The environmental issues of concern to manufacturers are related to specific emissions to air, water and soil. Some emissions can have global implications (global warming and ozone layer depletion), others regional (acid rain, fish death and smog) and some emissions only have local effects (toxic effects and waste volumes). In the UK, the management of toxic materials, emissions to air and water, and ozone layer depletion is generally effective, and the negative effects are declining. However, reducing climate-change gas emissions remains a major challenge.

In the UK, the impact of the manufacturing sector is skewed, as most goods are imported, so their environmental effects are felt elsewhere. Globally, one of the key sources of increased carbon emissions at present is the opening of new coal-fired power stations in China (at the rate of one per fortnight) – but one of the drivers for these power stations is manufacturing goods for UK consumption.

Energy use in manufacturing is dominated by the production of primary materials, in particular cement, petro-chemical products (petrol, diesel, plastics, synthetic fibres, fertilizer), iron and steel, aluminium and paper. Papermaking is surprisingly energy-intensive, due to the need for heat to evaporate water from the pulp, and additionally releases methane – a ‘worse’ greenhouse gas than carbon dioxide when it rots in landfill.

The key to reducing emissions from the manufacturing sector is to re-use materials and reduce our demand for primary materials production. For metals, thermoplastics and paper this is generally possible, although it is dependent on material-sorting, and the yield from existing recycling processes can be less than 50 per cent. However, at present it is impossible to recycle concrete, and a serious attempt to develop a low-carbon economy would need to consider alternative building materials.

There are three ways that manufacturers can attempt to reduce the environmental burden of their products. Products can be redesigned to use less energy, to last longer, use less material or avoid stressful inputs.

Processes can be redesigned to use less energy, to have lower emissions or to use fewer auxiliary materials. And supply chains can be redesigned by using intelligent supplier-selection (with environmental as well as economic criteria), by promoting end-of-life waste separation, by moving from freehold to leasehold customer transactions to promote repair, re-use and recycling, or by moving to more localised production.

The ideal for more environmentally benign manufacturing is to have ‘closed material loops’ with the same mass of material re-used in many forms. We have been motivated by this ideal to look at technologies that facilitate localisation to promote such material re-use. A good example of this is our work on ‘un-photocopying’ – we could reduce our demand for primary paper if we could remove toner from photocopies and re-use the paper directly. Surprisingly, abrasion with sandpaper is relatively effective, and we are working to optimise this process.

We are also working on a novel process for recycling scrap aluminium by cold-bonding – in effect squeezing together scrap, by extrusion or rolling, to form a new solid. Our ‘incremental sheet-forming’ machine, able to form many shapes under computer control, demonstrates that a crashed car could be reshaped in a local garage, with part geometries downloaded from the internet, rather than requiring new parts to be sent to the garage for each bent component.

An interesting side effect of promoting closed material loops is the requirement for increased manufacturing capability in the UK based around novel, flexible technologies able to form and re-form materials without high labour or tooling costs. Innovative flexible manufacturing technologies may drive an improved environmental performance for products, and provide new and valuable opportunities for UK business.