Carolina Material Technologies
Carolina Material Technologies - Bulk Material Handling Solutions
Charlotte, NC 704-846-3737

COVID-19 Update: Open For Business

Bulk Bag Systems Case Histories
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3Sigma Bag Handling Systems
Fork Truck - Split Frame Bulk Bag Unloader

Bulk Bag Unloader Case History 3S-1218

An integrator, working for YKK, was looking to automate a process and needed a new system installed. The plant needed a system that would accurately batch zinc pellets to create the proper ratio with the other raw ingredients, which varies with every single batch. YKK originally desired a BBU with a belt conveyor to deliver the product at a 4.5’ elevation.  We suggested a gravity, inline system which offered numerous advantages and minimized the capital investment.  Advantages of 3Sigma’s system: no moving parts and mass flow design, led the customer to choose 3Sigma to provide the desired equipment.

Customer Need:

  • Reliable feeding of the 3/8” zinc pellets
  • Highly accurate batching – amount changes with each batch, ranging from 4 to 64 lbs.
  • Safe bulk bag discharging
  • Minimal maintenance issue
  • System must fit within 20’ with a 4.5’ discharge height
Zinc Pellets

Zinc Pellets


  • 3Sigma provided the client with a bulk bag unloader, vibratory feeder, bag dump station, Aeromechanical conveyor and bulk bag filling system.
  • The bulk bag unloader is set on four load cells, for loss-in-weight batch feeding.  50 lb. sacks are manually added through the bag dumps station.
  • 3Sigma combined both a bag dump station and bulk bag unloader into one seamless unit.  The GeoMate™ feeder discharges through the rear of the bag dump hopper.
  • The GeoMate™ feeder was chosen, specifically for Ti02 as there are no moving parts, no friction, no heat and no binding that is found with screw feeders.
  • The hoppers were coated with Teflon for best product flow.
  • The AMC conveyor includes special SS aeration media at the AMC inlet, inlet sprocket and outlet sprocket to prevent Ti02 buildup and eventual blockage.
  • In operation the recipe is chosen.  The operator is prompted for product and amount required.  Once this is reached, the next product and amount required is prompted.  Bulk product is added first, through the unloader, then 50 lb. sacks are added as prompted by the PLC
Split Frame Bulk Bag Unloader - Gain in Weight Vibratory Feeder

Split Frame Bulk Bag Unloader
GeoMate™ Mass Flow Feeder, Weigh Hopper

 Sequence of Operation:

  1. Load the bag hanging frame.
  2. Lift and set bag hanging frame atop the flow frame.
  3. The fork truck mast is now below the bag/bag adapter thereby saving approx. 3’ of head room.
  4. The bulk bag is opened.  A mechanical brace ensures the bag is supported to protect the operator.
  5. Client sends batch size requried – i.e. 33.5 lbs.
  6. Our batch control chooses the correct fast and dribble speed (based on batch size ranges) and runs.
  7. When batch setpoint is hit, the feeder stops.  A signal is sent to client’s PLC – “Read to Discharge”.
  8. Client robotically places his plate under the weigh hopper and signals, “Discahrge”.
  9. The valve opens and closes.
  10. Repeat.
Top Half of Bulk Bag Unloader

Top Half of Bulk Bag Unloader

Geomate Mass Flow Vibratory Feeder

GeoMate™ Mass Flow Feeder

Better By Design
Made in America
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