Manufacturers are rapidly adopting bulk bags, also known as Flexible Intermediate Bulk Containers (FIBC), as their preferred method for storing and transporting dry, flowable materials. More efficient transportation, easier handling and smarter storage (vs. standard rigid IBCs) are just a few of the primary drivers behind the bulk bag industry’s continued growth.
Despite the growing popularity of the use of bulk bags for dry bulk ingredient handling, many manufacturers have still not invested in automated bulk bag handling systems. These manufacturing sites still rely on manual processes performed by an operator for bag rigging, filling and removal. The introduction of automation at key points in the bulk bag handling process can amplify the already attractive benefits of bulk bags with a better ROI in the long run (and often with a quick payback due to cost savings on labor).
Automation in Bulk Bag Handling
When our engineers are planning for automation in bulk bag systems, we consider everything from control systems integration and engineering, to powered or gravity roller conveyors to move the bags on pallets, to the use of Autonomous Guided Vehicles (AGV’s).
Filling a bag involves three key operational steps: rigging the bag, filling the bag and taking the filled bag away from the filling machine. Anything and everything that reduces the need for human intervention, involvement and oversight in each of these processes results in a higher throughput of more accurately filled, safer bags.
Now, let’s dive deeper into the following places to introduce automation along the bulk bag filling line for a great return on your investment:
- Automatic Unstacking & Delivery of Pallets to Bulk Bag Filling Station
- Automatic Slip Sheet Dispenser
- Automatic Inflation, Taring & Fill Cycle
- Programmed Vibrating Densification Table
- Automated Shrink Wrap & Labeling System
- Automated Bag Removal by Conveyor & Driverless Forklift
Automation Opportunity #1: Automatic unstacking of pallets & delivery of pallet to bulk bag filling station
In a manual bulk bagging operation, team members are required to stack and unstack empty wood pallets by hand, which could lead to a number of health and safety issues. Pallets are sometimes removed using tools like a pick hook to allow the pallet to be reached from the back and pulled forward for safer unstacking. Manual pallet stacking also necessitates that the pallet stack height be limited to a maximum height of 4 feet (for safer handling). This takes up much room on the warehouse floor just to stack and store the pallets.
An automatic pallet dispenser removes the need for manual unstacking of pallets, saving on time and backbreaking manual labor. When combined with a conveyor, the unstacking and delivery of the pallets to the bulk bag filling machine can be fully automated. This provides significant savings on labor to provide a short payback period for the investment. An automatic pallet dispenser can be easily integrated into an existing bulk bag filling line, delivering throughput to up to 180 pallets/hr and enabling pallet stack heights of up to 20 pallets.
After unstacking the pallet in a manual operation, operators then place the pallet on the bulk bag filler either manually or with a forklift before filling commences. In an automated process, the pallet with slip sheet (if required) would instead be delivered by roller or chain conveyor to the bulk bag filling station. This reduces the risk of operator injuries associated with lifting and carrying the pallets and also possible forklift accidents and also takes much less time.
Automation Opportunity #2: Automatic slip sheet dispenser
Once the pallet is unstacked, a slip sheet may be placed on top of the pallet. Slip sheets are thin plastic or cardboard sheets that sit in between the pallet and the bulk bag to protect the bag from the wood pallet. The sheets prevent rips, tears, contamination and other damage to the bag. Additionally, they create an even surface for bag placement and make the bag easier to remove from the pallet. An automatic slip sheet dispenser can be controlled by a PLC unit to feed each pallet with a slip sheet after unloading the pallet onto the conveyor.
Automation Opportunity #3: Automatic inflation, taring & fill cycle
A manual bulk bag filling operation requires the bag to be unfolded and rigged onto the filling machine, the weight of the bag and pallet to be tared out, the fill cycle to be initiated, the densification and compaction to be cycled (if required), and the fill rate to be controlled to successfully achieve the target weight. If all of this is done manually by the operator, starting and stopping in between each step and requiring them to be actively involved during the entire filling cycle there are significant labor requirements and many potential sources of fatigue and human error.
An integrated control system and automatic filler can allow almost all of these steps to be automated. Once the operator has rigged the bag, the press of one button can initiate a fully automated fill cycle. The automated cycle includes all of the following steps: inflate bag spout collar, inflate bag, TARE, start flow, vibrate, dribble feed, final densification (if required), auto loop release and auto index to outfeed conveyor for tie off and removal.
This automated process can result in an output of 30+ bags per hour, whereas the manual process described above typically results in around 6 to 8 bags per hours. The automated, controller-based fill cycle also reduces the risk of human error in stopping and starting the ingredient flow for more accurate weighing and better densification. Lastly, the operator does not have to reach into the machine as much, reducing safety risks.
Automation Opportunity #4: Programmed vibrating densification table
Many bulk bag filling systems use some type of vibration technology for densification of the product during or after bulk bag filling. These often utilize a vibrating platform / table on which the bag sits while it is filled, and that can be manually switched on and off during the fill cycle in order to better compact and densify the product in the bag.
For maximum benefit it is also desirable to have the bag hanging during the fill cycle to achieve the optimal stretch of the fabric. To achieve this a specialized bulk bag filler can be programmed to lower the bag onto a densification table and raise it after the vibration cycle is complete at timed intervals throughout the fill cycle. This maximizes the amount of material that can be filled into the bag and its stability.
Automation Opportunity #5: Automated shrink wrap & labeling system
For bulk bags that would benefit from added stability or protection (ie. preventing hygroscopic materials from absorbing outside moisture), shrink wrapping or stretch wrapping your bulk bags on their pallets may be necessary.
An automatic bag and pallet wrapper and labeling system wraps each bag with a clear plastic film and then places a label on each bag with the batch number, weight and contents. In addition to considerably speeding your bulk bagging process, a fully automatic shrink wrap machine wraps the load more tightly and uses less plastic wrap, providing a cost savings on both time and materials.
An automatic labeling system based on control integration with the filler to automatically label each bag as they come off the line saves considerably on time and increases label information accuracy.
Automation Opportunity #6: Automated bag removal by conveyor & driverless forklift
With the advent of increasingly sophisticated automated warehouse and storage systems the roller conveyors on the outfeed of a bulk bag filling line can now also be designed to be compatible with AGVs (Automated Guided Vehicles). AGVs are unmanned forklifts that can be programmed to take the pallets with bags directly off of the end of the roller conveyor line. If you are considering this option for your bulk bag filling line, make sure to look for an AGV specifically designed to move palletized loads, as there are several types of AGVs now used in manufacturing. AGVs have several benefits vs. traditional manned forklifts. Compared to traditional forklifts, AGVs offer a small footprint, labor cost savings and help to reduce product damage with more precise load positioning.
If you are interested in adding automation solutions to your bulk bag filling process, find a bulk bag equipment manufacturer with experience in industrial control systems engineering and process automation. Since control panel and software knowledge will be crucial to the successful operation of your automated bulk bag filling processes, finding a partner that has knowledge of both control systems and equipment will ensure a smoother automation implementation and more efficient final process.