What Top Style Does My Bulk Bag Need?

For many that are new to using an FIBC (also called a bulk bag, tote, or Super Sack™), the 20+ design parameters can be intimidating. 

At the most basic level, an FIBC is a large woven plastic bag with a top and bottom. The bag is moved from point to point using four lift loops attached to the corners of the bag. In general, these industrial containers are designed to safely transport 2,000 to 4,000 pounds of material.  

We find that the majority of our new users are most interested in the bulk bag’s top style. The following information is intended to give new or inexperienced users of FIBCs a basic understanding of the most commonly available top styles.

What’s the Difference Between a Spout Top, Duffle Top, and Open Top Bulk Bag? 

The question is best answered by a short explanation and a few intuitive images. 

What Is a Spout Top Bulk Bag?

Spout tops (or top spouts) are one of the most common bulk bag top styles. 

A spout top is a standard bulk bag feature that includes a narrow cylindrical tube sewn onto a flat base. The flat base is sewn into the body of the FIBC to form a fully closable top panel. The top panel and spout are made from coated woven polypropylene. Note that these components are not designed to be load-bearing.

Spout top bulk bags are ideal for packing dusty products. When the fill spout or top spout of the bulk bag is connected to the filling equipment, it creates a closed filling process that reduces or eliminates dust and spillage. After the bulk bag is filled, an operator is able to tie off the top spout with pre-installed ties.

Common spout top applications include:

• Food ingredients
• Fine chemicals
• Cement
• Resin
• Silica 

While top spouts are completely customizable and can be tailored to your needs, the most common spout size is 14” in diameter and 18” in length. 95% of all stock Southern Packaging bulk bags have a 14” by 18” top spout.

Spout tops are generally more expensive than open tops but less expensive than duffle tops. 

What Is a Duffle Top Bulk Bag?

A duffle (or duffel) top is a standard bulk bag feature that includes a large tubular skirt sewn directly into the top of a bulk bag. The duffle is made from coated woven polypropylene.

Also a fully closable top style, the duffle top allows the user to enjoy the functionality of an open top bag during filling and the security of a spout top bag for closure. The primary difference between a spout and a duffle is that a duffle allows full open access to the body of the bulk bag. Duffle tops are extremely common and used in a wide variety of applications.

Common duffle top applications include: 

• Aggregates
• Animal feed
• Granular material
• Chemicals
• Beans and seeds

In general, a duffle top bulk bag does not connect directly to a filling apparatus. Rather, the bag sits below the chute or hopper and receives material through the large opening. As a result, this style is generally not recommended for dusty products, and it is not designed to be load-bearing.

Duffle tops are sized based on the length and width of the bulk bag and can be custom designed to meet the requirements of the customer. In general, the wider the bag, the longer the duffle will need to be. This allows the operator to easily gather the duffle and tie it off at the top. Pre-installed ties are also included on a duffle top. 

Duffle top bulk bags are generally more expensive than open top and spout top bulk bags.

What Is an Open Top Bulk Bag?

An open top (or full open top) bulk bag is a less common bulk bag top style that has no top closure whatsoever. Material is deposited directly into the FIBC and is exposed to the elements after filling.

Common open top applications include:

• Soil
• Sand
• Rock
• Landscaping materials
• Construction debris 
• Scrap
  
  

Open top bags are often confused with duffle tops. Yes, the duffle opens completely for filling, but it can be reclosed and tied off. Full open tops have no top closure. Additionally, open top bags are generally more economical than spout top or duffle top options, but they’re no less strong than bulk bags with a top closure.

While Southern Packaging does not currently stock full open top bags, they are available as a custom order. 

Need additional help determining the proper bulk bag top style? Contact us today!