Recyclability and life cycle thinking in the design of vehicles and work machines

The main goal of increasing the recyclability of vehicles is to decrease their environmental impact during their life cycle and to take the sustainable development of resources into consideration in the use of raw materials. In the life cycle assessment of a passenger car, its environmental impacts during its life cycle were found to be highest when it was in use. In an effort to cut down the amount and hazardous nature of exhaust emissions, vehicles have been improved technically in a number of ways, particularly through modifications of the engine. Fuel consumption has been decreased by reducing the weight of vehicles, which has led to a decrease in exhaust emissions. In addition to technical improvements, the dissemination of information on a more economical driving style has been a contributing factor in the lowering of fuel consumption. The hazardous nature of exhaust emissions has been mitigated by developing additives that replace lead for use in petrol. Additionally, new technology has been introduced in vehicles so as to curb the detrimental effects of exhaust emissions. In addition to the environmental impacts generated during use, other stages of the life cycle of a car have an impact on the environment. The manufacturing of metals, starting from when ore is mined up until to the finished product, is a lengthy and energy intensive process. More than half of the particle emissions generated result from the processing of raw materials, as does approximately 40 % of sulphur dioxide emissions. Of liquid emissions, oil wastes, heavy metals and other organic matter originate mainly in the processing of raw materials and parts or components. Emissions produced when the car is scrapped are small in comparison to those generated in the processing or use of raw materials and parts or components. In determining the recyclability of a car, the quantity of waste produced in connection with its disposal, scrapping, is considered. According to the car's life cycle assessment, waste produced during the life cycle of a car is generated mainly in connection with the processing of raw materials and fuel. The amount of waste accumulated during the life cycle of a car is nearly three times its body weight. It follows that the amount of waste produced during post-use processing, or scrapping, averages only 10% of the total amount of waste generated throughout the life cycle of a car. The amount of waste from servicing and repairs during the life cycle of a car is close to that produced during scrapping. From an economic standpoint, the recycling of a car is problematic with the exception of its metal parts. Presently, the parts of a car recovered include the metal, tyres and the lead contained in the battery, whereas the rest of the car is dumped as waste. Several entities are currently looking into the possibility of using, for example by burning, the scrapped waste, a mixture of non-metallic materials used in the manufacture of a vehicle, typically including such materials as plastic, rubber, textile and glass. The mixture is of no significance in terms of the waste flow, but the possibility of using it has attracted attention owing to the fact that there is general interest in raising the recycling rate of the product. To increase consumption of secondary materials in the manufacturing processes of metals, it is important maintain the quality scrap unalloyed. The use of mixed scrap will lead to the concentration of undesirable substances, as copper, tin, lead, zinc, in the raw material. These substances may weaken the material properties of the metal being manufactured or cause process technical or industrial hygiene problems in the manufacturing processes. An ideal recycling system entails a closed system, in which the recycling of each removed part or component is recycled either as spare parts or as a material. This would ensure the best possible use of the material, for example the mixture ratio, of the part or component, while the amount of new primary material manufactured using the same mixture ratio could be decreased. In future, economically profitable disassembly procedures should be found. One of the main goals in the development of product design that promotes recycling, that is design for recycling, is to enable the systematic sorting of materials used in vehicles in order to achieve a competitive quality and price level for the sorted material as compared to that of the corresponding.