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Bulk Bag Unloaders

Technical Details: Loss-in-weight Bulk Bag Unloader

Our loss-in-weight bulk bag unloader allows you total control over the amount of product you wish to dispense from the bag. This can be varied for individually selected batch amounts, or fully interfaced with your plant process control for continuous batch production.

The T3 loss-in-weight bulk bag unloader incorporates all the proven features of our Universal T2 model, but the bag support dish is mounted on load cells. This enables highly accurate weighing of your product as it is discharged from the bag. If necessary, the integral transfer conveyor can also be suspended from the weigh frame as shown opposite, to provide a totally self-contained discharge and loss-in-weight dispensing unit.

This loss-in-weight bulk bag unloader is used in Spiroflow's North American test lab.


  • Batch or continuous weight control - load cells are located at the mid-section, preventing the risk of damage by forklifts and dirt/debris when located at the base of the unit.
  • Recipe management system
  • Bag tensioner ensures complete emptying of bag
  • Integral conveyor or feeder
  • Full dust control
  • Designed to discharge poor flowing materials
  • Suitable for all bulk bag types and sizes up to 6.5 ft (2 m) high and 2 tons (1.8 tonnes) in weight


  • Bag massagers to aid flow
  • Vibration
  • Bag spout closure bars for dust-free and easy untying & re-tying of bag
  • Mobile frame
  • Bag dump door
  • Hygienic liner clamp
Spiroflow provides loss-in-weight bulk bag unloading and batching control systems.

Our specialized batch controller provides both 'bulk' & 'trickle' feed for loss-in-weight dispensing. The Pause-Resume feature pauses the discharging operation when one bulk bag is empty and retains the amount dispensed in memory. When a fresh bulk bag is placed on the unloader, the controller recalls the remaining weight required and resumes discharging. All components, including the integral conveyor, are 'above' the load cells and are weighed, while the lower frame is isolated from the load cells and secured to the floor.