However essential industrial packaging is, it is an often overlooked part of logistics and so can be a source of waste, damage, chaotic lineside practices leading to slower throughputs, unnecessary waste disposal, accidents and wasted space. One major approach to combat these problems is to invest in ship to line, one-touch packaging, of the kind particularly favoured by car manufactuers. Another is to look at some re-usable ‘green’ products that promise to reduce the environmental impact of your logistics processes
A good example of this is from the US firm, Reusa-Wraps Reusable Logistics Solutions. It is a solution to the expensive mess of stretch film, comprising heavy duty, vinyl-coated mesh and velcro type hook and loops for wrapping around palletised loads. Being 100% recyclable, it is aimed primarily at closed-loop distribution channels. Compared with stretch film, they are 10 times stronger, leading to lower damaged goods, and even faster to install than traditional stretch film. The return on investment is usually six to twelve months. By abandoning stretch film, users also cut the cost of waste removal – there are no more landfill sites to be filled with stretch film, though, of course, the film can be recycled.
Such is the importance of packaging that is should heavily influence the design process for automated warehousing and any planning exercise should begin with an appraisal of stored materials regarding their size, weight, method of load restraint, pallet, tote and tray variations. Understanding the full range of secondary pack shapes is also vital. While it may be difficult to enforce some kind of uniformity of packaging from suppliers, automated warehouse operators must, nevertheless, strenuosly attempt to liaise closely with their suppliers over wrapping, pallets, and labelling at an early stage.
Compared with manual hanlding, warehouse automation requires better quality packaging and pallets, more consistency and more care over palletising and labelling. But handling engineers may also need to look at the type of conveyors they use. Generally, belt conveyors pose fewer problems than roller conveyors for sub pallet loads, like shrink or stretchwrapped cartons or trays. A move over to belt conveyors would cut down any snagging problems with loose stretchwrap or banding. Loose, trailing stretchwrap could also give incorrect signals to sensors and cause inefficient accumulation or machinery stoppage.
End-of-line packaging carries its own peculiar set of problems which start with the palletising method. It requires much thought to design an effective, packaging and palletising system to ensure products will remain intact during transition. If considering robotic palletisers, in particular, users should work with materials handling manufacturers who offer a consultative service from beginning to end.
One of the problems with palletisers is safety. The HSE recognises that palletisers need particular attention. Most palletiser injuries occur when people enter the machine and are trapped between its many parts. Operators can also be exposed to loads falling off moving pallets. It is essential that palletiser guards are the correct sizes and opto-electronic devices correctly positioned. An extra safeguard to improve safety at entry/exit points is to use a captive key exchange system. While the key is with the person, the machinery cannot be restarted until the operator returns it.
Once loads have been squarely and uniformly assembled on their pallets, the loads must be secured and the most favoured method remains stretchwrapping. The main problem here is poorly affixed stretchwrap which causes false signals and jamming. Buyers of automatic stretchwrappers, therefore, should choose hardware with positive, tail-end sealing to prevent loose film tails being left. The method of stretchwrap also needs careful consideration. Of the two basic types of stretchwrap, the rotating head and the turntable, the former is preferable because turntables which spin the pallet load can cause load bulge, which subsequent wrapping might not fully rein in, and excessive bulge could lead to rejection at the pallet profile guage.