A carbon black manufacturer in southern Ohio required an automated bulk bag filling system for a new packaging line for filling granulated activated carbon. Their project had several requirements. First, the client needed to fill bags weighing 500 – 2,200 pounds with a large variety of dimensions and little to no change-over time. Second, they requested a system that could fill one bag directly on top of another (double-stacked) to minimize the number of motions it would take a forklift to load a two-bag consolidated pallet into a truck for transport.

To achieve the client’s objectives, Choice Bagging Equipment designed a system with a dust-tight fill head assembly that could be raised and lowered on demand to an infinite number of positions and allow for double filling and stacking directly on the filler. Pneumatic, retractable bag strap holders not only automatically released the bag after filling, but they also simplified the placement and removal of the bags (this was a critical element when filling double-stacked bags high above floor level).

Other standard design elements included an integrated pallet indexing conveyor. This automatically transferred empty pallets into the system and discharged filled pallets out, a pre-fill bag inflation assembly to expand empty bags to their full shape and size prior to filling.

Each filling sequence was initiated by a simple button push. Each bag was filled automatically to a pre-determined weight selected by the operator. The filling machine was built on four load cells which worked in combination with a single PLC-based control package customized specifically for the client’s application.

The flow of material was automatically started and stopped by a multi-position slide gate. The system controls signaled the slide-gate to reduce flow at a pre-programmed weight. The slide-gate would actuate by degrees to reduce product flow gradually before closing at the end of each weigh cycle. This prevented overfilling of the product. An inflatable bag seal cuff provided a dust-tight bag connection and a pre-filling bag inflation system enabled a positive bag shape and correct positioning on the pallet.

The system provided a high level of weight accuracy than would have been possible with a manually controlled system. Even with the bag changeovers, the system operator required no additional assistance from other plant personnel to run the system. The new system was integrated with an automatic pallet dispenser and filled pallet conveying system so that empty and filled pallets could be exchanged from the system without interruption.