Recycling vehicles and their components is a serious concern to manufacturers. (More information on the European End-of-Life Vehicle Directive.) The core materials used in most vehicles today are quite straight-forward to recycle. This page takes a look at recycling considerations within the automotive industry.

Steel

Steel is the most common material in vehicle production. It is relatively easy to reclaim and recycle. Two-thirds of steel used in US car manufacturing is recycled (source: Steel Recycling Institute); the remainder is new. Aside from environmental considerations, it is economically preferable to recycle due the large costs in obtaining steel from ore. New steel is generally used when recycled supply cannot meet demand.

Aluminium

Aluminium is still a small material by volume in car production. Obtaining Aluminium from Bauxite (ore) is an expensive process that requires considerable electric current; it is for this reason that Aluminium was once a semi-precious metal and has only (relatively) recently entered mainstream use. Recycling is quite straightforward with aluminium and, like steel, is economically preferable.

Plastics

Plastics come in two types – Thermosets and Thermoplastics.

Thermosets are made up of strong bonds that are created with heat and subsequently do not melt with heat. This means that they cannot be reused and are either scrapped when finished with or ground down to make a filler material for something else. Thermosets are being phased out from car production as and when possible.

Thermoplastics, on the other hand, become fluid (plastic) with heat. This means they can be melted down and remoulded or added to new material. This characteristic makes them ideal for recycling on cars; it is necessary however, to match the properties of Thermoplastics carefully to their role on a vehicle; polypropylene and nylon are often used for the demanding conditions of the engine bay.

Precious Metals

Electronic components and circuitry are often made up of thousands of complex elements which are almost impossible to seprate and recycle. Within this componentry there is a variety of toxic metals such as lead and cadmium in circuit boards, mercury in switches and flat screens and brominated flame retardants on printed circuit boards, cables and plastic casing.

When dumped, these metals contribute to a range of types of pollution with serious consequences to human health and the environment. As increasing amounts of electronics feature in cars, this will become of greater concern.

On September 18th 2000, the European Parliament and the Council of the European Union produced a directive relating to End-of-Life Vehicles (ELVs). This will form the basis of future legislation for, and implementation of, greater recyclability of motor vehicles. Much of the directive relates to the legislation needed to ensure the aims are met but some significant points are raised which refer to the ways in which design and manufacture will need to be changed.

Currently, the proportions of material in a car are approximately as follows:

Ferrous metals 70%

Plastics 10%

Rubber/Elastomers 7%

Light Alloys 5%

Glass 4%

Miscellaneous 4%

Use of plastics has increased in recent years as manufacturers attempt to remove weight from vehicles. Plastics have often been used where their use represents improvements in structural ability, durability and appearance. For example, rubber coated metal bumpers have long since been replaced by more aesthetically pleasing and impact absorbing moulded ABS. Roof rails, windscreen wiper mount areas, inner wheel arches and engine components are typical of the parts of a vehicle that have changed in material.

Where cars may have had a double skin inner wheel-arch some years ago, a plastic skin may now be used which is more resistant to corrosion, offers greater sound damping qualities and reduces weight. Under the bonnet, some metal ducting, manifolds and mounts can be replaced with durable, heat-resistant plastics, again saving on weight. As Siemens puts it: “lightweight, recyclable plastics reduce costs, simplify vehicle assembly and improve under-bonnet packaging”. Such changes typically mean less ferrous metals are being used in vehicles than a decade or so previously. The replacement of these metals with lighter plastics represent significant weight savings.

In the US and Europe, more than 94 % of End-of Life Vehicles are processed. Of these processed vehicles, 75 % of the vehicle by weight is recycled or recovered. Generally speaking it is composite components that prove most difficult to recycle. They are made up from combinations of materials that have to be separated before they can be successfully recycled. The complexity of some of these items, and in the case of batteries, the toxicity of the materials used tend to mean they are land-filled instead of reused or recycled.

The End-of Life Vehicles Directive lays down some very stringent guidelines regarding recycling over the next few years and for the foreseeable future. By January 1st 2006, all ELVs must be at least 85% reused and recovered and at least 80% recycled. By 2015, reuse and recovery must increase to at least 95% whilst recycling must be at least 85%.

Material that isn’t recycled is known as ASR (automotive shredder residue). Despite recycling a greater proportion of the end product than most other industries, the auto industry still landfills millions of tonnes of waste a year in Europe alone. The problem with recycling is cost; the cost to dismantle; the cost to the process; and the ability to find uses for recovered material. In the European ELV Directive, it specifically refers to an overall coherence in approach to the issue, “particularly with a view to the design of vehicles for recycling and recovery”. It states that “it is important that preventative measures be applied from the conception phase of the vehicle onwards”. This will obviously have a bearing on the early design and development stages of a vehicle.

Measures such as the prohibition of Lead, Mercury, Cadmium and hexavalent chromium and the increasing percentages of reuse and recyclability will force car and component manufacturers to develop products that can be more easily dismantled and broken down. Processes will be sought to deal with composite components as well as alternatives if they prove more practical or where a material is banned from use. The greatest demands will fall upon the manufacturers to create networks of dismantlers and recyclers and on component suppliers to ensure their products can be easily recycled. It appears that because figures for reuse and recovery are high, anything that cannot be recycled will mean additional cost to the manufacturer.

Designers will need to look always towards the newest materials and processes. It will be necessary to design and engineer vehicles to be more easily dismantled and avoid creating complex mixtures of materials. Parts of a car will need to be “labelled or made identifiable” to aid the recovery process. Ford began issuing its designers with “design-for-recycling” guidelines in 1991. The Focus, for example, is designed to have 50% of its components dismantled in thirty minutes.

The increasing demands for recyclability and environmental accountability may mean designers are forced to look at more intelligent solutions – making use of new materials and technologies rather than using existing inefficient and wasteful devices and components. Despite the ever increasing demands on electrical power within the car, it may be necessary to look towards more efficient energy use rather than simply increase battery capacity which will cause significant problems with recycling and recovery. In essence, designers must apply a greater degree of intelligence to design. Careful selection of materials and components will be key to making a vehicle design a viable proposition. Having designed a range of durable thermoplastics capable of withstanding the conditions of the engine bay, Siemens now use fully recyclable thermoplastics in all new designs; illustrating how a change of approach needn’t affect the overall result. Designers should also push to bring new technologies to the fore earlier to ensure vehicles meet the increasingly stringent requirements of legislation.

Taking a general view, it is unlikely that designers will need to make large changes to their practices or to make substantial concessions. However, it will be necessary for designers to be aware of the legislation that their vehicles will be required to meet and to be prepared to take different approaches to design to account for this. For example, computer design systems exist which take into account the ability of a product or vehicle to be recycled. By taking account of the structures and materials involved, the process of evaluating the impact to the environment can be automated. Designers will increasingly be required to use computer design systems which will outline these issues to them before any concrete decisions are made to manufacture the product or vehicle.

In the next five to ten years, we will see vehicles being made from increasingly reusable and safer materials. They will be easier to dismantle and will have a far smaller impact on the environment in terms of their ultimate disposal than the current materials of choice. Designers will need to be aware of the restrictions of legislation imposed upon them whilst engineers and scientists will be required to find safe, efficient alternatives to the hazardous and complex parts of a motor vehicle.