How safe is your palletiser?
As most palletiser related injuries occur when personnel are working inside the machine, it is important to safeguard these automated packaging systems with an appropriate safety interlocking device.
Virtually all beverage bottling plants use In-line Palletisers in their end-of-line packaging operations to automatically and rapidly stack cases of bottled product onto wooden pallets. Each pallet is then stretch-wrapped with a layer of protective film, ready for shipment to their required point of distribution for public consumption. In-line palletisers utilise a continuous motion flow divider that guides the cases of bottles into the desired area on the layer forming platform.
Operators and/or plant engineers may require access into the Palletiser in the event of a machine breakdown or to perform scheduled maintenance activities. However, due to its high speed processes and hazardous moving parts, these machines are notorious for causing fatal injuries and pose inherent safety risks to all plant personnel that may need to work on the inside of the machine.
EN 415-4: The Safety of Packaging Machinery Part 4: Palletiser and depalletisers is an international safety standard that was created to specifically highlight all of the risks associated with the use of this type of automated machinery and outlines methods of mitigating these risks with adequate safeguards. such as the use of interlocked guards that prevent access into the machine until the Palletiser has; finished its current stacking cycle, returned to its home position, and all of its moving parts have ceased operation.
One of the most optimal ways of safeguarding Palletiser systems is by using a safety gate switch with guard locking functionality and an integrated push button for basic machine control.
This particular application requires the use of a safety interlock switch with guard locking that holds the door closed until the Palletiser has entered a safe state of operation and has subsequently returned to its home position. This protects the manufacturing process and saves any unnecessary loss to production, caused by interrupting the palletiser mid-cycle.
To simplify the entry procedure, the bottling plant safeguarded all of its Palletiser systems with an amGardpro safety interlocking switch which enables operators to initiate safe access into the machine. Thanks to its modular configuration, the safety gate switch utilised a lever-operated handle actuator that is perfectly suited for use on hinged access doors, eliminating the need for fabrication of a door handle.
For safe access into the machine, an operator must initiate the shutdown procedure by requesting entry from a local push button. For ease of use, basic machine control has been integrated into the safety device, removing the need for additional hardware and associated wiring costs. This signals to the machine's control system to bring the Palletiser to a controlled rest once it is safe to do so.
Once the Palletiser has entered a safe state of operation, the machine's control system sends a signal to the safety gate switch to release its guard locking function. In turn, the blue push button is illuminated and flashes intermittently to notify the operator that it is now safe to enter the machine.
However, the highest degree of risk occurs when personnel must work inside the hazardous machine area and may remain hidden from view from other plant personnel. Unexpected machine restart is a common risk associated with this type of machinery and, as such, EN 415-4 states that some form of Trapped Key interlocking should be used to mitigate this risk.
Consequently, the safety gate switch configuration includes an Extratced Key module that will only allow the handle actuator to be disengaged from the interlocks head mechanism once the Safety Key has been removed from its lock. This safety key must remain an the operators person while they remain inside the interior of the machine to prevent unexpected machine restart.
The amGardpro configurator enables you to create your ideal safety gate switch that has been tailored to your individual safety requirements. You can even size up relevant mounting plates for your devices to simplify the installation process.