Minimum Order Quantity (MOQ): 1 pallet (typically 125–250+ bulk bags)
To specify coated fabric on an FIBC purchase order, do not simply write “coated bulk bag.” State that the FIBC requires coated woven polypropylene fabric, identify the approved fabric and coating requirements, and then define the rest of the packaging system: product, particle characteristics, bulk density, target payload, Safe Working Load (SWL), safety factor, body construction, top, bottom, seams, liner, lift loops, dimensions, tolerances, filling method, air-displacement requirements, discharge method, pallet requirements, printing, packing, and approved specification revision. Coating is one fabric characteristic. It is not a complete FIBC specification.
Here is a purchase order line that looks specific but really is not:
“White coated FIBC. Heavy duty. With liner.”
That leaves a mountain of unanswered questions.
Why coated?
What product?
What particle size?
What bulk density?
What payload?
What SWL?
What safety factor?
What body construction?
What top?
What bottom?
What coating requirement?
What liner?
What seams?
How is the bag filled?
How does displaced air escape?
How is it discharged?
What revision?
Until those questions are controlled, you do not have a repeatable FIBC specification.
Coated fabric generally refers to woven polypropylene fabric with an additional polypropylene coating or lamination applied to the woven material.
Standard woven polypropylene has small openings between the woven tapes.
Coating helps close those openings.
That can help:
Reduce fine-particle migration through the fabric.
Improve resistance to moisture moving through the fabric.
Reduce fabric breathability.
The last point is just as important as the first two.
A useful starting point is:
Fabric: Coated Woven Polypropylene Per Approved FIBC Specification and Drawing
If the controlled specification contains more detail, the purchase order can reference that document and revision.
For example:
Fabric Construction: Coated Woven Polypropylene, Per Approved Specification [Revision]
The important thing is that “coated” points back to a controlled technical requirement.
Two coated FIBCs can be completely different.
One might be:
Circular construction.
Open top.
Flat bottom.
Unlined.
Another might be:
Four-panel construction.
Filling spout.
Discharge spout.
Lined.
Both are coated.
They are obviously not the same packaging system.
This is one of the most useful questions purchasing can ask.
Why?
Fine-particle containment?
Moisture resistance?
Reduced product loss?
Cleaner handling?
If nobody knows why coating is required, you may be paying for a feature nobody actually needs.
Avoid using “waterproof” as a substitute for a real barrier specification.
Coating can improve resistance to moisture moving through the fabric.
But the complete FIBC still includes:
Seams.
Top.
Bottom.
Closures.
Spouts.
Other interfaces.
Define the actual moisture requirement.
Same problem.
Coating helps reduce fine-particle migration through the fabric.
Dust can still escape through:
Seams.
Needle holes.
Top closures.
Bottom closures.
Filling interfaces.
Discharge interfaces.
Specify the complete containment requirement.
| Specification | What to Define |
|---|---|
| 📦 Product | Actual material being packaged |
| 🔬 Particle characteristics | Size, shape, dust behavior |
| ⚗️ Bulk density | Actual value or approved range |
| ⚖️ Target payload | Intended product weight |
| ⚖️ SWL | Required Safe Working Load |
| 🛡️ Safety factor | Required intended-use classification |
| 🧶 Body | Circular, U-panel, four-panel, baffle, etc. |
| 💧 Fabric | Coated woven polypropylene |
| 🎯 Coating requirement | Approved construction/performance |
| 🪡 Seams | Structural and containment requirements |
| 🛍️ Liner | Type and configuration if required |
| 🔝 Top | Open, duffle, filling spout, etc. |
| ⬇️ Bottom | Flat, discharge spout, duffle, etc. |
| 💨 Air | Air-displacement requirements |
| 🌫️ Dust | Containment requirement |
| 💦 Moisture | Barrier requirement |
| ⚡ Static | Electrostatic requirements if applicable |
| 🪢 Loops | Style and dimensions |
| 📐 Dimensions | Required empty dimensions |
| 📏 Filled geometry | Critical loaded dimensions |
| 🪵 Pallet | Required compatibility |
| ⚙️ Filling | Actual filling process |
| 🔻 Discharge | Actual unloading process |
| 🏷️ Printing | Approved artwork/markings |
| 📦 Packing | Empty-bag packing requirement |
| 📄 Revision | Current approved specification |
Do not write only:
Powder.
Or:
Granules.
Identify the actual product.
The product determines whether coating provides meaningful value.
Particle size is especially important with coated FIBCs.
Why?
Because one of the major reasons to coat woven fabric is to reduce fine-particle migration.
If the material is too large to migrate through the weave, coating may be solving a different problem—or no problem at all.
Particle shape affects:
Flowability.
Abrasion.
Fabric wear.
Discharge.
Handling.
Document relevant characteristics.
Does the product create significant airborne dust?
Does material appear on the outside of existing FIBCs?
Is dust primarily escaping through fabric?
Seams?
Top?
Filling equipment?
Find the actual source.
Bulk density influences:
Required volume.
Target payload.
Filled geometry.
SWL.
Warehouse cube.
Transportation.
Use actual data when possible.
State the intended amount of product in each FIBC.
Do not use:
Fill completely.
Or:
One full bag.
Specify the target.
Do not substitute:
Heavy duty.
Industrial grade.
Extra strong.
Specify SWL.
State the required safety factor based on intended use.
Do not treat safety factor as additional carrying capacity above SWL.
Coated tells you about the fabric.
It does not tell you the body architecture.
Specify whether the FIBC is:
Circular.
U-panel.
Four-panel.
Baffle.
Another approved construction.
You might state:
Body Construction: Circular / Tubular Woven FIBC Body Per Approved Drawing
Fabric: Coated Woven Polypropylene Per Approved Specification
Now both variables are controlled.
State:
Body Construction: U-Panel Per Approved Drawing
Fabric: Coated Woven Polypropylene Per Approved Specification
State:
Body Construction: Four-Panel Per Approved Drawing
Fabric: Coated Woven Polypropylene Per Approved Specification
If shape-control construction is required:
Body Construction: Approved Baffle / Form-Stable FIBC Construction
Fabric: Coated Woven Polypropylene Per Approved Specification
Then reference the complete drawing.
Do not assume all coated woven polypropylene fabric is interchangeable.
The controlled specification should define the fabric required for the approved FIBC.
That specification should support:
Payload.
Handling.
Containment.
Abrasion.
Filling.
Discharge.
Overall performance.
If coating construction, application, or other characteristics are critical, control them in the approved technical specification.
Do not rely on the word:
Coated.
The supplier needs a controlled reference.
If the location or orientation of the coating is technically important to the approved design, state it clearly in the specification or drawing.
Do not leave critical construction details open to assumption.
This is critical for fine powders.
Coating addresses the woven fabric.
It does not eliminate leakage through seam areas.
Define the required seam construction separately.
If the product is fine enough to migrate through small seam openings, define the containment requirement.
The exact construction should be part of the approved specification.
Sewing creates needle penetrations.
For coarse products, this may be irrelevant.
For very fine powders, it may matter.
Containment should be evaluated using the actual product.
Do not automatically add a liner because the fabric is coated.
Ask:
What problem does the liner solve?
Moisture?
Fine particles?
Contamination?
Product cleanliness?
Chemical compatibility?
Another barrier requirement?
Then specify accordingly.
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Do not write only:
With liner.
Specify the approved configuration.
For example:
Liner: Loose-Insertion Liner Per Approved Specification
or
Liner: Form-Fit Liner Per Approved Specification
If the liner material affects:
Chemical compatibility.
Barrier performance.
Product contact.
Temperature.
Other performance requirements.
Control it.
If liner thickness is important to the approved design, include it in the controlled specification.
The liner needs to work with the filling system.
If the FIBC uses a filling spout, make sure the liner configuration supports it.
The liner must also work with the discharge system.
A liner that performs beautifully during filling but collapses into the outlet during discharge is not a successful design.
Coated fabric does not tell you how the FIBC is filled.
Specify:
Open top.
Duffle top.
Filling spout.
Another approved configuration.
A purchase order might state:
Top Construction: Full Open Top
Then reference the approved drawing.
State:
Top Construction: Duffle Top With Approved Closure
Then define critical details through the controlled specification.
State:
Top Construction: Filling Spout Per Approved Drawing
Then control:
Opening.
Length.
Closure.
Equipment interface.
Critical tolerances.
Tell the supplier how the FIBC is actually filled.
For example:
Filling head.
Chute.
Conveyor.
Gravity system.
Manual loading.
Other equipment.
This becomes particularly important with coated fabric.
Coating reduces fabric breathability.
High filling rates can therefore make air displacement more difficult.
This may be one of the most overlooked details on coated FIBC specifications.
Product enters.
Air must leave.
If you have:
Coated fabric.
Fine powder.
High-speed filling.
Liner.
Closed filling system.
You need an air-management plan.
If the filling process requires a specific approved venting solution, document it.
Do not rely on production operators to improvise after the bags arrive.
If dust containment matters, define where containment is required.
Consider:
Fabric.
Seams.
Top.
Filling connection.
Air displacement.
Liner.
Coating tells you nothing about discharge.
Specify:
Flat bottom.
Discharge spout.
Duffle bottom.
Another approved configuration.
State:
Bottom Construction: Flat Bottom / No Discharge Spout
Then reference the complete design.
State:
Bottom Construction: Discharge Spout With Approved Closure
Then define:
Outlet opening.
Outlet length.
Closure.
Receiving-equipment interface.
State:
Bottom Construction: Duffle Bottom / Wide-Opening Discharge With Approved Closure
Then verify that the receiving system can handle the product flow.
Does the product:
Flow freely?
Bridge?
Cake?
Clump?
Compact?
Interlock?
The bottom needs to match actual product behavior.
Where does product go?
Hopper?
Mixer?
Conveyor?
Bin?
Process vessel?
Other container?
Design discharge around the real system.
Does the operation need:
Controlled flow?
Rapid full discharge?
Metering?
Partial discharge?
Define the requirement.
If operators need to stop and restart flow, say so.
Do not discover that requirement after production bags arrive.
Do not simply write:
Moisture resistant.
What does that mean for the application?
Consider:
Humidity.
Rain exposure.
Storage duration.
Condensation.
Transportation.
Top closure.
Bottom closure.
Liner.
Define the actual requirement.
This matters.
If FIBCs are stored outside, communicate:
Duration.
Rain exposure.
UV exposure.
Humidity.
Temperature conditions.
Covering method.
Coating alone does not make the package outdoor-proof.
If the FIBCs will spend meaningful time outdoors, document the expected exposure and applicable approved requirements.
Not every moisture problem comes from direct water penetration.
Temperature changes can contribute to condensation.
Consider the complete environment.
Coating does not determine the electrostatic classification of the complete FIBC.
If the application requires a specific FIBC type for electrostatic considerations, specify it independently.
Coated does not mean food grade.
If food-contact requirements apply, document them separately.
Coated does not mean UN certified.
If regulated dangerous goods packaging is required, specify the applicable approved UN packaging requirement separately.
Abrasive material can wear:
Fabric.
Coating.
Seams.
Bottom areas.
Discharge components.
Communicate the real product characteristics.
Sharp material can create:
Puncture risk.
Localized wear.
Coating damage.
Fabric damage.
Do not hide that information behind a generic product description.
If material enters the FIBC at an unusual temperature, state the actual operating conditions.
Define:
Loop style.
Loop location.
Loop dimensions.
Equipment compatibility.
Loop length can affect:
Forklift access.
Filling equipment.
Discharge equipment.
Overall hanging height.
Operator efficiency.
Calculate:
Body.
Loops.
Top.
Bottom.
Then verify that the complete suspended FIBC fits the equipment.
Define the required empty dimensions and realistic tolerances.
If the loaded FIBC must work with:
Pallets.
Racking.
Equipment.
Warehouse layouts.
Transportation plans.
Then control the dimensions that actually matter.
Do not write:
Standard pallet.
Identify the approved pallet requirement.
Then test the loaded FIBC on it.
If overhang matters, define acceptable limits.
Do not rely on:
Must fit pallet.
Evaluate:
Loaded footprint.
Loaded height.
Overhang.
Storage clearance.
Handling.
Humidity.
Storage duration.
Other relevant conditions.
Consider:
Loaded dimensions.
Payload.
Pallet configuration.
Humidity.
Temperature changes.
Settling.
Vibration.
Handling.
Transportation duration.
The packaging system must work after it leaves the filling line.
Call or Text us at 832.400.1394
Define:
Company information.
Product identification.
Warnings.
Handling instructions.
Lot information.
Traceability information.
Other required markings.
Use controlled artwork when appropriate.
If placement matters, define:
Location.
Orientation.
Number of printed sides.
Approved artwork position.
How should the unused FIBCs arrive?
Folded?
Baled?
Palletized?
Liners installed?
Specific orientation?
Packing can affect production efficiency.
Give the approved FIBC a controlled identity.
For example:
FIBC Item COAT-210 — Rev. B
Now purchasing can reorder a controlled packaging specification.
If the design changes, update the revision.
Changes may include:
Coating.
Fabric.
Body construction.
Seams.
Top.
Bottom.
Liner.
Loops.
Dimensions.
SWL.
Printing.
Other critical requirements.
That sentence causes more confusion than buyers realize.
Which last time?
Which revision?
Which coating?
Which liner?
Which top?
Which bottom?
Reference the controlled item.
Operations says:
“Add a liner.”
Quality says:
“Improve sift resistance.”
Production says:
“We need better venting.”
Warehouse says:
“The loaded bag is too wide.”
Those changes need to make their way into the controlled specification after approval.
A photo cannot reliably tell you:
Fabric construction.
Coating requirements.
SWL.
Safety factor.
Seam construction.
Liner.
Critical dimensions.
Tolerances.
Airflow requirements.
Use drawings and specifications.
A practical description might read:
FIBC — [Approved Body Construction] / Coated Woven Polypropylene Fabric / [Approved Top] / [Approved Bottom] / [Required SWL] / [Required Safety Factor] / [Liner Requirement] / [Lift Loop Configuration] / Per Approved Specification and Drawing [Revision]
That is much better than:
Coated bulk bag.
A controlled specification might include:
Product: Approved dry bulk material
Particle Characteristics: Per approved product data
Bulk Density: Approved value or range
Target Payload: Approved fill weight
Body Construction: Approved circular, U-panel, four-panel, baffle, or other construction
Fabric: Coated woven polypropylene per approved specification
Coating: Per approved construction/performance requirement
Top Construction: Approved configuration
Bottom Construction: Approved configuration
SWL: Required Safe Working Load
Safety Factor: Required intended-use classification
Seams: Structural and containment requirements per approved specification
Liner: Approved configuration if required
Air Management: Per approved filling-process requirement
Lift Loops: Approved style and dimensions
Empty Dimensions: Per drawing
Critical Filled Dimensions: Per approved specification
Tolerances: Per approved drawing
Pallet: Approved configuration
Filling Method: Approved process
Discharge Method: Approved process
Dust Requirements: As applicable
Moisture Requirements: As applicable
Static Requirements: As applicable
Printing: Per controlled artwork
Packing: Per approved requirement
Revision: Current approved revision
Before releasing the order, confirm:
Common mistakes include:
Writing only “coated bag.”
Assuming coated means waterproof.
Assuming coated means dustproof.
Assuming coated means airtight.
Assuming coated means food grade.
Assuming coated means UN certified.
Assuming coating eliminates all sifting.
Ignoring seams.
Ignoring needle holes.
Ignoring the top.
Ignoring the bottom.
Ignoring closures.
Ignoring filling equipment.
Ignoring filling rate.
Ignoring air displacement.
Ignoring breathability.
Adding a liner without defining why.
Writing only “with liner.”
Ignoring liner behavior during filling.
Ignoring liner behavior during discharge.
Ignoring particle size.
Ignoring bulk density.
Ignoring flowability.
Ignoring abrasion.
Ignoring sharp particles.
Ignoring product temperature.
Ignoring moisture conditions.
Ignoring condensation.
Ignoring outdoor storage.
Ignoring UV.
Ignoring static requirements.
Ignoring SWL.
Ignoring safety factor.
Ignoring body construction.
Ignoring lift loops.
Ignoring filled geometry.
Ignoring pallet fit.
Ignoring warehouse conditions.
Ignoring nationwide transportation.
Ordering from a photograph.
Writing “same as last time.”
Allowing specification changes to live only in email.
Failing to control revisions.
Ask:
Why do we need coated fabric?
Is the existing product sifting?
Where does the product escape?
How fast are we filling?
Does the bag inflate during filling?
Does the liner move?
Is filling dusty?
Does the product discharge properly?
How much residual material remains?
Operations sees problems purchasing may never see from the office.
Ask:
What containment requirement are we trying to achieve?
Is moisture protection required?
Is product-contact control required?
Are specific seam requirements needed?
Is a liner required?
Are there static requirements?
What must be inspected at receiving?
Turn those answers into controlled requirements.
Ask:
Does product appear on the outside of the FIBC?
Are pallets getting dusty?
Does moisture exposure create problems?
Does the loaded FIBC fit the pallet?
Does it store efficiently?
Does the packaging get damaged during handling?
Ask:
What environmental conditions occur during transportation?
Are loads exposed to humidity changes?
How long are they in transit?
Does condensation occur?
Does the loaded geometry affect transportation utilization?
What packaging failures have occurred during nationwide shipments?
An empty sample tells you very little about whether coating is correct.
Fill it with the actual product.
Use the intended payload.
Use the real filling equipment.
Run at the intended production speed.
Watch:
Air displacement.
Bag inflation.
Dust.
Product backup.
Liner behavior.
Then inspect:
Fabric.
Seams.
Top.
Bottom.
Closures.
Product containment.
Measure:
Width.
Length.
Height.
Overhang.
Then allow representative settling.
Measure again.
The packaging system needs to work loaded.
Evaluate:
Humidity.
Temperature.
Storage duration.
Handling.
Outdoor exposure when applicable.
Do not assume coating alone solves environmental problems.
Evaluate:
Vibration.
Settling.
Handling.
Humidity changes.
Temperature changes.
Pallet movement.
Product containment.
Use the real receiving equipment.
Measure:
Discharge time.
Bridging.
Surging.
Dust.
Spillage.
Liner movement.
Residual product.
Operator intervention.
After successful testing, lock down:
Internal item number.
Approved drawing.
Fabric.
Coating.
Body construction.
Top.
Bottom.
Seams.
Liner.
Loops.
Dimensions.
SWL.
Safety factor.
Printing.
Packing.
Revision.
Now purchasing has something repeatable.
The purchase order itself does not necessarily need to contain every technical manufacturing detail.
It does need to point clearly to the documents that do.
For example:
FIBC Item COAT-210, Rev. B — Coated Woven Polypropylene Construction Per Approved Drawing and Specification
That can work when the referenced documentation fully controls the FIBC.
Make sure every supplier is quoting the same:
Product application.
Particle characteristics.
Bulk density.
Target payload.
SWL.
Safety factor.
Body construction.
Fabric.
Coating requirement.
Top.
Bottom.
Seams.
Liner.
Loops.
Dimensions.
Tolerances.
Filling requirements.
Air-management requirements.
Discharge requirements.
Printing.
Packing.
Revision.
Otherwise you are comparing different products.
Start with the reason for coating.
What problem are you solving?
Fine-particle migration?
Moisture?
Product loss?
Cleanliness?
Then define the actual product.
Particle size.
Particle shape.
Bulk density.
Flowability.
Dust.
Moisture sensitivity.
Abrasion.
Temperature.
Static considerations when applicable.
Target payload.
Then determine:
SWL.
Safety factor.
Body construction.
Now define:
Fabric: Coated Woven Polypropylene Per Approved Specification.
Then specify:
Coating requirement.
Seams.
Top.
Bottom.
Liner.
Loops.
Dimensions.
Tolerances.
Pallet.
Filling.
Air displacement.
Discharge.
Printing.
Packing.
Revision.
Then test the FIBC.
Use the actual product.
Use the intended payload.
Use the real filling equipment.
Run it at production speed.
Time the filling cycle.
Watch displaced air.
Watch dust.
Inspect the fabric.
Inspect the seams.
Inspect the top.
Inspect the bottom.
Watch the liner.
Put the loaded FIBC on the actual pallet.
Measure:
Width.
Length.
Height.
Overhang.
Allow representative settling.
Measure again.
Store it under representative conditions.
Move it through representative nationwide transportation conditions.
Then discharge it through the actual receiving equipment.
Measure:
Discharge time.
Flow.
Bridging.
Surging.
Dust.
Spillage.
Residual product.
Liner behavior.
Operator intervention.
If it works, approve the specification.
Assign the item number.
Control the drawing.
Control the revision.
Then purchase against that controlled standard.
Because “coated” should identify a specific fabric requirement—not become a vague substitute for moisture protection, dust containment, or the rest of the FIBC design.
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