Fully automated warehouses are costly, complex and full of snares for the unwary. Although disastrous failures of such investments to perform to expectations are now much rarer than decades ago diligence is still needed even for the smallest and cheapest components in the overall investment. One such area this writer has seen overlooked on more than one occasion is packaging for automation. Packaging may cost peanuts but neglect of appropriate packaging and pallets can foul up mega investments. It is for this reason that packaging should heavily influence the design process for automation.
If arriving goods vary widely in size, weight and method of load restraint on diverse pallets then such data is fundamental to the design process and so requires adequate investigation. In this respect it should be said many blue chip companies using automation are better placed than medium-sized companies owing to buying clout.
It is crucial for automated warehouse operators to liaise closely with their suppliers over wrapping, pallets and labelling at an early stage because any changes take time. The ability, however, to influence packaging suppliers depends on the buyer’s size. Compared with manual handling, automated handling requires better quality packaging and pallets, more consistency and more care over palletising and labelling. Suppliers, however, are reluctant to do this if it means such demand is only a small part of their business, yet it is an issue that must be resolved.
Pallets are a minefield for automation, and even when new are probably the greatest problem area. Damage is a big factor, with broken boards, and protruding nails causing major problems like jamming on a conveyor. The obvious answer to this is the pull damaged pallets out of the system when they are damaged but experience shows that many damaged pallets are not removed in time. There is also a problem of inconsistent pallet quality from the same supplier. “The quality of dimensional accuracy is paramount,” opined one warehouse automation supplier.
Solutions to the timber pallet problem include use of plastic pallets, slave pallets or slave boards, but they all involve added cost. Some problems posed by poor packaging and pallets can be relieved by considering the handling equipment. An example could be a move away from roller conveyors towards belt conveyors. This would cut down any snagging problems with loose stretchwrapping or banding. All-round forklift access to conveyors at the front end could also make sense because if a pallet jams on a conveyor it saves much time compared with manual load removal.
In terms of packaging, the second most vexatious problem for automation is probably stretch wrapping. This is because any flapping wrapping will send false signals to sensors on stacker cranes and conveyors, leading to rejects. Stretchwrappers, therefore, should have positive tail-end sealing systems to prevent loose film tails being left.
Care is needed over banding because excessive tension could damage cartons or cause load bulge. Carton quality also needs watching. If there are mixed pallet loads then the heavy cartons must be placed at the bottom and to maintain carton integrity users might consider humidifiers. Damp, cold warehouses should be avoided.
There is good news and bad news on the packaging quality front. More companies are moving over to plastic tote bins and trays, which offer palletless, dimensionally accurate tolerances and so they sit well with automated mini stackers. The bad news is that suppliers are expected to cut costs and so one measure is to downgrade packaging. Even so, due diligence on packaging issues will help assure a successful warehouse automation investment and the fact is that it would be difficult to cope with the pressures placed on distribution centres by retail upheavals like online shopping without more recourse to automation.
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