A Guide For Buying FIBCs (Flexible Intermediate Bulk Containers)

What is an FIBC?

FIBCs or Flexible Intermediate Bulk Containers are a type of large, flexible container typically used to transport and store bulk and large quantities of dry and flowable materials such as grains, powders, and granules. FIBCs go by many different names and can also be known as bulk bags, big bags, jumbo bags, and tote bags.

FIBCs are made of woven polypropylene fabric, which is a very strong and durable material. They can hold up to several thousand pounds of material and are commonly used in industries such as agriculture, construction, and chemical manufacturing. They are often transported using forklifts or cranes and can be loaded onto trucks or shipping containers for transport.

FIBCs come in a variety of sizes, shapes, and designs to suit different applications. They may have various features such as spouts or discharge chutes for easy material handling. Some FIBCs may also have liners to protect the material from contamination or moisture.

FIBC Styles

U-Panel

A U-Panel FIBC is constructed using 3 main body panels. This includes a panel that runs the full length of the bag and forms the bottom and 2 sides of the container. Two other pieces of woven polypropylene are then sewn to the larger panel. The U-Panel style FIBC is a popular choice for its strong durability and high Safe Working Load(SWL).

4-Panel

A 4-panel bag is constructed with four pieces sewn together to form a square shape. When filled, 4-panel bags will hold its square shape like other construction types. Typically, 4-panel bags will hold their shape better than the U-panel bags, and a U-panel bags will hold their shape better than a circular bag.

The biggest drawback to 4-panel bags is the large amount of stitching required to keep the bag together. This can allow for more areas of the bag prone to failure. However, 4-panel bags are ideal for storage due to the way they hold their shape when filled.

Circular

A circular bag is made with a tubular piece of fabric that forms the bag allowing for only the top and bottom of the bag to be stitched. While the fabric that the bag is made from is still tubular, this style of FIBC will still somewhat look like a traditional square bulk bag.

Despite the name, these bulk bags aren’t literally circular; they are made using a single piece of woven polypropylene fabric that forms all four sides of the bag. Even though they still look like traditional FIBCs, they will hold that shape the least of the construction types when filled.

FIBC Top Construction Options

There are 4 main ways that the top of an FIBC can be configured. Here is a brief description of all 4:

Open Top

An open top FIBC is a type of bulk bag that features an open top with no closure mechanism. This means that the bag does not have a top flap or cover and is completely open at the top, allowing for easy filling and dispensing of the contents.

The lack of a top closure allows for quick and easy access to the contents, making it easier to fill and empty the bag. Additionally, the open top design allows for efficient filling of the bag using automated equipment or manual methods such as shovels or scoops.

Flap Top

A flap top FIBC, is a bulk bag that features a top flap or cover that can be folded over and closed to protect the contents of the bag. The flap top is typically secured with fasteners such as Velcro, ties, or buckles to keep the contents of the bag secure during transport and storage.

Flap top FIBCs are commonly used for products that require a higher level of protection or containment, such as chemicals, pharmaceuticals, or food products. The flap top design helps prevent contamination or exposure to the elements and can provide additional protection against spills or leaks.

In addition to the top flap, flap top FIBCs may also feature a spout or discharge chute at the bottom of the bag, which allows for controlled dispensing of the contents. This can be particularly useful for products that are difficult to handle or require precise dispensing, such as powders or granules.

Duffle Top

A duffle top FIBC is a type of bulk bag that features lightweight panel at the top of the bag that is the same width and depth as the other 4 sides of the bag. This large opening allows for more flexibility in filling the FIBC and the different types of machinery the bag can be used with. After filling, the duffle top can be closed to protect the contents of the bag and allow for easier transportation.

Spout Top

A spout top FIBC is a bulk bag that features a cylindrical spout or opening at the top of the bag. The spout is typically made of the same material as the bag and is designed to be pulled open and closed using drawstrings or other fasteners.

Spout top FIBCs are commonly used for products that are difficult to handle or require precise dispensing, such as powders or granules. The spout design allows for controlled dispensing of the contents, making it easier to fill and empty the bag without spilling or wasting product.

In addition to the spout, FIBCs may also feature a bottom discharge spout or chute, which allows for even more precise dispensing of the contents. This can be particularly useful for products that require a high degree of accuracy or consistency in their dispensing.

FIBC Bottom Construction Options

In addition to the 4 main ways the top of an FIBC can be configured, there are also several ways the bottom of a bulk bag can be configured. Here is a brief description of 3 most common ways the bottom of an FIBC can be configured:

Plain Bottom

A plain bottom FIBC features a simple, flat bottom without any discharge spout or chute. This design is often used for products that can be easily emptied from the bag, such as aggregates or other large, heavy materials.

The absence of a discharge spout or chute makes the bag simpler and less expensive to manufacture, as well as lighter and easier to handle. To empty the contents of a plain bottom FIBC, the bag must be turned upside down or tilted to allow the product to flow out through the opening at the top of the bag. This can be more time-consuming and difficult than using a bag with a discharge spout or chute but is often the most practical solution for materials that do not require precise dispensing or handling.

Spout Bottom

A spout bottom FIBC features a discharge spout or chute at the bottom of the bag. This design is often used for products that require precise dispensing or handling, such as powders, granules, or other materials that can be difficult to control or contain.

The spout on a spout bottom FIBC is made of the same material as the bag and is designed to be opened or closed using drawstrings or other fasteners. This allows for controlled dispensing of the contents, making it easier to fill and empty the bag without spilling or wasting product. The presence of a discharge spout or chute makes the bag more complex and more expensive to manufacture, but also more versatile and useful for a wider range of products and applications.

Full Open Bottom

A full open bottom FIBC, sometimes referred to as a Diaper Bottom, features bottom openings that span the full length and width as the dimensions of the bag. The bottom opening also features a flap somewhat like the one found on duffle top bags. This flap is tied or sealed when the bag is used and during filling, then untied for rapid discharge of the bulk bag’s contents.

Rapid discharge is one of the primary benefits of a full-bottom discharge bag. No other construction type allows for this rate of discharge, giving this bag a distinct advantage for those seeking a bag that allows for quick and efficient emptying of the bag.

What is the Difference Between Coated and Uncoated FIBCs?

The main difference between coated and uncoated FIBCs is that the coated FIBC has an additional layer of protective coating on its fabric surface, while the uncoated FIBC does not.

Coated FIBCs are made by applying a layer of coating material, such as polypropylene or polyethylene, to the surface of the fabric. This coating can help to improve the strength and durability of the bag, as well as provide additional protection against moisture, dust, and other contaminants. Coated FIBCs are commonly used for transporting materials that require extra protection, such as chemicals or food products.

Uncoated FIBCs, on the other hand, are made from plain woven polypropylene fabric without any additional coating. These bags are generally less expensive than coated FIBCs and are commonly used for transporting materials that do not require extra protection, such as sand or gravel.

Overall, the choice between a coated and uncoated FIBC will depend on the specific needs of the material being transported, as well as the transportation and storage conditions. Factors such as moisture, dust, and the level of protection required will all influence the decision of whether to use a coated or uncoated FIBC.

What is an FIBC Liner?

An FIBC liner is a removable, flexible, and often transparent bag that is placed inside a Flexible Intermediate Bulk Container (FIBC) to protect the contents from contamination or moisture and to prevent the contents from leaking out of the bag.

FIBC liners are commonly used in the transportation and storage of various materials, including food products, chemicals, and powders. They are made from a range of materials, including low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and polypropylene.

The liner is typically designed to fit snugly inside the FIBC and is suspended from the top of the bag using loops or tabs. Once the liner is filled with the contents, the top of the liner is typically folded over and secured, and the FIBC is then closed and secured using various mechanisms, such as a drawstring closure or a zip tie.

Lined bulk bags come with liners already built into the woven polypropylene. The advantage of FIBCs with liners installed is the many options you have. One disadvantage of lined FIBC bulk bags is that the liners are usually either sewn into the seams of the bag or tabbed to the bag’s material and cannot be removed. This makes it difficult to reuse when compared to using removable poly liners.

Conclusion

RUNCHEN specializes in delivering reliable FIBC flexible bulk bag solutions for global customers. Whether you need to transport powders, granules, chemical raw materials, agricultural products or other bulk materials, we can match suitable bag styles, top openings, discharge spouts, lifting structures, inner liners, coatings and safe working load configurations according to material properties, loading weight, filling and discharging methods, transportation conditions as well as moisture‑proof and anti‑contamination requirements. From standard bulk bags to customized FIBC packaging solutions, RUNCHEN helps you mitigate issues such as leakage, moisture ingress, contamination, difficult handling and low transportation efficiency, making bulk material packaging safer, more efficient and better aligned with practical application requirements. Contact RUNCHEN now and inform us of your materials, dimensions, load capacity and operating scenarios to obtain exclusive selection recommendations and quotation proposals.