TBMA Europe recently completed a double big-bag filling plant for a manufacturer of high quality feed for cattle. The installation fills up to 30 big bags per hour, and can be operated by one person. Two filling lines were chosen to prevent product contamination.
The product is fed to the TBMA big-bag filling machines from storage hoppers by horizontal screw conveyors. The rotational speed of the conveyors can be adjusted to provide accurate dosing during the weighing cycle. Both big bag fillers are equipped with a fixed position filling head, a weighing system and a vibrating table, which is mounted on a lifting platform. Due to the fixed position of the filling head and the stepless lifting / lowering device, all operator actions are performed at an ergonomic working height by the operator. The two rear big-bag support are mounted on linear cylinders which allows them to travers to the front of the machine to facilitate suspension of the bag loops. The big-bag filling spout can easily be pulled up over the filling head to ensure a dust-free connection. An integrated fan blows the folded big-bag into shape. The operator is able to use the control panel to select the desired process outcome for the upcoming big bags. Next, with only the push of a button, the filling process is started.
Filling and weighing
During the filling process, the conical vibrating table is raised to support the big-bag. The vibrations ensure that the product is vented, compressed and that the corners of the big-bag are filled. The vibrating table can be activated multiple times per filling cycle dependent upon the filling rate. The suspended big-bags are weighed during the filling cycle. The combination of vibration and suspension allows the bag’s to stretch (big-bags stretch approximately 3-5%), which provides a stable and vertical big-bag. The suspended weighing principle is also less susceptible to the influence of external factors.
During the filling cycle, a pallet is automatically transferred from the pallet dispenser. A shuttle conveyor transports the empty pallet underneath the big bag and lifts it until the suspension loops are slack. At that moment the filling spout seal is deflated and the loops are automatically released. The operator ties of the filling spout, and confirms via the control panel that the big-bag is ready for transport. The lift-table then descends to the connecting roller conveyors and the shuttle is driven out of the filling machine. During this operation the operator hangs a new big-bag on the filling machine hooks and starts a new filling cycle. The filled big-bag and its pallet are transferred from the shuttle conveyor to the last available position on the accumulation conveyors. By this method of operation time losses are minimised, which allows each filling line to produce 15 big-bags of 1000 kg per hour.