Making the most of stuff

One of the joys of being out in the wild is that I meet a wider variety of people and learn more – and from a different perspective. Several recent conversations have caused a number of ideas I have run into over my career to converge. The final trigger was a presentation on “subtractive” manufacturing – it was about advanced machine tools. That we have to rename the past to accommodate a potential future struck me as worth thinking about.

Let us start with waste. The “waste industry” is a strange one. In some ways, it runs like the manufacturing industry in reverse. It takes the materials that other bits of society produce but don't want and make them “go away”.

Waste itself, as far as I can see, comes in three main types. There is waste that is potentially harmful to humans, wildlife or the environment over a long time. Examples are radioactive waste and heavy metal residues. The best thing to do with these types of waste is put them somewhere safe – where they cannot leak out into the environment and do harm. The second type of waste is potentially harmful to humans, wildlife or the environment in its current form, but can be transformed into other materials that are either harmless or useful to other activities. Most plastics and organic residues fall into this category, but the cost of collection and transformation often means they get classified along with the first type. The third type of waste is not harmful to humans, wildlife or the environment, but is commercially irrelevant, and discarding it is easy (and cost effective!). Often these three types of waste are mixed and tend to be classified as the most harmful of the components. An effective waste industry therefore needs the means to separate out the different types of waste, ways to transform the currently harmful stuff and a safe place to store the rest.

However, despite attempts over the years to systematise it, it still seems to mostly function as a spot market, with people phoning up and asking “I’ve got 20 drums of waste to get rid of, what’s your price?” This is despite the fact that many waste streams are predictable outputs of known, (more or less) steady-state processes. With the focus on corporate environmental and social responsibility, many companies are attempting to minimise waste and/or realise whatever value it might have for other companies, giving added impetus to the development of a modern waste industry, but this change feels like a “work in progress”.

This has a huge overlap with the concept of “material productivity”. We are used to the idea of financial productivity, although we don't tend to call it that. We invest money where we can get the maximum return – and therefore maximise its productivity. The term “productivity” seems to be most often associated with effectiveness of workers – we constantly compare the productivity of workers in different countries. With the increased use of automation in factories, we are probably strictly talking about “asset productivity”, but it all comes down to financial productivity through the money needed to pay the wages or purchase the machines. The other inputs to a factory are materials and energy. In the end, they are all liable to end up being measured by the metrics of “financial productivity”, and although energy is getting more airtime, the material aspects are the most complex and (historically) least addressed.

This “material productivity” is often cited as an argument for additive layer manufacturing – since the only material used is that required for the product, there is no waste. This is contrasted with “subtractive manufacturing”, where a solid lump of material has material removed to end up with the required structure. Additive manufacturing has come a long way from its incarnation as rapid prototyping about 30 years ago, but it still has limitations in the material microstructures it can produce and so the mechanical properties it can provide for the designer to use. The MacBook this is being typed on was hewn from a solid lump of aluminium and is very much stronger that the old assembled predecessor or the sintered version that could be made by additive manufacturing.

As additive manufacturing gets more sophisticated and able to produce the required materials microstructures, will it mean manufacturing waste is a thing of the past? Or will waste remain an inevitable consequence of us not being able to implement our knowledge of materials? And what of the other sources of waste? And can the waste industry transform itself to a service that takes any waste and returns its maximum value to society?

By now, we are used to the dictum that the circular economy (or cradle to cradle depending on which articulation you first ran into) lives by – reuse, recycle, or repurpose. Will additive manufacturing add “redesign” as a means of eliminating manufacturing waste?