Disassembling planet Earth

Citation

Loughlin, C. (2007), "Disassembling planet Earth", Assembly Automation, Vol. 27 No. 4. https://doi.org/10.1108/aa.2007.03327daa.001

Disassembling planet Earth

It used to be the case that a manufacturing engineer was largely concerned with putting components together. Before that the ability to dismantle and repair products was also required, but these days if something fails we almost always go out and buy a whole new unit. Not necessarily, because we want to but because the cost of repair, even if we could find someone to repair it, greatly exceeds the original cost of the product. It is simply not worth the bother, and besides, we are lured into buying the newer model anyway.

Recycling is now being taken very seriously (at least here in the UK) and manufacturers are required to operate a returns policy that includes the dismantling and re-use of the component materials. This is not the same as repair but is perhaps the next best thing.

Recycling is all about energy and materials. Materials like iron and plastics are a finite resource and so there is a good argument for reusing them. Recycling takes energy (ultimately heat) but this needs to be balanced against the energy costs of producing the materials in the first place.

Technology and the power of marketing have a lot to answer for. Most of the products we buy are to replace similar products that we already have, be this a new car, computer, printer or mobile phone. Technological advances in hardware and software essentially force us to replace products with which we were perfectly happy just a few years before. We have not changed, we are still much the same height and weight with the same visual, audio and tactile senses and our needs have not changed that much either – so why are we so easily persuaded that we need such “improvements”.

Although, design for assembly and design for disassembly might be considered similar fields; in many cases they do actually directly conflict with each other. In our tutorial on mechanical attachment by Robert Messler, he describes a variety of snap fits that are designed to be easy to assemble and, by nature of the job they have to do, difficult if not impossible to disassemble.

If we are to be serious about recycling then we need to come up with designs that satisfy both our wish to assemble parts easily and cheaply, and our requirement that the component parts are able to be disassembled at least to the point that makes material recycling viable.

Will this be enough to give us a sustainable future? Probably not. Even if we achieved the very unlikely target of 90 per cent materials recycling then that still leaves a lot of material that is just destined for land-fill.

Even as recently as 40 years ago, people saved up for products and then they looked after them and expected them to last for a long time. These days we buy things when we want them and expect to replace them within three years or so.

If 40 years has seen such changes then what will the next 40 bring? Perhaps, we need to move beyond design for assembly and design for disassembly and change our attitudes so that we aim for design for re-use or design for repair?

Clive Loughlin