Minimum Order Quantity (MOQ): 1 pallet (typically 125–250+ bulk bags)
To specify a duffle top on an FIBC purchase order, clearly state “Full Duffle Top With Closure” and then define the rest of the bulk bag separately—including body construction, bottom style, Safe Working Load, safety factor, lift loops, fabric, coating, liner requirements, dimensions, printing, and any product-specific or handling requirements.
Here is where buyers get themselves into trouble.
They write:
“Duffle top bulk bag.”
And assume everybody knows exactly what they mean.
They don’t.
Duffle top tells you one thing.
It tells you how the top of the FIBC is constructed.
It does not tell you the Safe Working Load.
It does not tell you the bottom.
It does not tell you the body construction.
It does not tell you whether the bag is coated.
It does not tell you whether there is a liner.
It does not tell you the lift-loop configuration.
And it definitely does not tell you what product is going inside.
A good FIBC purchase order eliminates those unanswered questions before production begins.
A duffle top is an extended fabric section around the upper opening of the FIBC.
During filling, that fabric can be opened to provide broad access to the interior.
After filling, the duffle can be gathered and secured over the product.
That gives you something an open top does not:
A large filling opening plus an integrated top closure.
That distinction should be clear on the purchase order.
A straightforward description is:
Top Construction: Full Duffle Top With Closure
If you need to distinguish it from other configurations, you can make the description even clearer:
Top Construction: Full Duffle Top — No Filling Spout
The exact controlled specification should then define the closure construction and any critical dimensions.
The goal is simple.
Nobody reading the PO should wonder whether you want:
An open top.
A duffle top.
A filling spout.
Or another top design.
Imagine ordering a vehicle and writing:
“Four-wheel drive.”
Okay.
What vehicle?
What engine?
What payload?
What wheelbase?
What transmission?
What are you using it for?
Same problem.
“Duffle top” is one feature.
Two FIBCs can both have duffle tops and be completely different bags.
One may be designed for lightweight material.
Another may handle dense industrial product.
One may have a flat bottom.
Another may have a discharge spout.
One may use circular construction.
Another may use four-panel construction.
One may have coated fabric and a liner.
Another may be completely uncoated and unlined.
Specify the complete bag.
At minimum, think through these categories:
| Specification | What to Define |
|---|---|
| 🟢 Top | Full duffle top and closure |
| 🏗️ Body | Circular, U-panel, four-panel, baffle, etc. |
| ⬇️ Bottom | Flat bottom, discharge spout, or other design |
| ⚖️ SWL | Required Safe Working Load |
| 🛡️ Safety factor | Required classification |
| 🪢 Lift loops | Style and critical dimensions |
| 🧵 Fabric | Required woven polypropylene construction |
| 💧 Coating | Coated or uncoated |
| 🛍️ Liner | Type and configuration if required |
| 📐 Dimensions | Required bag dimensions and critical tolerances |
| 🏷️ Printing | Labels, warnings, artwork, identification |
| 📦 Packing | Pallet, bale, or other packing requirements |
| ⚙️ Application | Product and process information |
| 📄 Revision | Approved specification or drawing revision |
That is an actual purchasing specification.
“Duffle top bag” is not.
Do not stop at the word “duffle.”
How is the top supposed to close?
If the closure configuration matters to your operation, document it.
Think about what operators actually do.
Do they gather the fabric manually?
How is it secured?
Does the closure need to be reopened later?
Does the product need repeated access?
Does the closure need to remain secure during nationwide transportation?
The more important the closure is to the process, the more clearly it should be defined.
If the duffle extension requires a specific height for your process, document it on the controlled specification.
Too little fabric may make the top difficult to gather or secure.
Excessive fabric may add unnecessary material and become awkward for operators.
Do not copy a dimension from an old bag without knowing why it exists.
Ask:
What does the duffle need to accomplish?
Then specify accordingly.
This is a simple way to remove ambiguity.
If you want the full duffle opening rather than a filling spout, state it.
Full Duffle Top — No Filling Spout
That extra phrase costs nothing.
Miscommunication can cost plenty.
Especially when you are ordering pallets or truckloads of custom FIBCs.
The duffle describes the top.
Now define the body.
Possible constructions include circular or tubular, U-panel, four-panel, and baffle designs.
Body construction can influence filled shape, handling, pallet utilization, and other characteristics.
Do not assume duffle top automatically means one particular body style.
It does not.
What happens when the product needs to leave the bag?
That question should be answered before the purchase order is released.
A duffle top FIBC can have a flat bottom.
It can also have a discharge spout.
So your specification might include:
Full Duffle Top / Flat Bottom
or:
Full Duffle Top / Discharge Spout Bottom
Those are very different packages.
The top controls how you fill.
The bottom controls how you discharge.
Specify both.
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Safe Working Load is one of the most important numbers on the specification.
It defines the maximum load the FIBC is designed and rated to carry under its specified conditions of use.
Do not write:
“Heavy duty.”
That tells you almost nothing.
Do not write:
“Large capacity.”
Also vague.
Specify the required SWL.
Then make sure the actual filling process stays within it.
The required safety factor should also be documented where applicable.
Safety factor is part of the FIBC design and testing classification.
It is not additional usable payload.
If the FIBC has a specified Safe Working Load, stay within that limit.
Do not assume the safety factor means operators can keep filling because the bag still looks like it has room.
Bulk density connects product weight with product volume.
Without it, you are missing a major piece of the sizing calculation.
A dense product may reach the SWL before the bag appears full.
A lightweight product may fill the available volume while remaining well below the SWL.
If you are designing or changing the FIBC, provide realistic bulk-density information.
Do not size the bag by visual volume alone.
Tell the supplier what the bag will carry.
Pellets?
Powder?
Recycling material?
Agricultural product?
Mineral?
Industrial material?
Manufacturing scrap?
The product can influence fabric, coating, liner, top construction, static requirements, and other features.
If the exact formulation is confidential, provide the relevant physical characteristics.
Bulk density.
Particle size.
Flowability.
Sharpness.
Dust generation.
Moisture sensitivity.
Those characteristics matter.
This is particularly relevant to duffle tops.
One of the primary reasons to use a duffle is broad filling access.
If the product contains large or irregular pieces, communicate that.
It helps explain why the top was selected.
That information also allows the rest of the FIBC construction to be evaluated against the material.
A large opening may make sharp material easy to load.
That does not mean the standard fabric is automatically right.
Sharp or abrasive products can challenge woven polypropylene.
The body construction and fabric need to withstand the real product.
Weight alone is not enough information.
A smooth product and a jagged product at the same payload can behave very differently inside an FIBC.
Do you need coated fabric?
Or uncoated?
Document it.
Uncoated woven polypropylene provides greater breathability.
Coated fabric can improve fine-particle containment and resistance to moisture passing through the woven material.
But do not assume coated fabric makes the entire duffle top FIBC waterproof.
The closure still matters.
Seams matter.
The liner matters.
The entire construction matters.
A duffle top and a liner can work together.
The duffle provides the external top closure.
The liner can provide an internal barrier.
But “duffle top with liner” is still incomplete.
What type of liner?
Loose insertion?
Form fit?
Attached?
What material?
What thickness or performance requirement?
How does it remain positioned?
How does it close?
The more critical the liner is, the more detailed its specification should become.
This is easy to overlook.
You may actually have two closures.
The inner liner closure.
And the outer duffle closure.
They may perform different jobs.
The liner may provide the primary moisture or fine-particle barrier.
The duffle may provide mechanical coverage and protection.
If both matter, specify both.
Do not assume closing the duffle automatically closes the liner correctly.
These liner styles behave differently.
A loose-insertion liner may be simpler but can move during filling.
A form-fit liner more closely follows the shape of the FIBC and may provide more predictable positioning.
If your current process depends on a particular liner style, document it.
Do not let it change accidentally when you switch suppliers.
Product goes in.
Air comes out.
With an open duffle, displaced air can escape through the large opening.
That is usually straightforward.
But add a liner and things can change.
Air can become trapped.
The liner can balloon.
Film can move.
If filling speed is high or the product is dusty, airflow deserves attention.
Provide information about the filling process rather than specifying the bag in isolation.
If the product creates dust during filling, communicate that.
A large duffle opening may allow dust to escape with displaced air.
That may be acceptable for coarse materials.
It may be unacceptable for fine powders.
If dust containment is important, the correct solution could involve a filling spout, coated fabric, specialized seams, liner design, dust collection, or another process change.
Do not expect the duffle closure to solve a dust problem that happens before the duffle is closed.
“Keep product dry” is a start.
But it may not be enough.
Are you protecting against direct rain?
Warehouse humidity?
Water vapor?
Temporary exposure?
Long-term storage?
These are different requirements.
A duffle provides more top-side coverage than an open top.
But it is not automatically a moisture barrier.
If the product is highly moisture sensitive, specify the barrier requirement separately.
Does foreign material need to be kept away from the product?
How critical is that requirement?
A closed duffle can provide more top-side coverage than an open top.
But contamination control may also depend on:
Fabric.
Liner.
Manufacturing cleanliness.
Product-contact requirements.
Storage.
Handling.
Transportation.
If contamination matters, make it part of the controlled specification.
Do not forget the loops because you are focused on the top.
Lift loops affect handling.
Common configurations include corner-seam loops and cross-corner loops, among other engineered arrangements.
The appropriate configuration depends on the FIBC body and equipment.
If the plant requires a particular design, document it.
Loop length can affect forklift engagement and compatibility with filling or discharge equipment.
If the loops are too short, operators may struggle.
If they are unnecessarily long, they can create other handling issues.
Measure the requirement.
Then document it.
Do not use “standard loops” when the process actually depends on a specific geometry.
This is a practical plant-floor consideration.
When the FIBC is suspended for filling, can the duffle open properly?
Does the fabric interfere with the loop arrangement?
Can operators reach the closure?
Does the filling frame hold the bag in a way that allows the top to stay open?
An FIBC can be perfectly manufactured and still be awkward because the bag and equipment were never considered together.
Document the required bag dimensions using an agreed measurement convention.
Do not assume everybody reads dimensions in the same order.
If particular measurements are critical to equipment fit, pallet utilization, or storage, identify them.
Remember that an FIBC is flexible.
Empty dimensions do not guarantee exact filled dimensions.
Product characteristics and body construction affect final shape.
Not every measurement deserves the same level of attention.
Some dimensions may have flexibility.
Others may determine whether the FIBC physically fits a machine.
Identify the critical ones.
If the duffle needs to reach around a filling component, for example, that requirement should be communicated.
Do not wait for the bags to arrive before discovering a critical dimension was assumed.
If the filled FIBC sits on a pallet, communicate the pallet requirement.
The filled footprint matters.
Overhang matters.
Weight distribution matters.
Stability matters.
Body construction and product characteristics influence the final shape.
The purchase specification should account for how the bag exists when full, not just how it looks folded.
Does the filled FIBC need to fit a defined storage location?
Is dimensional stability important?
Does the product sit for extended periods?
Does the duffle need to remain closed throughout storage?
If warehouse efficiency matters, document the requirements behind the bag design.
A slightly different FIBC can change storage utilization across thousands of loads.
If the filled bags travel nationwide, the specification needs to account for transportation and handling.
The duffle closure should remain functional through the intended logistics process.
Think about:
Vibration.
Forklift handling.
Loading.
Unloading.
Product movement.
Environmental exposure.
The bag’s job does not end when it leaves the filling station.
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If the FIBC needs printed information, document it.
Product identification.
Handling instructions.
Warnings.
Lot information.
Company information.
Other required markings.
Use controlled artwork when appropriate.
Do not rely on an old email attachment or somebody’s memory.
How should the empty bags arrive?
Baled?
Palletized?
How many per packing unit?
Are liners already inserted?
How should the bags be oriented?
These details can affect warehouse handling and production efficiency.
If your operation has a preference, document it.
If you repeatedly buy the same duffle top FIBC, assign it an internal item number.
Then connect that number to a controlled specification.
Instead of:
“White duffle top super sack.”
You order:
FIBC Item ABC-456 — Rev. D
The item number identifies the approved configuration.
The controlled specification contains the technical detail.
Much cleaner.
Specifications change.
Maybe the duffle height changes.
Maybe the closure changes.
Maybe a liner gets added.
Maybe the loop length changes.
Maybe the bottom becomes a discharge spout.
Every change should create a controlled revision where appropriate.
Otherwise, old specifications keep floating around.
Eventually somebody orders the wrong bag.
This is one of the worst purchase-order shortcuts.
“Same as last order.”
Which last order?
Which revision?
Did the supplier make an approved change?
Did operations change the liner?
Was there an email modifying the loop length?
Did the last order contain an exception?
Use controlled specifications.
Tribal knowledge disappears.
Documents remain.
They are not.
The height of the fabric can differ.
Closure designs can differ.
Fabric construction can differ.
The way the duffle interfaces with liners can differ.
Even if two bags both say “duffle top,” they may not perform identically in your filling process.
Specify the features that actually matter.
This is where procurement can save real money.
Ask operations:
Do we actually close this?
If the answer is no, investigate why the duffle exists.
Maybe the original product required it.
Maybe a customer used to demand it.
Maybe the process changed years ago.
Specifications have a habit of surviving longer than the reasons behind them.
Review them.
The opposite mistake is just as bad.
Maybe purchasing sees an open top bag at a lower unit price.
Great.
But now operations needs separate covers.
Or product gets contaminated.
Or material escapes during transportation.
Or customers complain about exposed product.
Saving money on the bag does not automatically save money overall.
Calculate the process cost.
A useful PO line could conceptually follow this structure:
FIBC — Full Duffle Top With Closure / No Filling Spout / [Body Construction] / [Bottom Construction] / [Required SWL] / [Required Safety Factor] / [Lift Loop Configuration] / [Coated or Uncoated] / [Liner Requirement] / Per Approved Specification [Revision]
That is much better than:
“Duffle top bulk bag.”
The PO line identifies the major construction.
The controlled drawing or specification carries the detailed engineering requirements.
A controlled specification might look like this:
Top: Full duffle top with approved closure
Body: Approved FIBC body construction
Bottom: Flat bottom or approved discharge configuration
SWL: Per approved application requirement
Safety Factor: Per intended-use requirement
Lift Loops: Approved configuration and critical dimensions
Fabric: Woven polypropylene per approved specification
Coating: Coated or uncoated as required
Liner: Per approved product-protection requirement
Printing: Per controlled artwork
Packing: Per approved logistics requirement
Application: Approved dry bulk material
Revision: Current controlled specification
The exact selections will vary.
The structure is what matters.
For an application that does not need controlled bottom discharge, the PO could reference:
Full Duffle Top With Closure / Flat Bottom
Then the controlled specification defines the remaining construction.
This gives operations broad filling access, a top closure, and a simple bottom.
Before finalizing it, make sure the discharge process actually works with a flat bottom.
Another application may require:
Full Duffle Top With Closure / Discharge Spout Bottom
Now you have broad access during filling.
A closure after filling.
And controlled discharge at the bottom.
The specification should then define the discharge-spout construction and closure separately.
Do not assume “spout bottom” is enough detail when the outlet interfaces with production equipment.
Before releasing the order, confirm:
If several answers are “I don’t know,” do not guess.
Find out.
Common purchasing mistakes include:
Writing only “duffle top.”
Failing to define the closure.
Forgetting the bottom construction.
Ignoring Safe Working Load.
Ignoring product bulk density.
Forgetting the liner.
Failing to distinguish the liner closure from the outer duffle closure.
Assuming coated means waterproof.
Ignoring dust during filling.
Forgetting loop requirements.
Using old drawings.
Ordering “same as last time.”
And specifying a duffle that nobody in operations actually uses.
All of these are preventable.
Do not design the FIBC from a desk.
Go watch it.
Ask operations:
How do you open the duffle?
How is the bag held during filling?
What equipment fills it?
Does the fabric interfere with anything?
Does the product create dust?
Does the liner move?
How long does filling take?
Do you close the duffle every time?
How long does closure take?
Does the closure stay secure?
What would you change about the current bag?
Those answers can expose specification problems immediately.
Warehouse personnel can tell you what happens after filling.
Does the bag fit the pallet?
Does it bulge excessively?
Does the duffle stay closed?
Do loops work well with forklifts?
Do filled bags remain stable?
Does the product sit for long periods?
Is contamination an issue?
Packaging exists in the warehouse much longer than it exists in a purchasing spreadsheet.
Listen to the people handling it.
A new sample should be tested in the actual process whenever practical.
Do not just unfold it.
Fill it.
Open the duffle.
Watch the material enter.
Watch the liner.
Close the top.
Lift the FIBC.
Move it.
Put it on the pallet.
Store it.
Discharge it.
The empty bag tells you almost nothing compared with the filled bag.
Before approving a new configuration, verify that:
The duffle opens properly.
The opening works with filling equipment.
The product enters efficiently.
Dust is manageable.
The liner remains positioned if used.
The payload stays within the SWL.
The filled shape works with pallets.
The loops work with handling equipment.
The duffle closes efficiently.
The closure remains secure through expected handling.
The bottom works with the discharge process.
Then document the approved specification.
Detailed enough that nobody has to make an important assumption.
That does not mean the PO line itself needs to become a novel.
Use a concise item description.
Then reference a controlled technical specification or drawing containing the complete construction.
That gives purchasing simplicity without sacrificing technical control.
Standardization reduces mistakes.
It simplifies quoting.
It simplifies receiving.
It improves supplier comparisons.
It prevents accidental feature changes.
And it makes cost optimization much easier.
Once you know exactly what the approved FIBC is, you can start asking better questions.
Do we still need the liner?
Do we still need this duffle height?
Can the filling process be improved?
Would another body construction improve pallet utilization?
You cannot optimize what you have never properly documented.
First make sure every supplier is quoting the same thing.
Same top.
Same closure.
Same body construction.
Same bottom.
Same SWL.
Same safety factor.
Same fabric requirements.
Same coating.
Same liner.
Same loops.
Same printing.
Same packing requirements.
Otherwise, you are comparing prices for different bags.
That is not procurement savings.
That is a specification mismatch.
Keep the top description simple:
Top Construction: Full Duffle Top With Closure — No Filling Spout
Then define the rest of the FIBC separately.
Body construction.
Bottom.
Safe Working Load.
Safety factor.
Fabric.
Coating.
Liner.
Lift loops.
Dimensions.
Critical tolerances.
Printing.
Packing.
Product.
Filling process.
Storage.
Transportation.
Discharge.
And the approved specification revision.
The goal is not to make the purchase order complicated.
The goal is to make the order unambiguous.
Because once thousands of FIBCs are produced, “that’s not what we meant” is a very expensive sentence.
Specify the duffle.
Specify the bag.
Control the revision.
Test the configuration.
Then reorder the exact FIBC that works.
That is how you buy duffle top bulk bags without turning a simple piece of industrial packaging into an expensive purchasing problem.
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