Product
Baffle / Q-Bag FIBC
A four-panel FIBC with internal baffles or corner ties that holds a near-cube shape when empty and when part-filled. Specified when container fill rate and stack stability matter more than fabric cost.
A baffle bag is a four-panel FIBC with something sewn inside the corners to stop the body going round. The panel layout is the same as a standard four-panel bag; the difference is the internal baffle web or the corner tie straps that pull the four vertical corners in toward the axis of the bag.
What that buys the buyer is predictability. A filled Q-bag measures close to its nominal footprint at the top as well as the bottom, so container floor plans, pallet patterns and stack heights can be drawn from the bag drawing rather than measured after the first delivery.
It also costs something. Baffles add fabric, cutting operations and sewing time, and they take a small slice out of the usable volume. A Q-bag is normally the right answer when the load has to arrive square — resin pellets, mineral powders, granules and dry chemicals — and the wrong answer when it does not.
We quote baffle bags from the product data, not from a stock size list: bulk density and angle of repose set the volume, the stacking plan sets the baffle layout, and the lift method sets the loop specification.
Product Summary
A four-panel FIBC with internal baffles or corner ties that hold a near-cube shape whether the bag is empty or part-filled. Built for loads that have to stack square in a container or on a pallet without the bag slumping.
Core Construction
The body is sewn from four separate flat panels, and each vertical corner carries either an internal baffle web or a set of corner tie straps. The baffle is a folded fabric panel sewn across the corner so that it opens as the bag fills; the ties pull the corners toward the vertical axis. Both do the same job: they stop the body going circular under load and keep the side walls flat.
Loops are the usual four-corner type, sewn into the vertical seam with a double-row stitch and a folded loop base. Because the filled bag stays square, the load footprint is predictable, which is what container and pallet planning needs.
Baffles add fabric, cutting and sewing time compared with a plain four-panel bag, so a Q-bag is specified when the cube shape is worth paying for rather than as a default.
Key Benefits
| Benefit | Why It Matters |
|---|---|
| Square footprint when filled | A 90 x 90 cm bag stays close to 90 x 90 cm at the top as well as the base, so container floor plans and pallet patterns can be drawn before the order is placed. |
| Stacks without slumping | Flat side walls pass load straight down the stack instead of letting the bag bulge, lean and shift against its neighbours. |
| Cube shape when empty | Empty bags fold to a rectangular block, so warehouse space and palletising before the fill line are easier to plan. |
| More bags in the same container | Because the walls stay vertical the filled bags sit closer together, which usually means more units per 20 ft container than the same SWL in a tubular bag. |
| Shape held during filling | Baffles or ties keep the panel geometry while the bag is being filled, which reduces leaning bags and re-stacking on the fill line. |
Configuration Options
| Option Group | Available Range | Notes |
|---|---|---|
| Size | Square base 85 x 85 x 85 cm to 105 x 105 x 120 cm | The square base is the point of the design. Non-square bases can be quoted but lose most of the stacking advantage. |
| SWL / Safety Factor | 500-1,250 kg at 5:1; 1,000-2,000 kg at 6:1 | Baffle and corner seams are the limiting element, so the SWL is fixed after the baffle layout is settled. |
| Top | Duffle, filling spout, or open top with separate cover | Duffle with a tie is usual where the bag is closed after filling; a spout suits a fixed filling head. |
| Bottom | Flat, discharge spout, or full-drop | Discharge spout diameter follows the product's angle of repose; fine powders need a wider spout than granules. |
| Lifting loops | Four corner loops, single-trip or multi-trip, 50-70 mm wide | Loop width and stitch pattern are set by the SWL and the lift method, not by the bag size. |
| Fabric & coating | 140-200 gsm woven PP, unlaminated or laminated | Lamination stiffens the panel and helps the baffle keep its fold; unlaminated fabric breathes better. |
| Baffle or corner ties | Folded fabric baffle, or corner tie straps | Baffles give the firmer cube; ties are lighter and cheaper where the product is free-flowing and shape is less critical. |
| Liner | None, LDPE tube, LDPE gusseted, or PE film insert | A gusseted liner follows the square section better than a round tube and is the usual choice for fine powders. |
| UV stabilisation | 50-300 kLy | Set by the outdoor exposure the filled bag will see, not by the fabric weight. |
| Printing & packing | Up to 3 colours per side or unprinted; bales of 20-50 pieces or single-folded cartons | Baffle seams cross the print area, so artwork is checked against the panel drawing before the plates are made. |
Performance & Range
Rated 500-1,250 kg SWL at 5:1 and 1,000-2,000 kg at 6:1 for single-trip use with a four-point crane or forklift lift. The envelope assumes a free-flowing to slightly cohesive product at 0.5-1.2 t/m3, filling through the top, and a level, dry floor for stacking. Practical stack height is limited by how the product compresses rather than by the bag: two to four high is typical for mineral and resin loads. These are typical values for the construction, confirmed per project against the product data and the sample.
Validation & Testing
In-house checks on every production lot: panel and baffle dimensions against the cutting drawing, fabric weight by sample cut and scale, seam strength on a strip tensile tester, and a trial fill where the customer supplies product for sampling. Lot records are kept per run. Third-party testing arranged on request and quoted separately.
Limitations
A baffle bag is the wrong answer when the product is dusty and dust control is the priority - a lined bag with a different closure does that more cheaply. Baffles take a small slice of usable volume, so a bag sized for a given weight of a low-bulk-density product may need to go up a size. The extra seams are also more places for a fine powder to work through, so fine free-flowing powders are quoted with a liner. Above roughly 1,500 kg the baffle seams become the cost driver and an internally braced four-panel bag may be the better route.
Selection Guidance
- Best For
- Loads that must arrive as a cube: resin pellets, mineral powders and granules, and dry chemicals, where container fill rate and stack stability matter more than the last few percent of fabric cost.
- Consider Alternatives When
- The product is a fine dusty powder and shape does not matter (a U-panel or tubular bag with a liner is cheaper); the load is above roughly 1,500 kg; or the bag is emptied on the floor after one short hop.
- Must Confirm Before Quoting
- Product bulk density and angle of repose, the stacking height and how long it stands, whether lifting is by crane hook or forklift, and the container or pallet pattern the customer has to hit.
Test & Production Evidence
| Evidence Type | Evidence Note | Stage |
|---|---|---|
| Production Record | Lot records for panel and baffle cutting dimensions, fabric weight and seam strength on each Q-bag run. | Per production lot |
| Sample | Pre-production sample in the customer's fabric and print, with the baffle layout marked on the panel drawing. | Before order confirmation |
| Drawing / Artwork | Panel cutting and baffle placement drawing issued with the quotation and revised after the sample is approved. | Quotation and pre-production |
Evidence Note
The panel and baffle drawing, fabric weight records and in-house seam results can be shared with a buyer on request. Lot traceability numbers and customer-specific trial-fill notes stay internal.
Related Applications
Information Required for Quote
Product to be filled and its bulk density Required
Bulk density in t/m3 sets the volume for a given weight, and a baffle bag has less usable volume than a plain panel bag of the same outside size.
Target SWL and safety factor Required
Common values are 500-1,250 kg at 5:1 and 1,000-2,000 kg at 6:1. If your customer has not fixed a factor, say so and we will quote the usual one for that market.
Filled dimensions you need to hit Required
Square base size and filled height, so the baffle layout can be matched to the container or pallet pattern.
Filling and discharge method Required
Duffle, filling spout or open top on the way in; flat base, spout or full-drop on the way out.
Stacking height and storage conditions Required
How many bags high, for how long, indoors or outdoors, and the UV exposure the filled bag will see.
Artwork for printing, if any
Print is checked against the panel drawing because the baffle seams run across the print area. A PDF or AI file at final size is enough.