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Life Cycle Assessment (LCA) is a method of assessing and quantifying the environmental impact of products taking into account the methods and materials used for manufacture. It also considers the impact on the environment during use of the product and its disposal, whether through recycling, incineration or dumping in a landfill site. Much of the necessary data for performing an LCA can be found in various software packages available commercially. However, there is some debate as to the accuracy of this information as the technique is still in its relative infancy. The main use of LCA is to provide a comparison between the use of different materials or manufacturing processes for a given product to determine the benefits or disadvantages or adopting a specific design strategy. It is, however, very difficult to assess the impact caused by a single product without a comparison, since the impact scores obtained in the analysis cannot be taken as absolute. This is because no way exists to quantify an exact damage to the environment from a particular process or emission. Hence, the best way to interpret the data is to compare with a similar product or design. There is also the potential problem that the impact factors calculated for the same product in different commercial packages may be different as the parameter and data used in the analysis are unique to that package. A point which is increasingly important is the issue of cost and no package yet includes any method of inputting cost into the equation.
The main potential problem with LCAs is the lack of international standards. The ISO14000 [30] series of standards are currently being created to deal with these areas but until that process is complete, there will be no definitive answer to many of the problems faced by users of the LCA software. There is no standard method of applying the weightings to the different environmental effects that occur to take into account the seriousness and potential for environmental damage. Each package has its own weightings and, without years of research, these cannot be either discounted or recommended. There is also the issue of whether to include the internal environment of the manufacturing facility within the LCA.
The main emphasis of LCA is also in question as different reports have suggested different ways of looking at the environmental impacts. These can be either defined as the risk to human health or the potential damage to the earth's ecosystem, there are convincing arguments for both ideas. As with any method, the data used are of critical importance, particularly in respect of the disposal of the products at the end of their use.
The main problem facing designers when working with composites will be deciding on how to input the material into the LCA. This could be done either by calculating and measuring a new set of data for each material, or by calculating the data from the constituents of the material summed together. This second method has a number of potential flaws in that the processes used during manufacture may be completely different, or because by adding materials together certain benefits or disadvantages could be gained in terms of environmental impact. Equally, the disposal of the composite product after use could result in significantly different data for assessing the environmental impact. Also, the processes that can be used to dispose or recycle the components may be significantly different from those used for single materials. In the short term the way forward for using LCA tools with composites is to concentrate on comparing the impact of the composite material with the impact of the equivalent single material. This will allow designers to see how they can use composites to benefit the 'greenness' of their products. The main aim should therefore be to produce a set of guidelines that designers can utilise to help them design with composites by using LCA tools. Hopefully, this will show designers how to reduce the environmental impact damage of their products whilst letting them explore the possibilities of composites. The long term aim would be to incorporate comprehensive data for a range of composites in the software LCA tools that are available so that designers have to think less about how to use and interpret the data.
Various life cycle assessment tools are available:
Green Guide to Composites: This guide has been created to allow the composites industry to understand the environmental and social impacts of different composite materials and manufacturing processes.
The life-cycle impacts of each material and process choice from the cradle to the factory gate are presented in simple A to E comparative rankings, for the first time allowing informed decisions to be made on the environmental and social effects of composite materials and process choices.
SimaPro 4 (PRé Consultants BV) SimaPro is a full-featured LCA software tool. Complex products with complex life cycles can be compared and analysed. The process databases and the impact assessment databases can be edited and expanded without limitation. The ability to trace the origin of any result has been implemented in a very flexible and powerful way. Special features are: multiple impact assessment methods, multiple process databases, automatic unit conversion. Furthermore, there are powerful tools to analyse take-back and disassembly of products, as well as complex waste treatment and recycling scenarios.
ECO-it: (PRé Consultants BV) Eco-Indicator Tool for environmentally friendly design. ECO-it allows you to describe a complex product and its life cycle. By entering the materials and processes that are used. ECO-it immediately calculates the environmental load, and shows you which parts of the product contribute most. Based on this information you can design to reduce the environmental load of the product.
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