What Are the Different Bulk Bag Discharge Types?

Flexible Intermediate Bulk Containers (FIBCs, jumbo bags, big bags, bulk bags) are made from flexible, woven materials and can typically hold between 500 kg and 2,000 kg of flowable product. There are several different bulk bags construction methods and bulk bag discharge types to consider, depending on your application.

Please remember that there are multiple FIBC unloader methods. Some companies use a pneumatic, forklift or screw conveyor, stationary frame, special discharge stations, or a hoist to empty their FIBCs. Choosing the right unloading methods and the perfect type of FIBCs will depend on the material handling techniques used in your factory.

Customers can combine some different bulk bag discharge types with a variety of protection methods. A dust-free bulk bags normally have a discharge spout or a plain bottom, depending on your requirements.

The seven main bulk bag discharge types are:

  1. Flat bottom
  2. Discharge spout
  3. Discharge spout with star closure and petal closure
  4. Discharge spout with flap
  5. Conical discharge spout
  6. Duffle bottom
  7. Iris closure

1. Flat Bottom (Plain bottom/ Closed bottom)

A flat bottom big bag without a spout (also called a plain base bulk bag) is an economical option but can only use this bag once because when discharging the product, you need to cut open the bottom. These FIBCs are usually used in application where you need fast discharge without needing to reuse the bag.

2. Discharge Spout

The discharge spout is on the bottom of the bulk bag that remains closed until you are ready to discharge the product. The spout is a great way to discharge product because it is controlled directly and does not destroy the bag while the product is being discharged.

Discharge spouts come in multiple sizes and can be customized to your application. The normal size of the spout ranges between 14 inches in diameter and 18 inches in length. Bulk bags with a discharge spout are the most popular in the industry.

3. Discharge Spout with Cover (Star Closure & Petal Cover)

The petal and star closures are sewn from heavy fabric to cover the discharge spout. A piece of fabric is sewn between the spout and the petal closure or star closer to hold in/protect the spout. It prevents bulging and minimizes contamination risk.

4. Discharge Spout with Flap

With the aim to protects the entire bottom surface of the bag for cleanliness, you can opt for a discharge spout with a flap also known as a sanitary flap. The flap, act as access doors for the spout, attaches to the base of the bag before securing it with a band to prevent dust collection. When contamination is a concern, protecting the discharge spout with a flap is the best option.

5. Conical Discharge Spout

Bulk bag sometimes are designed with a spout sewn in a cornical bottom. A conical discharge spout helps you empty the entire bag of its product. One common issue with standard FIBCs is that material accumulates in the corners of the bag.

With standard discharge options, customers need to shake the bulk bags to remove all the material. A conical discharge spout lets material flow easily from the bottom of the bulk bag without any leftover product remaining in the corners.

6. Duffle Bottom

A duffle bottom allows you to discharge all the contents of the bag quickly and easily. This type of FIBC bottom is mainly used for bulk material, the entire bottom of the bag opens to release product that doesn’t flow easily or clumps together over time.

Customers fasten the bottom of the bag using a polypropylene tie that may include a perimeter closure to secure the product during transport and storage. Some duffle bottom bulk bags also use a flap to protect the bag until discharge.

7. Iris Closure

When you don’t need a fixed connection, an iris bottom provides you with a way to controlling the flow of material being discharged from the bags bottom spout by using a valve. The discharge spout pulls through the valve, which you then secure around the spout.

These are commonly used in situations where it is imperative to be able to control the flow of material OR where there are hazardous materials that are discharged from the bag. Once you gradually open the valve, the material starts discharging and you can prevent any uncontrolled blasts, limiting dust from spreading through your plant area during product flow.

For any kind of bulk material packaging where the product is flowable, you can find a discharge type that suits your needs.

Even when the above types do not fit your exact requirements, custom discharge designs are available that will ensure you can transport, store, and discharge your product safely.

To learn more about bulk bag discharge types, you can contact EPP VIETNAM who will guide you through the entire selection process.