January 30, 2023

How to Increase Your Bulk Bag Fill Rates: Strategies for Optimization

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Introduction to Bulk Bag Filling

The bulk bag filling process is a critical aspect of material handling and logistics that ensures a stable, dense package for storage, transport, and discharge. The goal of the process is to minimize operational and labor costs while maximizing the bag fill rate, which is measured in bags per hour.

Which Factors Affect Bag Fill Rate?

The fill rate depends on various factors such as material characteristics, infeed source, and plant environment. A typical fill rate ranges between 10 to 40 bags per hour. High-quality bulk bag fillers are designed to adjust for different bag types, and sizes, as well as a wide variety of dry bulk products.

Steps To Optimizing for More Bags per Hour

The process of optimizing bags per hour involves a number of considerations, such as equipment, air displacement, bag stability, and densification strategies. To achieve a seamless process, the filling application typically includes three steps: rigging (hanging and spouting) the bag, filling the bag, and removing the filled bag from the filler.

1. Rigging the Bulk Bag

Before proper filling, the bag corners must be suspended off of the pallet by 3-4 inches to allow the bag side-walls to stretch properly. This is important to ensure the bags are stable and upright once filled. 

2. Filling the Bulk Bag

The bag spout is positioned over the fill head to create a tight, dust-free seal. Next, the bag/liner may be inflated with air. The bags are typically gross weighed, which involves a valve or conveyor that is actuated in bulk, then dribbled flow, and then stops at the target weight. 

Another approach is pre-weighed systems, where a product charge drops into the rigged bag, and the next bag’s charge enters the hopper as the previous one drops. For best results, the product is densified and compacted to form a stable package suitable for safe and efficient stacking.

3. Fast Bag Removal After Filling

Fast, consistent bag removal is essential for an optimal fill rate. An automated roller or chain conveyor quickly removes the filled bag to make way for the next empty bag. Pallet and slip sheet dispensers speed up the process, as the operator does not have to add these items manually.

Using Automation in FIBC Filling Equipment

Fillers that operate in automatic or semi-automatic modes help to minimize the required handling and facilitate a higher fill rate. Operators should match all filling equipment and bags to product characteristics, such as solids that clump or particulates that become suspended in the air. 

Fill rates can be adjusted for safety and efficiency, from a slow dribble to a steady river. Each bag should be filled to a precise, predetermined weight.

Upstream Equipment and Weighing

Upstream equipment, such as conveyors, can also play a crucial role in the bulk bag filling process by conveying the product to a surge hopper. Once in the hopper, a metering device, such as a slide-gate valve, rotary valve, butterfly, or screw feeder, is used to start and stop the flow to complete the desired weighment. 

The surge hopper helps deliver a consistent volume and impacts efficiency, accuracy, and capacity. The weighing of the product into the bag is also an important step in the process. Most fillers work with load-cell-based scales, but support frames for the bag can be set on a platform scale as well.

Final Thoughts about Maximizing Bulk Bag Filling

The bulk bag filling process is a critical aspect of material handling and logistics. It requires advanced equipment and technology to ensure a stable and dense package, minimize operational and labor costs, and maximize the bag fill rate. The use of automation, densification strategies, and proper equipment selection can greatly improve the efficiency and effectiveness of the process. 

It’s important to consider the desired production rate and weigh it against the cost of an extra filler. By paying attention to these details, the bulk bag filling process can be streamlined and optimized for success. 

If you need information on advanced bag filling equipment, contact us at FormPak. We have the knowledge and experience to answer your questions and build customized systems to meet your needs. 

Videos of FormPak Bulk Bag Fillers



Properly and efficiently filled bags can boost productivity and cut down on unnecessary operating costs. Quality bulk bag filling equipment, combined with proper operating techniques, help to maximize bags per hour. 

If you need information on advanced bag filling equipment, contact us at FormPak. We have the knowledge and experience to answer your questions and built customized systems to meet your needs.