CLOSE attention to quality and productivity has always been the key priority to the continued success of a well-known Australian biscuit manufacturer.
The addition of a new wrapping machine in the company’s packaging plant provided the increase in speed required.
Whilst the dough mixer and ovens had the capacity to make more biscuits, to meet the demands of the new flow wrapper, the existing accumulation and infeed conveyors were unable to cope satisfactorily with the increased production capabilities.
Speed, however, was not the only problem.
The accumulation section of the packaging process was rejecting all biscuits presented with gaps between the stacks.
This had a negative impact on productivity levels.
It soon became evident that only a solution addressing the issues of both speed and accuracy at the accumulation stage of the process would provide the missing link the manufacturer was looking for.
Innovation through integration
OVENS at the large-scale manufacturing plant produce 2400 biscuits per minute. These are dispatched, lying flat, along 11 lines.
Two drives controlled the accumulation section of the process, accumulating biscuits at a 15 degree angle and unable to eliminate gaps between the biscuit stacks.
Identifying this stage as the weak link in the process, Machinery Automation & Robotics (MAR) created an integrated system that maximised speed, accuracy and productivity through the effective use of servo drives.
Complementing the two existing drives, 11 new drives were integrated into the packaging process, one for each of the accumulation lines.
The new servo drives enable the system to perform a four-minute accumulation of biscuits.
The servo drives selected were SEW Movidrives, complete with DRS synchronising cards. A Sick diffuse sensor is used on each shuttle conveyor to signal to the servo drive to step back, ensuring precise biscuit placement.
Meanwhile, buffer belt servo motors and drives receive feedback from high accuracy incremental encoders.
Interfacing to the control system is achieved via an Allen Bradley PLC.
Conveyed from the ovens, the biscuits are now accumulated at the required 30 degree angle on servo indexing “finger” conveyors.
This ensures a reliable supply to he downline wrapper, whilst at the same time providing a buffer for the upline ovens.
Another outcome of the upgrade is that all gaps between the biscuit stacks have been eliminated.
Following accumulation, the biscuits are counted into a packet quantity and indexed into the flow wrapper, before being automatically packed into a carton and palletised, using robotic palletisers.
This, in turn, ensures continuous end-of-line packaging without interruption, during the short periods throughout the day when ovens go off-line.
Following the design and programming, MAR completed all installation and commissioning during the client’s non-productive hours, guaranteeing no downtime to productivity.
MAR provided onsite staff training, full compliance with occupational health and safety requirements, and “on call” servicing.
The successful integration of the new servo drives provided the manufacturer with the accuracy and speed required to handle the capabilities of the new flow wrapper, completing the upgrade of its biscuit packaging process.