on 13th July 2021

What is an FIBC Bag (aka Bulk Bag)?

We get a lot of questions from first timers who have been tasked with buying FIBC bags for their company. It’s OK if you’re unfamiliar with them—after all, most of us aren’t in the FIBC bag business.

We’re here to help. Knowing about the basics of an FIBC bag can help you make a decision that maximizes efficiency and safety while minimizing cost. In some situations, it could literally make the difference between life or death.

What is It?
The easy part of the answer is that FIBC stands for “Flexible Intermediate Bulk Container.” It’s a bag made of woven polypropylene material that is used in multiple industries to handle, move and store thousands of different products and is recyclable. The FIBC bag can be made into various lengths, widths, heights and weight capacities.

Where it gets complicated is explaining the different pieces of the bag that you’ll need to consider before making a solid buying decision for your company.

Anatomy of an FIBC Bag

NOTE: this is not all-inclusive but does cover the main items needed to make a buying decision. A professional bag supplier will be able to offer in-stock or customized options based on your requirements.

• Bag size: Length, width and height required to maximize storage or transport
• SWL: This stands for Safe Working Load, which tells you how many pounds of product the bag can hold.
• Bag style: Circular, U-panel, four-panel, or baffled
• Lift Loop: Quantity, length, width and position
• Fill type: Spout, duffle or full open-top
• Discharge type: Spout, full-dump bottom or none
• Discharge cover: Star closure, iris closure, full-flap cover or none
• Electrostatic type: A, B, C or D
• Coating: To reduce moisture or materials seeping through fabric
• Sift proofing: For very fine powder products
• Product going into the bag: Chemicals, fertilizers, food product, pharmaceutical products, hemp, grains, plastics, minerals, scrap seeds and much more
• Certifications: ISO, BRC or UN
  • Most manufacturers carry standard ISO certifications for quality management process.
  • Depending on the product, a food or pharmaceutical certification may be required. The top certification in the industry is a BRC certification.
  • UN certifications are required for safety and hazardous materials.

FIBC Anatomy: Top Three
To further clarify some of the anatomy, let’s go over the top three things you’ll see when looking at an actual bag, whether it’s online, or in your plant or warehouse. These are: Style, Lift Loops and Size.

Style

• Circular Woven: Made from fabric that is woven into a tube on a circular loom and then cut to the desired size. Despite having a square top and bottom sewn onto the bag, circular-woven bags still have a circular/cylindrical shape when filled. One advantage to circular-woven bags is the minimal amount of stitching needed (just the top and bottom). The possible downside: They do not hold their shape as well as other styles of bags.
• U-panel: Made up of three panels. One panel runs the full length of the bag, forming a U and creating the bottom and two of the sides. Two more panels are sewn to the U to form the other two sides. U-panel bags maintain a square shape when filled, especially if it has baffles.
• Four-Panel: Made of four individual panels sewn together to create a square. One advantage of a four-panel bag is that it maintains a square shape when filled.
• Baffle: Help a bag keep its shape and prevents bulging. Baffles are pieces of fabric with holes that are sewn to the inside corners of the bag. The holes let the product flow through them to fill the entire space.

Lift Loops

• Quantity
  • Four-Loop: Most bags will have four loops at the corner of each bag and are used for lifting bags using forklift.
  • Two-Loop: Mainly used for lifting bulk bags with smaller capacities and are ideal if you don’t have a forklift.
• Type
  • Corner Loops: Sewn into each corner seam of the bulk bag and are the most common loop type. When using a forklift, all four loops must be used.
  • Cross-Corner Loops: Sewn into eight points on opposite corners of the bulk bag. This makes the loops bigger and stand upright, so forklifts can grab them more easily. Cross-corner loops require a circular woven bulk bag.
  • Stevedore Straps: Heavy-duty straps that thread through two sets of lift loops on a bulk bag to offer additional ways to lift the bag.

Size

• This is possibly the most important element when making FIBC bag decisions. Here are some things you should ask when deciding on size.
  • How much space do you have to ship and/or store the product?
  • How heavy is the product that you want to put in the bag?
  • What is the density of the product?
    • A bag supplier should always ask what the product is and if you know its density. Without this information, they will not accurately be able to maximize the bag’s weight capacity.
    • For example, let’s say you have a 35” x 35” x 50” bag with a SWL capacity of 2,000 but you are not getting 2,000 lbs. in the bag. You would if your product weighs approximately 55 pound per cubic foot, but if the product weighs more than 55 pounds per cubic foot you could be paying more for the taller bag when a shorter one will work. If the product weighs less than 55 pounds per cubic foot, you can’t put 2,000 pounds in that bag. You would have to change the width or height to make that work.
    • A good bag supplier is knowledgeable about this requirement and should be able to tell you what bag size you need. We offer a bag calculator to assist in finding the right bag based on the weight of the product.

You can find more details on these features here.

As you can see, when someone asks us what an FIBC bag is, the conversation can go from basic to a full dissection of bulk bag anatomy pretty quickly. The more you can educate yourself about bulk bags, the better prepared you will be to save your company money and keep employees from getting hurt when it comes time for you to call someone regarding your bulk bag needs.

Here are some additional resources you can find on FIBC Bags:

UN Testing information for FIBC bags

Food Grade Recognized Certifications

FIBC Food Safety Guide

FIBC Bag handling guidelines

Safe Storage and Transportation of FIBC bag guidelines