At Power Plastics, hand-packing 3000 polyethylene condiment bottles an hour was taking a toll on labour costs and operator health and safety. Six months after utilising robots from ABB Australia , two-thirds of the line’s staff had other jobs, efficiency was on target and weekend output from the line was up 30 to 40 per cent.
Power Plastics considered robotic solutions from ABB Australia due to the rising raw material prices, operational and human costs of hand-packing 60,000 bottles a day, in 250ml and 500ml sizes and in five different colours.
Another deciding factor for installing robots was the workers’ compensation claims from RSI (repetitive strain injury). To ensure that Power Plastics didn’t have any RSI issues, a robotic solution was necessary.
Sydney-based systemsintegrators, Apex Automation and Robotics, have built a non-robotic automation solution for Power Plastics. When Apex Automation and Robotics’ General Manager, Dany Seif, surveyed the condiment bottle line, he found two operators on each shift filling plastic-lined cardboard boxes with the bottles, sealing them and placing them on pallets. Seif concluded that Power Plastics required high flexibility and ability to handle product diversity.
The robotic cell built for Power Plastics is based on a 6-axis IRB 4400L robot, with a 2.43 metre reach and 30 kilogram payload. Bottles are fed from two extrusion blow moulding machines (EBMs), along accumulation conveyors, from which the robot picks 8, 9 or 10 bottles using a gripper, depending on the size. The gripper uses vacuum cups to pick up a row of bottles, space them and place them upright on a stainless steel platen.
In the next cycle, the gripper rotates 180 degrees, spaces and places the bottles upside down between each bottle in the first row. When the platen is full, the cell signals the operator, who inspects the bottles, slips a plastic bag over them, seals them and takes them to a pallet.
The robot sits between two in-feed conveyors, which supply two identical packing zones 180 degrees apart. When the operator is bagging one platen of bottles, the robot works in the opposite zone. Barber added that they could automate the whole line, but was more concerned about going from essentially 100 per cent inspection to zero inspection. The line initially began with six employees over three shifts. Now it is down to one per shift. Barber further added that since the line runs 24 hours a day, measuring any improvement in output was difficult. On weekends, output is up by 30 and 40 per cent.
APEX Automation and Robotics designed and programmed all the elements such as the gripper, marshalling equipment, PLC (programmable logic controller), HMI (human-machine interface) and the safety integration, which is in accordance with the relevant Australian Standards.