Let us introduce here an intralogistics system composed of a pallet handling system line and a Technowrapp pallet wrapping machine that we have realised for a customer of ours in the beverage sector. His need was to connect the production line on the ground floor to the warehouse on the first floor by means of intralogistics system coordinated between them by a complex software.
In this installation, a central and 4 peripheral PLCs manage and coordinate automatically 4 different missions.
1) Wrapped pallets handling from the production to the warehouse for their storage and shipment
2) Handling of empty pallets stacked in groups of 15 from the warehouse to the empty pallet dispenser
3) Materials supplying from the warehouse to the entire production line
4) Handling of the materials to be disposed of from the production line to the warehouse
Installation data and main parts of the intralogistics system
- Technowrapp pallet wrapping machine by rotating ring Twin Rings E: it wraps and covers the load hermetically
- Pallet lifter: it carries up and down 2 pallets at a time (6 meters height and 2.000 kg payload)
- RGV shuttle conveyor: it carries empty pallets to the empty pallet dispenser
- Empty pallet dispenser: it collects 15 empty pallets and it releases them one at a time depending on the request of the palletizer
- Labelling machine: it applies a label on the wrapped pallet
- 2 roller-to-chain transfer devices
- 3 roller-rotating platforms
- 29 conveyors
- 1 central PLC
- 4 peripheral PLCs i/o (256 in – 272 out)
- 6 safety areas
- 20 inverters
- 300.000 program rows
- 24h / 6 days a week
The real complexity of this installation lies in the software that has the task of managing the various missions avoiding that one interferes with the other, monitoring all up and down movements of the material to and from the warehouse.
To ensure an efficient flow of the line, the following aspects have been handled:
a) Accumulation conveyor after the pallet wrapping machine: when the line has to accomplish the missions 2-3-4, the flow of wrapped pallets is interrupted and the pallets are accumulated on the outgoing conveyor, waiting for the end of the mission. Once the mission is ended, pallets can resume their way to the warehouse.
b) Areas of accumulation of empty pallets: the stacks of 15 empty pallets sent from the warehouse to the empty pallet dispenser are not accumulated only in that device. Two additional areas of accumulation have been created along the line (on the conveyor before the RGV shuttle and on the RGV shuttle itself) in order to guarantee a continuous flow that does not generate waiting times and that satisfies the constant demand of empty pallets coming from the palletizer.
c) The system is supervised by six safety areas, so that only the area of interest is stopped in case of emergency, assuring continuity to the rest of the line.
d) A central PLC controls the entire system and communicates with other 3 PLCs distributed along the line. One of them is exclusively reserved to the functions of the pre-stretch carriage installed on the pallet wrapping machine, and it communicates possible anomalies in pre-stretch performances to the main PLC.