Measuring light curtain helps check pallet stability

Andrews Automation has recently launched the Pallet Profile Checker, aimed at companies that are under increasing pressure to ship correctly stacked and aligned pallets to ensure a 'perfect' fit into the recipients' warehousing and racking systems. It is not unheard of for complete shipments to be rejected by the logistics contractor simply because one palletised load is unsteady and unsafe.

In developing the Pallet Profile Checker, Andrews Automation looked to its application department to create a design capable of simultaneously scanning all four sides of pallets looking for uneven loading, stack tilt, etc, and also have the inbuilt precision to detect any plastic wrap overhang. This is crucial to ensure that correctly stacked and wrapped palletised loads are released for final despatch safe in the knowledge that receiving parties will have no complaints regarding stack neatness and stability.

Having previously successfully collaborated with Leuze Mayser and used its products on other handling control developments, Andrews Automation had no hesitation in approaching the company again regarding the new development, confident of buying robust, reliable systems. Discussions resulted in the Konturflex Measuring Light Curtain being integrated into the profile checker for monitoring the front and back of a pallet while clear object sensors from Leuze Mayser's IPRK range scan the left and right sides.

Versatile and programmable

Designed to monitor standard pallets such as EURO and CHEP, the versatility that the Leuze Mayser Konturflex and photoelectric sensors give to the new pack-line equipment also enables it to be easily programmed to handle bespoke pallet sizes. Konturflex light curtains are characterised by fast response times, a top speed of 50us per beam, and can easily adjust to diverse application situations whether checking length, width or height measurement, position, hole detection or multi-dimensional contour detection.

An essential component of the Konturflex system is its Quattro control unit that enables connection of up to four light curtains with a total of 512 beams and without mutual interference to ensure precise output. Quattro takes charge of preliminary measured value processing and passes data in compressed form via RS232/485, Profibus, Modbus or CANopen to a higher-level control system. In the case of the Pallet Profile Checker, it interfaces directly to a PLC-based control system developed by Andrews Automation.

While the control system co-ordinates the scanning process, a simple multi-coloured beacon stack indicates to operators when each scan result is complete. For more complex applications, Andrews Automation is able to tailor the system configuration to suit individual needs such as inclusion of a reset counter to audit pallet reject quantities.

The Pallet Profile Checker has all of the opto-electronic sensors pre-mounted to simplify installation whether for a new build line or as a retrofit. It is envisaged that in the majority of applications the unit will sit immediately downstream of an automatic stretch wrap machine and before the fork truck pick-up point.

For the new Pallet Profile Checker, the Konturflex KT10-2080 Measuring Light Curtain is specified with a resolution of 10mm; however, Leuze Mayser can offer a range of scanning resolutions from 5-40mm to cope with many widely differing profile measurement needs.