Issue link: https://www.e-digitaleditions.com/i/1242780
28 / May 2020 powderbulk.com Quality FIBC construction. Robust bulk bag con- struction using durable materials is crucial to ensure a long FIBC working life and protection from potential damage by forklifts. Operator access. Operators need easy access to the FIBC and filling equipment, which will keep pro- duction flowing smoothly and decrease downtime. Operators should be able to easily attach the loops to the FIBC support arms, which hold the FIBC in place while filling happens. The operators should also be able to easily connect the filling spout and liner to the fill head, disengage the filling spout and liner from the fill head, and tie off the filling spout. The opera- tors must be able to complete these three functions at shoulder height without the need to climb on or in the machine. Lastly, the electrical controls should be easily accessible to operators. All bag-filling functions need to be able to be performed manually (as required by the operator) and automatically (once the filling cycle is initiated). Technology for filling These basic filling principles have also been augmented by various options designed to further automate the filling operation and reduce operator involvement. Pallet dispenser. Several pallets can be placed on top of one another ready for the filling operation to commence. Then, a pallet dispenser selects the top pallet from the stack to be sent to the filling machine. Slip sheet dispenser. A slip sheet, which we'll discuss more in-depth later, is made of cardboard or plastic and goes underneath an FIBC to prevent contamination of the package's bottom. A slip sheet is typically placed on the pallet automatically prior to filling. Automatic bag loop release. Just as its name suggests, once the FIBC is filled, it's automatically released from the filling machine and ready for automatic removal. Take-off or accumulation conveyor. The filled bag is automatically conveyed away, allowing a new bag to be placed ready for filling. FIBC handling, stacking, and stability Most applications call for FIBCs to be on pallets. Pallets are typically used to move filled FIBCs and are subject to a few considerations. • The correct pallet size will allow the FIBC's rounded section to overlap the edges of the pallet so that when two palletized bags are placed side by side, the bags touch but not the pallets. This increases the bags' stability when packed in con- tainers and trailers. to some extent during filling. The FIBC should be posi- tioned so that the FIBC seams can stretch downward during the filling cycle and the bag's actual corners only touch the filler's base when the fill cycle is com- plete, as shown in Figure 3. FIBC densifying. For thorough densification, vibra- tion must be applied to the FIBC's base. The material's bulk density in the filled bag should be as near as possible to its tamped bulk density. This should be achieved while the FIBC is in the bulk bag filler. Filling and air displacement. Fill-rate control and displaced air exhaust are important to successfully fill an FIBC. Complete control of the material passing through the fill head must be maintained for a steady filling rate, which makes establishing a consistent bag-filling cycle easier. The fill head must also allow for the displaced air to exhaust, which prevents dust and FIBC pressurization during filling. Liner usage. For FIBCs with loose liners, inflating the empty FIBC and liner with air is particularly nec- essary prior to filling to eliminate folds in the liner. Failing to do this will usually lead to the material filling over the folds in the liner, resulting in a limited amount of material that can be filled and an unstable package. The liner also needs to be properly sealed to the fill head to ensure there's no dust release. During inflation and filling, however, the liner must also be free to move inside the FIBC and take up the shape of the bulk bag without stretching. FIGURE 3 FIBC with filling spout tied off ready to be removed from filler