with non-dangerous goods, covering construction, safety factor and performance tests (cyclic top lift, drop, tear, stacking). The baseline certification for any export FIBC. Where a supplier claims "ISO certified" without a scope naming FIBCs, treat the claim as unverified.

Jumbo bag — product term

A trade synonym for FIBC, widely used in Asia and Europe. No dimensional or technical meaning beyond the FIBC definition. Like "bulk bag", it should never replace a written specification.

LDPE — material

Low-density polyethylene, the most common bag liner film. Flexible, cheap, food-contact capable in the right grades, and available from 50 µm upward. Its moisture barrier is good; its oxygen barrier is poor — which is why EVOH or foil laminates exist.

Lifting loops — component

The four straps by which an FIBC is lifted. Loop strength and attachment are the most common failure point in service. Best practice is loops sewn through the bag body with a double-row chain stitch, not merely into the top hem. Never lift a filled bag by fewer than all four loops.

MOQ — commercial

Minimum Order Quantity. For FIBCs, typically 500 bags for standard unprinted specifications and 1,000–2,000 for custom printing or certified programmes. Below MOQ, setup, testing and documentation costs are spread over too few units and unit prices rise steeply.

Multi-trip FIBC — product term

A bag designed and tested for repeated use, normally at safety factor 6:1, with a documented inspection regime between trips. Distinct from single-trip bags (usually 5:1), which must be retired after one journey. Using a single-trip bag for a second trip is a safety violation in most jurisdictions.

Packing group — regulation

The UN dangerous-goods severity classification — I (great danger), II (medium), III (minor) — encoded in the UN marking on a certified bag as X, Y or Z respectively. A bag marked "Y" may not be used for Packing Group I goods. Mismatched packing groups are one of the most common causes of rejected hazardous shipments.

PP (polypropylene) — material

The polymer from which FIBC fabric is woven. Resin accounts for roughly 60–70% of bag production cost, which is why bag prices track crude oil and refinery dynamics with about a one-quarter lag.

Q-bag — construction

See baffle bag. The "Q" refers to the bag holding a quasi-cubic shape when filled.

REACH — regulation

EU Regulation (EC) 1907/2006 on the registration, evaluation, authorisation and restriction of chemicals. For FIBC buyers it means the supplier must control restricted substances in the materials used, and should be able to issue a REACH statement for the specific bag.

Recycled content — material

The proportion of post-industrial or post-consumer polypropylene in a bag, expressed as a percentage. Recycled PP lowers material cost and satisfies circularity requirements, but degrades load-bearing performance — which is why the percentage must be matched to the load rating, not applied globally.

RoHS — regulation

EU Directive 2011/65/EU restricting hazardous substances such as lead, cadmium and certain phthalates in electrical and electronic equipment. Applied to packaging only indirectly, but frequently demanded in tenders, so a declaration is worth holding.

Safety factor (SF) — specification

The ratio between a bag's tested failure load and its safe working load. SF 5:1 means a 1,000 kg bag is proof-tested at 5,000 kg. Single-trip bags are commonly 5:1; multi-trip and UN-certified bags are usually 6:1. A quoted price without a stated safety factor is not a comparable price.

Sift-proof seam — construction

A seam engineered to prevent fine powder from leaking through stitch holes — achieved by coated fabric, folded seam tape, or specific stitch patterns. Essential for powders below roughly 100 microns; without it, a "leak" is not a bag failure but a specification failure.

Static dissipative — electrostatics

Material behaviour that allows charge to migrate and dissipate in a controlled way, keeping spark energy below the ignition threshold of the surrounding atmosphere. The property behind Type D bags. Performance must be verified by test, not assumed from fabric branding.

Super sack — product term

A trade name that became a generic term for FIBC in North America. Structurally identical to a bulk bag or jumbo bag.

SWL — specification

Safe Working Load: the maximum mass an FIBC is designed to carry, e.g. 1,000 kg. This is the figure you load to. It is not the failure load, and it is always paired with a safety factor.

Tear test — test method

A test measuring resistance to tear propagation in the woven fabric, typically after a defined cut or puncture. Relevant wherever cargo has sharp edges or handling is rough — minerals, aggregates, recycled material.

Type A / B / C / D — classification

The four FIBC electrostatic classifications. A: no static protection, non-flammable cargo only. B: low breakdown voltage, for dry flammable powders where no flammable gas or vapour is present. C: conductive, must be grounded. D: static dissipative, no grounding required. Using the wrong type for a flammable product is a safety failure, not a quality complaint.

UN marking (13H3 / 13H4) — regulation

The certification marking on an FIBC approved as packaging for dangerous goods. It encodes packaging type (13H3 woven without liner, 13H4 woven with liner), packing group (X/Y/Z), maximum gross mass, year of manufacture, country and manufacturer code. A bag without a valid, correctly matched mark may not be used for hazardous cargo.

U-panel — construction

A construction in which a single piece of fabric forms the base and two opposing sides, with separate panels sewn in for the remaining two sides. Strong, economical and the most common export FIBC construction.

UV stabiliser — material

An additive that slows degradation of PP fabric under sunlight. Standard bags degrade noticeably after weeks of outdoor exposure. If bags will be stored outside or used in high-insolation markets, specify UV-stabilised fabric and ask for the expected outdoor life.

Virgin PP — material

Polypropylene resin that has not been previously processed, as opposed to recycled or regrind material. Virgin PP gives predictable strength and consistent food-contact compliance, which is why food-grade and UN-certified programmes typically specify it.

Woven polypropylene — material

The fabric from which FIBCs are made: PP tape extruded from resin, woven on circular or flat looms into fabric, then cut, coated if required, printed and sewn. Fabric weight, tape quality and weave density together determine strength, sift resistance and printability.

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