Safety in pallet transport lines – ReeR Safety solutions
Protection of a pallet transport line with a layer palletizer and wrapping machine
The project involved protecting a pallet transport line that uses a layer palletizer to stack boxes of different heights. The automated system is well-structured and needs strong safety measures to protect operators from hazardous areas.
Boxes of various heights are loaded onto a roller conveyor. From there, they move to a hoist, which lifts and rotates each box 90°. The boxes are then stacked on a pallet by the palletizer. Once the pallet is full, it is sent to the wrapping machine, where the packaging film is applied.
This setup requires a safety solution that recognizes the different box heights and protects both the entrance to the hazardous area (before the hoist) and the exit.
ReeR Safety solutions for layer palletizers
To meet these safety needs, ReeR Spa developed a system with:
- Three photocells to measure the height of the boxes (A)
- An EOS 2 safety light curtain (B) with 90 mm resolution to protect the entrance to the hazardous zone. It features bi-directional muting (entry and exit) using two photocells (M1 and M2).
- A second EOS 2 safety light curtain (C) with 90 mm resolution to protect the exit, using one-way muting (exit only) with two photocells (M3 and M4).
Both EOS light curtains have automatic start/restart and are 1060 mm tall. For flexible management, the safety light curtains, photocells, safety switches, and emergency stops are all controlled by the Mosaic M1 Safety Controller with an MI802 expansion module.
How bi-directional protection works with EOS
Two photocells are placed on either side of the safety light curtain to serve as muting sensors. The Muting function starts when both sensors are blocked at the same time, within a time frame set in the Mosaic: Sensors Time parameter (2 to 5 seconds). The Muting function stays active as long as both sensors are blocked.
When the first sensor is cleared, the Muting function ends. The maximum time for Muting is programmable via the Mosaic: Timeout parameter (from 10 seconds to infinity).
ReeR Solution
EOS2 Safety light curtains
EOS2 is a compact safety light curtain range with competitive performance and innovative features. Includes models with integrated safety functions such as self-monitoring static outputs, control of external contactors (EDM), and selectable automatic or manual restart.
2 safety PNP static outputs. Easy connection and installation thanks to the M12 connectors and the use of unshielded cables up to 100 meters.
EOS2
For this application:
- Automatic Start/Restart
- 90 mm resolution
- Connections and configurations through M12 5-pole connectors. Unshielded cables up to 100 meters long can be used to connect the light curtain.
- Protected heights: 1060 mm protected height is used
One-way Protection for Pallet Exit
The two photocells are also used at the pallet exit for one-way muting. This function activates when both sensors are blocked at the same time, using the Mosaic: Sensors Time setting (from 2 to 5 seconds). The Muting function remains active while both sensors are occupied. When the first sensor is cleared, the system allows the material to pass through for a set time, defined by the Mosaic: End of Muting Time parameter (from 2.5 to 6 seconds).
Once the pallet has left the protected area, the Muting function is disabled. If the light curtain is blocked again, the machine will stop for safety. To prevent stoppages caused by small pallet movements or parts sticking out, the Mosaic includes a Blind Time setting (from 250 milliseconds to 1 second). This allows for a brief re-entry into the light curtain without triggering an alarm. The Mosaic timeout parameter can also be used to adjust how long the Muting condition lasts (from 10 seconds to infinity).
ReeR Solution
Safety Controllers and Interfaces
Mosaic is a safety hub able to manage all safety functions of machinery. Configurable and scalable, provides cost reductions and minimal wiring.
MOSAIC M1
- 8 Inputs
- 2 OSSD pairs (SIL 3)
- Screw terminal blocks
In this application, additional input/output are given by the expansion unit MOSAIC MI802, with:
- 8 digital inputs
- 2 inputs for Start/Restart interlock and external device monitoring (EDM)
- 2 pairs OSSD safety outputs
- 2 status outputs
- 4 test outputs
To ensure maximum safety in your pallet conveyor lines with layer palletizers and wrapping machines, choose ReeR Spa.
Our safety solutions provide advanced protection, efficiency, and operational flexibility.
Contact us now to discover how to implement a tailored safety system for your production needs.
ReeR, your future’s safe!