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Your Guide to FIBC Terminology


If your work frequently requires you to interact with FIBC technology, then it can be helpful to learn a bit more about this world. Perhaps in your job, you frequently see opaque terms floating around and you know they have something to do with FIBCs, but you’re not entirely sure what all the different terms mean.

We want to help fill in a few of those blank spaces and question marks in your head. That’s why we’ve created this guide to FIBC terminology, and built a comprehensive FIBC bulk bag glossary. One by one, we’ll address many of the common terms you’ll see associated with these types of containers and provide a clear definition. For your convenience and ease of access, we’ve listed these terms in alphabetical order.

Table of Contents

What Is an FIBC?

Firstly, by way of broad definitions, let’s clarify what an FIBC is. An FIBC is a Flexible Intermediate Bulk Container. In other words, an FIBC is an industrial carrier or container built from flexible fabric and designed to transport goods from one location to another.

While these containers can take different shapes and be constructed in various ways, most FIBCs are built from woven polypropylene and mostly commonly carry 2,000+ pounds.

Because these bags are so large and heavy, they’re typically moved by placing them on a pallet and moving the pallet instead of the bag directly. Otherwise, they can be carried by the loops on top of the bag. Emptying these containers is much simpler, and is typically done by releasing a special opening in the bottom of the bag, something like a spout, which allows the material being transported to spill out.

Just a few of the items you might find being transported in these containers include:

  • Chemicals
  • Drugs and other pharmaceutical supplies
  • Fertilizer
  • Fiberglass
  • Food products
  • Grains
  • Gravel
  • Hazardous Waste
  • Plastics
  • Sand
  • Seeds
  • Starch

Essentially, anything that is relatively small in individual size, but that also needs to be transported in bulk, is an excellent candidate for FIBC use. Things such as chemicals, foodstuffs and building materials are just a few of the overarching common categories that you’ll often find being transported in FIBCs.

FIBC Glossary

The following are a collection of terms that you’ll likely run into when dealing with industries and businesses that frequently use FIBCs. If you’ve ever found yourself wondering, “What is a Stevedore strap?” or “What is a baffle?” then you’ll find your definitions here.

Approval Drawing

This is a mock-up, a drawing usually supplied by the plant and presented to the customer. This drawing will usually show the bag or container in question and is intended for the client to review and approve before the operation can move forward.

 

Baffle

Baffles are pieces of fabric that have been sewn across each corner of a four-panel or tubular-shaped bag to give it a more square appearance while also increasing the stability of the load and helping maximize space in large shipping areas.

 

Bag Height

Exactly what it sounds like, bag height measures the exact height of a particular FIBC. This measurement is typically calculated by measuring from the bottom seam to the top seam.

 

Belt Patch

This is a piece of material sewn into place either on top of the lift belt or between the bulk of the bag body and the lift belt. Its purpose is to improve the sift resistance and create a safer working load.

 

Bias Strap or Bias Tape

This might be called by either name. Both refer to straps constructed of multifilament yarns, polypropylene or polyester. They’re commonly used for tying off inlet and outlet spouts alike. You might also hear them referred to as web ties or strap ties.

 

Body Fabric

The term body fabric refers to the large, main sheets of material that make up the majority of the bag’s surface area. This term is the same whether the container is a four-panel, U-panel or circular bag.

 

Bottom Fabric

This swath of fabric forms the base of a four-panel or tubular bag, and connects with the body fabric along the edges to create the rest of the bag.

 

Bottom Spout

You might also hear this referred to as the discharge spout. It’s used to empty out the bag and acts as the exit point for all the material being transported in the FIBC.

 

Breathable Bags/Fabric

This material is uncoated and is used to make bags that are lighter, less insulated and more breathable.

 

Circular Woven Bags

This bag is also occasionally referred to as a tubular bag, thanks to its distinctive shape. The fabric is shaped and woven on a circular loom before being cut to the properly specified bag height. The result is a circular bag without any corner seams or angular edges.

 

Coated Bags/Fabric

The opposite of breathable fabric, coated bags have been laminated with polypropylene to prevent excess moisture from entering the bags and to prevent the contents from shifting around as much.

 

Cone Top

A slight variation of an inlet, a cone top refers to a pyramid-like structure on the top of a bag that allows the bag to be overfilled beyond what would fit in an ordinary flat top.

 

Cord Lock

This is a device used for closing off the spout, designed to hold the rope or cord that controls the spout. A cord lock can take many different shapes or sizes but is convenient because it eliminates the need for hand-tying knots.

 

Denier

The denier refers to the weight of yarn every 9,000 meters, measured in grams.

 

Discharge Spout

Another term for a bottom spout, this is the spout through which FIBCs are emptied of their contents.

 

Document Pouch

Often made of either polypropylene or polyethylene, this pocket is built into the bag and usually is where identifying documents and shipping information is placed. This pouch might also be called a pocket or an envelope.

 

Drawstring Closure

This is another variation of spout closure construction. It’s similar to a petal closure, but with the addition of a string looped around the circumference of the closure.

 

Duffel Top

Sometimes known as a skirt top, a duffel top is a type of FIBC top where the inlet reaches all the way from the top seam and follows along the bag’s base.

 

Extended Belt

This is a specific type of FIBC construction that allows that webbed material to extend around to the bag’s bottom.

 

Fabric Mesh

A standard way of measuring the weight of the fabric. This unit is typically expressed in ounces per square yard or grams per 100 centimeters squared.

 

Fill Spout

The fill spout is used to pour the contents of an FIBC into the container itself. You might also hear it referred to as an inlet spout or a top spout.

 

Filler Cord

This cord is ordinarily constructed from a polypropylene material, and is used when constructing FIBCs that need to be particularly resistant to sifting. It usually takes the form of a rope or braid that is sewn into the seams themselves to prevent leakage.

 

Form-Fitted Liner

These liners are designed to match the exact shape of FIBCs and nest perfectly inside them to allow for improved filling and discharge processes. These form-fitting liners represent an increase in quality over an ordinary liner because they’re designed to fit so tightly along the fill and discharge spouts.

 

Full Open Discharge

The slight variation of a typical discharge design, this outlet reaches all the way from the bottom seam to follow the dimensions of the bag’s base.

 

Hem/Hemming

This is an operation performed by sewing, gluing or folding, and it prevents the cut fabric from fraying along the edges while also strengthening a bag’s seams and providing a more polished finish. It can be performed on both the inside and the outside of an FIBC.

 

Lay Flat Width

This distance represents how wide the tubular fabric is if laid flat on the ground.

 

Loop Height

This dimension is calculated by measuring from the top of the bag to the very apex of the loops secured along the top of the bag.

 

Main Fabric

This fabric forms the U-panel of a U-shaped bag.

 

MFY

This acronym stands for multi-filament yarns, which are commonly used to weave lift belts and bias straps. They may be constructed from polyester threads or other materials.

 

Multi-Trip FIBCs

Because these bags are designed to stand up to multiple repeat trips, instead of just one single trip, they need to comply with the additional regulations found under ISO 21898.

 

Perimeter Band/Belt

You might hear this item called a perimeter band, a perimeter belt or even a safety belt. It consists of bias tape that’s been sewn around the perimeter of the top seam both for extra stability and to act as a distinguishing mark.

 

Petal Closure

This spout construction features four petal-like structures that work together to hold the spout closed when not in use.

 

Petal-Type Patch

This is a variation of the petal closure that is a separate piece of fabric, detached from the main material of the bottom, and is used to hold in the spout when it’s not being used. The petal-type patch might also be called a reinforcement square.

 

Polyester

Polyester is a type of polymer material typically used to create MFYs and other threads that are then used to construct FIBCs.

 

Polypropylene

Another variety of polymer used in the production of the various filaments, yarns and threads that are then woven together to create the bags.

 

Port Hole

The port hole is an outlet for your FIBC, and a place where the goods being transported can exit the container. Unlike most other spouts, however, there is no actual spout here. Instead, it is just a cut hole reinforced along the sides with bias tape.

 

Production Drawings

These sets of documents are prepared and produced by the manufacturer and are shown to the client. These typically consist of drawings and descriptions of the FIBC’s planned features, dimensions and components. The idea is that these documents will then be returned to the manufacturers along with the customer’s notes or approval.

 

Reinforced Section

This refers to a portion of the fabric where the lift belt has been sewn directly into the fabric, thus creating a more secure material. This piece of the fabric will then have additional Warp yarns, which contribute to creating a stronger bag overall.

 

Remote Open Discharge

Occasionally abbreviated as R.O.D., this is a type of outlet that can be opened by the operator without physically having to reach under the bag to open a spout.

 

Safe Working Load

The safe working load, also known as the SWL, is the amount of weight in pounds that an FIBC can properly carry before it becomes overloaded.

 

Safety Factor

This is an industry standard that stipulates all FIBCs must be able to handle about five or six times their safe working load.

 

Sanitary Flap

Also referred to as a protective bottom, the sanitary flap protects the bottom surface of the bag from becoming dirty or wearing out too quickly.

 

Seam

A seam in an FIBC is the same as any other type of seam. It is the place where the edges of two or more pieces of fabric have been sewn together.

 

Shelf Life of FIBCs

There is no official shelf life for FIBCs. No tests have ever been done to determine what this number should be or if it should exist at all. Any determinations made in this regard are thus the sole responsibility of any company making such declaration, and everyone using an FIBC should make their own decisions about their containers’ shelf life.

 

Side Panel

These are the pieces of material that form the sides of the bag, and that connect to the top and the bottom on their ends.

 

Sift-Resistant Construction

A specific type of FIBC weave the uses filler cords and coated materials to create a more sift-proof container.

 

Single Trip Bag

An FIBC that is only intended for one trip and one use only.

 

Spout Cover

Another word for a petal cover, this is a piece of material sewn into place over a spout to protect it and prevent leakage.

 

Spout Height

This is the measurement for the spout from the point where it’s attached to the bag all the way to its end.

 

Stevedore Strap

A belt that connects the loops at the top of the bag to make for single secure lifting point.

 

Stitches per Inch

This is a sewing specification for an FIBC, one that requires a particular number of stitches for every inch of fabric.

 

Top Fabric

As the name suggests, this is the piece of fabric that forms the top of an FIBC.

 

Tube Liner

A liner in the shape of a straight cylinder, with no additional spouts or other shape deviations. One end may or may not be closed with a heat seal.

 

UV Stabilized

This is an additional feature built into most FIBCs that protects them from extended exposure to harsh sunlight and prevents the fabric from weakening under this exposure.

 

Volume

The volume refers to the measurement of goods that can be carried in an FIBC, typically measured in cubic feet.

 

Warp

This is the term for the yarn or tape that is woven perpendicularly to the Weft yarn, and runs from the top to the bottom of the FIBC.

 

Web Tie

A strand composed of many different yarns and filaments and used to tie off inlets and outlets. These ties may also be known as bias tape, bias straps or spout ties.

 

Weft

The opposite of warp, these yarns run horizontally in the material of an FIBC and run from one side of the fabric to another.

 

Yarn/Tape

Both different terms for the same thing, yarn and tape form part of the tight fabric weave of an FIBC.

 

Request a Quote for Your FIBC From Midwestern Bag & Supply

Looking to get a bag or container built for your precise needs and specifications? Midwestern Bag & Supply is here to help. Contact us today to tell us a bit more about what you’re looking for and request a quote to get started.


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